United Nations

E/C.13/1996/CRP.1


Economic and Social Council

 Distr. GENERAL
   19 March 1996
ORIGINAL: ENGLISH


COMMITTEE ON NEW AND RENEWABLE SOURCES OF ENERGY AND ON 
ENERGY FOR DEVELOPMENT
Second session
New York, 12 - 23 February 1996
Item   of the provisional agenda *
     * E/C.13/1996/1.
             Renewable sources of energy with special emphasis on biomass:
                               progress and policies
                          Report of the Secretary-General
                                         SUMMARY
       Bioenergy  is experiencing a surge in interest stemming from a
combination of factors:  greater recognition of its current role and future
potential contribution as a modern fuel; its availability, versatility, and
sustainability; its global and local environmental benefits; and the
development and entrepreneurial opportunities.  Significant technological
advances and knowledge have recently accumulated on many aspects of biomass
energy.  However, despite these advantages and advances, bionergy still faces
many barriers stemming from economic, institutional and some technical
factors.  In many countries where bioenergy is presently so important, both on
socio-economic and energy terms, few resources are allocated to biomass.
       There is an enormous untapped biomass potential, particularly in
improved utilisation of existing resources, forest and other land resources,
higher plant productivity, and efficient conversion processes using advanced
technologies.  Much more useful energy could be economically derived from
biomass than at present.There is considerable potential for the modernisation
of biomass fuels to produce convenient and less polluting energy carriers such
as electricity, gases and transportation fuels whilst continuing to provide
for traditional uses of biomass. When produced in an efficient and sustainable
manner, biomass energy has numerous environmental and social benefits:  job
creation, use of surplus agricultural land in industrialised countries,
provision of modern energy carriers to rural communities of developing
countries, improved land management, and a reduction of CO2 and sulphur levels
in the atmosphere.
       Most biomass energy technologies have not yet reached a stage where
market forces alone can make the adoption of these technologies possible. 
Costs are very specific depending on a large number of variables ranging from
raw material, management practices, type of technology, and environmental
considerations.  One of the principal barriers to the commercialisation of
renewable energy technologies, including bioenergy, is that current energy
markets mostly ignore the social and environmental costs and risks associated
with conventional fuel use, the hidden subsidies, the long-term costs of
depletion of finite resources, and the costs associated with securing reliable
supplies from foreign sources.   Growing environmental and ecological
pressures, combined with technological advances and increases in efficiency
and productivity, are making biomass feedstocks more economically attractive
in many parts of the world.
     Technological advances are opening up many new opportunities for
bioenergy which were regarded only a few years ago as long term prospects.
These include: (i) advanced steam cycle technology with
cogeneration; (ii) cofiring with fossil fuels; (iii) integrated
gasification/advanced technology; (iv) biocrude-fired combustion turbine
technology; (v) production of methanol and hydrogen from biomass, (vi) fuel
cell vehicle technology; etc.  Energy demand will continue to grow although
the pace will depend on population, economic growth, and technological
advances. Bioenergy, both in its traditional and modern forms, can make a
significant contributions to sustainable energy supply, socio-economic
development and cleaner environments.  However, for bioenergy to take
advantage of these opportunities it needs to cease being considered the "poor
man's fuel". 
I.     INTRODUCTION
       The Committee on New and Renewable Sources of Energy and on Energy for
Development, at its first session held in 7-18 February 1994, requested the
Secretary-General to prepare a report on renewable sources of energy: 
progress, policies and coordination. 1  At its special session, the title of
the report was changed to renewable sources of energy with special emphasis on
biomass:  progress and policies, and adopted by ECOSOC at its substantive
session in July 1995. 2  The present report has been prepared in response to
the latter's request. 3  
II.    BACKGROUND
       The growing interest in bioenergy worldwide as a modern energy carrier
is due to: 
   
    (a) Awareness of the enormous potential of biomass energy.  It has been
estimated that if biomass plantations were established on 10 per cent of the
present cropland, forests and woodland, that the annual biomass energy
production would equal fourth-fifths of the present global commercial energy
consumption . The recognition of the increasing demand to provide modern
energy to provide energy at accessible costs, particularly for rural and urban
poor; the reflection of considerable technical gains of the past decade,
mainly in the industrial world; the possibilities of converting biomass to
other convenient "modernized" energy forms such as electricity and liquid and
gaseous fuels, which can help spur rural industrialization and help to stem
urban migration; recognition of the potential of biomass energy to diversify 
energy supplies and induce greater competition.
       (b) Increasing concern with the environmental implications of fossil
fuel use combined with the potential local and global environmental and
ecological benefits arising from bioenergy when produced sustainably.
       (c) Better perception of the potential local economic benefits of
biomass; the realization that since biomass energy technologies are relatively
small-scale and modular compared to most existing  energy facilities, the pace
of development and introduction of bioenergies can be speeded up if the right
conditions exist; employment opportunities e.g. in Brazil the modern bioenergy
sector employs about one million people.
       (d) Despite low oil prices, a combination of factors (e.g. concern with
the environment, sustainability, technological advances, increasing energy
demand, etc) is making bioenergy economically more attractive.
       (e) New possibilities for reducing government subsidies to farmers
through economically viable bioenergy production on surplus land e.g.
currently the US government pays farmers $1.8 billion/yr to keep erodible
lands out of production; in addition, price support payments, required by 
many farmers to maintain profitability add another $16.1 billion/yr. There is
also a growing interest in using new crops for other products in addition to
food, and for new uses of established crops, reflecting growing environmental
and sustainability pressures.
       Nonetheless, despite this growing interest, bioenergy still faces
difficulties because of inadequate political, financial, and institutional
support; insufficient funding for R&D and demonstrations particularly in the
developing countries; exclusion of external costs and the non-monetary
benefits in economic evaluations of energy that place biomass energy on an
unequal footing compared to conventional energy sources; low  oil prices; the
varied and sometimes unpredictable nature of biomass energy sources and uses;
and the perception that land availability could be a problem by competing with
food production. A major additional problem is that many biomass energy
sources, particularly woodfuels, are still obtained free or at low cost
especially in developing countries; therefore there is little incentive
to improve energy efficiency or to find alternative energy sources unless they
can be provided on an equal delivered cost basis. Thus improving biomass fuel
efficiency has not always been a primary concern, and other non-energy factors
such as convenience can be priorities. 
       One of the problems with perception of the role of biomass energy is
the lack of reliable data on country, regional and global use.  FAO statistics
indicate that only 6 per cent of the world's energy is derived from biomass
but other estimates show that about 14 per cent (equivalent to 55EJ) is
derived from all form of biomass. These discrepancies allow the dismissal of
the importance of bioenergy by energy planners which can be especially harmful
at the country  level where sometimes 80-90 per cent of the country's energy
could be biomass derived.
III.  BIOENERGY RESOURCE POTENTIAL 
1 Historical perspective
       Four broad categories of biomass use can be distinguished:  (a) basic
needs e.g. food, fibre, etc; ( b) energy e.g. domestic and industrial; ( c)
materials e.g. construction; and (d) environmental and cultural e.g. the use
of fire. Biomass use through the course of history has varied considerably,
greatly influenced by two main factors: population size and resource
availability.
       Wood and charcoal fuelled industrial development until well into the
19th century in Europe. In the USA, forests played a particularly key role in
the socio-economic development of the country. From the seventeenth century to
the early twentieth century forests produced wood as the most valuable raw
material for American life and livelihood.Today there are still very many
biomass-based manufacturing and service industries around the world, ranging
from brick and tile making, steel manufacture, metal working, weaving, to
bakeries, food processing, weaving, restaurants. In India, for example, around
50 per cent of rural industrial production is biomass driven, and in Tanzania
over 2 Mt of woodfuel were consumed by these industries in 1992.  Most rural
industries will continue to use biomass as their main source of energy in the
short and medium term. A major problem is that the techniques used are usually
highly energy inefficient.
       Biomass energy use, particularly in its traditional forms, is difficult
to quantify thus creating additional problems. There are two major reasons for
this: (a) biomass is generally regarded as a low status fuel, as the "poor
man's fuel", and thus rarely finds its way into official statistics, and when
it does it tends to be downgraded. Traditional uses of bioenergy e.g.
fuelwood, charcoal, animal dung, and crop residues, are inaccurately
associated with problems of deforestation and desertification. In Central
Zambia, the main charcoal producing area of the country, there was no evidence
of land degradation due to deforestation caused by woodfuel harvesting either
for firewood or charcoal;  (b) difficulties with measuring, quantifying, and
handling biomass since it is a dispersed energy source, together with its
inefficiency of use, results in little final energy being obtained. 
Charcoal, for example, is a very important fuel in many developing countries
but charcoal yields are notoriously low, e.g. about 12 per cent in Zambia, and
8-10 per cent in Rwanda on a dry weight basis. There is a great potential for
increasing charcoal production efficiency e.g. in Brazil the best kilns have
an efficiency of about 35 per cent.
       What distinguishes modern biomass energy carriers from its traditional
forms is its ability to produce clean and convenient energy with greater
efficiency, by applying modern technology, often as by-product of another
major activity e.g generation of electricity from sugarcane bagasse and
forest/wood residues in the pulp and paper industry.  In the USA, for example,
most biomass installations are independent power and cogeneration systems (in
the range of 10-25MW), many based alongside pulp and paper mills which have
abundant residue supplies. By the year 2020, between 5 and 10 per cent of the
US's power generation capacity is expected to come from these types of plants.
Traditional bioenergy, in contrast, is mostly used in small scale
applications, and often forms part of the informal and non-monetarized, local
economy.
       The relatively poor image of biomass is now changing  for three main
reasons:
(a) considerable efforts over recent years to present a more balanced and
realistic picture of the existing use and potential of biomass through new
studies, demonstrations, and pilot plants;
(b) increasing utilization of biomass as a modern energy carrier, particularly
in industrialized countries;
(c) increasing recognition of the local and global environmental advantages of
biomass and of the measures necessary to control net CO2 and sulphur
emissions.
       Contrary to a general view, biomass utilization worldwide remains
steady or is growing for two reasons: (a) population growth, and (b)
urbanization and improvement in living standards. As living standards improve,
many people in rural and urban areas in developing countries convert to
different uses of biomass e.g. charcoal, building materials, cottage
industries, etc. Thus urbanization does not necessarily lead to a complete
shift to fossil-based fuels.   In the Thazi and  Meiktila districts of Myanmar
, population growth together with the prosperous development of cottage
industries, has resulted in a substantial increase in woodfuel consumption in
recent years. In Zambia and Rwanda urbanization has led to a considerable
increase of fuelwood in the form of charcoal.   In Madagascar, it was
found that with increased living standards, urban dwellers continued to rely
on woodfuel and charcoal.
2. Present Potential
   
    Bioresources are potentially the world's largest and sustainable source of
fuel- a renewable resource comprising 220 billion oven dry tonnes (about 4,500
EJ) of annual primary production. The annual photosynthetic storage of energy
in biomass is eight to ten times more than the present energy use from all
sources.  The problem is not availability but the sustainable management and
delivery of energy to those who need it. In practice only a few types of
biomass feedstock  can seriously be regarded as potential sources of energy
due to various economic and environmental constraints. Residues from forestry
and agriculture are invaluable as immediate and relatively cheap energy
resources to provide the initial feedstock for the development of bioenergy
industries. They are also frequently an environmentally acceptable way of
disposing of unwanted and polluting wastes, but their use must encompass
environmental sustainability.  Thus the ash from burners and effluent from
digesters can be returned to the land as fertilisers.  The energy content of
potentially harvestable residues  is about 93 EJ/yr worldwide.  Assuming that
only 25 per cent of this is realistically recoverable, this could provide 7
per cent of the world's energy.
       While residues can provide an important kick-start for the bioenergy
industry, the development of large-scale energy production from biomass will
probably rely in the future on specifically-grown energy crops such as
sugarcane, miscanthus, switch grass, and trees (particularly short rotation
forestry).  Biomass productivities must be improved since they are generally
low, being much less than 5 t(dry weight)/ha/yr for woody species without good
management.  It is now possible with good management, continued research, and
planting of selected species and clones on appropriate soils to obtain 10 to
15 t/ha/yr in temperate areas and 15 to 25 t/ha/yr in tropical countries. 
Record yields of 40 t/ha/yr have been obtained with Eucalyptus in Brazil and
Ethiopia.  High yields are also feasible with herbaceous (non-woody) crops;
for example, in Brazil, the average ethanol yield from sugarcane has risen
from 2,400 l/ha (1876/77) to 5,000 l/ha (1993/94).
3. Future- Biomass Energy Scenarios
       In the past few years a number of global energy scenarios have been
published most of which include substantial roles for energy efficiency and
renewable energies, while some have studied biomass in more detail and
incorporated large roles for bioenergy.  The Renewables - Intensive Global
Energy Scenario (RIGES) proposes a significant role for biomass in the next
century. It concludes that by 2050 renewable sources of energy could account
for three-fifths of the world's electricity market and two-fifths of the
market for fuels used directly". Within this scenario biomass should provide
about 38 per cent of the direct fuel use and 17 per cent of the electricity.
Detailed regional analyses show how Latin America and Africa may become large
exporters of biofuels in the future.
       The Environmentally Compatible Energy Scenario (ECS ) developed by
IIASA  predicts that primary energy supply will be 12.7Gtoe (533EJ) by 2020 of
which biomass energy would contribute 12 per cent (62EJ) derived from wastes
and residues, energy plantations and crops, and forests - this excludes
traditional uses of non-commercial biomass energy as fuelwood in developing
countries.  A Fossil-Free Energy Scenario (FFES) by Greenpeace forecasts that
in 2030 biomass could supply 24 per cent  (=91EJ) of primary energy supply
(total = 384EJ) compared to today's 7 per cent  (=22EJ) out of a total of
338EJ. The biomass supply could be derived equally from developing and
industrialized countries.  
       The World Energy Council examined cases of global energy supply to 2020
spanning energy demand from a "low" (ecologically driven) case of 475 EJ to a
"very high" case of 722 EJ, with a "reference" case total of 563EJ.  In the
ecologically-driven case traditional biomass could contribute about 9 per cent
of total supply while modern biomass could supply an additional 5 per cent of
the total equal to 24EJ. New renewables combined (modern biomass, solar and
wind, etc) could supply 12 per cent of the total. In the high growth case
these contributions could be 8 per cent and 5 per cent,  respectively, of a
higher total supply.  The International Energy Agency (IEA) examined world
total primary energy demand over the next 15 years and estimated a need for
486 EJ by 2010 compared to 330 EJ today.  Most of the increased demand is
predicted to arise in non-OECD countries. Within the IEA analysis biomass is
part of "coal and other solid fuels" where worldwide demand is predicted to
rise by 2.1 per cent per annum.  In the Conventional Development Scenario, a
conservative view of bioenergy is taken. Bioenergy represents about 4-5
per cent  (36-45 EJ) of the global primary energy supply (over 900 EJ) in the
year 2050. An optimistic scenario (GREENS) proposes that biomass could supply
75 per cent of the world's energy as soon as 2015.  In the Conventional Wisdom
Scenario (CWS)  electricity from energy crops grown on set aside land plus 10
per cent of developing countries' land, could generate 46 EJ (33 per cent) of
a total of 136 EJ in 2050, or 12 per cent of the estimated primary fossil fuel
and nuclear energy. 
       Shell International Petroleum  has developed two scenarios. In
Sustained Growth (SG) abundant energy supply is provided at competitive
prices, as productivity in supply keeps improving in an open market context.
Global average energy per capita values increase from about 13 boe (75 GJ)
today to 25 boe (143 GJ) by 2060, and 40 boe (229 GJ) in 2100. By 2020 new
renewables, particularly biomass, PV and wind, become major players
representing about 10 per cent (80EJ) of the world's energy market.  By 2050
renewables provide between 40 and 50 per cent of the world's energy
requirements. This model also envisages that by 2060, about 200 EJ of
primary energy could be obtained from 400 Mha of biomass plantations, with an
average productivity of 25 t/ha.  In Shell's Dematerialisation (DM) scenario
human needs are met through technologies and systems requiring a much lower
energy input. Global average energy per capita remains at 13 boe annually
(total energy supply is 1,200 EJ compared to 400 EJ today) and reaches 17 boe
(57 GJ) by 2100. In this model, energy conservation technologies become
economically more effective, with biomass benefitting from major advances in
technology.  
       What is evident from examining all these scenarios is that biomass
could be a major contributor to future energy supplies especially as a modern
fuel - while still playing an important role as a traditional fuel, mainly in
developing countries. How much bioenergy will contribute in the next century
will depend on many factors which are implicit in the various scenarios
proposed in each study.
IV.  ENVIRONMENTAL AND SOCIAL IMPACTS
1.  Environmental
       Human dependence on biomass has affected the environment in various
ways depending on the scale of use and environmental sustainability, although
the extent of such influence is unknown. Some authors have suggested that
pre-industrial societies were able to manipulate the environment on a vast
scale. "Regardless  of the degree to which pre-industrial activity is
demonstrated to have impacted the global carbon cycle, it is clear the even
small non-industrialized human populations can alter the landscape in ways
that can require decades or centuries to correct".
Today biomass use can have various environmental effects but a major concern
is CO2 emissions from biomass combustion both deliberate (usually) and
accidental. Biomass use is CO2 neutral when produced and used sustainably. In
practice, however, this is not always the case as biomass energy is often used
in a non-renewable manner and very inefficiently in many rural areas of
developing countries. There are three main ways in which biomass contributes
directly to CO2:(a) traditional uses of biomass energy of which there are two
main related problems: firstly, very low efficiencies result in excessive
consumption of biomass in order to produce a small amount of useful energy;
secondly, often biomass energy sources are obtained at zero or near zero cash
cost and therefore there is little incentive to improve efficiency or to
replace the trees and other biomass sources. The result is that far more
biomass is removed than replanted or allowed to regrow; ( b) Tropical
deforestation, particularly for non- energy uses, is an important
source of CO2; ( c) Tropical grasslands burning which is also a significant
source of GHG emissions and should not be overlooked. This is because large
areas are burned every year, some 750 M ha in Africa alone. 
1.1. The Role of Biomass in Mitigating Greenhouse Gases- Forest Alternatives
        There are various measures which are available in order to slow,
stabilize or reduce the GHG emissions. There are three strategies for using
forests to reduce atmospheric CO2 levels: (a) preserving existing forests; 
(b) planting trees to create sinks to sequester CO2;  (c) substituting fossil
fuels directly by biomass fuels. No option is necessarily cheap or easy.  
       Preserving existing forests seems to be to the most sensible option in
the short term. The forests will thus continue to act as a reservoir of
carbon, while at the same time reducing the deforestation rate and resulting
in less CO2 being emitted to the atmosphere. Other benefits include commercial
products, preservation of biodiversity, landscaping, recreational value, etc.
However, there are at least two problems to this option: ( i) socio-economic
pressures on existing forests makes it difficult to implement, particularly in
developing countries; and (ii) mature forests grow slowly and thus less CO2 is
absorbed in comparison to fast-growing trees.
       
       Reforestation on non-agricultural lands with fast-growing trees has
been widely proposed as a major alternative to sequester CO2 from the
atmosphere. As trees grow they remove CO2 from the atmosphere and thus slow
down the CO2 build-up. This is perhaps the most widely proposed strategy so
far since it can also bring important ancillary benefits such soil and water
conservation, biodiversity, etc. However, this option is increasingly being
questioned since the complexity of such a strategy is becoming more apparent
e.g. costs, lack of experience with large environmentally acceptable
plantations, local antipathy, etc. Implementation would prove difficult,
unless there were substantial and long term guaranteed incentives
for tree growing which provided an impetus to local people to actively
participate by addressing both their short and long term interests.
     Forest plantations can accumulate large amounts of biomass, particularly
in the tropics where experimental productivities as high as 70 t/ha/yr dry
biomass has been reported. The figures often quoted for a well managed forest
range from 15 to 25 t/ha/yr of dry biomass. On a global scale, 10 t/ha/yr may
be more realistic, although over the coming years productivities are likely to
increase quite significantly with the application of modern plant management
and breeding techniques.
       There have been a number of studies to determine the potential of
reforestation to sequester CO2, but they must be treated as rough guides,
given the difficulties involved in providing reliable estimates of such a
long-term nature and that plantations of various types have been notorious for
their many failures. Forest plantations have increased from about 80 Mha in
the mid-1960s to about 130 Mha in 1990, but this is small in comparison to the
estimated 14 to 20 Mha which were being deforested annually, although in the
past few years the deforestation rate seems to have declined slightly.
     It is possible to reduce global CO2 emissions substantially by adopting
various measures such as optimal ecosystem management practices and use of
bioenergy. The Enquete Commission (Bonn) states that if ecological, economic,
organizational, and socio-cultural constraints are taken into
consideration, a rough estimate indicates a potential of C fixation of about
2.6 + 1.1 billion tC/year by afforesting available land, and a further 0.1-1.1
billion tC could be saved by the use of bioenergy. 
Table 1 Summary of Current and Potential Future Impact of Human Activities on
Forests and their Carbon Budget.
------------------------------------------------------------------------------
                               (a)           (b)           (c)       (d)
                     ---------------------------------------------------------
                              Percent       Mha/yr       GtC/yr     GtC/yr
------------------------------------------------------------------------------
Boreal forests                c.0.5         -0.7e3       0.07+/-    --
                                                           0.02
Temper.forests                c.2.5         +1.4e4       0.54+/-    0.1-0.9
                                                           0.2
Tropic.forests                c.0.5         -17.0        2.0+/-     0.0-0.2
                                                           0.9
------------------------------------------------------------------------------
Total                         c.0.8         -16.7        2.6+1.1    0.1-1.1
------------------------------------------------------------------------------
(a)Annual felled area as percentage of total usable forest area.
(b) Current stand development
(c) Potential C fixing due to afforestation.
(d) Potential additional C reduction by use of wood as energy
Source: Enquete Commission (1995), table 6.13, p. 487.
This will be particularly positive if areas have been unforested for long
periods. If all potential available land (150 - 1200 Mha) was to be
afforested, the potential for C fixation would in the range of 1-7.5 billion
tC/year.
         A simple model has been constructed of C sequestration during forest
growth and the fate of this C when forests are harvested and used as fuel to
replace fossil fuels. They consider that trees are equally effective in
preventing the CO2 build-up if they remove a unit of C from the atmosphere or
if they supply a sustainable source of energy that substitutes  for a unit of
C discharged by burning fuels. Their main conclusions are:  (a) for forests
with large standing biomass and low productivity, the most effective strategy
is to protect the existing forest; (b) for land with little standing biomass
and low productivity, it is best  to replant or otherwise manage the land for
forest growth and C storage; (c) where high productivity can be expected, it
may be best to manage the forest for a harvestable crop and to use the harvest
with maximum efficiency either for long-lived products or to substitute for
fossil fuels. 
1.2  Carbon Sequestration versus Fossil Fuel Substitution
         Direct substitution of fossil fuels by biomass appears to be the more
effective strategy for offsetting CO2 emissions from fossil fuel combustion,
as greater benefits might be obtained. If biomass is grown for energy with the
amount grown equal to that burned  for a given period, there would be no net
build-up of CO2 as the amount released in combustion would be compensated  for
by that absorbed by the biomass during photosynthesis. For example, if the
conversion efficiencies are equal, then each GJ of biomass substituted for
fossil fuel would reduce emissions by the C content of one GJ of fossil fuel
displaced - 0.014 tC, 0.019-020 tC, and 0.023-0.025 tC, for natural gas,
petroleum, and coal, respectively.
     The substitution of energy from biomass for non-renewable is gaining in
some recognition. Thus tax incentives are available in USA, Sweden, Denmark,
etc, for biomass fuelled heat and electricity utilities.  In India where
between 1980 and 1992 about 17 Mha have been afforested mainly to meet
fuelwood needs of local communities, the annual woody biomass production was
estimated at 58 Mt in 1993. Considering, that the annual fuelwood demand in
India is about 227 Mt, much of it unsustainably harvested, the contribution
from plantations is quite significant. In China also about 6 Mha have been
afforested to meet fuelwood requirements; the biomass production from this is
still small compared to the annual coal use.
1.3  Estimated Costs for Reducing CO2 Emissions
         Cost estimates for reducing CO2 emissions vary quite considerably-
often by a factor of two or three- due to the many variables involved, ranging
from productivities to socio-economic and political issues. The cost of
offsetting CO2 emissions by sequestering C in trees is directly related to the
costs of growing the biomass. Forest plantation costs can vary quite
considerably since they tend to be very site-specific and influenced by a
large number of factors e.g. biological, topographic, transport, etc. Cost
estimates for afforestation are still controversial and poorly documented; a
figure of $400/ha is often quoted in the literature. But this can be 4 to 5
times higher if maintenance, protection, etc, is added over the lifetime of
the forest. In France and the UK afforestation costs are $2,000 to $2,500/ha
and in Germany about $12,500 in 1993.
               
1.4 Environmental & Ecological Concerns with Forest Plantations
         There are concerns as to the short and long term environmental
effects of large scale use of energy plantations. However, recent studies
indicate that any potential negative environmental effects are largely
dependent on management practices. For bioenergy to have such a large scale
contribution, its production, conversion, and use must be sustainable and
environmentally acceptable and also be accepted by the public.  If plantations
were to replace natural forests, there would be destructive environmental
effects and negative effects on carbon inventories and thus should be avoided.
On the other hand, forestry projects established on degraded land or abandoned
cropland can have numerous positive environmental effects.  Reforestation/
afforestation of such land can have numerous benefits such as improving the
soil structure, soil organic matter and nutrients, reduce runoff and increase
soil water storage, increase local rainfall and modify local temperatures,
increase biodiversity and preserve wildlife habitats, reduce pressure
on natural forests, create windbreaks, and, of course, store carbon. Recent
experience with the US's Conservation Reserve Program showed that the erosion
rate declined 92 per cent on 14 Mha of highly erodible U.S. cropland taken out
of annual production and planted with perennial grasses and trees.
     Care in species selection and good plantation design and management can
be helpful in controlling pests and diseases, rendering the use of chemical
pesticides unnecessary in all but special circumstances.  Good plantation
design includes: (i) areas set aside for native flora and fauna to harbour
natural predators for pest control, and perhaps (ii) blocks characterized by
different clones and/or species.  If a pest attack breaks out in a block of
one clone, a now common practice in well-managed plantations is to let the
attack run its course and to let predators from the set-aside area help halt
the pest outbreak. Well managed plantations in Brazil now leave 20-30 per cent
of the area (required by law) in a natural/undisturbed state. Establishing and
maintaining natural reserves also enhances biodiversity; however, preserving
biodiversity on a regional basis will require land-use planning in which
natural forest patches are connected via a network of undisturbed corridors
(riparian buffer zones, shelterbelts, and hedgerows between fields), thus
enabling species to migrate from one habitat to another.
         Attention must be given to long-term soil fertility which also
involves soil management.  For short-rotation forestry, it will usually be
desirable to leave leaves and twigs in the field as nutrients tend to
concentrate in these parts of the plant.  Also, the mineral nutrients
recovered as ash at the energy conversion facilities should be returned to the
site.  Species can be selected for efficiency of nutrient use; in addition,
either selecting a nitrogen-fixing species or intercropping the primary crop
with a N-fixing species can make the plantation self-sufficient in nitrogen. 
The promise of intercropping strategies is suggested by 10 year trials in
Hawaii, where yields of 25 t/ha/y have been achieved without annual 
N fertilizer additions when Eucalyptus is interplanted with  N-fixing Albizia
trees. Biodegradable agrochemicals should be used whenever possible, and their
application should be carefully planned to match the needs of the plants. 
Furthermore, careful water management will reduce the risks of water pollution
from run-off and make optimum use of rainfall in dry areas.Good fire
management practices must also be included.
2.  Social
          Three major implications associated with bioenergy production are (
i) land availability, (ii) food versus fuel, and (iii) employment generation.
         
2.1. Land Use and Availability
   
      Many studies have been carried out on land availability and they give
very wide-ranging results depending on sources of data and assumptions used. 
There are large areas of degraded and abandoned lands in the tropics which
could benefit greatly from the establishment of environmentally sustainable
biomass plantations.
     Land availability is perceived as a constraint to large scale production
of biomass; however, there are considerable areas potentially available even
under the present production systems.  In the USA, farmers are paid not to
farm about 10 per cent of their land, and in the EU about 15 per cent of
arable farmland is being "set-aside".  Apart from over 30 Mha of cropland
already set aside in the USA to reduce production or conserve land, another 43
Mha of croplands have high erosion rates and a further 43 Mha have "wetness"
problems, which could be eased with a shift to various perennial energy crops.
In the EU, at least 15-20 Mha of good agricultural land is expected to be
taken out of production by the year 2000/2010.  If all this land were used to
plant trees, it would represent an annual sink of 90-120 Mt C for the near
future.  Alternatively, this area of land could provide 3.6-4.8 EJ/yr of
biomass energy, displacing 90-120 Mt of carbon emissions from coal, 72-96 Mt
from oil, or 50-67 Mt from natural gas.  It has  been estimated that in
Western Europe if 10 per cent of useable land (33 Mha) and 25 per cent of
recoverable residues were used, biomass could provide 9.0 - 13.5 EJ of energy
which represents about 17 -30 per cent of projected energy requirements in
2050.
      
   In tropical countries there are large areas of deforested and degraded
lands that could benefit from the establishment of bioenergy plantations.  An
analysis of 117 tropical countries suggested that 11 countries were suitable
for expansion of the forest area up to 553 Mha.  Another study found that
within 50 tropical countries, 67 Mha could be realistically converted to
plantations over the next 60 years, more than 200 Mha could be regenerated,
and a further 63 Mha are available for agroforestry.  The land would
theoretically be needed to meet all of present energy consumption with biomass
(a very unlikely scenario)  has been estimated.  Assuming a productivity of 12
t (oven dry)/ha/yr, and that recoverable residues (25 per cent of potentially
harvestable residues) are also used, it is showed that 950 Mha would be needed
to grow biomass energy crops to substitute for all fossil fuels in
industrialised areas, while developing countries would require 305 Mha. 
Therefore, on a global scale, there is enough land available to allow
biomass to make a significant impact on atmospheric carbon levels and energy
production without affecting food production.
2.2. Impacts on Food Production- The Food vs. Fuel Issue
         "Food versus fuel" is an old, controversial and complex issue whose
detailed analysis is beyond the scope of this paper.  On a global scale there
is available land; also biomass energy crops can be managed for minimum water
and nutrient inputs to a greater extent than food crops.  There are people who
state that the doom and gloom about the declining food production is based on
several misconceptions and the following needs to be carefully considered: 
(i) taken as a whole considerable progress has been made in food supply since
the 1950s e.g. from 300 kg food per capita in the 1950s to 350 kg per capita
in the 1980s;  (ii) the decline in world cereal output has been largely
unconnected to population growth but more to the cut in grain production in
the USA and EU; (iii) generally, the world's food production has been keeping
ahead of population growth and diets are now more diverse e.g. land withdrawn
from cereals production has been converted to the production of higher value
foods; (iv) average per capita cereal production is a poor guide to measure
global food availability. Even if per capita production increases, per capita
food consumption will decline because population growth will come mostly from
the poorer countries; (v) the two most populous countries, China and India,
have kept food production ahead of population growth. India provides a
good example of changing trends in food production, energy, population, and
environment- it presently (1995) has over 30 Mt of surplus grain while halting
deforestation, increasing tree cover and maintaining the same cultivated area.
 The FAO Agroecological zone Database was used  to estimate the potential land
available after supplying food in 2025.  Theoretically,  if biomass was
produced at 10 T/ha on "remaining land", bioenergy could provide sufficient
energy for developing countries. In Africa for instance, it seems that social
and cultural factors e.g. the key role that many women play in food
production, will be vital in trying to reverse the downward spiral caused by
the interlinked factors of overpopulation, poor agricultural productivity and
environmental degradation.  An extensive study of global land and food in the
next century comes to an "encouraging conclusion" with qualified caveats
depending on institutional arrangements, sustainable agriculture and land
pressures; Africa and the Middle East are highlighted as being most
vulnerable.
          It should be noted that both food and fuel are important
requirements that need not compete, particularly when planning ensures
ecological conservation and sustainability of production methods.  Forestry
policies and programmes such as agroforestry and integrated farming systems
can in fact improve food security by providing food (from the tree directly
and from animals in the habitat provided), fodder, energy, and income for food
purchase.  For example, in Brazil where the area used for ethanol from
sugarcane represents less than 0.2 per cent of total land area, crop rotation
in sugarcane areas has led to an increase in certain food crops, while some
byproducts of the industry are used as animal feed.
   
2.3.  Job Creation
         Employment opportunities have been heralded as a major advantage of
biomass because of the many multiplying effects which help to generate more
economic activity and help strengthen the local economy, particularly in rural
areas.  In the USA, the National Wood Energy Association has estimated that
the USA's 6500 MW biomass power contribution sustains 66,000 direct jobs and
this could reach as much as 284,000 jobs by 2010.    For example, the
Wisconsin Energy Bureau recently  found that the use of renewable energy
generates about three times more jobs, earnings and sales output in Wisconsin
than the same level of imported fossil fuels use and investment. Given a 75
per cent increase in the State's renewable energy use, the Bureau found that
the State would realize more than 62,000 new jobs, $1.2 billion in new wages
and $4.6 billion in new sales for Wisconsin business.  Another study
completed recently in Vermont (USA), showed that the wood energy industry
generated almost 53,000 jobs in the Northeast and $2.9 billion in income. Wood
energy use annually eliminates the need for about one billion gallons of oil,
65 per cent  of which would be imported from outside the NE region. The
region's wood energy activities pay an estimated $46 million in state and
local taxes, and $355 million in federal taxes annually.  
            In the EU as a whole, according to the Madrid Declaration (1994),
"the substitution of 15 per cent of conventional primary energy demand by
renewable energy sources by the year 2010, could create between 300,000 and
400,000 new jobs, increasing the turnover of the renewable energy industry to
6 billion ECU, and avoid 350 Mt of CO2 emissions".  It has been estimated that
if the EU was to implement a large-scale bioenergy sector, "about 7 M new
direct and indirect jobs" could be created within the next 40 years.  In the
UK a preliminary study has also shown the potential for job creation,
particularly in locations suffering from high unemployment. By the year 2005
some 48,700 jobs could be generated in renewable energy of which 11,600 would
be net jobs generated in the economy.  Another well known example is Brazil
where the ethanol-based industry supports about 700,000 jobs, and the
charcoal-based sector  about 200,000 direct jobs. Charcoal making
provides  considerable employment in rural areas and is a major activity
particularly in Africa e.g. the value of the charcoal market for 26
Sub-Saharan countries is over $1.8 billion annually. In Kenya and Cameroon it
employs 30,000 people and in Ivory Coast some 90,000.
V.  TECHNOLOGY TRENDS AND MODERN BIOENERGY
1.  Technology Trends
      There are emerging and improved biomass technologies with immediate
potential applications such as integrated biomass gasifier/gas turbine systems
for power generation; improved techniques for biomass harvesting,
transportation and storage;  gasification of crop residues such as rice husks;
briquetting; treatment of cellulosic materials by steam explosion which may be
followed by biological or chemical hydrolysis to produce ethanol or other
fuels; cogeneration technologies; biocrude technology; co-firing technology;
fuel cells technology,  methanol and hydrogen from biomass; improvements of
small Sterling engines capable of using biomass fuels efficiently, etc.  The
main trends of recent years thus can be summarized as follows.
1.1. Direct combustion/gasification of biomass to produce heat, steam and
electricity
      Considerable RD&D efforts have gone into gasification as this is
regarded as one of the most promising areas. Advances have been made in
designing and improving furnaces and boilers to burn different types of
biomass e.g. furnaces such as the spreader-stoker types fuelled by wood and
bark, suspension furnaces, and fluidized bed combustion systems. 
Unfortunately insufficient attention has been paid to those
aspects which consider the needs of rural industries in developing countries
e.g. low-cost, efficient, easily operated furnaces and kilns to provide
entrepreneurial opportunities.  In the household energy sector, a notable
achievement has been the installation of millions of improved cooking stoves
(e.g. some 129 million in China from 1982-92, 0.78 million in Kenya, and 0.2
million in Burkina Faso and Niger) with an average energy saving of 20 per
cent, but in some cases reaching over 60 per cent.
      The present biomass combustion power plants have efficiencies in the
range of 15-20 per cent, with electricity costs of $0.05-0.08/kWh.  In
contrast the advanced power generation cycles have potential efficiencies of
35-40 per cent with electricity costs of $0.045-0.055/kWh.  The most important
technical concepts being developed for biomass power generation include:
direct firing of biomass, co-firing of biomass with coal, gasification, and
pyrolysis of biomass to produce biocrude, either in liquid or gas forms.
      Simple open-cycle gas turbines discharge the hot exhaust gas directly to
the atmosphere which is very wasteful (around 33 per cent overall efficiency)
when the heat can be used to produce steam in a heat recovery steam generator.
The steam can then be used for heating in a cogeneration system, for injecting
back into the gas turbine and thereby improving power output and generating
efficiency - known as a steam-injected gas turbine (SIGT) cycle (40 per cent
efficiency), or for producing more electricity through a steam turbine - a gas
turbine/steam turbine combined cycle (GTCC) (48 per cent efficiency
achievable).  Therefore, advanced gas turbines can have far greater
efficiencies than conventional steam turbines and there is also
considerable potential for continuing technological improvements, and capital
costs are lower.
      Much of the work on coal gasifier/gas turbine systems is directly
relevant to biomass integrated gasifier/gas turbines (BIG/GTs) and GTCC.
BIG/GTCC technology uses either low pressure or pressurized gasification.
Pressurized BIG/GTCC is more efficient but is likely to be more capital
intensive below a certain capacity range. Biomass is easier to gasify than
coal because it is more reactive and has a very low sulphur content.  Also,
BIG/GT technologies for cogeneration or stand-alone power applications have
the promise of being able to produce electricity at a lower cost in many
instances than most alternatives; this includes large centralised, coal-
fired, steam-electric power plants with flue gas desulphurisation, nuclear
power plants, and hydroelectric power plants.  Efficiencies of 40 per cent or
more will be demonstrated in the mid 1990s, and by 2025 these could reach 57
per cent using gasification technologies being developed for coal.  The
sugarcane industries that produce sugar and fuel ethanol and the pulp and
paper/timber industries are particularly promising targets for near
term-applications of BIG/GT technologies.
     Biomass integrated-gasifiers (BIG) and the GTCC technology will be
commercially available by the year 2000. A BIG/GTCC system is being built at
Vaernamo, Sweden, with a capacity of 6 MWe + 9 MW combined-cycle district
heating cogeneration. A 30 MWe BIG/GTCC demonstration plant is due for
commissioning in 1997 or soon thereafter in Northeast Brazil at a total cost
of $75M, of which $30M is a GEF grant. As much as 200 GW of potential BIG/GTCC
capacity has been identified from future plantations in the NE Brazil.  The EU
has plans to implement commercial biomass gasification projects e.g. IGCC
power plants of 8-15 MWe by late 1990s, 20-30 MWe by the year 2000, to be
followed by 50-80 MWe by 2005. The plants must be biomass-based, and be
able to use high-yield energy crops, demonstrate advance energy conversion
systems, and be environmentally friendly.  Three demonstration gasification
projects are already receiving financial support from the EU e.g. a 11.9 MWe
plant in Italy, a 8 MWe in UK, and a 7 MWe district heating cogeneration
system in Denmark.  A further 15-30 MWe plant is planned to be built in
Haarlem, (Holland).  In addition, two other projects are ongoing in the US,
with financial support from the Department of Energy- a 3-5 MWe air-blown
pressurized, bubbling fluidized-bed gasification of bagasse for gas turbine
power production in Hawaii, and a 200 t/day biomass (45 Mwe) plant in
Burlington, Vermont.
1.2. Production of liquid fuels
      Ethanol from crops such as sugarcane and maize are the main feedstock.
In the field of ethanol production advances have taken place in continuous
fermentation e.g. the Melle-Boinot and Biostil processes; simultaneous
saccharification and fermentation; anaerobic fermentation; use of bacteria;
heat recovery in the distillation process; and better use of by-products e.g.
bagasse which is used as animal feed and for electricity cogeneration.  Two
good country examples of electricity cogeneration from bagasse are Brazil and
Mauritius.  Brazil has been using bagasse to raise steam for on-site processes
for centuries, but very inefficiently.  Because large amounts of bagasse were
available, there was little incentive to improve energy efficiency since
disposing of the surplus bagasse was often a major problem. Recently many
sugarcane distilleries have become energy self-sufficient and some are selling
electricity to the grid. With the development of SIGT, electricity generation
in the sugar mill or alcohol distillery of the future, may become one of its
main activities.
1.3. Production of charcoal
      Significant advances have been made in some areas of charcoal technology
e.g. improved carbonization techniques and improved kilns with better energy
efficiency; better use of by-products; improved blast furnaces; integrated
charcoal-based steel plants; etc. A major development has also been the
development of sustainable natural forest harvesting and biomass plantations,
and greater awareness of the environmental implications of such production
systems. For example, in 1993 about 43 per cent of charcoal production in
Brazil originated from plantations which was mostly used in pig-iron, steel,
cement, and metallurgy industries, compared to only 12 per cent in 1978.   
However, industrial charcoal consumption is progressively being replaced by
imported coke in Brazil with negative global environmental effects; also
little use is being made of charcoal by-products.
1.4. Thermochemical conversion of biomass
      In this field, advances include: low temperature pyrolysis, fast
pyrolysis, direct catalytic liquefaction with more effective heat transfer to
a liquid phase, and reduction in reactor times. 
1.5. Anaerobic digestion of biomass residues, wastes, and dung
      The increasing commercial interest in this area is partly due to
environmental considerations (coupled with energy supply) both in developed
and developing countries. This has been helped by financing incentives, energy
efficiency advances, dissemination of the technology, and the training of
personnel particularly in China and India, has also been improved.  During the
past few years, this technology has been carefully examined in Denmark, which
has been at the forefront of demonstrating large commercial biogas plants for
treating manure and for heat and power generation. A significant change in
biogas technology has been a shift away from energy efficiency toward more
"environmentally sound technology" which allows the combination of waste
disposal with energy and fertilizer production. Biogas technology is reaching
technical and economic maturity in many situations.
1.6. Technology- related policy development
      The non-technical issues which have recently gained attention include
(a) environmental and ecological factors e.g. carbon sequestration,
reforestation and revegetation; (b) biomass as a CO2 neutral, low sulphur,
replacement for fossil fuels; (c) greater recognition of the importance of
biomass energy, particularly modern biomass energy carriers, at the policy and
planning levels; (d) greater recognition of the difficulties of gathering good
and reliable biomass energy data, and efforts to improve data provision for
energy planning; (e) studies on the detrimental health effects of biomass
energy particularly from traditional energy uses; (f) greater awareness of the
need to internalize the externality costs of conventional energy carriers to
place them on more equal terms with alternative energy sources.
2. Modern Uses- Summary of Major Programmes
      
2.1. Developing Countries
      India:  Gasification has been one focus of attention in India because of
its potential for large scale commercialisation to meet a variety of energy
needs e..g. irrigation pumping and village electrification, as well as captive
industrial power generation and grid-fed power from energy plantations. Recent
estimates put the potential of biomass-based gasification power generation in
India at 17,000 MW, and the potential for using sugarcane residues at 3,500
MW. 
      Mauritius is dominated by the production of sugar, which represents
around 88 per cent of the cultivatable area. About 10 per cent of total energy
requirements in the country are met by bagasse-fired generation of power and
steam in the sugarcane industry.  The theoretical potential has been estimated
at 2,500 - 3,500 GWh at conversion efficiencies of biomass to electricity of
30 per cent and 40 per cent, respectively.
2.2. Industrial Countries 
      Austria obtains about 13 per cent  (147 PJ) of its primary energy from
wood- a sixfold increase in 15 years.  A comprehensive study of the potential
of bioenergy indicates that bioenergy could double to 280 PJ by the year 2015.
The total investment would be around ECUM 600 and between 10,000 to 15,000 new
permanent jobs could be created. 
      Denmark. Bioenergy contributed about 7 per cent (19 PJ) of the country's
energy in 1994. The potential is estimated at 127 PJ or 16 per cent of
Denmark's gross energy consumption, or about 140 PJ if set aside land (about
230,000 ha) was also used for bioenergy.   In June 1993, the Parliament agreed
to expand the use of biomass for power generation to 1.2 M t of straw, and 0.2
M t of wood before the year 2000, which will increase the biomass component by
a further 20 PJ. 
      Finland is a leading country in the use of modern bioenergy. The
country's primary energy consumption in 1993 was 1260PJ of which more than 19
per cent came from biomass (c.240PJ), wood-derived- 14 per cent and 5 per cent
from peat). The Government's aim is to increase this by a further 25 per cent
by the year 2005.
      Sweden obtains about 17 per cent of its energy (256 PJ) from biofuels. 
The use of these fuels can be split into three different sectors:  (a) forest
products (157PJ); (b) individual households (40PJ);  (c) district heating
(49PJ) which is growing fast; (d) 9PJ used in electricity generation from CHP,
obtained from various woodfuels.  There is much more potential to produce
energy from indigenous biomass fuels particularly from agroindustrial wastes
and energy crops grown on marginal and other land. Currently over 14,000 ha of
short rotation willow is being grown under bioenergy schemes.  Sweden also
imported a small amount of biomass fuels indicating the potential for the
future development of an international trade in biofuels.  A recent study of a
205 MW district heating biomass plant in Vaxjo, concludes that a combination
of monetary and social factors has made Sweden's first biomass plant
commercially viable.
      UK. In the early 1990s renewable energy (RE) contributed barely 1 per
cent of its primary energy (a third from biomass and the rest hydro). However,
estimates put the potential contribution to electricity generation from RE at
5-25 per cent in 2005 and 5-63 per cent in 2025.  Renewable energy has been
given a stimulus by the start in 1990 of the Non-Fossil Fuel Obligation (NFFO)
which empowers the Government to make orders obliging the Electric Utilities
to contract for specified minimum amounts of non-fossil fuel sources for
electricity generation.  The aim is to achieve 1,500 MW electricity from
renewables by the year 2000; so far 900 MW has been awarded. This has been
achieved with relatively little public subsidies compared to nuclear and coal,
thanks to a competitive bidding process.  Combined heat and power biomass
projects have recently been included within NFFO.
      USA currently obtains 4 per cent of its energy from biomass and at a
recent peak about 9,000 MW of biomass fired electric power was installed. A
combination of factors e.g. low oil prices, intensified competition in the
utility sector, shut down of old less efficient plants, and lower energy
demand, have resulted in a reduction of this capacity to over 7,000 MW.  The
USDOE, in partnership with the private sector, is increasing efforts to double
biomass conversion efficiencies and reduce biomass power costs. It is
estimated that by 2010, over 13,000 MW of biomass power generation could be
installed, supporting over 170,000 jobs.   Other projections indicate as much
as 22,000 MW and 50,000 MW of biomass electric capacity, and about 283,000
jobs by the year 2010.
2.3. Briquetting
     Briquetting is making a comeback in a number of countries due to various
factors e.g. existence of readily available residues, convenience, advances in
densification technology, attractive costs and entrepreneurial opportunities.
In Sao Paulo state, Brazil, some 30,000t are consumed monthly- 20,000 by the
commercial sector such as bakeries and pizzerias, and 10,000 by the industrial
sector. Briquettes are produced from sawdust and other processed residues. The
main reasons given for using briquettes include convenience, homogeneity and
high energy content, and price.  India has also good possibilities e.g there
260 Mt/yr of agricultural residues of which about 100 Mt are wasted that could
be used for making briquettes.
2.4. Liquid Fuels
      Global interest in liquid biofuels for transportation has increased
considerably over the last decade despite low oil prices and there are
detailed studies available on costs and environmental factors.   An EU
Committee proposed a target that up to 5 per cent of the liquid fuel market
could be supplied by bioethanol and biodiesel by 2010 and that an agricultural
area of 7 Mha (5.5 per cent of the utilised agricultural area of the EU) will
be necessary to produce 7 Mtoe.  The world's major producers of liquid
biofuels are Brazil and USA, followed by the EU. The rest can be considered as
small producers by comparison.  
      Biodiesel.  This comprises ethyl or methyl esters of edible oils.  Rape
methyl ester (RME) produced from oilseed rape is the main source in Europe and
Canada, while soya oil is used in the USA. The CO2 benefits of biodiesel
depend on the inputs used  and the use of byproducts and are therefore
variable.  Other environmental benefits include negligible sulphur, reduced
particulates, and a product that biodegrades within a few days (making it
particularly suitable for use on inland waterways and other fragile
environments).  Furthermore, rapeseed-based lubricants have superior
lubrication properties.  Biodiesel is also in various developing countries
e.g. Brazil, Mali and Thailand. In Mali a project is underway to determine the
potential of producing vegetable oil from Jatropha curcas as a diesel
substitute and other applications with encouraging results.
      Bioethanol is produced from crops with high sugar or starch content. 
Alcohols have favourable combustion characteristics, namely clean burning and
high octane-rated performance.  Furthermore, there are numerous environmental
advantages, particularly with regard to lead, CO2, SO2, particulates,
hydrocarbons, and CO emissions.  Brazil and USA have pioneered large-scale
ethanol fuel programmes, and on a smaller scale various sugarcane producing
countries e.g. Zimbabwe, Kenya and Malawi. Some countries have modernised
their sugar industries, and are able to produce sugar, alcohol and electricity
with low production costs.  In the EU trials of bioethanol have been carried
out in Germany, Italy and Sweden and a small amount is already blended with
gasoline in France. The most promising feedstocks include cereals, sugarbeet,
sweet sorghum, Jerusalem artichoke, and grapes.
      Brazil is a major user of biomass, particularly in modern industrial
applications. The ProAlcool programme was set up in 1975 and since then about
180 billion litres of bioethanol have been produced, presently replacing about
200,000 barrels/day of imported oil. At its peak (late 1980s) almost five
million automobiles ran on pure bioethanol and a further nine million ran on a
20 to 22 per cent blend of alcohol and gasoline. Late in the 1980s the
combination of high demand for ethanol, higher prices for sugar, uncertain
government policy, resulted in a shortage of ethanol, and as a result the
fraction of new neat ethanol cars dropped to 51 per cent in 1989 and to less
than 20 per cent in 1994.   Since 1976 some 119 billion litres of gasoline
have been replaced by ethanol with a total value of $27 billion (at 1994$).
This compares with $11.3 billion total investment in the ProAlcool Programme. 
The government established several support mechanisms: insuring a market,
guaranteeing a price, providing financial incentives to ethanol producers and
car owners, and investments in R&D.  About 700,000 direct jobs with perhaps 3
to 4 times this number of indirect jobs have been created. However,
ProAlcool has certain economic difficulties (mainly due to the changes in the
oil and sugarcane markets) which will have to be overcome or the industry's
future may not be as secure without a stabilised supply and demand of alcohol.
      The USA is the world's second fuel ethanol producer. In 1994 production
was about 5.3 billion litres (1.4 billion US gallons), and a further 908
million litres (240 million gallons) of new capacity is under construction.
Further expansion is planned, as ethanol is expected to enter into the ether
market in the form of ETBE and as "neat" fuel. Ethanol is now produced in
twenty one States, represents 10 per cent of the USA's fuel sales, and is used
by over 100 million motorists.  Ethanol is produced from grain, cheese whey,
citrus wastes, and forestry residues, but the predominant source is corn
(maize). Provisions of the Clean Air Act of 1990 and the National Energy
Policy Act of 1992 have created new market opportunities for ethanol, methanol
and natural gas, by phasing in requirements for fleet vehicles to operate on
cleaner fuels. The GEC estimates that by 2005, some 5 million vehicles
will be running on non-petroleum fuels. 
      Zimbabwe.  Annual production of ethanol at about 40 M litres has been
possible since 1983, except during the severe 1991/2 drought.  The ethanol
plant at Triangle has operated successfully for almost 15 years, financed
mainly by local capital, with home based technology required whenever possible
rather than over sophisticated equipment from abroad. The capital cost was
only $6.4 million (1980 prices) - the lowest capital cost per litre for any
ethanol plant in the world.  Triangle offers an example of good use of
relatively simple technology, local infrastructure, and political commitment.
      Methanol Fuel. Until recently, biomass-derived methanol was not seen as
a promising alternative to fossil fuels due high costs of biomass feedstock
and economics of scale. However, important technical advances of recent years
is changing this view.  Biomass-derived methanol can make major contributions
to energy requirements for road transportation if used in fuel cell vehicles
(FCV).  Such systems offer attractive economics in the year 2010 time-frame
and the potential for both very low emissions of local air pollutants and low
net CO2 emissions if the biomass is grown sustainably.
 
2.5.  Biogas
      Biogas is produced by the anaerobic fermentation of organic material.
Production systems are relatively simple and can operate at small and large
scales practically anywhere, with the gas being as versatile as natural gas.
Anaerobic digestion can make a significant contribution to disposal of
domestic, industrial and agricultural wastes. The economics of biogas
production has received considerable attention, particularly in industrial
countries where energy production is combined with waste treatment, air
pollution abatement and meeting environmental legislation. The economics of
biogas production show considerable variations.  
      China. At the end of 1993, about five and a quarter million farmer
households had biogas digesters, with an annual production of approx. 1.2
billion m3.  In addition, China has over 600 large and medium size biogas
plants that use organic waste from animals and poultry farms, wineries, etc,
with a combined capacity of 220,000 m3. They process about 20 million tons of
organic waste annually, servicing 84,000 households. China has also built
24,000 biogas purification digesters to treat wastes in urban areas, with a
capacity of nearly one million m3, treating waste water for two million
people.   Biogas is also used to generate electricity in China. There are
about 190 biogas-based power generation units with a total installed
generation capacity of almost 3500 kW and an annual generation of 3 GWh of
electricity.
      India.  In 1980, about 80,000 family biogas plants were already in
operation, reaching 1.85 million in 1993, of which about two-third are
operational. The number of community biogas plants was 875. The total market
potential for family biogas plants has been estimated to be around 12 million
units. The National Programme on Biogas Development (NPBD) main goals include:
(i) provide clean cooking energy, (ii) produce enriched manure to supplement
chemical fertilizers;  (iii) improve the quality of life of rural women; and
(iv) improve sanitation and hygiene.  
      Denmark.  Since the mid-1980s, 10 centralised and 10 single-farm biogas
plants have been established, with an output of 14 million m3 per annum (0.5
PJ). The concept of centralized plants has been well developed in Denmark. The
centralized plants co-digest animal manure and vegetable wastes producing
biogas and fertilizer as a result. Their capacities range from 50 to 500
t/feedstock/day, producing between 1,000 and 1,500 m3 of biogas per day. Most
of the biogas is used for CHP generation. The costs of biogas (tax excepted)
is DK1.60-1.70/m3, ($0.15 to $0.16);  October 1994 prices.
VI.  ECONOMICS  AND COSTS OF THE BIOMASS OPTION 
1. Introduction
      Most biomass energy technologies have not yet reached a stage where
market forces alone can make the adoption of these technologies possible.  One
of the principal barriers to the commercialisation of all renewable energy
technologies is that current energy markets mostly ignore the social and
environmental costs and risks associated with conventional fuel use.  
Furthermore, conventional energy sources tend to receive large subsidies and
support e.g. Hubbard  estimated the total external costs of energy in the US
at $100-300bn/yr; and in many developing economies, energy prices are
subsidised by 30-50 per cent.  Other external costs of conventional energy 
which are usually not taken into account include the long-term costs of
depletion of finite resources and the costs associated with ensuring
supplies from foreign sources.
      Competition in the world's energy markets does not take place on a
'level playing field'. Existing infrastructure, tax regimes, finance for R&D,
and the power of political interest groups all  tend to work in favour of
fossil fuels and nuclear, at the expense of renewables such as biomass. Thus,
at present, it is difficult for biomass to be competitive with such fossil
fuels, except in certain niche markets or where sufficient tax incentives
exist. To improve this situation attention needs to be focused on two key
areas: Reducing the cost of producing biomass fuels/feedstocks; and reducing
capital investment costs for plant converting biomass to useful energy
carriers (such as electricity or liquid fuels). 
      Capital costs for biomass energy facilities tend to be high because of
their novelty (except for ethanol) and relatively small scale. These factors
raise prices compared to fossil-fuelled plants, where economies of scale and
experience are exploited. This underlines the need for demonstration plants
for  newer and more promising technologies, and their replication and
progressive improvement. Elliott predicts that specific investment costs for
biomass integrated gasifier - gas turbine (BIG-GT) electricity generation
plant would fall from 3000 $/kW to 1300 $/kW over the course of 10
replications.4/ 
      
2. Biomass production. Agricultural crops for biomass energy, such as maize,
sugar cane and rapeseed already achieve high yields as a result of long
standing R&D efforts. Trees and herbaceous energy crops on the other hand are
under research as energy feedstock but are starting to be the focus for
research into high yielding species for energy production. At experimental
stations hybrid poplar cultivars in northwestern USA can produce up to 29.6
odt/ha/yr, and switchgrass in southeastern USA up to 30.4 odt/ha/yr.5  
      As a yardstick, internationally traded coal presently costs
approximately $1.8/GJ ($45/t).  By 2010 the US Department of Energy predicts
this will fall to $1.3/GJ for coal supplied to electricity utilities.  In
order for a large market to develop a reliable supply of biomass at $2/GJ or
less is needed. This corresponds to approximately $40/odt (oven dry tonne). 
In Brazil the lower costs and better growing conditions allow plantation
biomass to be produced more cheaply. Carpentieri et al  estimate that 13 EJ/yr
of biomass could be delivered from plantations in northeast Brazil, at $1.5/GJ
or less (1988 US $).
      Other sources of biomass include industrial residues (e.g. pulp and
paper waste), forestry residues, and agricultural residues (e.g. straw). These
sources can be very cheap or even free of cost, depending on the competing
demands and ease of transport.  Generally the costs of agriculture are higher
in Europe than in the USA; the same applies for biomass energy production. 
Current costs tend to be in the range $4 - 6/GJ, compared to $2.5 - 4/GJ in
the USA.6/
       The cheapest form of biomass is industrial residues.  Agricultural
residues such as straw are currently cheaper than plantation wood but could be
undercut in future by short rotation co-pricing.  In Denmark, biofuels are
competitive for district heating because of heavy taxation on fossil fuels.
Energy and carbon dioxide taxes raise the price of coal from $3.03 to 8.64/GJ,
and natural gas from $3.03 to 10.15/GJ.  A study from the Netherlands
concluded that it would actually be cheaper to import wood from the Baltic
states or developing countries rather than produce it domestically.
      La Rovere and Nogueira  compare prices for plantation wood in Sweden
($2.39 - 3.39/GJ) and Finland ($3.1/GJ) with plantations in developing
countries such as Brazil ($1.41 - 1.50/GJ), India ($1.41 - 1.91/GJ), Thailand
($1.69 - 1.91/GJ) and the Philippines ($1/GJ).  Despite these low plantation
costs in developing countries, wood can often be obtained even more cheaply by
felling native forests.  Charcoal is a valued commodity in Brazil, where it
provides 41 per cent of the energy used in the steel industry. Charcoal
produced from plantation wood costs $3.03 - 3.15/GJ to produce, compared to
$1.43/GJ from unauthorized deforestation and $2.05/GJ from authorized
deforestation.  Further R&D to improve yields and reduce costs for plantation
wood is needed in order to discourage further tropical deforestation.
3. Electricity and heat. Electricity is a much higher value energy carrier
than solid or liquid fuels. Electricity wholesale prices are typically 5 ›/kWh
($14/GJ) compared to liquid fuels at $4 - 5/GJ. Thus, for a relatively high
cost feedstock such as biomass, conversion to electricity could be
economically attractive. However, biomass is still in direct competition with
fossil fuels, specifically coal for electricity generation. BIG-GT could
benefit from lower specific capital costs than clean coal technology, since it
does not require flue gas desulphurisation, and lower temperatures are
required for wood to gasify compared to coal.  A number of authors are
predicting electricity generation costs of approximately 5 ›/kWh ($14/GJ) in
the near future for industrialized countries, and for the present day in
Brazil.
      Sale of heat in combined heat and power (CHP) facilities could generate
revenue which would reduce the net cost of electricity production from
biomass.  Sale of heat will be an important measure to improve the
competetivity of biomass, given the economies of scale enjoyed by large fossil
fuelled plants.  In a UK study, a lower selling price is assumed for heat, of
1.56 ›/kWh. It concludes that the net cost of electricity from wood residues
would be 7.6 ›/kWh, and from short rotation co-pricing plantations 14.4 ›/kWh.
      Biomass costs 30 - 40 per cent more than fossil fuels. This is confirmed
by operating experience in Austria, where wet bark (a by-product from saw
mills) is available for $2.8 - 8.3/GJ, and is used for district heating.  Heat
is sold for 6 - 9 ›/kWh.  Biomass for district heating is about 30 per cent
more expensive than fuel oil in Austria.A recurring problem in the promotion
of biomass for energy is that potential suppliers are discouraged by the lack
of market, and potential users are discouraged by the lack of reliable supply.
In France grants are awarded for capital investment in biomass district
heating, but only once a critical number of installations are planned in one
location.  This policy is aimed at creating a secure market for biomass
producers and manufacturers of conversion technologies.  Cofiring biomass with
fossil fuels in conventional power stations could also provide a stable market
for biomass producers. Interest from the power industry has grown as cofiring
could be a low cost approach to meeting sulphur emissions standards.
Cofiring organic residues could be the most economically attractive biomass to
energy conversion available with current technology.
4. Liquid and gaseous fuels. Table 2 compares three types of biogas production
in Europe. The first example is primarily a system for dealing with the
organic fraction of municipal waste, or organic wastes from food processing.
Income would be largely from disposal fees rather than biogas sale.  However,
the high biogas yield of such waste makes it a valuable feedstock addition to
livestock slurry in the Danish biogas programme, where the increase in yield
improves the economic performance overall. The Danish Energy Agency  is aiming
to reduce operating costs to $3.75/m3 of feedstock. Revenue from gas sales
(for district heating or CHP) is estimated at $6.68/m3 of feedstock.  Capital
investment grants of approximately 20 per cent are still considered necessary.
The third example, small scale on-farm anaerobic digestion, can be
economically viable. However, the small engines suitable for on-farm
electricity generation have been very inefficient, though more efficient
dual-fuel diesel engines are available.  An electricity selling price of 10-15
›/kWh is necessary for farmers and investors in Europe to become seriously
interested in biogas for electricity. Dagnall and Dumbleton confirm this for
the UK, as they calculate that using farm biogas for CHP, with heat sold for
1.56 ›/kWh, gives a net electricity cost of 9.1 ›/kWh.
      Table 3 presents data for a case study of a community
biogas-for-electricity facility a village in South India.  The feedstock is
cattle manure.  The conclusion of the study was that at higher rates of
interest (above 7.5 per cent) and capacity utilization (hours per day) the
facility could produce electricity more cheaply than the costs of supplying
centralized grid electricity to this village.
      In industrialised countries experiencing food surpluses, farmers are
keen to diversify into these crops, to make use of idle land, machinery and
labour. However, with current low oil prices these costs are typically 2 to 3
times the cost of the competing fossil fuel (the gasoline wholesale price is
$4 - 5/GJ, and the retail price in the USA is approximately $7.5/GJ.  The
lowest costs are in Brazil where sugarcane production costs are low, and
capital costs have fallen with experience. Production costs fell by 4 per cent
per year from 1979 to 1988, and a further 23 per cent reduction would be
possible with relatively little investment.  Revenue from the sale of
electricity generated from cane bagasse (using BIG-GT technology) could
make ethanol competitive in Brazil, even at today's low oil prices. In
industrialized countries efforts have been made to find cheap feedstocks.
      Woody biomass could provide the cheap feedstock needed to make liquid
fuels from biomass more competitive. It has been calculated that ethanol from
woody biomass would presently cost $15.1/GJ to produce. Costs as low as 8.6
$/GJ are possible in the future.  By comparison the wholesale price of
gasoline is projected to rise from $4.5/GJ (1993 average) to $6.8/GJ in 2010. 
Methanol has generated interest as a possible fuel for fuel-cell vehicles.
Methanol is normally produced from natural gas or coal.  It has been
calculated that biomass feedstock prices would have to fall to $1.5/GJ for it
to compete with coal.  For comparison, estimates of production costs for
methanol from natural gas and coal are $7.3/GJ and $11.7/GJ,
respectively.Table 4 represents production cost and selling prices for
biodiesel. Diesel is the competing fossil fuel, and has whole sale prices of
approximately 20 c/l ($5.5/GJ). Valuable co-products (animal feed and
glycerol) can reduce the net cost of production. If taxed at 10 per cent of
the rate levied on diesel, biodiesel could develope a market share in Europe.
Niche markets could exist where air and water quality is particularly
important, such as national parks,waterways and ski areas.
 
5. Comparison of biomass costs under a single methodology
      Comparisons of forms of biomass energy are made difficult by the
different assumptions made by authors in their calculations.  Mendelsohn and
Sweeny have modelled for biomass energy costs in Australia.8  On the basis of
their comparison, and taking account of available resources, market
opportunities and environmental impact, the authors select seven most
promising systems. They are the following (not in order of priority): - (i)
woody residues to electricity, (ii) MSW to electricity, (iii) animal/human
wastes to electricity, (iv) woody biomass to ethanol, (v) woody
biomass to methanol, (vi) oilseeds to oilseed esters (biodiesel); and (vii)
biomass to oxygenates.
6. External costs.  Environmental and social costs are hard to estimate since
human life and environmental amenity are difficult to assign a fixed value. 
It is easier to estimate medical costs or clean-up costs, for example the
Exxon Valdez oil spill cost $2.2bn, the Three Mile Island nuclear accident
cost $1bn.  Estimated external environmental effects of electricity production
in Germany have been estimated  to be 0.011-0.061DM (1982)/kWh for fossil
fuels and 0.012-0.120 DM/kWh for nuclear power.  When other external costs and
support are included, the total cost comes to 0.039-0.088 DM(1982)/kWh for
fossil fuels and 0.097-0.208DM(1982)/kWh for nuclear. (The exchange rate was
$1 = DM2.43, 1982).
      Therefore, renewable energy sources, which produce few or no external
costs and have several positive external effects are systematically put at a
disadvantage.  Internalising external costs and benefits and re-allocating
subsidies in a more equitable manner must become a priority for all renewables
to be in a better ("level playing field") position to compete with fossil
fuels. Some governments are trying to develop programmes to account for
external costs such as taxes on emissions and incentives for cleaner fuels,
but few schemes have yet been put into practice and most have met with strong
opposition.  In general, current emissions regulations and charges bear little
relation to the real damage imposed by fossil fuels and the waste disposal,
insurance, and decommissioning costs of nuclear plants as they tend
to be political compromises.
      The cost estimates above take account of private (internal) costs only. 
All economic activity, and particularly energy production, also leads to
external costs, which accrue to third parties other than the buyer and seller.
These can be environmental (e.g pollution damage to crops) or
non-environmental (e.g. direct subsidies, national security of energy supply,
R&D costs, goods and services publicly supplied).  Calculation of money values
of externalities is controversial. However, where a common methodology is
applied to all fuel types useful comparisons can be made, and there is some
agreement on values between authors. Ozdemiroglu  estimated the external costs
of renewables compared to coal for electricity generation in Scotland, UK.
Wind and hydro have lower external costs than biomass, but landfill gas and
MSW combustion have higher external costs. Coal is estimated to have an
external cost of 3.55 - 5.4 ›/kWh, compared to energy crops at 0.44 - 0.59
›/kWh.  Consideration of these external costs in planning investment in new
generation capacity would thus reduce the cost of biomass relative to coal by
3.1 to  4.8 ›/kWh. Thus biomass for electricity at 7 - 10 ›/kWh would be
competitive with the present electricity price of 4 - 5 ›/kWh.
       The approach taken to valuation of external costs by public utilities
in the USA has been examined. In total, twenty nine States take externalities
into consideration in resource planning and/or acquisition. Of these, twenty
two do so only in a qualitative manner.Only five States attempt to monetize
the external costs: California, Massachusetts, Nevada, New York and Wisconsin.
Focus has been almost exclusively on environmental externalities (not economic
or social), and particularly air emissions.There is a wide variation in the
valuation of externalities between States, as the values adopted for carbon
dioxide emissions range from $1.21/t in New York to $25.24/t in Massachusetts.
Of the five States only Massachusetts recognises that CO2 emissions from
biomass are offset by sequestration during growth. In Massachusetts this
reduces the external cost for a wood project from over 5 ›/kWh to about 1
›/kWh.
7.   Summary.   The most economically attractive forms of biomass energy are
based on organic residues from agriculture, forestry or industry.Where these
residues are locally available cofiring, CHP and district heating are already
attractive.As plantation wood costs are reduced, and capital costs fall,
biomass to electricity will become increasingly competitive.Advanced
gasification technologies for wood to electricity have certain cost advantages
over fossil fuelled plants, making them a particularly promising
technology.Technology for converting woody biomass to ethanol
technology is commercially unproven, and would require a significant oil price
rise to become competitive.Where valuable co-products are produced, as in the
case of rapeseed for biodiesel, economic performance is improved. Biogas
itself is a byproduct of treating organic wastes, and sale of energy can
generate significant revenue. In remote locations local production of biofuels
is often less costly than  delivering fossil fuels or grid electricity.
Considerationous fuels are generally less competitive.However, experience in
Brazil has shown that sugarcane for ethanol is approaching economic of the
relative external costs attached to biomass energy compared to fossil fuels
would significantly improve the economic viability of biomass.
VII.  POLICY REQUIREMENTS AND IMPLICATIONS. 
       The aim of any modern biomass energy system must be (a) to maximize
yields on a sustainable basis with minimum inputs, (b) optimize economic and
social benefits to the local and wider communities, (c) utilization and
selection of appropriate plant material and processes, (d) optimum use of
land, water, and fertilizer, (e) create an adequate infrastructure and strong
R&D base, (f) internalize the externalities. Much of this is still lacking
particularly under many developing country conditions. 
       Although it is expected that market forces will be determining factors
in the future development of bioenergy, past experience indicates that initial
political and fiscal support is necessary for bioenergy to succeed, given the
low price of conventional fuels, hidden subsidies, and institutional barriers.
For example, Austria provided political encouragement through favourable
legislation, capital grants, cheaper finance, and education.In Denmark, there
has been political support at the highest level to green energy and
sustainable development, and Finland allocated substantial funds to RD&D. In
Sweden a catalyst to bioenergy was the decision to phase out nuclear energy.In
the U.K. the main instrument has been the NFFO through a competitive bidding
process.The USA has introduced a number of legislative and economic measures
aimed at facilitating the introduction of alternative energies.  In developing
countries the situation is more difficult. Conventional energy prices e.g.
electricity, LPG, kerosene, and diesel, are often kept artificially low
through subsidies to facilitate industrialization and for other social
reasons, and thus little money is allocated to support bioenergy. Large
countries such as Brazil, China and India have alternative energy programmes
of some scale.For example, Brazil has been subsidising ethanol production
while China has been supporting biogas and woodstove programmes. In India, the
first country to set up a Ministry for renewable energy sources, artificially
low price energy supplies are hampering the development of bioenergy in most
cases.
       Although subsidies may be politically acceptable for renewable energies
until they reach some kind of maturity, ultimately it will be the market
forces that play the main role.Thus it is important that all costs and
benefits of energy are internalised. In the present political climate it would
not be possible to provide subsidies for long periods, as energy prices are
more likely to reflect prevailing international market prices. 
1. Fiscal incentives. Taxes and other fiscal incentives are well established
instruments used to stimulate particular energy sources. Taxes can be both
barriers and incentives for promoting new energy sources e.g. in the USA
federal taxes have played both roles, depending very much on type of the tax
measure.  Carbon taxes are a relatively new concept but can play a crucial
role in helping to implement low or non- CO2 emitting energy initiatives such
as biomass. Carbon taxes are basically a policy instrument and as such will
vary from country to country and specific circumstances.The use of taxes was
widely advocated in the 1980s as an efficient way of supporting renewable
energy and for GHG abatement.This advocacy seems to have subsided somewhat due
mainly to industrial hostility and political constraints. Although the cost of
taxation may not be necessarily high, the idea of higher taxes coupled with
the global nature of the problem, has played against it.However, the
concept is beginning to be applied in some countries e.g. in Sweden carbon
taxes were introduced in 1991- the tax is roughly equivalent to $150 per tC,
affecting oil, coal, natural gas and petroleum. Norway's carbon tax is about
$120 per tC.  
       It has been estimated that a 0.2 per cent levy on fossil fuel
consumption in the OECD countries would raise some $833 million annually.If
half of the levy was spent on buying down the cost of the most promising
electricity generation technologies (wind, solar thermal, photovoltaic and
biomass energy) they could obtain full commercialization within 10 years or
so.An example is UK's Non Fossil Fuel Obligation programme which has
stimulated a decrease in the bid price for wind power from 14.4-17.6 cents/kWh
in 1990 to 6.4 cents/kWh in 1994, through a process of learning by doing. For
the 70 cheapest NFFO-3 projects, totalling 316 MW, the bid price averaged 6.2
cents/kWh, compared to 4.2 cents/kWh average price of electricity based of
fossil fuels that excludes environmental and social costs which has been
estimated to be as high as 6.4 cents/kWk.The total subsidy for NFFO-3 projects
is about $27 - 35M), or 48 - 64 cents person/yr over the 20 year contract
period, or less than 0.2 per cent of the national consumers' electricity bill.
(Exchange conversion rate œ1-$1,6).
 
2.  Future Energy Trends. Three main aspects will be examined:  (i) energy in
general, (ii) bioenergy, and (iii) biofuels (liquid and gaseous).
       2.1. Energy. All indications point to a more complex and varied future
energy supply matrix in which renewable sources of energy will have a major
and increasing share of the market. A more decentralized and diversified
energy supply system  would allow greater control at national, regional and
local levels. Energy efficiency will increase therefore allowing continued
economic growth without necessarily increasing energy consumption per capita
in industrial countries. In developing countries, energy demand will continue
to grow due to population growth and better living standards,but at lower pace
due to technological improvements.Fossil fuels will continue to be used on a
large scale well into the next century, but with a diminished role on a
percentage basis while  alternative energy sources, the so-called "carbon
free" energies, will see their market share increased quite considerably.The
transition from a predominantly fossil fuel energy system to a more
diversified and decentralized one could be accelerated greatly by the
increasing power of shared and processed information.
       2.2 Bioenergy.It is becoming clear that bioenergy could be a major
source of energy in the next century.Modern biomass energy use will increase
quite considerably while traditional uses will experience a decline in
relative terms.In absolute terms, however, due to population growth, it is
likely that traditional biomass will continue to increase.The use of bioenergy
on a large industrial scale will require important advances in
agro-technologies to increase productivity and reduce costs, as well as in
transformation technologies e.g. gasification.The most promising bioenergy
market is for CHP and bioelectricity which can use already established
technologies. In the medium term emerging technologies e.g. BIG, STIG,
BIG/GTs and GTCC, can open new economic opportunities. 
       2.3 Biofuels (liquid bioenergy). The combination of technological and
environmental factors and high fuel efficiency is making possible the
introduction of new transportation fuels at a faster rate than previously
thought possible a decade ago, despite low oil prices.This will, however,
depend on a mix of political, commercial and technical factors.High quality
liquid fuels will be reserved for road and air transportation and oil will
dominate at least until 2050. 
       Ethanol. Liquid biofuels will be dominated by ethanol from sugarcane
(Brazil), maize (USA), and a variety of crops in the EU, the three main
production areas.Many sugarcane producing countries will probably enter the
ethanol market but on a smaller scale. Non-transportation uses of ethanol may
include the chemical industry and cooking, and water pumping water in rural
areas. In the longer term the production of ethanol by enzymatic hydrolysis
from ligno-cellulosic feedstocks could increase the market very considerably
as it may be possible to produce ethanol at competitive prices.
       Methanol & Hydrogen. These fuels could play a role around the year 2010
when used in fuel cell vehicles (FCV). Initially methanol and hydrogen would
be produced by steam-reforming natural gas, which is the more economic route
in the short term.Although much needs to be done, methanol and hydrogen from
biomass could potentially make a major contribution to transport fuel
requirements on a competitive basis and bring many economic benefits
particularly when produced in rural areas of developing countries.
       Biodiesel.There has been an increasing interest on biodiesel, but
excluding a few countries such Brazil, EU and possibly USA, the market will be
a small and a localized one because of high costs and the high demand for
edible oils.In remoter rural areas of some developing countries where there is
a high production potential, biodiesel could play a role in meeting local
needs.For example, in Brazil with some 40,000 small isolated rural villages,
it makes sense to produce biodiesel to meet local needs e.g. lighting, pumping
water, etc.The higher cost may be justified on the ground of high connection
cost to the national grid and transportation cost of diesel.   In the short
term, biodiesel would probably be confined to OECD countries that, for
environmental, agricultural and other reasons, can afford to pay high
subsidies.
3.  Major Research Gaps. Despite the overwhelming importance of biomass energy
in many developing countries, planning for the management of production,
distribution, and use of biomass receives inadequate attention among policy
makers and energy planners.The few relevant policy provisions that may exist
are often ineffectively put into practice due to a combination of factors such
as budgetary constraints, lack of manpower, low priority, lack of data,
etc.Considerably more data on all aspects of biomass production and use are
required on an ongoing basis especially if biomass energy is to be placed on
an equal research basis as other energies. Lack of data hampers energy
planning for the production and use of biomass energy, few detailed studies
exist, at national or regional levels.For example, there are few biomass
energy flows at national levels besides USA  and Kenya and Zimbabwe.Biomass
energy flows are important because they are very useful methods of
representing data and can provide a good overview of national, regional, and
local conditions and opportunities  for energy provision and saving but very
little reliable data is available for their compilation.Unfortunately such
data is too often lacking.
       A major gap with biomass energy data is that the little research
performed has usually been aimed at obtaining supply and consumption data
along with conversion processes, but with insufficient attention and resources
being allocated to more basic research such as to production, harvesting, and
integrated conversion processes. Additionally, little research is done to
study market flows, economics and the role of entrepreneurs in making
bioenergies available to end uses and whether these services are provided in a
sustainable manner.
VII.  CONCLUSIONS
       The growing interest in bioenergy reflects a combination of
factors.These range over greater environmental, ecological, and sustainability
concerns; the potential biomass energy contribution both in its modern and
traditional forms; its versatility and global availability; substantial local
benefits; the growing interest in the industrial countries to grow energy
crops on set-aside land; and technological advances to improved economic
viability.  For the first time bioenergy is being recognized as a significant
component in many future energy scenarios, ranging from about 10 per cent to
over 30 per cent of energy supply by around the year 2050.The RIGES scenario,
for example forecasts that by 2050, 17 per cent of the world's electricity
could be generated from modern biomass.Given the nature of bioenergy, so
inadequately stated and undervalued in many official statistics, it is
not possible to present a more reasonably accurate picture. For so long the
main source of energy in many poor countries, and an important component in
many industrial countries, its future role as a modern energy source could be
prominent. However, in its traditional forms its contribution may be
relatively less important (but not in absolute terms). 
       A major problem with traditional forms of bioenergy, is that they are
often used inefficiently and too little useful energy is produced. Far more
energy can be economically produced from biomass than at present so that the
biomass energy potential could be considerably increased. Indeed low energy
efficiencies, particularly in rural areas of developing countries, have not
been adequately addressed nor has it been a priority.  When bioenergy is
inefficiently used it can be environmentally  detrimental.  However, if
produced efficiently and on a sustainable manner, bioenergy has many
environmental and social benefits compared to fossil fuels.These benefits
range from socioeconomic development, waste control and disposal and nutrient
recycling, to job creation, CO2 mitigation, improved land management, all
depending on the nature and technology in question.Of the various
strategies under consideration to mitigate GHG production, the substitution of
fossil fuels by bioenergy is an option which is gaining acceptance since it
appears to be an effective strategy  both economically and environmentally, in
particular for CO2 offsetting. The potential for CO2 abatement ranges from 1
Gt to 3.5 Gt per annum.
       A major, and perhaps misconceived concern, is the long term
environmental and ecological impact of large monoculture energy plantations.
Recent experience and research indicates that with careful management
practices, land use planning, and appropriate selection of species and clones,
most of the negative effects can be avoided and positive attributes can be
emphasized.
       Land availability and bioenergy production are intrinsically
intertwined. Many studies have been carried out to determine how such land is
available globally for non-agricultural purposes. These range from 150 Mha to
1,200 Mha reflecting lack of adequate criteria for classifying degraded and
abandoned lands. What these and other studies seem to demonstrate, is that the
perceived constraints on land are not well founded, not-withstanding local
priorities of land use. What is not questioned is that considerable amounts of
land in the EU and USA are being taken out of production while in tropical
developing countries there exist large areas of deforested and degraded land,
unsuitable for agricultural purposes, that could be enhanced in value from the
establishment of bioenergy plantations.
       Competition of bioenergy with food production is another voiced
concern. Some of the issues which need to be scrutinised before a proper
analysis of the "food versus fuel" problem can be undertaken are: food
production and consumption, distribution patterns, hunger, lack of purchasing
power, inequality, land and grains used for livestock, underutilization of
agricultural land, lack of inappropriate investments, export of crops, land
tenure, wars, and political interference.
       With proper support (R&D, infrastructure, financial, etc) farmers have
demonstrated that they can produce far more food. If more food is to be made
available to those who presently have inadequate nutrition, we need to make
the necessary changes to the present food production and distribution system. 
It is also important to remember that food and energy are mutually
interrelated and complementary. Bioenergy programmes which couple with
agroforestry and integrated farming can improve food production by making
energy and income available where it is needed.
       Of the many social benefits of bioenergy, job creation has been
heralded as one of the most important.Traditional bioenergy is labour
intensive and employs large numbers of people, often unrecorded e.g. charcoal
production in Sub-Saharan Africa is a major energy and economic activity,
worth about $2 billion and employing hundreds of thousands of people, and yet
it goes largely unnoticed by governments and most aid agencies. Modern
bioenergy production is less employment intensive, but generates more jobs
than similar industrial activities. 
       A range of technological advances are opening up new opportunities for
bioenergy considered only a few years ago as long term prospects.Notable
advances have been in gasification and other technologies being spearheaded by
the EU and USA, e.g. BIG, GTCC, co-firing, biocrude, etc, with Brazil and
India also becoming important players.  In biofuels, Brazil and USA dominate
the ethanol market and biogas by Denmark and also China and India. Promising
emerging fuels are methanol and  hydrogen from biomass and their potential for
utilization in fuel cell vehicles.Most biomass energy technologies have not
yet reached  a stage where market  forces alone can make the adoption of these
technologies possible.Exceptions are the use of residues from agriculture and
forestry when they are readily available for generating heat, electricity, and
biogas which can be sold at competitive prices. One of the principal barriers
to the commercialisation of all renewable energy technologies is that current
energy markets mostly ignore the social and environmental costs and risks
associated with conventional fuel use, the hidden subsidies, the long-term
costs of depletion of finite resources, and the costs associated with securing
reliable supplies from foreign sources.
       Growing environmental and ecological pressures, combined with
technological advances, and increases in efficiency and productivity, are
making biomass feedstocks economically attractive in many parts of the
world.The most immediate commercial prospects are in cogeneration (heat &
electricity) spearheaded by the pulp/paper and timber industries using wood
wastes, bagasse from the sugarcane industry, and other agricultural residues
for use in agroindustry.  
       For bioenergy to succeed, particularly in its modern forms, some
initial incentives (be it in the form of subsidies, financial incentives,
carbon taxes, etc) would be necessary to put bioenergy on more equal terms
with the long established fossil fuels.The experience from countries that have
a significant modern bioenergy contribution clearly indicates that this is a
necessary condition. In the longer term market forces must be allowed to play
their role.
       Predicting energy trends is notoriously difficult.The future energy
supplies could be more decentralised and with renewable energies playing an
increasing role. Increased energy efficiency  together with technological
developments would curtail increases in energy demand. Fossil fuels will
continue to dominate well into the next century, while bioenergy in its
various forms will also increase their market share.Oil will still dominate
the transportation system but biomass-based liquid fuels will increase their
share.Biodiesel may also grow in the OECD countries but will remain localized
in some developing countries.Methanol and hydrogen from biomass are possible
energy sources in the longer term.
       Major R&D gaps need to be addressed especially as they relate to
sustainable production  and use in an environmentally acceptable manner. A
major problem with bioenergy is that until recently it has had a low priority
in the allocation of resources for R&D, planning and implementation. It will
take time to reverse this previous neglect.
IX.   RECOMMENDATIONS
       It is neither feasible nor desirable to propose a uniform and universal
set of recommendations given the nature of bioenergy. To facilitate the
introduction of bioenergy, the following broad guidelines are recommended:
       (i) formulate clear policies to promote bioenergy on an equal footing
to conventional energy sources through rational energy pricing;
       (ii) provide financial incentives to bioenergy in particular to
utilities and local entrepreneurs and allow the sale of  bioelectricity, heat
and gases by private generators; provide capital and credit  to encourage
commercial activities;
       (iii) directed R&D in the most promising areas of biomass which will
help to increase energy supply and improve the technological base;
       (iv) examine closely past successes and failures so as to assist policy
makers with well informed recommendations, especially with regard to
environmental acceptability and sustainabilty at the local and regional
levels;
       (v)  internalize all external costs and benefits of bioenergy; develop
methodologies for doing so;
       (vi) develop bioenergy distribution systems that facilitate consumption
and use;
       (vii) consider interrelated socio-economic aspects of bioenergy;
       (viii) pay more attention to sustainable production and use of  biomass
energy feedstocks, methodologies of conversion, and efficient energy flows;
       (ix) allocate more R&D aimed at pollution abatement (especially at the
local level), energy efficiency, and development of newer conversion systems;
       (x) improve capacity-building in bioenergy management skills taking 
maximum advantage of existing local knowledge, encourage  multidisciplinary
approaches;
       (xi) sustainable development of large-scale biomass plantations to
reduce costs and achieve environmental acceptability;
       (xii) improve market opportunities and conditions for potential
suppliers; and supplies for potential markets.
                                          Notes
       1   Report of the Committee on New and Renewable Sources of Energy and
on Energy for Development at its First Session, E/1994/25, E/C.13/1994/8.
       2   E/1995/25 and Corr. 1.  For the final text, on Official Records of
the Economic and Social Council, 1995, Supplement No. 5.
       3   Hall, D. O., Rosillo-Calle, F., Scrase, J. I.  (1996)  "Biomass: 
an environmentally acceptable and sustainable energy source for the future".
       
       4   Ibid                   
       5   Ibid                   
       6   Ibid
       
       7   Ibid
       8   Ibid
Table 2.   Biogas plant yields, costs and revenues from sale of energy in  
           Europe
------------------------------------------------------------------------------
Type of plant           Gas yield-     Value of    Capital      Net value
                        m3 per m3      gas US$/    and ope      of energy
                        of feedstock   m3 of       rating       US$/m3 of
                                       feedstock   cost US$/    feedstock
                                         a/          m3 of
                                                   feedstock         
------------------------------------------------------------------------------
Specialized plant
 for sorted MSW b/           60 -150       7 -18       80 -150    < - 60 c/
Danish centralized
 biogas program              20 - 80       2 - 10      7 - 14      -12 - +3
Low cost on-farm AD
(Switzerland, Germany)        5 - 20       1 - 2       1 - 5       -4 - +1
------------------------------------------------------------------------------
    Source: Department for Policy Coordination and Sustainable Development of
the United Nations Secretariat, based on  -Biomass: an environmentally
acceptable and sustainable energy source for the futurež, by D.O. Hall, J.I.
Scrase, 1996. 
Note:
a/    - biogas selling price US$0.12 per m3 of gas
b/    - feedstock is source sorted municipal solid waste or
vegetable/garden/fruit waste
c/    - disposal fees would be the main source of revenue for this type of
plant 
Table 3.   Costs for a small community biogas-based electricity system in
           Pura, India
------------------------------------------------------------------------------
Cost per KW installed capacity (1992 US $)                      US$ 1014.00
Cost of electricity if generating for 4.2 hours per day
 (US cents/KWh)                                                 25 UScents/KWh
Cost of electricity if generating for 20 hours per day
 (US cents/KWh)                                                  7 UScents/KWh
Minimum interest rate at which biogas electricity is
 cheaper than centralized electricity system                       7.5 %
------------------------------------------------------------------------------
    Source:  Department for Policy Coordination and Sustainable Development of
the United Nations Secretariat, based on Rajabapaiah, et. al., 1993 and 1994
in Ravindranath and Hall (1995). 
Table 4.   Biodiesel costs in Europe and the United States of America
------------------------------------------------------------------------------
          Year   Location  Feedstock      Cost       Cost    Reference
                                          US cents/  US$/GJ
------------------------------------------------------------------------------
1         1994   USA       Soybean        81.9       22.7    James (1995) a/
2         1994   USA       Rapeseed       72.7       19.8    James (1995) a/
3         1994   EU/USA    Rapeseed       81.7-      24.9-
                                           115.8      35.3   IEA (1994) b/
4         1995   UK        Rapeseed       51.3       15.6    BABFO (1995b) c/
5         1995   UK        Rapeseed       79.1       24.1    BABFO (1995b) d/
6         1995   EU        Rapeseed       57         17.7    ADEME (1995)
7         2005   EU        Rapeseed       42         12.8    ADEME (1995)
8     "Future"   EU/USA    Rapeseed       41.0-      12.5-
                                           50.3       15.3   IEA (1994)b/
------------------------------------------------------------------------------
    Source: Same as Table 2.
Note:
a/   -       price for food grade oil from plants in Montana and Missouri, USA
b/   -       1994 price is a production cost using a 5% discount rate and
factor costs for feedstock (i.e. market price plus average subsidy to
farmers)-"Future" cost uses lowest 1991 price or world market price, and 5%
discount rate
c/   -       production cost of 85.1 US cents per liter minus co-product
revenue of US cents 34.8 per liter -  assumes capital cost repaid over 5 years
at 10% interest
d/   -       selling price assuming biodiesel is taxed at 10% of the rate of
taxation on mineral diesel (selling price US cents 85.1 per liter)