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Chapter 5 Technology transfer and energy transition
Direct combustion
Thermochemical conversion
Biochemical energy conversion
A new energy order
Wood energy transition
Many new and more advanced technologies employing renewable source of energy (RSE) have emerged in recent years, particularly in industrialised or rapidly industrializing countries. During the 1970s and early 1980s these technologies benefited from a surge of investment in indigenous energy sources, a consequence of world fuel-oil price rises.
Such investment slumped in the 1980s as trade in oil settled into a more stable pattern but it has revived more recently, partly in response to the high priority set by the international community on energy systems with fewer adverse environmental consequences than fossil-based fuels.
Developing countries have not, on the whole, gained as much from these innovations as the industrialised countries where most of the research and development effort to find renewable sources of energy has tended to originate.
Technology transfer could prove a vital link in sustainable energy development in countries or areas where 'energy famine' is already a fact of life or a likelihood, yet these are often the countries least able to afford to invest heavily in 'hi-tech' RSE development. Steps are needed both to speed up the transfer of RSE technologies and to find ways to scale them up or down to fit specific circumstances.
For example the JOULE programme, a major joint energy research initiative under way in several countries within the European Union, has paid specific attention to renewable energy technologies suitable for decentralised operation in areas isolated from mains power supplies, such as mountain regions or small offshore islands. Many of the results of this research could be adapted for use in rural areas of developing countries.
Technically advanced commercial or industrial conversion processes involving wood energy are currently in use or under active development in industry in many parts of the world. They can be divided into three main categories: direct combustion, thermochemical and biochemical processes. Many are suitable for use only on a large industrial scale but others lend themselves to scaled-down use at village level and some are themselves scaled-up versions of traditional, small-scale practices.
Direct combustion processes can be used to convert various raw fuel materials besides wood, including municipal garbage and crop wastes. If they burn woody materials, these commonly take the form of woodchips, bark or sawdust that originate as waste by-products of forest industries.
Direct combustion furnaces take various forms. Some involve a two-stage process, the first stage for drying the raw material, the second for complete combustion. Others use jets of turbulent hot air to suspend crushed fuel particles in mid-air as they burn, or a bed of superheated sand into which the fuel is dropped or injected.
Like many other biomass-to-energy conversion processes, direct combustion installations are often adapted to combine or alternate biomass and fossil-based fuels to provide basic energy feedstock. 'Co-firing' woody materials or crop biomass with coal - the usual combination in direct combustion furnaces - can have several advantages. Typically, direct conversion facilities are situated close to a large and convenient source of cheap biomass, such as wastes from a sawmill or sugar refinery.
In many cases their output includes electricity for sale to power distribution utilities or combined heat and power (CHP) outputs for district heating as well as electricity supplies. If there are seasonal or temporary shortfalls in the supply of plant materials, co-firing allows energy production to be switched entirely or partly over to coal.
In this way, energy output continues without interruption and equipment and labour need not fall idle or be laid off. The utility and its customers can rest assured that power supplies will be maintained and the producer often gains a higher premium or bonus in return for greater reliability. Co-firing also creates less air pollution than power generation using fossil-based fuels alone and so does less incidental harm to its surroundings and the wider environment.
The most familiar thermochemical conversion process is carbonization, the time-honoured process of producing charcoal from wood and other solid plant materials. In traditional charcoal-making, wood is piled in earth mounds or covered pits and slowly fired till most of the hydrogen, oxygen and volatile components have been driven out. The conversion efficiency of traditional methods is normally low but more advanced industrial charcoal production processes can convert over 30 per cent by weight of raw wood to useful energy. They achieve this transformation by 'cooking' the wood within special reactors (pyrolysers) under controlled temperature and atmospheric conditions that exclude oxygen from the process.
POWER PREMIUM Electricity is the ultimate 'convenience' energy source. It can be put to practically any standard use, either for household heating, cooking and lighting or for larger-scale industrial, municipal and commercial applications. A high investment premium has therefore been set in many countries on novel renewable energy systems that yield electricity. Systems based on photoelectric 'solar cells', solar-thermal energy collectors, wind turbines or wave power converters have been developed to a point where their operation on a commercial scale can prove feasible. As noted earlier, liquid and gaseous fuels derived from biomass have also developed as effective alternatives and these, too, can be employed to generate electricity. In this latter context, the EC-ASEAN COGEN programme aims to accelerate the implementation of proven technologies to generate heat and/or power from wood and agroindustrial residues, through partnership between ASEAN and European countries. The programme provides for economic cooperation between the European Commission and the Association of South East Asian Nations, through its Sub-Committee on Non-Conventional Energy Research. The programme is coordinated by the Asian Institute of Technology, Bangkok. COGEN's managers give credence to the view that options to use woody biomass, particularly residues and wastes, have not been implemented in the region simply because they have not been tested under conditions specific to ASEAN countries. To remedy this omission, the Programme provides financial and technical assistance to implement Full Scale Demonstration Projects in existing industrial enterprises. This involves demonstrating the technical and economic viability of woodfuel energy in real situations and provides a shop window for ASEAN end-users interested in turning biomass into a key energy source for their companies. The results should provide cost-savings, as well as environmental gains. |
COMBINED HEAT AND POWER In parts of Scandinavia and Central Europe, combined heat and power (CHP) systems are now an established feature of energy production and use. CHP systems generate electricity from steam or gas turbines, fuelled by wood or biogas, while using waste heat from this process to heat water which is then piped to households for space heating. In Sweden, biomass provided 15 per cent of the country's primary energy consumption in 1991, much of it through CHP systems. Over 8000km of pipes were laid for heat distribution and 2.4GW (24 trillion watts) of installed CHP capacity were generated. Sweden continues to invest heavily in methods to increase its energy production from renewable sources, both through research into new woodchip and wood energy conversion processes and through resource management research to optimise production of wood from fast-growing willow, poplar and other hardwood tree species in energy plantations. In Austria, almost 100 district heating schemes are now in place, fuelled by the country's plentiful conifer forests. They produce 1200MW (thousand watts) of total capacity, representing 10 per cent of the country's entire energy consumption in 1991. District heating alone, as distinct from CHP, is still an economic output where trees abound, as in mountain areas of countries such as Austria or Switzerland where forests have been conserved for centuries, partly to preserve their function as avalanche barriers. |
Biochemical energy conversion processes currently in wide use entail fermenting or distilling biomass to form biogas or alcohol. Wood is not normally a standard source of feedstock for these processes, though such use is technically feasible.
Field crops with a high sugar or carbohydrate content such as sugarcane, sweet sorghum, sweetcorn or cassava are generally used as feedstock for the fermentation and distillation processes that produce fuel alcohols.
Wood cellulose can be converted to simpler carbohydrates for such processes but requires more preparation in return for a somewhat lower energy yield so is generally regarded as uneconomic. Current research and development efforts on wood alcohol production could alter this situation in due course (see box, Biofuels for transportation).
Converting vegetable oils into fuel oil is another bioenergy process with forestry implications, as raw oil suitable for processing can be obtained from several tree crops, including the fruits of the oil and coconut palms. Diesel engines were originally designed by their German inventor, Rudolf Diesel, to run on vegetable oils. Now the use of modern biodiesel fuels - which can run existing diesel engines without major modification - is promoted in Germany and elsewhere as an environmentally sound alternative to fossil-based diesel. In many tropical countries, new sources of plant-based diesel are under rapid development (see box, Biodiesel energy).
All these commercial biofuel technologies are likely to affect the pattern of energy production and forest management around the world, and not only in industrialised situations.
Hi-tech renewable wood energy applications are not necessarily the ideal means of transition from unsustainable towards more sustainable forms of energy use. Any wood energy technology (however basic) that functions in a steady balance with the growth and regeneration of the forests and trees that provide the energy feedstock, is compatible with a sustainable approach to woodfuel production and use. Conversely, any system that places more demand on the biological resource base than the latter can regularly adjust to, is (by definition) unsustainable.
BIOFUELS FOR TRANSPORTATION A number of transportation fuels can be produced from biomass. The major fraction of woody biomass, cellulose and hemicellulose, can be broken down into sugars that can be fermented into ethanol. This bioethanol can, with isobutene and catalysers, be converted into ETBE (ethyl tertiary butyl ether) which can be used as an octane enhancer for reformulated 'unleaded' gasolines. Use of these additives can reduce the net release of carbon dioxide to the atmosphere from transportation gasolines, and moreover can contribute to the diversification of agricultural and forestry activities and promote the use of marginal lands for specific crops for energy purposes. It can also create new jobs and income for rural areas. New technologies are being developed in several research and development institutes in Malaysia and elsewhere, which are expected to be released on the market in the next three or four years and could have the effect of altering the traditional role of forest and agricultural activities. In the meantime, Argentina, Brazil, Paraguay and Uruguay are initiating studies to determine the feasibility of transforming existing 'gasohol' or 'alconafta' programmes into ETBE-based processes. Such novel technologies and their future commercial application will much depend on international oil prices and, more particularly, on national energy policies. |
BIODIESEL ENERGY FROM OILSEED TREES Use of plant oils in the energy sector is growing, particularly in industrialized countries. Four main technical solutions are being studied, some of which are being piloted commercially:
These solutions have been widely tested in different countries with excellent results and different field crop species (rapeseed, soya, groundnut, sunflower and others) are being intensively evaluated. Although the technical, environmental and socioeconomic advantages are quite well established, economic viability has to be proven and subsidy is necessary in most cases. However, many developing countries with plentiful available land and low-cost labour do not face this obstacle. In addition to field crops, established oilseed plantation trees such as oil palms can lend themselves to use as non-wood forest products for energy applications. Novel oilseed tree crops are also being put to this purpose in several tropical countries. For example, Curcas Oil extraction from Jathropa seeds is a simple process which can be undertaken in small, local presses. The cost of extraction equipment varies from as low as a few hundred dollars for simple, hand-operated equipment to $15000 for more sophisticated diesel engine powered systems. Jathropa is a fast-growing shrubby tree that thrives in poor quality soil (including semi-arid wasteland soils) and starts to produce within the first or second year. As a fuel or fuel extender for engine use, Curcas Oil needs to be further processed but can be used for lighting and heating in its crude state. Pilot units for Curcas Oil production have been successfully launched in Mali, Thailand and elsewhere. |
Modern sustainable development thinking has given rise to an ambitious vision of a 'New Economic World Order' based on a comprehensive reassessment of natural assets and the wealth of
nations with a view to more equitable, productive and environmentally responsible management of global resources.
Energy is central to this challenging vision of a sustainable future for all. In the first place, the new scenario requires social and environmental costs and benefits of energy production, delivery and use to be factored into decision making along with market and investment factors. Following this reckoning, progress towards matching regular energy supply and demand will then have to be integrated at all levels if it is to do lasting good in terms of economic growth, better living standards and environmental security.
The emerging formula for a 'New Energy Order' has won tacit general acceptance in the international arena but transition from current practices and circumstances to this ideal state of affairs will not be easy or straightforward. Pragmatic guidelines for change are called for, that can be applied and flexibly adapted to real situations that confront the resource planner, manager or user under everyday circumstances.
As to the future financing of developments in the wood energy sector, it is evident that major new investment will be called for. Though the amount of investment finance that the sector attracts will continue to be decided largely according to conventional cost-benefit criteria, social and environmental measure. How capital funds are allocated then becomes a key consideration in human terms. If investors favour industrial applications of wood energy over fossil-fuel based applications, the resulting redistribution of benefits may create 'loser' communities and environments as well as winners, so such changes should not be undertaken lightly.
'Forests should be sustainably managed to meet social, economic, ecological, cultural and spiritual needs [in such forms as]... wood and wood products, water, food, fodder, medicine, fuel, shelter, employment, recreation, habitats for wildlife, landscape diversity, carbon sinks and reservoirs and... other forest goods, products and services.'
UNCED Forestry Principles, Section 2b
The term 'wood energy transition' denotes a shift away from unsustainable wood energy practices, regardless of their scale or relative complexity, towards a new energy order. In this perspective, traditional, small-scale or local wood energy applications can play a crucial stabilising role within a larger dynamic of sustainable resource management. Making wise use of this dynamic requires astute assessment, accurate monitoring and the informed participation of people engaged in energy production and use at all levels of development planning and practice, including members or representatives of communities and social groups that rely on wood to meet practically all energy needs.
At the national planning level, developing renewable sources of energy (RSE) is almost certain to assume added priority in years to come, despite apparently plentiful oil reserves and stable oil prices on the world market at present. The world economy is gradually recovering from two recent recessions, thanks largely to growth and processes of transformation occurring in many rapidly industrialising economies, such as those of China, Brazil, Thailand, Indonesia and Malaysia.
Despite widespread adoption of energy conservation measures, production in these economies is bound to grow increasingly energy-intensive, which could force demand for oil (and with it the price of oil) sharply upwards in the medium term. According to World Bank projections, electricity demand in the developing world is likely to grow at 7 per cent a year over the next 20 years, compared with a growth rate of just 2 to 3 per cent in industrialized countries. The cost of importing supplies of oil sufficient to fuel this high growth rate is estimated at over $3 trillion for the coming decade, or $100 million a year. Yet the current spending power of even the most rapidly developing economies falls far short of this level.
Developing power generation systems based on wood energy and other renewable energy sources is an alternative energy supply strategy that could help bridge this gap. Moreover, RSE development does not require the high investment cost and long lead-time associated with projects for energy generation using oil, coal or hydro-power. RSE systems can be scaled to meet user needs and expanded piecemeal to keep in step with rising demand. They also happen to avoid many of the environmental drawbacks associated with conventional energy production systems.
Even without enlisting environmental arguments in its favour, RSE development makes sense solely in energy planning and economic terms. Achieving full integration of wood energy and other RSE use into national plans and policies is, however, a course limited by many obstacles.
Institutional barriers include a crucial lack of appropriate skills and attitudes in the planning units of energy agencies, which are often dominated by engineers and economists unused to dealing with the dynamics of energy flow between living production systems and the energy consumer. Even renewable energy units within natural resources planning departments, whose experience is likely to be limited to research and pilot projects, are liable to balk at the sheer size and complexity of the planning task.
Wood energy systems, like most other RSE applications, are typically small and decentralised, requiring a similarly decentralised, energy planning approach that accounts for the modular character of the technologies in question, the site-specific factors that determine productivity (such as availability of the natural resource and local capabilities) and interaction with centralised or grid-based power supply systems.
Such planning requirements are completely different from those that govern current oil industry and power systems planning methodologies. Ways to counter these and other limitations on systematic planning and investment for wood energy development at senior levels will be suggested in the section that follows.
In the context of energy transition, the other major shift liable to come about at more local levels is that consumers of wood-based and other RSE-based energy systems will increasingly become the operators as well as the users of these systems.
Farmers, for instance, may have to get used to operating small-scale wood-based power plants for electricity generation and/or steam production (see box, Combined heat and power, page 56) on a compact scale, as well as setting aside and tending woodlots to supply adequate woodfuel feedstock on a sustained-yield basis at district and community levels.
In view of this prospect, the need arises for intensive research and development to make both mechanical and wood husbandry systems as 'user-friendly' and efficient as possible, and to ensure that technical backup, such as the provision of fast-growing nursery tree stock and spare parts for essential machinery, is not lacking.
These provisions and innovations require a combination of initiatives from the 'top-down' and the 'bottom-up', orchestrated by means of frank dialogue between people responsible for the planning and administrative superstructure of entire states or districts, and local community and user groups (see Fig. 9 p27 and Fig. 10 p31). Only if information, knowledge and skills are shared in this open manner will the conviction grow at both extremes that energy planning and sustainable development is a shared responsibility.
At the very least, planners and administrators should avoid policies that might stand in the way of such developments or betray a bias in favour of technologies they regard as more familiar and less testing than sustainable wood energy and other RSE systems.