Back to the Energy Crisis: The need for a coherent policy towards energy systems



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Method

Notes


Combustion


Efficiency depends on type of biomass used, water content and methods of combustion. Energy efficiencies range from 18.6-20.9 MJ/kg dry weight for wood chips to e.g. 9.5 MJ/kg for sugar cane bagasse. Open fires are amongst the least efficient forms of combustion.

Pyrolysis


Heating biomass in the near-absence of oxygen. Used in the production of charcoal, which has the advantage of being light and clean, but is wasteful of energy in conversion.

Gasification


Heating biomass at a higher temperature than in pyrolysis, with limited oxygen, creating a producer gas mixture. Can be followed by: condensation to produce methanol; production of methane; further conversion to ammonia, or for electricity generation.

Hydrogasification

Conversion of biomass to methane or ethane by reduction with hydrogen at high temperatures and pressure.

Anaerobic digestion


Breakdown of wet biomass (often manures) in the absence of oxygen by anaerobic bacteria, releasing methane gas as a by-product. Not usually from wood.

Fermentation


Fermentation of biomass to alcohol in the absence of oxygen, achieved by use of yeasts. The most common end product is ethanol. Again not from wood.

Reduction

Reduction of aqueous biomass to produce a range of fuel oils.

However, there are serious implications for land-use and forest management:



  • Very large land areas would be required to supply even a small proportion of the energy requirements of an industrialised country;

  • The most efficient type of biomass production for energy is from short-term rotations, so that large areas of forest or agricultural land could be turned over to intensive production of this type;

  • Exotic or genetically manipulated trees, chosen for maximum biomass gain in a given period, would become widespread;

  • Such plantations would require substantial inputs in terms of fertilisers, pesticides and herbicides to maintain such high levels of production.

Such changes could undermine many of the gains made in terms of forest management. We might see, for example, governments arguing that such energy plantations were agricultural crops rather than forests and thus exempt from any controls or guidelines that have developed over forest management. If future energy supplies were seen to be in serious question, such arguments would become compelling. The impacts of biofuels have already been exhaustively assessed by activist groups13.



But what are the alternatives?


At the moment, the global environmental movement (if such a thing exists) is in serious danger of arguing against every form of energy and therefore, by tacit implication, excluding itself from the debate. The nuclear industry has been quite successful in claiming itself as the environmentally acceptable alternative to coal and oil and the potential saviour in terms of climate change. Large-scale biomass use would fit the aspirations of the transnational companies that currently control the world’s energy supply and is already being presented as a clean and renewable resource.
Opposition to everything is pointless and self-defeating. As fuel prices increase, the pressure to exploit alternatives – such as coal shales, Arctic oil reserves, nuclear technology and large-scale biomass plantations – will grow. The conservation movement has regularly failed to halt such developments and there is little reason to think that the situation will change. There is an urgent need for research, debate and policy development that could lead to a consensus about future energy supplies, at least in the beginning amongst NGOs.
This will not be easy. There are very few totally “clean” supplies, so that support for one over another will be a matter of careful judgement and some trade-offs. The overall impacts of most will depend to a large extent on how they are applied, on what social and environmental safeguards can and will be attached, whether these will actually be applied and on the aspirations of the majority. What might seem an impossible compromise to environmental and social activist groups may not elicit the same response from other people. Sacrificing the Amazon rainforest for cheap fuel would be a done deal for many of today’s drivers. The energy industry will be able to draw on powerful and apocalyptic images to make its case. If NGOs are going to oppose the worst excesses of the energy industry with any hope of success we will need to speak with one voice and be clear about the sacrifices as well as the potential gains.
IUCN could play an important facilitating role in this process. It will not be easy, because positions are in many cases already entrenched and time is short. But the current state of chaos will simply lead to lack of effective opposition against any energy supply, however damaging this might be.
Nigel Dudley (equilibrium@compuserve.com) is a member of WCPA and CEESP and works mainly on issues related to protected areas and forest conservation. At one time he lived and worked at the Centre for Alternative Technology in Wales, researching the practical application of renewable energy systems.



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