Renewables and sustainables
Last month, Dr Mark Everard, Director of Science at the UK office of The Natural Step (TNS), described how the TNS framework had been used to evaluate the sustainable development implications of PVC. Here he describes a smaller study, again in association with the Environment Agency, applying the TNS framework to the sustainability implications of the renewable energy sources being considered for exemption from the Climate Change Levy.
- Wind Energy
- Small-scale Hydro Power
- Tidal Power
- Wave Energy
- Photovoltaics (PV)
- Geothermal Hot Rocks
- Geothermal Aquifers
- Municipal and Industrial Wastes
- Landfill Gas
- Agriculture and Forestry Wastes
- Energy Crops
By strict definition, renewable energy is obtained from continuous repetitive currents of energy in the natural environment, used at the rate they are replenished. Some of the twelve sources are not naturally renewable. Neither should it be assumed automatically that renewable energy is sustainable energy. The Natural Step, therefore, initiated a workshop with the Environment Agency, with input also from Forum for the Future and the University of the West of England, conducting a sustainability assessment of the 12 sources based on the science-based TNS framework (see IEM November 1998), with the following conclusions.
Energy efficiency and demand reduction, at least in the energy-hungry developed world, are crucial to the sustainability of resource use and may be cheaper options than deployment of additional fuel sources or infrastructure. The removal of institutional and market barriers to the uptake of energy efficiency measures could enable dynamic energy efficiency markets to occur.
Renewable energy needs to be addressed at the overall system level. Many sources of renewable energy are more amenable to localised generation, and an effective transmission and distribution model for renewable energy may be profoundly different to the present developed-world model of highly centralised generating units linked to dispersed users via a high voltage transmission system. All renewable energy technologies have implications - ecological, social and economic - that vary with geographical location and scale. Direct impacts of collection, conversion and distribution technology may be significant, and will require constant improvement. However, issues considered peripheral today (aesthetics of wind turbines, downstream effects of water impoundments, distribution infrastructure, etc) in both construction and operational phases may be responsible for much of the sustainability impacts of a more de-centralised system.
Local and inclusive
De-centralised renewable energy generation could also entail more local and inclusive decision-making, better communications about energy needs, demands, and the acceptability of different options. However, localised decision-making cannot work in isolation from centralised planning of distribution infrastructure, pricing, energy security, and the meeting of government targets. Peak generation from renewable sources such as wind, wave and tidal power may only occur under ideal conditions, and supply may also be intermittent. A mix of energy sources, both local and centralised, as well as compensation between them to meet peak demand and intermittent supply, requires careful planning to ensure flexibility, energy security and assessment of risks.
Substantial technological advances will be required, particularly in electricity storage. Fuel cells, which are already a more efficient means of generating electricity from natural gas than conventional combustion techniques, offer a flexible two-way generation and storage mechanism. They may be important in a renewables-based energy economy.
Waste-related energy options are not themselves naturally renewable, and indeed may actively discourage substantial reductions in waste, but may provide an important interim step towards sustainable energy through the beneficial use of problematic landfill gas and other types of waste that cannot be eliminated in the short term.
A global view must be taken to encourage a leap in technology in the developing world. Technology transfer is an issue both of ethics and of enlightened self-interest. Were the rising energy demands of the growing population to be met with traditional sources of energy, the global consequences would be profound. Decentralised energy production could confer a range of benefits in developing countries, making local energy available in remote communities not connected to a centralised distribution grid.
Phasing in renewable energy would not necessarily have a negative impact on the economy. Today's sustainability challenges provide an incentive for technological innovation and investment in future energy efficiency and renewable energy markets. Maintaining a competitive edge for the UK will be important in driving uptake of renewable sources of energy, and incentives from Government would help overcome the obstacle of perceived risk. Adjustment of market prices for fossil fuels to reflect externalised environmental and social costs would remove a further barrier to sustainable development.
Energy systems are embedded within the workings of economy and society. Increased deployment of renewable energy technology can only contribute significantly to sustainable development to the extent to which society as a whole becomes more sustainable. A range of complex and interconnected technical, environmental, social and economic issues are implicit in determining the role of renewable energy options in the long-term achievement of sustainability. Strategic thought is important if we are to avert steering investment down 'blind alleys' with no pre-determined route towards the final goal. As we have seen, some options which may not themselves be inherently sustainable, may provide 'stepping stones' from today's technologies and levels of demand towards tomorrow's sustainable needs and solutions.