6.3 Other innovations: decentralised energy
Moving beyond the single-building scale, another major area of innovation is decentralised energy (DE). This means moving away from a centralised model of a few large power stations which send electricity to relatively distant consumers via the National Grid to a system of interconnected local networks. Currently, a typical power plant in the UK is only around 38% efficient; and by the time we use electricity in our homes and workplaces, nearly 80% of the usable energy from burning fossil fuels has been lost. The main reason for this is that we have two separate energy systems: one for electricity and another to heat water and buildings, with heat contributing more to climate change. For electricity about two-thirds of available energy is lost within the power plant as waste heat, and during transmission, with another 13% lost through inefficient use in buildings. For heat, we burn more fossil fuels (mostly natural gas) in boilers in our homes and workplaces.
However, a DE system based on CHP avoids this problem and is the most efficient way to burn fuel because so little energy is lost as waste heat – CHP plants in Denmark reach up to 95% efficiency. As the heat needs to be captured and piped around the local district, CHP plants are usually sited in the towns and cities where electricity and heat will be used. This makes it efficient for electricity generation as well as heat, as little is lost in transmission. CHP has considerable potential in the transition from fossil fuels, as they can switch to low-carbon fuels such as biogas and biomass. Most organic matter can be used to produce biogas, with farm waste the most famous example, but the biodegradable waste making up about half our landfill could be used. Combining CHP with improved efficiencies (e.g. effective insulation and minimum efficiency standards for appliances), much of the wastage of our current system would be prevented. However, DE has components other than CHP, including the full range of renewables – the UK Government has stated that just using wind, wave and tidal resources could meet 40% of our energy needs by 2020, and more in the longer term.
DE is also scalable and flexible – a supermarket could have a tiny CHP plant while a large industrial facility can have an large plant. This tailoring to local needs is one reason why DE systems can be installed much more quickly than large centralised power plants. Using many small energy generators instead of a few major ones greatly reduces the risk of system failure; and if a local DE network does fail, then it only affects a small area, which could in any case use the inbuilt connectivity to import from nearby areas. Linking to a wider scale still, DE allows decoupling from fossil fuel markets, which not only aids energy security and reduces costs (by removing the subsidies required for the current inefficient infrastructure), but is one of the requirements for moving towards a post-petroleum global economy.
Although some pioneering UK councils have adopted DE schemes (e.g. Manchester, Eastleigh, Southampton, Woking and Birmingham), the Labour Government (unlike the other UK parties) remains unwilling to move towards DE, focusing on new centralised power plants, including coal-fired (CCS-enabled or otherwise) and nuclear. Although recent developments have indicated some governmental support for renewables and microgeneration, policy such as the 2003 Energy White Paper has not moved away from the current centralised model, despite the existing need to replace the National Grid infrastructure, which was built in the 1950s and 1960s and is nearing the end of its design life. Other areas of Government are looking at low-carbon technologies; for example, via the Environmental Transformation Fund.
Activity 18
There are many areas of innovation – too many to cover in detail here. Imagine you are attending a UNFCCC meeting and need to choose one technology to promote as part of the wider suite of solutions to climate change. Use the information provided by Energymap to search for the technology you would choose and list three features that you think make it particularly effective.
Visit the virtual Greenpeace EfficienCity which combines areas such as DE, renewables and improved energy efficiencies. Consider how the technologies you see here might be applied where you live.
6.2 Other innovations: smart energy systems