In Sydney last night, Allan Jones, Chief Development Officer of the London Climate Change Agency, described some of the initiatives which have made London a leader in reducing carbon emissions and dependence on coal and nuclear power stations.
The key to the strategy is the use of cogeneration and trigeneration power plants. These are small local electricity generators which capture the heat which is wasted in conventional power stations to provide heating and, in the case of trigeneration system, cooling, Recently, systems which also capture waste water have been developed. Most co- and tri-generation systems currently run on natural gas but London is increasingly using methane, produced from the city’s waste, to power the systems. Mr Jones believes that half of London’s electricity could be generated from waste.
Co- and tri-generation systems are best suited to supplying power for mixed communities of residential and commercial consumers which have their electricity peak requirements at different times. Restricting distribution to a local community also avoids the huge overheads in supplying power across a national grid and creates a system which is much less vulnerable to natural disasters or terrorist attack.
A well as mandating co-generation units to supply all major new developments, London now requires them to obtain at least 20% of their power from on-site renewable sources. All London buildings are now required to display an energy rating label. These requirements are estimated to add less than 1% to development costs while significantly reducing long-term operating costs.
Mr Jones said that he believed that we should be aiming to reduce carbon emissions by 60% by 2025 and that the barriers to achieving this are not technical but regulatory and vested interests.