3.4.2 Using waste heat from large power stations
This option is little-used in the UK, since the trend has been to build large coal-fired power stations well away from major built-up areas. However, many gas-fired power stations are close to major urban centres. For example, the 1 GWe Barking Combined Cycle Gas Turbine (CCGT) station is less than 20 km from central London and pumps hundreds of megawatts of waste heat into the Thames.
There is obviously enormous potential for using waste heat from such large power stations, but it comes at a cost of reduced electricity generation efficiency.
Typically there will be a loss of one kWh of electricity generated for every six kWh of useful heat produced. However, in a purpose built CCGT power station specifically designed for combined heat and power operation, this could be improved to a loss of one kWh of electricity for every 10 kWh of heat produced (Pöyry, 2009).