It is a sad fact that here in the UK we are very wasteful in using the heat generated from our power stations. Before the understanding of climate change and scarce fossil fuels, energy was so cheap we didn't need to worry about wasting the heat.

In the UK WtE context, only 4 of the 19 plants (2005) produce heat as well as electricity in what is known as combined heat and power operation. The others simply let their heat energy after electricity generation rise into the atmosphere - a form of pollution in itself.

A WtE plant that produces both heat and electricity can efficiently use up to 80% of the total primary waste energy input. Making sure that all of the heat is used and not wasted, has implications for the scale of WtE plant chosen and where it is located.

Large-scale combined heat and power use may be difficult in rural areas for example.  Generally smaller uses of heat are more easily found than large ones, meaning that smaller-scale WtE plants could be the way forward in ensuring this energy resource is fully used. Selling the heat provides an extra revenue, which can help ensure smaller scale plants are profitable.

If 75% of the energy content of your input material is wasted, this doesn't provide a good basis for sustainability and the future. In short, the size of the plant, large or small should be considered in light of the local need for heat. This could be a public building, hospital, swimming pool, college, factory or maybe a collection of all these!

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