The UK is waking up to the importance of heat in the bigger energy picture, and is planning a long-term project eventually to decarbonize the heat sector altogether, as well as electricity.
Of course, meeting local heat loads is the key to the successful deployment of CHP, whether within a district heating scheme or not, but heat pumps, solar thermal and biomass CHP also do a low carbon job.
Given the amount of attention given to electricity; its generation, smart grids and the growth of technologies to generate power from renewables, you could be forgiven for thinking that the heat sector is less important in policy (and carbon) terms. No so – the provision of useful heat is responsible for nearly half of the UK’s total carbon emissions, and most domestic gas bills are two or three times larger than those for electricity.
Currently, fossil fuels are overwhelmingly the main energy source used for generating heat in the UK, with electricity accounting for just 15%. As with the electricity sector, the UK heat industry is going to have to change almost beyond recognition if the UK government’s target to reduce greenhouse gases by 80% (from 1990 levels) by 2050 is to be met. The target is for zero fossil fuels use for heat by 2050.
There is much to do, starting with reducing demand, and the UK heat sector is still heavily locked into individual gas boilers. Nevertheless, the government launched a low carbon heat strategy in 2012 and has what is said to be the world’s first incentive scheme for renewable heat. There is also new government support for both the development of urban heat networks and water source heat pumps.
Speaking at the third in an annual series of conferences on heat held in London a couple of weeks, ago Professor of Sustainable Energy at Imperial College London, Jim Skea suggested that Britain has a long way to go. Comparing ‘Sankey’ diagrams of energy flows for Britain and Denmark, Skea showed how the majority of fuel energy entering UK thermal power stations ends up discarded as waste heat; while losses in Denmark are remarkably small, due to its large CHP and district heating sectors. The UK is also second to bottom of EU league tables on the use of heat pumps and biomass.
Yet this just adds to the considerable scope for CHP – particularly where used with heat storage – to help balance intermittent renewables on the UK electricity grid, added Skea.