The work carried out for output 1 identified two large sources of CO2 that would have to be addressed if the UK (and, by inference, many other developed countries) are to cut emissions by 80%. The first is road transport, which was discussed in the subsequent report [output 2]; the second is low grade heat (LGH), mainly domestic and commercial central heating.
At present, most LGH is provided by natural gas. This has the benefit that the energy stored in the gas distribution system can smooth the diurnal peaks and troughs and large investment in infrastructure is not required to deal with the differences between summer and winter. Switching the load to renewable energy would result in a large inter-seasonal imbalance in the need for infrastructure, which would make many renewables financially unviable.
Conventional wisdom is that renewable energy would feed heat pumps, as is common in Northern Europe. However, experience of heat pump installations in the UK environment are much less positive, due to the climate, property ownership and building standards, and there is evidence of a large skills gap.
Together these problems cast serious doubt on the practicability of plans to decarbonise the LGH sector.