The energy transition to a zero carbon energy system will require both a shift to renewable energy and a major increase in energy efficiency. These are usually treated separately, but are not independent. Where renewable electricity replaces other fuels in heat and transport, there is a fundamental shift in energy supply from sources of heat to sources of work. This allows technologies such as heat pumps and electric vehicles to deliver large improvements in energy efficiency.
Where new energy sectors such as hydrogen are required, there are more complex implications for energy efficiency, depending on the details of the energy conversion processes. The paper sets out a scenario for the UK where energy is provided solely by solar and wind energy. It makes plausible assumptions about which end uses of energy can be supplied directly by electricity, and assumes others will be supplied by electrolytic hydrogen. It shows that reductions of final energy demand by 50% and primary energy demand by 60% from current levels.
The main driver is the improvement in conversion efficiencies at the point of energy use. This has major implications for the levels of renewable energy needed, which could be supplied entirely by UK indigenous resources. These types of changes to energy demand not fully captured by many global energy models and scenarios used to inform climate policy. They may therefore be unreliable and significantly over-estimating likely energy demand. The findings have important implications for policymakers in terms of lower and more realistic expectations of future energy demand.
Eyre, N. 2019. Energy efficiency in the energy transition. In: Proceedings of the eceee 2019 Summer Study on energy efficiency, Paper 2-041-19. Hyères, France, 03–07 June 2019.
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