Decarbonising UK homes will be an essential part of delivering Net Zero. Analysis of the different pathways for achieving this relies on credible, evidence-based assumptions about domestic heating and cooling needs over the coming decades.

To ensure UK analysis continues to draw on the best available evidence, Energy Systems Catapult (on behalf of the Department for Business, Energy and Industrial Strategy) commissioned a study by Robert Sansom (Vendura Ltd) to provide updated assumptions.

The Domestic heat demand study drew upon the latest UK Climate Projections (UKCP18) to understand how future changes in average – and extreme – temperatures might affect the energy needs of households as part of the Net Zero transition.

The study extends out to 2100. Although 2050 is the target date for Net Zero, it is essential that strategies for delivering emissions reductions can be tested for their suitability for the period beyond, as lag effects mean that further climate impacts can be expected long after the UK’s net contribution to global emissions has ceased.

Key points

Energy System Catapult’s Domestic heat demand study found:

• Rising average temperatures, due to climate change, will lead to reductions in space heat demand in winter, but also an increase in demand for building cooling in summer.
• Space heat demand continues to decline beyond 2050 as a result of climate induced temperature increases and UK housing stock improvements.
• Water heat is not expected to change very much but as a proportion of total heat demand it becomes more significant as space heat falls, particularly for the period beyond 2050.
• UKCP18 climate projections has stated that climate change will mean that in the future cold weather events will be less cold, with important consequences for system capacity.  So far the assumption has been that cold weather events are independent of climate change.  If this is no longer the case then there is scope to adjust design strategies accordingly resulting in potential cost savings in infrastructure and other assets as well as implications for heating technology.
• UKCP18 has identified that climate change will result in a higher frequency of hot summers with temperature increases up to 6°C in the south of the UK by 2080 and with higher temperatures in large towns and cities due to the urban heat island effect.  This will result in an increase in the demand for household cooling which could be met by passive measures, e.g. building insulation, shading ventilation but also with air-conditioning.  Projections of cooling energy demand indicate that they will be much less than heat and the impact on energy demand is not significant.