Abstract

The electrification of heating and transport in Great Britain will allow households to provide more flexibility to the grid. This research seeks to understand how much flexibility can be achieved, how this flexibility interacts between the two sectors, and how the benefits are spatially distributed. Using a novel linear optimisation model PyPSA-FES, designed to simulate pathways in National Grid ESO Future Energy Scenarios, we model the future power system in Great Britain at high spatio-temporal resolution and integrate demand flexibility from both smart charging electric vehicles and thermal storage-coupled heat pumps. The model then optimises the trade-off between reinforcing the grid to align charging and heating profiles with renewable generation versus expanding dispatchable generation capacity.

Key findings

The modelling shows there are significant system benefits associated with demand flexibility from domestic heat and transport, while providing insights into its role over time and space. Headline findings are:

① Maximising renewables
Domestic demand flexibility can unlock up to ~30 TWh additional renewable generation in 2030, or 7% of total demand, reducing costlier and dirtier fossil fuel generation.

② Optimising grid infrastructure
Domestic flexibility ensures networks operate more efficiently: compared to a scenario with no flexibility, reducing distribution capacity needs by ~25% from 2030 and supporting cost-optimal transmission expansion.

③ Reducing peak demand
Domestic demand flexibility could shift up to ~17 GW, or ~30%, out of peak demand load by 2030.

④ System savings
These changes reduce system costs by ~£5 bn every year by 2035, and a total of ~£95 bn over the period 2025-2050.

⑤ EV managed charging
The intelligent charging of EVs has huge potential to match variable supply of renewables, in particular during the early stages of rollout.

⑥ Smart heat pumps
These are more likely to support reduction of peak demand on cold days; the addition of thermal storage can increase the potential for within-day head flexibility, but this may begin to “compete” with EVs to absorb renewable generation.