The impact of low-carbon technology adoption on peak electricity demand

This study is relevant to UK distribution network operators, energy policymakers, and researchers working on residential electrification strategy. Using longitudinal smart meter data from over 1,800 UK households within the Smart Energy Research Lab (SERL) Observatory (January 2024 to March 2025), we employ a normalised Energy Use Intensity (EUI) framework (W/m²) to observe the “as-operated” behaviour of multi-technology households, covering heat pumps (HP), electric vehicles (EV), photovoltaics (PV), and battery energy storage systems (Batt), compared to gas-heated controls across varied UK building fabrics. Unlike the Nordics which have long relied on electrified heating, the UK is in mid-transition from a gas-dominated system, making the identification of peak demand signatures from real metered data particularly policy-critical.

In gas-heated homes, the evening electrical load historically remains low; peak power density averaged 6.4 W/m² during the 17:00 to 21:00 winter peak. When heating is electrified via HPs, this peak density nearly triples to 18.5 W/m², shifting the primary thermal load onto the local grid during its most constrained hours.

The data reveal a significant gap in standard thermal models: in gas-heated terraced houses, the least-insulated homes recorded a lower peak gas power density (17.4 W/m²) compared to partially-insulated homes (23.6 W/m²), suggesting that heat loss does not always translate to instantaneous peak loads in practice.

The results suggest that while insulation reduces total annual energy intensity, it does not significantly mitigate high-amplitude evening power density. However, the integration of system stacking (HP combined with PV and Battery Storage) showed a 22% reduction in cumulative evening grid reliance during cold weather (<5.5°C). Furthermore, in battery-equipped EV households, peak evening demand was maintained at just 4.2 W/m², though these households still rely heavily on gas for heating, peaking at 25.8 W/m²; this figure therefore reflects electrical decoupling of transport only, not whole-home decarbonisation.

These findings have direct implications for UK distribution network planning: combining onsite generation and storage with electrified heating delivers more robust peak management than insulation-only interventions, and the persistence of gas use in HP combined with PV and Battery Storage households signals that the electrification transition is currently partial rather than complete.