The UK and similar countries are well underway in transitioning to heat pumps, but it is not certain that consequences concerning the electrical grid have been properly considered. Gas boilers operate independent of the electrical grid, whilst heat pumps shift the heating demand completely into electricity. If this is scaled across entire streets, neighbourhoods and towns, there is a significant increase in power demand.
The Core Issue
Gas boilers don’t have any meaningful effect on the electrical grid as they burn fuel directly [1], aside from minor electrical consumption for ignition, circulation pumps, and control systems, typically ranging from 100 to 200 W [2]. However, heat pumps, even with their much higher efficiencies (Coefficients of Performance – COP) still require electricity to function, drawing around 3-5kW per home during peak heating hours [3].
Multiplying this by an entire street means a sharp increase in demand, potentially requiring costly infrastructure upgrades [4].
Why Is This Important?
A typical 500 kW local substation will serve a given number of homes [5]. If widespread heat pump adoption isn’t planned in tandem with electrical grid upgrades, this could result in overloaded substations as well as voltage instability in colder months [6]. In the past, water towers were key for handling spikes in power demand, providing stored potential energy to run through pumps to create supplementary power during peak periods. Now, we’re talking about battery storage for energy, but some proposals for these sites have been met with opposition from residents, especially those living close to prospective installation sites [7]. All this and we haven’t even considered the mass electrification of vehicles yet, which will push every household’s electricity demand up further if EV charge points become the norm [8].
Is Our Grid Ready?
Electricity use in the UK is falling, but local peaks can strain older substations in areas where heat pumps undergo mass installation [9]. At the same time, overdeveloped housing estates are often built without any real consideration for future electrification needs, with the focus instead being on simply squeezing in as many homes as possible and selling them [10]. As a result, we may well see large-scale retrofitting costs in the future as these developments struggle to handle new grid demands.
This raises a key question: Are we properly considering infrastructure before installing heat pump technology?
References
[1] Carbon Trust (2024) Decarbonising Heating in the UK: Challenges and Opportunities. Available at: https://www.carbontrust.com
[2] IHeat (2024) Does a Gas Boiler Use Electricity? Available at: https://iheat.co.uk/boiler-help/does-gas-boiler-use-electricity
[3] International Energy Agency (2023) Heat Pumps – Tracking Clean Energy Progress. Available at: https://www.iea.org/reports/heat-pumps
[4] National Grid (2024) Future Energy Scenarios: Heat Electrification and the Grid. Available at: https://www.nationalgrid.com
[5] UK Power Networks (2023) Local Substation Load Capacity and Electrification Impact. Available at: https://www.ukpowernetworks.co.uk
[6] Energy Systems Catapult (2023) The Challenge of Peak Demand with Heat Electrification. Available at: https://es.catapult.org.uk
[7] The Guardian (2024) Battery Storage Projects Face Local Resistance. Available at: https://www.theguardian.com/environment
[8] Department for Transport (2024) The Impact of EV Adoption on Domestic Energy Demand. Available at: https://www.gov.uk/government/publications
[9] National Grid ESO (2024) Electricity Demand Trends and Future Challenges. Available at: https://www.nationalgrideso.com
[10] BBC News (2024) Housing Developments and the Missing Infrastructure for Net Zero. Available at: https://www.bbc.co.uk/news
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