Heatpump Mythbusting
What I learnt crunching 20.5m datapoints from HeatpumpMonitor.org
HeatpumpMonitor.org is an open-data project run by the OpenEnergyMonitor community: real UK households running heat pumps and publishing their meter readings at ten-second resolution. I pulled the full history of every public system into DuckDB — 730 heat pumps, ~20.5 million half-hourly readings, going back to early 2017.
The map shows where the fleet sits. A few quick takeaways before we dig into the findings:
The geography is a bit skewed south and east: East England (78), South England (85), South West (52), Yorkshire (48) dominate; though London is the most under-represented region per capita — flats and shared systems are a poor fit for an owner-installed, monitoring-engaged community.
North Scotland is over-represented per capita (0.038 systems / 1,000 dwellings) despite being the coldest part of the country — early-adopter density matters more than climate.
The panel is self-selected: HPM users are technical, engaged and predominantly Octopus customers. This is a quality sample, not a representative one. Anything I say below is about how well-installed, well-monitored heat pumps behave — not the full UK fleet.
What follows are several things that surprised me most from working through this data, or reinforced existing priors I have.
