The answer
Can rooftop solar power a heat pump through the Scottish winter?
Solar panels can supply some of a heat pump's electricity, but they cannot normally run it through a Scottish winter on their own. The heating load rises during the shortest, darkest days. Design the heat pump to heat the property without solar, then calculate how much solar actually overlaps with its use month by month.
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Why annual totals give the wrong impression
A year's solar generation may look close to a year's estimated heat-pump electricity use. But much of the solar arrives in summer, when there is little space-heating demand, while winter heating requires electricity during long evenings and dull days. Compare the two month by month and, for a sharper view, by time of day. A battery shifts energy by hours, not from July to January.
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Can controls improve the overlap?
A hot-water schedule may use some electricity when solar is generating, subject to the household's hot-water needs and system hygiene settings. Spring and autumn can also offer useful daytime overlap for space heating. Avoid turning the heat pump on and off aggressively just to follow every passing cloud; comfort and efficient operation matter more than maximising a self-use percentage on paper.
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What should a combined design check?
The heat pump needs a heat-loss calculation and a design that works at the cold outdoor design condition without relying on panels. The solar proposal needs a roof and shade assessment, generation estimate and realistic self-use forecast. Check the electrical supply and network process for the heat pump, inverter, battery if proposed and future EV charger. The final model should show residual grid imports, not imply that the roof will erase winter bills.
What happens when winter brings less solar power?
Ask for a graph with twelve monthly bars for expected solar generation and heat-pump electricity demand. Highlight the December and January gap rather than quoting one annual 'self-sufficient' percentage. If a battery is included, show which day's surplus fills it and which evening load it displaces. An annual generation total cannot establish that timing.
The survey also needs to identify what remains from the existing heating and hot-water setup. If an old boiler is retained for some rooms, the quote should not imply that solar-powered heat-pump operation replaces all current fuel use. If an immersion heater is used for hot water, include its electricity consumption in the combined model.
A joined-up design can still be worthwhile: panels may reduce daytime imports across the year, and the heat pump can make efficient use of electricity. The useful conclusion is a realistic bill forecast and a heating system that keeps the property comfortable when solar output is low.
What to check next
Your next steps
Where we checked the facts
Check the original information.
These official pages back up the rules and technical details above. They can change, so check them again before spending money or starting work.
Apply this to your own property
Which improvements should come first?
A free survey checks heating, power and cooling together to see what may work for your building before you price the work.