Both cut bills. Both pay back over a decade. But the order you install them in changes the maths by thousands.
Solar PV typically pays back in 11–15 years; an air-source heat pump in 10–14. Solar has no grant in 2026 but VAT is zero-rated. Heat pumps qualify for the £7,500 Boiler Upgrade Scheme grant. For most UK homes the sensible order is solar first, then heat pump — solar drops the running cost of the heat pump by 25–35%.