Can you heat a home with solar PV?
Sources checked
Solar PV can contribute to heating, but production is weakest when a home needs the most heat. The source's Bratislava model for 5 kWp facing south averages about 195 kWh in December and 726 kWh in July. The grid or another source must cover much of the winter requirement.
Electricity and heat are different quantities
A direct electric heater or electric boiler converts roughly 1 kWh of electricity into 1 kWh of heat. A heat pump can supply more heat per kWh of electricity, subject to its operating conditions. Compare the home's heat demand and the heating equipment's electrical input separately.
Matching annual solar generation with annual heating electricity ignores when each occurs. Use monthly and hourly comparisons to understand the actual overlap.
Use surplus without promising winter independence
Summer surplus can heat domestic hot water in a compatible tank. Thermal storage and controls can move some useful demand into sunny hours, within comfort and safety limits.
A home battery transfers energy from midday to later hours, rather than summer to winter. Size the PV system from the whole year's useful demand, roof and connection rather than trying to eliminate December imports with array power alone.