Solar PV vs Solar Water Heating: What's the Difference, and Do You Need Both?
Many people confuse solar PV (photovoltaic) power systems with solar water heating systems, since both use panels that capture sunlight — but they work on entirely different principles and serve different needs.
Completely Different Operating Principles
Solar PV converts sunlight directly into electricity through semiconductor cells. Solar water heating instead absorbs heat from sunlight to warm water directly, with no conversion to electricity at all. This means the equipment and installation for each system are entirely different.
Which Homes Suit Solar Water Heating
Solar water heating suits homes with consistently high hot water use — larger households, or homes with specific hot-water-heavy activities — since it directly reduces electricity or gas use for water heating, a cost that's separate from a home's general electricity bill.
Solar PV Addresses a Home's Overall Electricity Use
Solar PV, on the other hand, addresses a home's overall electricity cost — covering air conditioning, appliances, and even an existing electric water heater. If a home already uses an electric water heater and doesn't have unusually high hot water demand, solar PV alone usually covers the need more comprehensively.
Can Both Systems Be Installed Together?
Homes with sufficient roof area can install both, dividing roof space between PV panels and separate solar thermal collectors for water heating. This suits homes with both high hot water demand and a desire to cut overall electricity costs.
How to Decide What Your Home Needs
A good starting point is reviewing your electricity bill to see whether most cost comes from overall electricity use or specifically from water heating. If unsure, consulting an expert who understands both systems helps identify what actually fits your home's real usage.
Let us help recommend the right system for your home
STR advises on both solar PV power systems and related building systems, to find the answer that fits your actual needs.
Get a Free Quote