Solar Water Heaters Explained: Are They Worth It?
Quick answer: A solar water heater typically costs around $3,700 to $4,000 installed and can cut water heating bills by 50% to 80%, according to the Department of Energy. With the federal tax credit gone, a heat pump water heater is often the better value, but solar water heating can still pay off in sunny, warm climates.
A solar water heater uses the sun’s heat, rather than electricity from solar panels, to warm the water for your showers, dishes and laundry. It’s one of the oldest and simplest solar technologies. Whether it’s worth it now depends on your climate, what you currently use to heat water, and how it compares with a heat pump water heater.
How solar water heaters work
A system has two main parts: collectors on the roof that absorb heat from the sun, and an insulated storage tank. Most homes also keep a conventional water heater, or a backup element in the solar tank, for cloudy stretches and heavy use.
Collector types
- Flat-plate collectors are insulated boxes with a dark absorber plate under glass. They’re the most common type for homes.
- Evacuated-tube collectors use rows of glass tubes with a vacuum for insulation. They hold heat better in cold or cloudy weather but cost more.
- Integral collector-storage (batch) systems combine the collector and tank in one unit. They’re simple and inexpensive but best suited to mild climates.
Active and passive systems
- Active systems use pumps and controls to move water or fluid between the collectors and tank. Direct active systems pump household water through the collectors and suit climates that rarely freeze. Indirect systems pump an antifreeze fluid through the collectors and a heat exchanger in the tank, so they work in cold climates.
- Passive systems have no pumps. Thermosiphon systems place the tank above the collector, so warm water rises into it naturally. They’re reliable and cheaper but heavier on the roof and less suited to freezing climates.
How much of your hot water can it provide?
The Department of Energy says solar water heaters typically cut water heating bills by 50% to 80%. ENERGY STAR describes it as cutting annual hot water costs roughly in half. The rest comes from the backup heater, and how much depends on your climate, the system size and how much hot water you use.
What it costs
- The Department of Energy uses about $4,000 as an estimate for a typical two-collector system.
- Angi’s July 2026 cost guide puts the average at about $3,700, with most projects between about $1,800 and $5,700.
The 30% federal tax credit that used to cover solar water heaters ended for systems installed after December 31, 2025. Some states and utilities still offer rebates. See solar rebates and incentives.
Solar water heater or heat pump water heater?
For many homes, a heat pump water heater is now the simpler way to cut water heating costs. It works like a refrigerator in reverse, pulling heat from the surrounding air. The Department of Energy says heat pump water heaters are two to three times more efficient than standard electric water heaters, and ENERGY STAR estimates savings of about $550 a year for a family of four switching from an electric resistance model. Angi puts installed costs at about $2,800 to $8,000.
A heat pump water heater installs indoors in place of your existing tank, needs no roof work and works in any weather. If you already have or plan rooftop solar panels, those panels can help power it. A solar water heater can still make sense in very sunny, warm climates, for households that use a lot of hot water, or where electricity is especially expensive.
Other things to consider
- Roof space and condition. Collectors compete with solar panels for sunny roof space, and the roof should have plenty of life left.
- Freeze protection. In cold climates you’ll need an indirect system with antifreeze or a drainback design.
- Maintenance. Active systems have pumps, controllers and fluid that need occasional checks. Antifreeze typically needs replacing every several years.
- Lifespan. Well-maintained systems commonly last around 20 years, and sometimes longer.
For heating a pool rather than household water, see solar pool heaters. For the broader picture, see how solar energy is used.
