PV + heat-pump systems pair solar panels with a solar heat pump water heater unit. The photovoltaic array generates electricity (typically 18–22% panel efficiency), which powers a heat-pump compressor that moves ambient heat into water with a COP (Coefficient of Performance) of 2–4. Whether you're evaluating a solar water heater vs heat pump for a sunbelt property or a cloudy Pacific Northwest home, you'll leave with clear criteria to match technology to your roof, budget, and hot-water demand. The core promise: By the end, you'll know which system type offers the best 10-year. Solar water heaters—sometimes called solar domestic hot water systems—can be a cost-effective way to generate hot water for your home. They can be used in any climate, and the fuel they use—sunshine—is free. Solar water heating systems include storage tanks and solar collectors. However, to prevent more people from experiencing the same thing, we have taken it upon ourselves to guide you through the buying process. Unlike traditional water heaters, solar water heaters utilize solar collectors on your rooftop to transform sunlight into solar energy, which is then used to heat the water in your. Use the power of the sun to heat your water.