Solar water heaters were cool in 1980s. They could be again.

Unlike photovoltaic panels, which can power your home, solar thermal panels are mainly used to heat water. But they’re smaller and more efficient. The technology converts 60 to 70 percent of the sun’s energy into heat. Even the best photovoltaics, which generate electricity, only achieve 24 percent efficiency.

https://source.unsplash.com/random/300x200/?home,solar