Yes, you can run a tankless water heater on solar power. You would need a solar panel system that is capable of generating enough electricity to power the unit. Unlike traditional heaters, they heat water as it flows through the unit, offering energy savings and space efficiency. Pairing that with solar power slashes electricity or gas. . Tankless water heaters are lauded for their energy efficiency, but as more home builders and owners are transitioning to innovative energy sources, the question emerges of can you run a tankless water heater on solar power? The answer is yes, but it depends on your configuration.