What's more, they're expensive to buy and install, and include limitations on hot-water flow rates, a possible issue in large households. And cooler incoming water in winter typically means your hot water may not be as hot as you like.
Hybrid electric heaters
These water heaters are a combination of the electric storage-tank water heaters and a heat pump. The heat pump extracts the air from the surrounding and aids in the heating of the water. As a result, most of the hybrid electric water heater used about 60% less energy when compared to normal storage-tank electric hot water heaters. Although they cost more than electric-only water heaters, they are fairly similar to install and also pay back on a short time. But hybrids also have their downsides. Because the heat pump is usually on top, they need as much as 7 feet clearance from floor to ceiling. You'll also need up to 1,000 cubic feet of uncooled space to capture enough heat from the air, along with a condensate pump (about $150) if there's no drain nearby. Hybrid heaters are noisier than conventional storage-tank heaters, exhaust cool air, and can rob some heated air in winter.
Solar water heaters
All solar heaters supplement an electric heater in basically the same way: A roof-mounted collector absorbs the sun's heat and transfers it to an antifreeze-like fluid in a closed-loop system that runs to the water tank. The collector is typically a flat panel or an array of glass cylinders called evacuated tubes. The best delivered stellar savings in summer, making them an attractive option for warm, sunny areas. One of the most important aspects about solar hot water heaters is that they have a considerably high amount of purchase price compared to other water heaters. It is fairly expensive to have a solar water heater installed, but it does pay off in the long run. By utilizing sun's energy, the operating cost for solar hot water heater reduces by up to 90 percent. Solar water heating systems require a conventional water heater as a backup water heating source to ensure hot water is available when solar energy is not.