101 Alternative Energy: On-Demand Hot Water
On-demand heating technology, also known as tankless heating, makes hot water available only when it’s needed, saving the energy required to heat it when it’s not being used. A tankless heater is much smaller than a typical hot water tank, containing just a set of coils through which water passes for quick warming. Though the on-demand system costs more than a standard hot water system, it saves money over its lifetime as it eliminates most of the energy (and costs) that heating your water normally demands.
There are many different manufacturers of tankless hot water systems and a range of options depending on whether you want gas or electric, what your demand is, how large a space you have for the heater, and how many points of use the heater is intended to serve. Tankless water heaters generally last longer than standard storage tanks.