One of the few drawbacks to a solar/electric water heater system is the fact some require manual activation. Sometimes there is no way to tell how much water is in the system or how hot it is, with such a lack of knowledge perhaps leading to wasted energy and damaging the water heater assembly or shortening its life. The problem is even greater in solar-driven water heating systems (even in California) simply because of the uncertainty of sunlight, even in summer, which causes users to leave the system on much longer than needed to achieve a showerful of hot water.
To solve that problem the “E-Sense” concept, a Green Dot Award challenger in the professional product category, is one that works equally well in new (solar/electric) residential hot water systems as well as in retrofits. Thus, not only does E-Sense address the huge waste of energy in hot-water heating, but it actually could enable homeowners to recapture up to 25 percent of that wasted energy. For most homeowners, heating water is fully 50 percent of the electricity budget.
The E-Sense design (from Nir Groff of Groff Industries LTD, Israel) is made up of three parts: a heater sensor unit, a smart controller installed in the home and a heat accelerator. Together, these three make it possible for homeowners to program the desired water temperature and the amount that will be needed per week – though additional supplies can easily be gotten without interfering with, or reducing, the amount requested.
E-Sense juggles hot water needs versus sunlight and electric costs, and by default operates the water heater during off-peak hours whenever possible. For the interior-design conscious, the controller is designed with existing manual heater controls in mind, and its low and unobtrusive profile blends seamlessly with various decors. In the future, as potable water supplies become less certain, designers might even want to incorporate solar thermal (hot water heating) energy with a solar water purification process to make the best of both worlds.