Solar thermal technology developer Sunnovations Inc. has launched the Ohm residential solar hot water monitoring system. According to the company, Ohm is the first system that can measure both solar and backup energy inputs as well as hot water energy usage, allowing solar hot water system owners to make smarter use of their solar-heated water.
The Ohm system is designed to provide homeowners with Web-enabled monitoring for unprecedented insight into their solar thermal system's performance. Ohm is available for pre-order on Sunnovations' website at a cost that the company estimates to be less than half of the retail cost of systems with comparable features.
The current technology paradigm in solar hot water monitoring is to measure the flow rate in the solar loop and extrapolate that rate into a measurement of solar energy put into the hot water tank. This approach is both inexact – it provides only an indirect measurement of energy input – and expensive, as flow meters are costly and time consuming to install, Sunnovations says. The Ohm system eliminates the flow meter and instead uses a patent-pending in-tank sensor to directly measure the energy in the hot water tank.
Independent accuracy validation on the Ohm system is currently being conducted by TUV Rheinland in Tempe, Ariz. Preliminary test results indicate a system accuracy of greater than 98%, with a full report to be issued soon.