System implementation aspects of supercapacitor based fast in-line water heating system

Delayed hot water in domestic water heating systems is a worldwide problem with an estimated loss of 15,000 litres of treated water annually per average household. Commercially available systems to overcome this issue cost several thousand dollars and they occupy space and modifications to plumbing. Supercapacitor (SC) assisted temperature modification apparatus (SCATMA), a patent-pending technique is developed to provide a short term high power burst into an in-line heater coil to overcome this problem. In developing a commercially useful prototype, special attention was paid in selecting the energy storage media and the complete system architecture. Several hybrid options with SCs and lead-acid batteries were tested including a series, parallel and an independent connection. The series hybrid proved to have the lowest depth of discharge in the battery pack, highest average power, autonomy time and predicted cycle life. This paper presents details of an experimental test set up, and details of tests to achieve the optimum SC bank size, and the target temperature profiles for best utilization of the optimum SC bank hybridized with a lead acid battery pack.