Powering Your Water Heater Using Solar Energy

Abstract

This report is a detailed overview of my research on solar water heating. Solar water heaters may be used to either supplement or even replace a standard water heater. In addition to being environmentally friendly, solar heaters can save a homeowner hundreds of dollars per year in electricity bills. Because all of the energy remains as heat, water heaters can achieve much higher efficiencies than photovoltaic solar panels. The objective of my research was to improve an existing solar water heater by optimizing its control system. I designed a circuit board to record temperature and flow rate data, and to control the system. In this circuit board I implemented a proportional control scheme designed to optimize the energy efficiency of the solar water heater. The circuit board also takes periodic temperature and flow rate measurements, and saves the results on a data server. I wrote a MATLAB script to parse and analyze the recorded data. My analysis showed that my control scheme performs much better than the previously used control method, particularly on colder days. The average increase in energy harvested by the system in a day was 3.22 kilowatt-hours. My research has shown the potential economic and environmental benefits of using a well-designed control system.