This study reports on the results of monitoring done to a sample of 70 solar thermal water heating systems installed across four cooperatives. Data loggers were installed in 30 of the solar water heating system homes, to monitor both the solar system and the energy usage of the conventional water heating systems. The systems had been installed with grants administered by the state of South Carolina. The final results of the study were positive. Solar thermal water heating homes were able to use solar heated water in the later afternoon and evening. On the energy side, customers were saving on average 6.91 kWh a day; and on the economic side, customers were saving on average $295 per year. These energy savings resulted in a payback period of 16-17 years. The researchers were pleased with the results of the study, as they were higher than rates they had seen at comparable utilities.
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