Optimal Operation of Integrated Heat Pump-instant Water Heaters with Renewable Energy

Abstract Developing nations such as South Africa are energy insecure despite their high potential for renewable energy sources such as solar. This has forced various governments to initiate energy efficiency and conservation programs. Water heating contributes to a significant percentage of the electricity consumption in domestic and office buildings. Therefore, integration of efficient water heating systems and renewable energy would ensure energy efficiency in these buildings hence lowering the electricity cost and greenhouse gas emissions. This paper introduces an optimal control strategy for heat pump and instant water heaters powered using integrated energy systems. The control strategy can lead to 35% of power-not-delivered, 7.5 kWh energy sold back to the grid while lowering the energy cost by about 19% in a day.