Optimization of an air conditioning unit according to renewable energy availability and user's comfort

The integration of renewable energy sources (RES) in the electrical system can be achieved on all voltage levels using both large power plants and individual/local small distributed renewable generation units. The present paper focuses on a low voltage consumer: a house with a dedicated photovoltaic system which supplies energy to an air conditioning unit. However the problem is the variability of this energy during the day. The solution proposed, in this paper, is the development of a home energy management system (HEMS), in which the air conditioning unit is controlled according to the solar irradiation during the day and the desirable inside temperature of the house between the hours of 9:00 to 18:00. The algorithm considers the thermodynamic model of the house and the photovoltaic panels' model to maximize the use of solar energy during the day. This optimization is implemented in CPLEX and the complete algorithm and a graphical user's interface (GUI) is developed in JAVA. At the end, the test simulations shows that the inside temperature during the day is closed to the desirable temperature in which the air conditioning unit is on according the algorithm developed especially on those moments with high irradiation. In the study, a comparison between the normal control of an air conditioning unit and the HEMS is developed.