Characterization of a stand-alone PV cooling/heating system

Abstract

Recently, the environmental objectives set by the European Union to reduce CO2 emissions and to increase the renewable share, together with the reduction of PV prices since 2010, have motivated a great interest in PV heat pump systems for heating and cooling applications. This papers describes the initial characterization test and results of a stand-alone PV heat pump prototype installed in Madrid (Spain), using a water tank as thermal storage instead of batteries as electricity storage (a more expensive and technically complex solution). This initial test has the objective of characterizing the response of the converter that operates the compressor of the heat pump. Such converter was powered by a constant frequency input (the electric grid), in order to quantify the variable frequency output that the compressor demands. In future work, the converter will be powered by a PV array (which means a variable frequency input) and programmed to provide the required output without overcoming any limit value of the system. This way, the heat pump system will be operated completely stand-alone.