Key Model of PV Solar Cooling

Widespread installations of solar energy systems and price reduction of solar energy absorbing equipment opens new opportunities for solar energy application. Solar radiation is available at the same time as cooling demand is needed in buildings. In this case solar cooling of buildings is a reasonable energetic and economic solution. Solar cooling systems have their main tasks of reducing peak electricity power demand and in general is an environmentally friendly – nature protecting – energy conversion method. In the current market situation Photo-Voltaic (PV)-electric driven compression chillers are favourable compared to solar thermal driven sorption cooling because some of the system components like the compressor and heat rejection subsystem have a smaller footprint. A solar cooling concept with Photo-Voltaic electric energy and compression chiller (PVSC) is developed. The definition, analysis of the working parameters and system yield are described. The system was developed and optimised by assessing results of pre-simulations of a solar PV-electric driven compression chillers system. The PVSC contains a cold tank to bridge the gap between solar energy gain and cooling demand. The energy from the heat rejection sub-system is used to pre-heat the domestic hot water. This concept has two advantages, on one hand it increases the heat rejection efficiency because of lower temperatures, and on the other hand it allows the use of indoor heat for hot water preparation. In addition, for a higher efficiency of the heat rejection subsystem during night time, a sensible hot storage tank was implemented in the system. To fulfil the domestic hot water demand in the non-cooling season the system will be operated in the reversed mode for pre-heating. The cooling load of the solar cooling system was adequate to the cooling loads of buildings in certain climatic conditions. The investigations include the analysis of a reference system and the working parameters in cold and hot temperate as well as in the Mediterranean climatic zone. In the simulation template three types of buildings are used for a comparison of the cooling loads. After definition of the simulation template a validation will be done to assess the influence of the components on the system yield