Photovoltaic Systems for Cooling Applications

Solar energy can be effectively employed for cooling applications through the use of photovoltaic cells and compression refrigeration plant. Practical experience to date has been limited to small refrigerators but the feasibility of larger installations for cold storage and air-conditioning has now been established. The costs involved are similar to the more widely known solar thermal/absorption cycle refrigeration approach. The paper discusses a design approach which has been developed for photovoltaic cooling in which high overall efficiency coupled with low cost is achieved. In this concept a direct current motor linked to a reciprocating compression chiller is driven directly by a photovoltaic array. The load is matched to the array electrical output by employing variable motor speed and capacity reduction of the compressor by unloading cyclinders. Reference is made to programmes underway to employ this approach in air-conditioning and cold storage demonstrations.