Photovoltaic hybrid system performance comparisons: prediction versus field results

A photovoltaic hybrid power system consists of a PV array and inverter that operate either alternately or in parallel with a conventional engine-driven generator. At present, hybrid power systems are being used to supply single-family residences, communications, and village power. This paper analyzes the various design constraints of such systems and suggests design changes that can improve overall system performance in some cases. The Southwest Technology Development Institute (New Mexico State University), under contract to Sandia National Laboratories and the National Renewable Energy Laboratory has installed data acquisition systems (DAS) on a number of hybrid PV power systems. These range from small residential systems to village-scale systems. At present, even larger systems are being installed with hundreds of kilowatts of PV modules, multiple wind machines, and multiple diesel generators