Photovoltaics in the Context of off-Grid Small Power Systems

Summary

The subject area is defined as:-’ stand alone, off-grid continuous power systems up to 20 kW’. The paper focuses on the practical criteria which determine cost/effectiveness to the user in different applicational areas. Both utilisation and load factors can be important in determining overall power costs in many systems, and their product, — which may be expressed as the average power off take factor, — gives a useful first order approximation for comparative costings. of the many systems studied, only those based on internal combustion engined generating sets and photovoltaic (PV) systems are presented. Both ‘standby’ and ‘mobile short-life’ construction type applications are not considered amenable to PV penetration. However, isolated non-mobile high utilization systems and ‘village electricity’ are potential areas for PV competition. Despite their current very high first cost, medium to high offtake PV systems are already competitive in overall power costs with small gasoline driven sets. With progressively lower module and balance of system costs, continuous power PV systems should be able to compete with the larger gasoline sets by the middle of this decade. Diesel electric systems are more reliable and fuel efficient so that power cost parity for a 5 kW PV system may not be achieved until the second half of this decade or the first half of the next decade,-depending on fuel cost scenarios.