ANALYSIS OF LOW POWER STAND ALONE HYBRID PHOTOVOLTAIC-WIND SYSTEMS FOR TELECOMMUNICATIONS

ABSTRACT: This work shows the convenience or not of the inclusion of wind energy systems operating in junction with photovoltaic systems, oriented to power small stand alone telecommunication systems. A PV generator, a wind generator and a battery system compose the basic hybrid system analyzed. Simple models are used to predict the power generation for the wind and PV generators. An hourly measured year of global horizontal irradiance and wind speed (at 10m height) in 6 different locations in Spain representative of different irradiance and wind speed correlations were used. Simulations have been performed to obtain the size ratios: Battery- PV array generator- Wind turbine, that lead to a predefined loss of load hours (LOLH). For a defined LOLH there are an infinite number of potential ratios battery-PV-Wind. Only the economic criteria (including the battery lifetime dependence with the SOC evolution) will lead to obtain the optimum system size. For some locations, with a considerable wind resource (i.e. good solar-wind correlation), the use of a small wind generator can reduce not only the number of a PV system faults, but also the PV array peak power to be installed. Nevertheless economic aspects, as the ratio price/W for wind, photovoltaic or battery, can modify these results. System costs can be analyzed in function of the different parameters: location (irradiance and wind speed correlation), load profile, PV/wind/battery costs ratios. This work shows that the use of small wind turbines in photovoltaic stand-alone installations for telecommunications can reduce the final system cost in function, among others, of the correlation wind speed/irradiance for a given location and the different technology prices