Evaluation of an onsite integrated hybrid PV-Wind power plant

Abstract

This paper examines technical opportunities and challenges of the combination of a wind and solar photovoltaic (PV) power plant to an integrated hybrid plant on the same site. The PV yield loss caused by the wind turbine shading effect is quantified, and the possibility of reducing local grid capacity via the use of a single transmission grid connection. The PV yield loss caused by the shading of wind turbines is quantified for a number of onsite integrated hybrid PV-wind layouts. The corresponding grid connection capacity reduction was also estimated by allowing curtailment when grid connection capacity, which should be lower than the nominal power capacity of the sum of each generator, is exceeded. This finding shows that the PV yield loss due to wind turbine shading was negligible. Even the PV yield loss at the worst case was significantly lower than the regular inter-array shading loss of the specific condition. Hybrid power plants can bring significant advantage over any of the independent PV and wind plants of the same capacity in reducing the grid connection requirement. For a hybrid system, composed of 50% PV and 50% wind capacity, the connecting power line capacity can be as low as 70% of the nominal capacity of the hybrid power plant by allowing a curtailment of approximately 0.07% of the total yield. By comparison, an independent equally sized PV and wind plant could have required a curtailment loss of about 6.2% and 3.6% of the total output, respectively. This is a direct consequence of the effect of both technologies reaching a high electricity generation simultaneously only on few incidences throughout the year. These advantages call for considerations of the effect of complementarity not only during new system design but also to upgrade existing wind plants due to its ability to economically optimise the use of resources.