Steady-State Performance of a Grid-Connected Rooftop Hybrid Wind-Photovoltaic Power System with Battery Storage

This paper reports the performance of a 4 kW grid-connected residential wind-photovoltaic system (WPS) with battery storage located In Lowell, MA. The system was originally designed to meet a typical New England (TNE) load demand with a loss of power supply probability (LPSP) of one day in ten years, as recommended by the Utility Company. The data used in the calculation were wind speed and irradiance of Logan Airport Boston (LAB), obtained from the National Climate Center in North Carolina. The present performance study is based on two-year operation (May 1996 to April 1998) of the WPS. Unlike conventional generation, the wind and the sunrays are available at no cost and generate pollution-free electricity. At around noon the WPS satisfies its load and provides additional energy to the storage or to the grid. On-site energy production is undoubtedly accompanied with minimization of environmental pollution, reduction of losses in power systems transmission and distribution equipment, and supports the utility in demand side management (DSM). This paper includes discussions on system reliability, power quality, loss of supply, and effects of the randomness of the wind and the solar radiation on system design.