Optimization of the inverter size for grid-connected residential wind energy systems with peak shaving

Abstract

This paper addresses the problems of output power distribution and variability of small wind turbines. The aim of the study was to increase the share of locally consumed renewable energy and decrease power fluctuation in residential houses that meet their energy demand using wind energy. A system with shiftable water heating and decreased inverter power, which avoids unnecessary conversion steps for shifting of power peaks is proposed. Autocorrelation functions were used to analyse the energy consumption and production patterns for optimization of the inverter and hot water storage tank size for load shifting. The optimal sizing of these components for applying the method was found for different wind conditions. The results of simulations with high temporal resolution data and experiments showed that the proposed system is able to shave stochastic power peaks and shift electrical loads. The analysis of net energy flow revealed that the renewable energy cover factors can be enhanced by 14.4–36.0% and the wind turbine's nominal inverter power can be decreased down to 29.2–52.3% without increasing the system's energy losses or changing the hot water consumption pattern.