Model study of combined wind and solar electricity production in Hungary

Abstract

Since large-scale and cheap energy storage is an unsolved problem, the main difficulty of using wind and solar electricity is caused by their intermittent nature. It is a widespread belief that the combination of the two renewable technologies generally improves the reliability and supply quality of electricity generation. Indeed, there are some locations where wind speeds are definitely larger during the nights because of the increased stability of the atmospheric boundary layer. However, a proper decision making requires to study the supposed benefits at the very location of designed installations. Here, we report on a model study, where the whole area of Hungary is evenly covered by wind generators and solar photovoltaic units of various composition and total rated power. The combined model output is compared to the recorded electricity consumption in Hungary. Our results indicate that the integrated output of combined renewable production can be definitely lower than the output of “pure” (either solar or wind) resource network of the same rated power. The main reasons are the lack of daily cycle of wind strength and the strong annual seasonality of insolation in the Carpathian basin. Benefits of combined production show up at unrealistically high rated power values which is a consequence of limited capacity factors of both renewable sources around Hungary.