In recent years, electricity markets were organized in many developed countries in the deregulation process of electric power industries. There have been many studies on electricity markets from the viewpoints of economics, mathematics, computer science, etc. Especially, agent-based models of electricity markets have been extensively studied. Meanwhile, many countries promote use of renewable energy for electricity generation. In this paper, we construct and analyze an agent-based model of electricity markets in which wind and photovoltaic power generation firms are introduced. Our results suggest that wind power generation needs to be improved in efficiency to survive in the market, and that bid prices of photovoltaic power generation are rather affected by change of the insolation amount than by change of the total demand.