Acciona Energy, a subsidiary of Acciona based in Madrid, is a Spanish company developing renewable energy projects, including small hydro, biomass, solar energy and thermal energy, and the marketing of biofuels. It also has assets in the field of co-generation and wind turbine manufacture. As of 2007, it is carrying out research projects to produce hydrogen from wind power and to manufacture more efficient photovoltaic cells. The company has a manufacturing facility in West Branch, Iowa which manufactures wind turbines.