Stillwater Hosting Energy Study

Published on Wednesday, 3 September 2014

Enel Green Power's Stillwater plant in the USA brings together PV solar, geothermal and solar thermal power and is an example of how to combine renewable energy technologies in a way that improves efficiency, sustainability and protects the environment.

Its excellence has attracted the interest of research bodies across the USA, and has led to the signing of a Cooperative Research and Development Agreement (CRADA) between EGP, the National Renewable Energy Laboratory (NREL) and the Idaho National Laboratory (INL) that under the supervision of the U.S. Department of Energy Geothermal Technologies Office (GTO), will see the plant's potential explored.

As part of this agreement, starting from next year EGP, NREL, INL and GTO will work jointly to model the combination of geothermal and concentrated solar systems, corroborating simulated results with real operational data from the Stillwater facility. The results of this activity will be used to look into and quantify the potential benefits of different operational strategies and integration models, with the aim of paving the way for the development of new hybrid plants running on renewable energy.

The construction of hybrid plants that combine two or more types of renewable energy within the same site is part of EGP's innovation strategy. The Stillwater geothermal facility is the world's first hybrid plant, combining the continuous generating capacity of binary-cycle, medium-enthalpy geothermal power with the peak capacity of solar energy. When the two-megawatt concentrated solar component currently under construction is completed, it will operate alongside the existing 33MW geothermal plant, which is already integrated with a 26MW PV solar park.

Hybrid plants will also take centre stage in Chile, where EGP is completing a plant that combines PV solar and small wind power with a co-generation system and will produce electricity and hot water for a school in the village of Ollag├╝e. Its installed capacity will amount to 232 kilowatts and will have a production capacity of around 460 megawatt-hours per year. It will be a stand-alone facility, meaning that it will not be connected to the domestic electricity grid and it will have its own 520 kilowatt-hour electro-chemical storage system.