Combining Offshore Wind and Wave Energy Farms to Facilitate Grid Integration of Variable Renewables

The ocean covers 71% of the earth's surface. It is abundant in renewable energy resources such as wind, wave, tidal, and gradients of salinity and temperature. With the exception of some offshore wind farms along the northern European coast, this vast reservoir of non-fossil fuel energy is untapped, even though roughly 40% of the world's population lives within 100 kilometers of the coast. With continued development of offshore wind power in Europe and initial projects planned for the US east coast, China, and Korea, larger contributions of offshore wind power are on the horizon. Similarly, several wave energy converters are in full scale prototype testing at sea. Development of both renewable energy sources in co-located sites may improve the electric power performance of a combined wind and wave energy farm. While wave energy is primarily a wind driven phenomenon, at a particular location and time, the energy levels in the wind and waves may be different. Analysis of wind and wave data along the US Pacific coast indicates a synergy where combining the two energy sources in a co-located offshore farm reduces the variability in electric power output. The variability of electric power from renewable energy sources has been identified as a challenge to their large scale integration in the electric grid, but combining variable resources mitigates this problem, producing smoother power output than either resource can separately.

Speaker: Eric Stoutenburg, Stanford