The variability of wind and solar is perceived as a major obstacle in employing otherwise abundant renewable energy resources. On the basis of the available geographically dispersed data for the Western USA, we analyze to what extent the geographic diversity of these resources can offset their variability. We determine the best match to loads in the western portion of the USA that can be achieved with wind power and photovoltaics (PV) with no transmission limitations.
Without storage and with no curtailment, wind and PV can meet up to 50% of loads in Western USA. It is beneficial to build more wind than PV mostly because the wind contributes at night. When storage is available, the optimal mix has almost 75% as much nominal PV capacity as wind, with the PV energy contribution being 32% of the electricity produced from wind. With only 10 GW of storage (twice the pumped hydro storage capacity that already exists in the Western Electric Coordinating Council), up to 82% of the load can be matched with wind and PV, while in the same time curtailing just 10% of the renewable energy throughout the year. Copyright © 2012 John Wiley & Sons, Ltd.