Renewable energy load matching for continental US

The variability of wind and solar energy technologies is perceived as a major obstacle to employing otherwise abundant renewable energy resources. Based on the available geographically dispersed data for the continental U.S. (excluding Alaska), we analyze to what extent the geographic diversity of these resources can offset their variability. We determine the best match to loads that can be achieved with wind power and photovoltaics with no transmission limitations. Without storage, wind and PV can meet up to 50% of loads in Western US. 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 40 GW of storage (twice the pumped hydro storage capacity that already exists in the continental US), up to 82% of the load can be matched with wind and PV, while at the same time curtailing less than 10% of the renewable energy throughout the year.