The problem then becomes distribution. It is not insurmountable but you can't just stick everything in a corner of the country. In fact they are currently doing work to send power FROM Cheyenne, Wyoming TO Las Vegas, Nevada to service the grids in NV, CA, and AZ. Seems crazy but it's complicated.
TransWest Express LLC is developing and constructing critical high-voltage interregional transmission infrastructure to make America’s power grid more reliable and more resilient.
www.transwestexpress.net