If they had that kind of technology, there wouldn't be a war on for Hoover Damn or Helios-One. Dynamo everything electrical in nature.
As I'm rather insane in my preparation for emergency situations (I used to live on a fault line, now I live on a flood plane in what is pretty close to the Murder Capital of Canada. Someday, I think I'll move somewhere SAFE!), I have quite a few items designed to work off dynamo or other self-generated power, and it's not an easy thing.
Which reminds me, I need a stationary bicycle, an alternator, and some car batteries. Thank you Soylent Green for that idea!