I'm a little stunned that these problems can be framed as technical...

How cheap would energy need to be for those problems to be solved? Can you provide a ballpark dollar figure for how low prices would need to go to solve each of the problems? Or a wild guess?

Also, if energy production is getting cheaper, but energy production is only provided by a few entities (e.g. for reasons like production being capital intensive, strategically relevant, or first movers advantage / natural monopolies) would you believe that energy prices go down to that level if production costs fall low enough?