There are several cheaper alternative energy sources, but you don't hear much about them.

Denmark gets 20% of its power from the WIND. Not will someday, but DOES today.

The use of the ocean thermal gradient is the cheapest way to make electricity from solar energy. I know a lot about this, having been affiliated with the only company in the World which is seriously pursuing this. The stuff on the web site is sort of out-of-date, since there are more pressing priorities, but here it is: Sea Solar Power

A pilot plant is currently being built in Guam. It is small, but will prove the practicality of the concept beyond any shadow of a doubt.

Sea Solar Power can produce electricity far, far below the cost of nuclear power.