In some ways I think the lack of an energy demand is playing a role in the relatively slow uptake of things like solar. Why swap over when your current plants are meeting demand just fine? It's certainly no coincidence that China, who has some of the most rapidly rising demand of energy in the world, is also installing orders of magnitude greater solar installation than the rest of the world. In particular China is expected to add about 50GW of additional solar capacity in 2017 alone, which is more solar than any other nation in the world has - in total (as of 2016).

Aside from that, the imagination is the limit to things we could do if we had orders of magnitude greater energy than we do today. Propelling spacecraft by lasers, charging electric vehicles wirelessly as they drive, conveyor style road systems, and certainly many things we cannot really even imagine today. Massive energy availability would create an entirely new field of industry.