I understand what you are saying, I simply don't agree.

Your focus is on energy, but as I noted the cost of energy is not due to "energy", it is due to the scarcity of other resources needed to capture it, store it, distribute it, etc.

Because energy cannot be destroyed (it can be transformed into different forms of energy or even into matter in theory), it is essentially free. In addition, the absolute supply of energy being supplied daily by the sun exceeds the ability of humans to consume all of it, which reminds me of why plants are green not black... if they were black, the amount of energy they would absorb would kill them, but rejecting part of the energy composing the color "green" allows them to harness the sun without burning up (sorry for the diversion, but it is relevant with respect to someday we will use "black chlorophyll to produce transform sunlight into other forms of energy".

But while the planet continues to get bathed with far more energy than it can possibly use all other resources are limited. Some argue with unlimited free energy we reshape matter into any form we want (the ultimate goal of alchemy), but there is a massive gap between theory and reality. And even then, from a human perspective there remains the most precious and limited resource of all... our time. And unless someone figures out how we can live forever, there will be a cost associated with human "time".

As such capitalism will always exist as a way to ration limited resources, whatever those resources are.