Agree with your point but it's hard to implement. Elon Musk has been working a lot on energy like Solar City and Tesla. A free energy device will require zero cost to produce but we know that the resources for producing (or better said as "transforming into" , strictly speaking) the kind of energy that we need are scarce in nature. Anything scarce requires some sort of allocation. I of course hope more renewable energy sources can be discovered and easily accessible and i am optimistic that it's gonna happen in the near future.