Free endless energy is already there: it’s the sun and oxigen everywhere. The thing is we need amounts of it, that are not parallel at the same time to what is delivered.
Burning fossile does that; which is fire; and and electro magnatism, that needs motion and therefore fossile energy, so the two need eachother and don’t disrupt economy.
Solar energy though comes from nowhere. You don’t need distributional chains. That’s the big difference, why the conventional economy does not like that.
On the other end though, it’s not able to create a static, that can be manipulated into what is needed at that time. Unless you have an overcapacity that can be tweeked into lower levels of demand. So, that’s possible to achieve.
To tap into neuron energy, without nuclear, has not been achieved yet, because it is too micro. I’m not sure if radio waves could do that, as the nasa machine somehow supposed to have done. If there is a constant high frequency next to a low one, you might be able to use that as an energetic difference.