It is the energy put to use from solar that needs to be monetised, that is the thing convertible directly to fuel, and which does work.

I am positive that as things progress (Free money ramping up, as solar ramps up), there will become apparent hard physical relationships between Joules put to use, and tokens of money, which will probably be uncovered by folk much cleverer (And younger!), later. The important thing for now is to get the vehicle moving, to enable control factors to be worked out by trial and error.

The reason we might feel instinctively that there has to be human time and effort involved for money to be issued in return, is that all forms of energy put to use other than solar, require a certain amount of work to be done in return for the Joules of energy received. That is the work of extraction. There is no such thing as energy from Earth which doesn't come at cost of some kind, and that cost usually translates to some human effort per Joules received. We are like babies, we think if energy didn't need any sucking to have it (like milk from a nipple), then it can't be energy. Money issued as debt can't represent it, because those promises to pay can only be redeemed by the effort of sucking needed to have the energy. Note also the sucking (extraction) is the part that produces pollution. No sucking means no pollution.

So we are gonna have to accept that there is such a thing as free energy, but that doesn't make it worthless, it makes it most valuable of all, but, we have to make money fit. I don't see any reason not to call it free money, it is the simplest, apolitical relationship to remember; free energy means free money.

Btw, it probably does contradict some of the teachings of Marx, who generally always bound up human labor intricately with issue of money. I wrote an article about that too. The point to note is that there was no solar energy when he was around, so how could we reasonably expect him to have known. Things have to move on, as knowledge develops, I think.