The efficiency isn’t important when the energy is free, though efficiencies are progressing in leaps and bounds. There comes a point when free energy becomes an avalanche, regardless of efficiency, a point at which it can be freely scaled upwards, fuelled by the energy from earlier installations.
Until then the installations can be funded and rapidly built with free money, chalking up all deficits against the future free power.
See the magic there is that money becomes migrated to energy in every way.
Trading in markets with free money is no longer an exercise of seeking profit, but of saving companies which might be bankrupt despite still offering things everyone wants.
We’ve already hit the end stops of the old system, not just of environmental damage, but of profit. That is why we no longer have interplanetary or supersonic mobility, and can’t even slap down a virus, and why millions of folk are right now losing their traditional jobs, becoming dependent on handouts.
Everything has been extracted from the people, there is no longer any wealth left to sustain profit.
You might still be able to get funding for an IPO from corporates, but they too have been eating themselves, buying their own shares for years, so how are people going to keep paying their bills for your electricity which can’t be for free?
Sorry if that sounds like an attack, it isn’t really, I am saying it because I love you, and all humans, I really do, hence I really hope we can wake up from what seems quite a bad dream, and smell the coffee.