Execting green energy to produce zero marginal cost is probably a bit too optimistic at this point. We have been adding green energy for at least 20 years now and energy keeps getting more expensive. Not even addressing whether its sustainable, but expecting a point at which additional solar panels or wind installations are going are going to produce extra energy at close to zero cost is expecting too much.

You might have that argument with nuclear energy, because most of the cost is upfront. But approval process for that will have to be expedited by congress.