The research has already been done. Generation and consumption of renewables still requires regulation to align incentives.
There is a role for regulation but a carbon tax is the way to go.
I agree a carbon tax would be ideal. It seems politically impossible though, so you achieve what you can.
I don't think it has. We still have to figure out ways to lower the cost of storage.
You're saying it is cheap enough that we can now mandate it?
It should be cheap enough when purely green energy is superior to any other source. Solar alone is cheap, but not solar + storage.