BTC + a very high carbon tax might actually be an interesting way to incentivize the desired overbuilding on renewables. But Texas is probably going to skip the second part.
Another interesting idea would be for the government to constantly buy any amount of energy produced by renewables at guaranteed price using tax money, and "distribute" it evenly to all enrgy users. This way people using least energy wouldn't pay for electricity at all and people building wind farms would have real good incentive to build more.
That is an interesting idea, I wonder how it would work out. Added benefit of just eating up any demand for energy, I guess crowding out any non-renewables. I bet administratively it would be easier than my idea -- people could proactively show they are selling renewables.