It doesn't clearly tie the choice of business model to the way the businesses are regulated, so it fails to support the claim that regulation is the cause of the lack of solar adoption. The examples it uses to make its case, the TVA and the state of Texas, are also not great.
The TVA is owned by the government. So the question of their pivot to solar power is more of a political question than an economic one. Is there any political will to spend tax dollars pivoting the TVA away from nuclear and hydro sources to solar? Which politicians support/reject the policy and why?
Texas is also not a great example given the recent tragedies arguably resulting from their lack of regulation. https://en.wikipedia.org/wiki/2021_Texas_power_crisis
In-line with other comments, Enron is a classic case-study of the consequences of allowing free markets unfettered control over essential infrastructure.