There's no barrier to entry on anything solar-related. A wise investor would assume that serious competition will occur prior to reaching a trillion-dollar jackpot.
There are in fact barriers to entry on everything solar.
It's: political connections, zoning, utilities, regulations, laws. Try putting up a huge solar farm without the right connections and insiders, don't grease the right wheels, see what happens. There's no bigger barrier to entry than that.
See: FirstSolar's benefit from being tied to the Walton clan (JWMA / True North Partners). FirstSolar is basically the world's largest independent solar company, is flush with cash, and very profitable. It's not a coincidence they've fared so much better than the rest of the industry.
"The Waltons own more than 112 million shares of First Solar, four times as much as the second-biggest shareholder"
Then you'd get stuck buying half assed divisions of a bunch of F500 companies who get into the market just to profit off you.
Plus you'd need unlimited capital for this plan. And current solar companies might go bankrupt before solar hits the scale needed to compete with fossil fuels.
And the DOJ would sue you for antitrust violations. Standard Oil did your plan. That sort of thing won't be allowed again.
