The statement that you quote about oil companies buying up solar companies and then killing them is perhaps written to imply that oil companies are buying up solar companies (and their patents!) for the purpose of stifling development of the technology, which seems very alarmist and poorly researched. (I understand it was not your statement.)
As an example, the list includes ARCO, which has been a subsidiary of BP since the year 2000. There was a company called “ARCO Solar” in the 1980s that was a subsidiary of ARCO. They had annual sales of up to $40 million (in the 1980s for solar panels, that sounds pretty big!), and the company had invested $200 million in R&D. They sold it to Siemens of Germany in 1989.
That hardly sounds like they killed it. Put it into more interested hands, if anything.
That took me one Google search to find.
If the other companies closed down solar units, it was almost certainly for business reasons peculiar to the company in question, not for some evil Monty Burns-esque plan to prevent the growth of solar power.
Coincidentally, it appears Siemens eventually sold that solar unit to BP, where it is now part of BP Solar, which is a very large player in the solar industry. Why? Because corporations are not entirely stupid. They know solar is a growing field, and they know that money will be made, and they want to be part of that.
Also, if oil companies were trying to get a stranglehold on the solar industry through controlling patents, they did a piss-poor job of it as annual installtions of solar panels range in the order of multiple gigawatts, and are growing rapidly.
I am no blind fan of corporations, but all of those solar panels are not going to be installed by hippies on communes for a few bags of weed. Those panels are being installed by, yep, big corporations.
Chevron, to take another corporation that you named, has invested in a company called Solazyme, which is a very promising player in the infant biofuels industry. They did not buy anything near a controlling interest (in other words, they are not trying to shelve Solazyme’s IP), and look to be working to help Solazyme’s research. I would imagine that other oil companies are doing the same thing. Solazyme’s technologiy is already proven as technologically feasible (for example, they are producing 150,000 gallons of fuel for the U.S. Navy this year, after 20,000 gallons last year), it is simply a question of scaling production up economically.
Solar power in the past did not fail to take off because oil companies were smothering the technology. It was because solar power was still too expensive on a relative basis. Although it is not quite down to grid parity, with government subsidies and with the benefits solar power supplies, the difference is close enough that solar power is now a huge and rapidly growing business.