And it sure has hell wasn't Greenpeace or the Clamshell Alliance.
It was the 1980s oil glut that did the deed. That was especially devastating following on the heels of the 1970s oil crisis, because so many companies who entered the alternative energy business in the late 70s only to have the floor cut out from under them in 1980. I had a good friend who quit his job at a software company in 1980 to go to work for a company developing a seasonal thermal energy storage scheme. He was an accountant and according to him the numbers were solid as long as oil prices were north of $100/bbl. That was in May of 1980 when oil was trading at $114/bbl. 13 months later the price of oil had fallen to $60/bbl. For the next five years the Saudis tried to prop up falling oil prices by cutting back production, but in '85 they gave up, opened the spigots, and oil prices dropped to $23/bbl.
The economic reaction was entirely what you'd predict with oil prices at a 40 year low. The development of new energy technologies stalled. Cars got bigger again and SUVs of unprecedented size and low fuel economy became wildly popular. And new nuclear plant starts dried up. Oh, the industry pointed the finger at the big, bad environmental movement, which is laughable because so far as I know they only nuclear power plant ever canceled due to protests was the monumentally stupidly sited Bodega Bay in 1964. Imagine for a moment the Clams and all those guys didn't exist; it wouldn't have mattered in the least. Nobody is going to invest in new nuclear power plants when oil is priced at $18/bbl. But it sounds better to say that the Greens have put you out of business than to say the prices you used in your revenue projections were off by an order of magnitude.