1. The conversion of airplane gas turbines to power generation which have about 1/10 the capital cost of the steam turbines used for coal and nuclear plants. (People still quote the cost of coal as if it was a benchmark but it has been uncompetitive since 1980. So much in energy research is like a stopped clock.)

2. A wrong model for what causes nuclear accidents (e.g. the pressure vessel doesn't burst, instead the power goes out like it did at Fukushima.) Existing plants and new designs had to be retrofit -- U.S. power plants went through post-TMI and post-911 upgrades, but Japan did nothing.

3. Racism and islamophobia. When Pakistan got the bomb the fear of proliferation exploded, putting an end to research in new nuclear reactors (which could have a gas-turbine based cost structure) and sustainable nuclear fuel cycles. (e.g. it's possible to not just use Plutonium as a fuel, but even destroy the most pernicious fission products.)