IITATE, Japan—Many residents of Fukushima prefecture are still angry about the nuclear disaster five years ago that contaminated towns, farm fields and forests. But as the cleanup continues, local governments and some business owners here are channeling their frustration into something positive: clean-energy development.

Fukushima prefecture, about 150 miles (240 kilometers) north of Tokyo and roughly the size of Connecticut, was the site of the devastating meltdown of the Daiichi nuclear-power plant following an earthquake...