Seven years after the triple meltdown at the Fukushima No. 1 nuclear plant, Fukushima Prefecture remains committed to becoming an international center for renewable-energy research and a domestic pioneer by meeting 100 percent of its energy demand via renewables by 2040.

But grid connection issues, investment costs and a government policy that still favors investment in other energy sources — especially nuclear — continue to present challenges to researchers, businesses and Fukushima policymakers with an interest in renewable energy.

In 2014, the prefecture announced it was aiming to have renewables supply 40 percent of its energy demand by 2020, two-thirds by 2030 and 100 percent by 2040.