Giant solar farm in Japan seen from the air
Following the Fukushima disaster in March 2011 all of Japan's 48 other nuclear reactors were shut down.
The predicted blackouts did not happen, the country kept running just fine, but there has been a cost.
Before the disaster nearly 30% of the country's power came from nuclear. That has been replaced by burning lots more coal and gas, and a subsequent rise in greenhouse gas emissions.
But in the four years since the nuclear plants were shut down, Japan has also begun to witness something else - a renewable energy revolution.
The BBC's Japan Correspondent Rupert Wingfield-Hayes visited a vast solar farm in Kagoshima to find out whether it could be the solution.
06 May 2015