1966
Ogami Island Lighthouse installed with solar cells, Nagasaki Prefecture; with 225W it had the worlds' largest solar power output at the time.

At the time, there was a lighthouse keeper, and a Coast Guard patrol boat was required to visit regularly to deliver food for the keeper and fuel for the diesel power generator. The installation of the solar cells meant the lighthouse could be unattended. It was necessary to develop high-level technology that would provide consistent operation despite harsh conditions, such as large waves and huge gusts of wind.