The system is called “solar sharing” (ソーラーシェアリング) in Japan. Who knows what expression will eventually take root in English. We’re talking about a new way of producing clean energy without compromising food production.
Solar panels are installed on a frame about 3 meters above the ground, with wide spacing between panel rows. About three quarters of sunlight reach the ground and the remaining quarter reaches the panels. In this way, the same area is used simultaneously for both agriculture and power generation.
Picture: Solar sharing project of Ken Matsuoka in Tsukuba, Ibaraki prefecture, Japan.
This revolutionary idea is based on the fact that most plants don't need all sunshine they receive in an open field. Plants do need light for photosynthesis, but only to a certain point. Everything beyond this saturation point does not increase photosynthesis rate and can even be harmful (e.g. causing more evaporation and lack of moisture). Solar sharing takes advantage of this fact - panels use the excessive sunlight for power generation while crops are cultivated below them.
Solar sharing was invented by a Japanese Akira Nagashima in 2003 and today there are numerous trial projects all over Japan.
This blog aims to introduce these projects and everything related – from institutional background to on-site technological challenges.
Link to the inventor Akira Nagashima's project in Chiba prefecture (website is in Japanese):