What is solar sharing system (Agrophotovoltaic system) in Japan ?

Solar sharing is a kind of agrophotovoltaic in Japan. This system was invented and named by Akira Nagashima in 2005. "Solar sharing" means power generation and agriculture share the energy from sun. Akira Nagashima defined this system as a system:

1 building above various fields, such as cropland, park, the surface of water, etc.

2 building the nearly horizontal shelf

3 using the power generating element keeping inclination, which is narrow in North-South direction and long in East-West direction, shaped like bar, wing, or plate

4 being compatible with the measures against wind pressure and the radiation intensity keeping that is necessary to the space below

5 toward exactly the south direction

(The bulletin of patent publication from Japan Patent Office P2005-277038A)

In many cases, the system was constructed above the open fields, and the crops were cultivated under the solar panels. Akira Nagashima started the first solar sharing experiment in Chiba prefecture in 2010. He planted peanuts, onion, bok choy, potato, turnip under the solar panels.  Affected by him, lots of people gathered in Chiba, and build many solar sharing facilities. They cultivate organic soybean and wheat, blueberry,  peanuts, garlic and various vegetables and fruits. Not just in Chiba, people cultivate tea in Shizuoka, rice in Akita, mushroom in Aichi, and so on. Many of them aim to support local agriculture by the income from solar power generation. They commit cultivation under solar panels to local farmers. 

In Japan, agriculture has been on the decline with the import of low-priced agriculture products from international market. High cultivation cost led lots of farmers abandoned their cultivation, which generate a large amount of abandoned cropland. In many cases, the problem of abandoned cropland led to local environment issues, such as illegal dumping.

Against this background, people who engaged in the promotion of solar sharing systems, aim to achieve a multiple goal contained sustainable energy and sustainable agriculture.