Leafy Vegetables and Agrivoltaics

One of the characteristic agricultural products grown under agrivoltaics is leafy vegetables such as cabbage and lettuce. 

Since they are easily affected by strong sunlight, shading with solar panels will help the growth of leafy vegetables.

Growing Cabbage and Lettuce

In the lowlands of Japan, summers are too hot for growing leafy vegetables. However, solar sharing makes it possible to grow leafy vegetables by blocking the strong summer sunlight.

Another known benefit of the presence of solar panels is that they help to control frost in winter. Therefore, in areas where leafy vegetables could not be grown in the winter, it has become possible to grow cabbage and other crops through solar sharing.

Of course, it's not just good for leafy greens. Shading by solar panels delays the drying of the ground after rain. This can lead to disease outbreaks due to moisture damage.

Nevertheless, the advantage of being able to grow vegetables that could not be grown within the region before will bring about a very significant change.

Rice Farming and Agrivoltaics

Rice is the staple food of the Japanese people, and rice farming is also being used in agrivoltaics.

A shading ratio of around 35% is suitable for growing rice, and famous varieties such as Koshihikari and Akitakomachi are grown here.

Planting of Akitakomachi rice

Impacts on the growing environment include slightly cooler water temperatures and delayed ripening, which generally delays the harvest time by about one week.

However, a slight delay in growth is not a problem for farmers, as the income from the sale of electricity from solar power generation is about 10 times higher than the production value of rice.

Since it is not practical to install agrivoltaic systems in all the paddy fields without any gaps, only some of them are installed to support the farmers' income.

With the increasing automation of agricultural machinery used in paddy fields, the decline in workability and other problems are expected to eventually improve.

About crops grown under agrivoltaics in Japan.

A wide variety of crops, including grains and vegetables, are grown in agrivoltaics in Japan. It can be installed on a variety of farmland, but there is a regulation that the yield must not be reduced by more than 20% from the regional average.

Soybean

Eggplant

Taro

In Japan, half of the country's agricultural land is paddy fields, which produce rice, the country's staple food. Rice can be grown without any problem if the shading ratio of agrivoltaics is about 35%.

Paddy field

Data on the shading rate of agrivoltaics and crop growth has been accumulated, and the future challenge is to improve productivity by taking advantage of the shading environment.