In Japan, solar PV systems were approved by the Ministry of Agriculture, Forestry and Fisheries in the Spring of 2013 for the practice of solar sharing. Blending solar PV with crop lands was the idea of a Japanese engineer named Akira Nagashima. He created a system that allowed solar panels to collect sunlight and for plants to as well, but they also were provided with some shade to protect them from overexposure.
For example, a Japanese farmer named Makoto Takazawa has farm land in Chiba Prefecture, where he has both solar PV and crops. He has nearly 350 kW of solar panels mounted on poles 3 meters above ground, and has grown crops like cabbages, eggplants, cucumber, taro, peanuts and yams underneath them. Both the solar panels and the food-bearing plants receive enough sunlight to be productive. Mr. Takazawa can make over $10,000 per year from his solar power system, and something less than $1,000 from growing vegetables. Additional revenue from solar power could help some farmers who have experienced declining incomes from crop sales.
Farmer Tsuboi, located in Aichi Prefecture, has a 50 kW system, with about 600 solar panels located over citrus trees. They are situated about 5 meters above ground on steel pipes. The solar panels could bring in over $20,000 this year. This notion and practice of solar sharing has also spread to other prefectures.
In Fukushima, some farmers are interested in solar sharing because it might help them recoup some of the money they lost due to the radiation exposure and lower sales of their produce. Of course, it makes perfect sense that solar panels would of interest to people who had suffered so much from radiation exposure, and all the fear and stress that resulted during and following the reactor accident.
It also has been suggested that solar PV systems placed above ground could work on pasture lands, because they could provide shade to animals like sheep, cows, and goats.
If you notice a theme in the solar sharing practice, it is one of entrepreneurship or small business management. Farmers are small business people, in addition to being agriculture managers. Solar power could help them be energy independent, and provide a second revenue source, so their economic stability could be bolstered.
A larger issue is the use of land for PV. For Japan to generate all its electricity from solar, about 2.5 million acres of land with solar pv arrays would be needed. Or 7 million acres of land using the solar sharing practice could be utilized, but Japan has over 11 million acres of farm lands, so theoretically solar sharing could contribute greatly to Japan’s energy mix some day.
It should also be noted that energy storage solutions are gradually becoming more robust, and solar panel prices appear to poised to decrease in price even more.
Solar sharing seems to have a great potential to become a major source of clean, renewable electricity in Japan. If Japan can achieve such success, there doesn’t seem to be any major barrier for other nations to trying solar sharing too.