Solar double cropping takes off in Japan
Solar power is all well and good, but how much land would we need to go solar in a big way? And how do we balance the need for energy with other important needs like, umm, food for example?
In the scorching sunlight of a North Carolina summer, Doug Jones of Piedmont Biofarm has already been exploring solar double cropping as a means to generate power and grow food on the same land.
Over in Japan, where agricultural land is highly prized, a group of farmers are pursuing a similar goal—developing what they refer to as "solar sharing". Junko Movellan of Renewable Energy World has posted an interesting exploration of the solar sharing phenomenon, explaining that until recently, solar power plants were restricted or banned from being built on active farmland.
In April of this year, however, the Ministry of Agriculture, Forestry and Fisheries (MAFF) approved installation of PV systems on existing, crop-producing farmland so long as they are not anchored with permanent concrete footings, and do not restrict either farm operations or crop productivity. Movellan explains that this has allowed farmers, like Makoto Takazawa of the Kazusatsurumai Solar Sharing Project, to roll out a concept that's been developing for some time:
The concept was originally developed by Akira Nagashima in 2004, who was a retired agricultural machinery engineer who later studied biology and learned the “light saturation point.” The rate of photosynthesis increases as the irradiance level is increased; however at one point, any further increase in the amount of light that strikes the plant does not cause any increase to the rate of photosynthesis. By knowing that too much sun won’t help further growth of plants, Nagashima came up with the idea to combine PV systems and farming. He devised and originally patented [sic] special structure, which is much like a pergola in a garden.
From solar power plants doubling as bee sanctuaries to greenhouses that generate their own electricity, we've already seen plenty of ways that land set aside for solar energy production can serve a useful double purpose. It looks like Japan's farmers are doing their part to make sure that happens.
Head on over to Renewable Energy World to learn more about the details of how solar sharing is integrating PV technology with agricultural practices.