There’s a tradeoff when sprawling solar farms pop up on agricultural land as a result the farmland disappears, perhaps forever, in return for growth in the promising renewable energy sector. But what if large solar installations could be built away from agricultural land, eliminating the competition between two important industries?
In a study published today in Environmental Science and Technology, researchers at the explored the possibility of developing solar installations on a variety of unconventional sites. They focused on this California region, which comprises 15 percent of total landmass, because it is an area where food production, urban development and conservation collide.
Michael Allen, a distinguished professor emeritus at Center for Conservation Biology, said many existing solar farms are built in unsuitable areas, where they encroach on natural or agricultural lands already under threat from urban sprawl. When a piece of land is developed for a solar installation, it is very unlikely to be reverted into agricultural land, even when the lease to the solar company eventually runs out. That’s because flattening and compacting the land, as well as the long-term application of herbicides to keep the site clear of weeds, spoils the land for future farming. For this reason, it is important that we explore alternative sites for new developments as the industry continues to grow.
The researchers evaluated four unconventional areas:
(1) Developed areas within agricultural landscapes, such as rooftops, transportation corridors, and parking lots;
(2) Land that is too salty for crops to grow, either because of naturally occurring salts or buildup from human activities;
(3) Reclaimed areas that were previously contaminated with hazardous chemicals; and
(4) Reservoirs and irrigation channels that can accommodate floating solar panels.
In India the state of Kerala Leads in Unconventional Solar Energy Projects , for instance the 6000 sqm Banasura Sagar Dam Floating Solar Power Plant. A reservoir is just a lot of water sitting around and doing nothing, with a massive, flat surface became an ideal place for solar energy generation. Kerala installed a 6000 square meter mammoth floating solar power plant on the waters of the Banasura Sagar Dam near Kalpetta, Wayanad district. With 500 kilowatts peak (kWp) capacity and production capability of 750,000 units (kWh) of electricity a year, this is also India’s largest floating solar power plant.
It wasn’t too long ago that China had a reputation as a coal-guzzling, smog-blanketed polluter. But that is changing and very fast. Today, China invests more each year in wind, hydro and solar power than any other country on earth. This week it further underlined its role as the global leader in renewable energy by switching on the world’s largest floating solar power plant. This facility is located in the city of Huainan, in China’s eastern Anhui province. It has a capacity of 40 megawatts (MW), enough to power a small town. And in a stroke of pleasing symbolism, the plant floats over a flooded former coal-mining region.
The benefits of floating solar panels on water come mainly in the form of increased generating efficiency. A study has found that the natural cooling effect of the water beneath the solar cells makes them up to 11% more efficient than solar panels placed on land. Furthermore, the location of the solar cells can make a big difference in longevity since there is a reduced risk of destruction due to wildlife, storms and earthquakes.
These floating solar panels are the solution to quite a few energy problems. They can keep the water from evaporating, they can save fertile land for agriculture, and they can be more efficient since the water cools them. On hydropower dams or reservoirs, it’s especially important that the water doesn’t evaporate so that we can use it for electricity and irrigation. This makes these locations particularly attractive for floating solar panels. It’s also easier to wash the panels, since you can just use the water they’re floating on to rinse them off with a brush.
SANJITH S. SHETTY