Picture and text from this New York Times article:
In Alaska, land is easy to come by. But energy and food are not.
So when the largest solar farm in the state, which can power 1,400 homes, was built two years ago, researchers wanted to test whether food could be grown between the arrays. The rows of panels on the 45-acre site are set 50 feet apart, much wider than at lower latitudes, and they collect solar power on both front and back in order to capture the maximum amount of summer sunlight as the sun dances across the horizon all day and all night.
This test case in Houston, Alaska, for combining food farms and solar farms, a practice called agrivoltaics, was designed as a model for other communities seeking energy and food security. Europe, which has ambitious climate goals and limited land, has been exploring high-latitude agrivoltaics in recent decades, but this is the first American project on an industrial-scale solar array.
“The purpose is to study how food and energy can be produced together, in a place where food and energy cost a lot of money,” said Glenna Gannon, an assistant professor at the University of Alaska Fairbanks who led the research. “Self-sufficiency is really important in Alaska.”
Although the project's funding is now in jeopardy, they have very promising data after just one growing season. Crops grown closest to the solar panels are noticeably larger and healthier.
The panels provide shade from intense sun, shelter from wind and heavy rain, they collect dew and rainwater, and they hold and emit heat longer than the surrounding earth--all beneficial for many crop species.
The hope is that this study can become a model for other high latitude locations pursuing agrivoltaics projects to meet food and energy needs.
Sheep living in pasture with solar panels benefit from shade in hot weather and more nutritious grass – and they stop weeds from growing on the panels.
Sheep living among rows of solar panels spend more time grazing, benefit from more nutritious food, rest more and appear to experience less heat stress, compared with nearby sheep in empty fields.
Earlier research suggested that agrivoltaic farms – which combine grazing animals with solar panels – offer more efficient renewable energy at lower overhead costs, as well as reducing wildfire risks. The latest findings show that the practice is also good for animal welfare, providing further evidence for a win-win situation, says Emma Kampherbeek, who carried out the work while at Wageningen University in the Netherlands.
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As for pasture quality, the nitrogen content was higher and carbon content lower in the solar panel fields, suggesting that the vegetation in this pasture – which was greener – was more nutritious and more easily digestible. That might be due to the reduced exposure to intense solar rays and to dew dripping off the panels, providing much-needed moisture, she says.
The results are likely to be even more pronounced in warmer seasons, she adds. Additional research is under way to analyse the data taken from temperature recordings during her study.
Sheep make good candidates for agrivoltaics because they are efficient foragers, keeping weeds off solar panels, and are small enough to pass under the panels, says Kampherbeek. And, unlike goats, they don’t chew the electrical wires.
The findings strongly suggest that solar power centres should be designed with a partner animal species in mind, she says.
Double harvest: Vertical solar panels and crops thrive side by side
Imagine a field where solar panels and crops coexist—with no trade-off. It sounds like science fiction, but that's precisely what researchers from Aarhus University have now documented in a full-scale agrivoltaic pilot project in the Danish countryside.
"Our measurements show that wheat and grass-clover mixtures grow just as well between vertical solar panels as in open fields. At the same time, the panels produce electricity in a daily pattern that better matches energy demand. It's a win-win," says Marta Victoria, lead author of the study and Associate Professor at the Department of Mechanical and Production Engineering, Aarhus University.
"Even with some shade, the yield per square meter is almost the same. The crops don't seem to mind the presence of solar panels and they like the wind protection that they provide," explains Professor Uffe Jørgensen from the Department of Agroecology, Aarhus University.
Food, energy and water insecurity are ongoing concerns in East Africa, agrivoltaic systems address all three
This paper shows data for agrivoltaic systems in Tanzania and Kenya that generate power, produce food and conserve water, demonstrating their viability for both grid-tied agribusinesses and rural, off-grid projects.
The research indicates that certain crops such as maize, Swiss chard and beans thrived in the partial shade offered by solar panels.
“The positive yield results for Swiss chard have promising implications for growing nutritious crops with agrivoltaics. The control plot was sufficiently irrigated, with yields comparable to those in a rainfed study in South Africa, so drought stress does not explain the lower yields compared to the agrivoltaic plot.
“Instead, the partial panel cover is potentially creating a more suitable growing environment by protecting the crops from heat stress and/or UV damage,” the report said.
It notes that some crops produced more food using less water, “valuable in a region where water scarcity threatens food security, most farmers rely on rainfall for their crops, and climate change is likely to make rainfall less predictable.”
It indicates that, while food, energy, and water insecurity are ongoing concerns for many East African communities, agrivoltaic systems
Agrivoltaic systems represent a next-level approach to farmland use, in which solar panels can be deployed strategically to generate electricity while the farmer continues to use the land for pollinator habitats, grazing, and other agricultural activities.
One key challenge involves enabling farmers to calculate how the revenue from electricity generation can offset the loss of farming space needed for the solar panels. In addition, although the emerging consensus is that solar panels do not interfere with grassland productivity, they do compete for sunlight with other crops, so productivity also has to be factored into the equation.
A research team from Germany’s Fraunhofer Institute for Solar Energy Systems has come up with a new calculating tool. The project focuses on apple orchards, with an eye on helping Germany achieve its renewable energy goals while optimizing apple production.
The focus on apples is particularly instructive because apples require different levels of light for optimal results throughout the growing season, from buds to blossom and fruition. The researchers also determined that Germany’s longtime experience in deploying hail-proof nets to protect apple orchards could help inform their research.
In addition to raw productivity, the study authors also indicate that an optimized agrivoltaic system can be tweaked to improve the quality of crops. They observe that “light quality, intensity, and duration profoundly affect a number of agronomic traits, including fruit ripening, coloration, and overall quality, which in turn influence marketability and consumer preferences.”
Solar fields turn out to be ideal for pollinators, too.
Excerpt from this story from The New Yorker:
We pulled off the two-lane highway and onto a short farm road, and then got out at an access gate along a wire fence that enclosed an eleven-acre field of solar panels. The reason we were there is that three years ago, when Encore Renewable Energy—a Burlington-based developer of solar arrays—set up the panels, it contracted with a nonprofit that the Kiernans started, called Bee the Change, to seed pollinator-attracting plants that are native to the area in the rows between them. The organization’s small crew tends more than twenty fields like this across the state, weeding and, at least once a year, mowing what they have planted so that it doesn’t grow so high it shades the panels. Most of the attention to “agrivoltaics”—use of one piece of land for both farming and for producing solar energy—has gone to more common agricultural practices, such as letting sheep graze between the panels. But at least fifteen states, including big players like Illinois, maintain solar-pollinator scorecards, which are used as accountability measures in the solar-development community. The theory is that we face two crises—climate change and the rapid loss of biodiversity—and that the same patch of land might be used to address them both.
The approach seems to be working. When the Kiernans are hired by a solar developer, it’s usually to plant on what was until recently a farm field; “the farmer has decided to take a dozen acres” and lease them to solar companies “to get a guaranteed income,” Mike said. Because the fields are typically monoculture and have been treated with pesticides for years, “the pollinator density is really low.” Mike uses a pollinator-counting method that involves walking on the margin of a field and counting unique pollinators for seven and a half minutes. Then a random-number generator tells him which row of solar panels to walk along, and as he walks he counts the pollinators he sees in seven and a half minutes, then adds the two numbers together. “On those abandoned farm fields, we might get a count of forty or fifty in fifteen minutes,” Mike said. “But now, once we’ve done our thing, you can see ten at a glance. You can see three hundred in fifteen minutes. You see a lot of them even this late in summer, during what we call a ‘dearth period.’ Wait till next month, when the asters come in!”
As the nonprofit’s name implies, their first tools were honeybees; they installed hives in solar fields. But, the more they learned about biodiversity, the more they wondered whether this strategy was actually the best for the environment. Honeybees are domesticated and are so persistent and numerous—more than thirty thousand can live in one hive—that, in Mike’s words, they “can put too much harvesting pressure” on the plants. There may not be enough nectar left behind for all the wild pollinators, a complication that spells peril not just for them but for the plants they’re particularly adapted to. “There are more than three hundred and fifty native bee species in Vermont,” Tawnya said. So they stopped placing hives and started installing native plants that attract wild bees.
“In New England, you’re often looking at five-megawatt projects, which means maybe twenty-five acres,” Farrell told me when we spoke by phone earlier this month. “We’re at four or five per cent of our electricity coming from solar now in this country. In order to hit the President’s target of forty-five per cent of our electricity by 2050, we have to grow. And that means we have to deliver the most visually appealing, environmentally responsible projects possible.” In 2020, his company pledged to build all their projects with some form of agrivoltaics. In many cases, that’s sheep grazing. “Not goats,” he said. “Goats will try to eat the wires between the panels, and also to jump up on the panels, which is not good for either one.” Sheep, though, appreciate the shade that the panels provide and are “some of the best asset managers we have in the business, mowing the grass for us. They do their job exceptionally well, and all they want is forage and water, which we can give them.”
Pollinators are even easier animals, though—once the plants have established themselves, they don’t need more than an occasional mow. “We think solar is a good neighbor,” Farrell said. “It’s clean, it’s quiet, and if it increases pollinators it’s helping the whole community.” And so—at a moment when new fossil-fuel-funded schemes are reportedly spreading disinformation about renewable-energy programs—“it can help reduce the friction. It can lower the hurdles to get over, which of course translates into dollars and cents.”
कृषी विषयी सर्व माहिती, नवीन संशोधन, शेती पूरक व्यवसायातील संधी आणि अशा प्रकारच्या सर्व नवीन माहिती *कृषिमित्र अॅग्रीटेक* सदैव आपल्या पर्यंत पोहचवण्यासाठी प्रयत्नशील राहील...
