Agrivoltaics: A New Land Use Model in the Shadows of Solar Arrays
Agrivoltaics: A New Land Use Model in the Shadows of Solar Arrays
Many ground-mounted photovoltaic plants are already developed with “low impact” operating models and provide benefits for the soil, the ecosystem, the community and agriculture. The rapid growth of the global solar power industry presents tremendous opportunity for low impact operating models to become integrated from project design through decommissioning. Introducing InSPIRE, a project from the National Renewable Energy Laboratory (NREL) that, together with Enel Green Power, is bringing about environmental sustainability in our solar plants of the future.
At Enel Green Power’s Aurora solar plant, in Minnesota, USA, a group of yellow helmets is just visible in the tall grass. Moving among the plant’s photovoltaic (PV) solar panels, they’re gathering soil samples, analyzing plants and vegetation and observing the pollinator insects circling overhead.
They are researchers from the National Renewable Energy Laboratory (NREL), the laboratory of the US Department of Energy dedicated to research on renewable energy, and – together with Enel Green Power – they’re hard at work to create the “low-impact” solar plants of tomorrow.
Solar plants are undoubtedly an irreplaceable source of sustainable energy. However, they can also have an impact on soil and can take up space used for agriculture.
Is it possible to design solar plants that have a low negative impact, or even a positive impact, on the land?
The Value of the Land
By 2030, solar plants in the United States could occupy 800,000 hectares of land (about 1,976,844 acres). That’s almost 10 times the size of New York City.
In addition to being home to solar panels, in the future this enormous area can be used to improve soil fertility, retain water, nourish native species, produce food and make the plants themselves even more efficient.
At three of its plants in Minnesota, Atwater, Chisaco and Eastwood , Enel Green Power is hosting NREL researchers working on InSPIRE, an acronym for Innovative Site Preparation and Impact Reductions on the Environment. The project studies how we can grow native plants and vegetables and favor pollinator insects.
“The development of low-impact solar, which includes the presence of native vegetation and pollinator insects, provides several advantages for the ecosystem and for operational efficiency, and favors positive relationships with stakeholders.”
– Marcus Krembs, Director of Sustainability, Enel Green Power North America
Native Bees Doing Good for the Environment
In the past, the construction of a large-scale solar plant required heavy modification of the soil, including levelling it and covering it with gravel or turf.
With the “low impact” solar designed by NREL and Enel Green Power, constructing solar energy plants is less invasive. After the installation of PV panels, native plants, flowering and other prairie grasses are planted to create a habitat for native bees and other pollinator insects, which benefits the surrounding ecosystem.
Native bees, as well as butterflies and moths, transport pollen from one flower to another, allowing for pollination and the formation of fruit. This is an advantage for nearby farms and pollinator-dependent crops, such as soy, which can benefit from the sustainability of a solar plant for more than just renewable energy.
“It’s surprising how quickly word spread about this important project. Every state we work with wants more information about this kind of approach.”
– Jordan Macknick, Head Researcher for the InSPIRE project
The presence of native plants is a benefit for soil quality as well. Compared to grass and gravel, local flora retains water better, both in the event of heavy rain or drought, and improves the health and productivity of the land.
What’s more, some native vegetation requires less intense maintenance and mowing compared to traditional approaches, which helps with maintenance costs.
Agrivoltaics is the Future
In Minnesota and six other US states, the InSPIRE team started cultivating nine different seed mixes and studying their impact on soil temperature and humidity. At the same time, researchers are trying to understand if the presence of plants will influence energy production and maintenance over the years.
And their goals are even more ambitious. In Massachusetts, Arizona and Oregon, researchers are studying how “low impact” solar plants can incorporate agriculture.
Although it might seem strange at first, the shadows from the solar panels allow for a more efficient use of water, in addition to protecting the plants from the sun during the hottest hours of the day.
Researchers have named this new method of cultivation agrivoltaics, a fitting neologism that combines agriculture and photovoltaics.
Of course, as the researchers themselves admit, agrivoltaics can’t be used for large-scale monoculture agriculture, where enormous land surfaces and heavy machinery are needed. Still, early research results suggest that in warmer areas and over time, solar panels can be used to increase the yield of certain crops.
In Arizona, for example, the harvest of cherry tomatoes grown in the shade of solar panels reduced the demand for water and more than doubled the yield.
Researchers believe that in the future, agrivoltaics may be able to help compensate for the impact of extreme weather conditions, reducing water use, increasing food production and limiting the negative effects of heat on solar panels.
For farmers, the mix between solar generation and cultivation could ensure a constant additional source of income and supports long-term, positive stakeholder relations.
The Future of Solar Energy, According to Enel Green Power
As recognized by the Sustainable Development Goal (SDG) number 17 in the UN’s 2030 agenda, Enel Green Power is aware that sustainability can be reached only if the private sector, public sector and research centers, like NREL, work closely together toward an ecosystem of innovative solutions.
In addition to projects like InSPIRE, Enel Green Power is working on its PV Environmental Mitigation, aimed at improving the environmental impact of its solar plants, calling on start-ups, universities and innovators.
And that’s not all. Already this year, Enel Green Power has implemented the Sustainable Plant Model, a project to make O&M plant operations more sustainable, at 182 plants. This covers 2/3 of our entire production, reducing environmental impacts, maximizing social benefits and plant efficiency. The goal is to cover the entire fleet by 2020.
With these projects, Enel Green Power is committed to making its solar plants more and more sustainable, a goal that can benefit biodiversity, the community and agriculture.