What Is a Solar Farm?

Solar Farms Are Coming to Rooftops, Parking Lots, and Even Landfills

With the push toward clean energy in the United States and abroad, there’s a lot of talk about solar farms. But what are solar farms, how are they constructed, and what are the advantages of this kind of technology?

The term “solar farm” may conjure images of fields with rows of solar panels, much like rows of any agricultural crop. And that’s exactly what many solar farms look like. But these projects take other forms, too, especially in areas where land comes at a premium or where land isn’t suitable for other uses.

‍What is a solar farm?

Solar farms are large-scale solar arrays — sometimes called photovoltaic power stations, solar parks, solar power plants, or solar projects — with photovoltaic panels that convert sunlight into electricity that is supplied to a power grid.

Beyond that definition, though, solar farms take many different forms. One common type is the ground-mounted solar farm, like the one Altus Power owns and operates in Kapolei, HI, a project that ranks as Hawaii’s first large-scale community solar array and delivers power to the Hawaiian Electric grid. “We’re excited the shared solar program is taking root and opening up to residential customers who haven’t been able to install private rooftop solar,” Lani Shinsato, co-director of customer energy resources at Hawaiian Electric, said in June 2023, when Altus announced the project. “Providing customers with options is critical, and shared solar projects like this will allow subscribers to reduce their energy bill and take part in the state’s clean energy transition.”

‍Where are solar farms built?
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Ground-mounted solar farms feature photovoltaic panels installed either at a fixed tilt or with solar trackers that move the panels to follow the Sun’s arc across the sky. These farms can be built on farmland, sometimes co-existing with agriculture in a practice called agrivoltaics. Such dual-use solar projects can provide benefits to both solar and agricultural industries and can involve crops, livestock, and pollinator habitats existing underneath or adjacent to solar panels, according to the U.S. Department of Energy’s Office of Energy Efficiency & Renewable Energy. And the German startup Next2Sun is installing bifacial photovoltaic panels vertically to allow agriculture and solar to coexist in places where land is limited, as IEEE Spectrum reports.

Solar farms can also turn brownfields into so-called “brightfields.” Brownfields are areas of land impacted by the detected or presumed presence of hazardous substances, pollutants, or contaminants, and there are more than 450,000 of these sites in the United States, according to the EPA. Brownfields like landfills can be used for solar farms, and in 2021, the local governments in the United States announced 21 landfill solar projects that would generate a combined 207 megawatts of energy, 10 times the amount generated from landfill solar projects the year prior, according to TIME.

Speaking of land re-use, rooftops are another popular site for solar farms. Altus Power’s Zerega community solar project, for example, generates electricity from the rooftop of a large self-storage facility in New York City. And in another innovative re-use of land, parking lots can host solar farms with carport canopies outfitted with photovoltaic panels. These canopies not only generate electricity for the local power grid, but they also provide shade for the cars beneath and can even provide electricity for EV vehicles. Another Altus Power project is a 2.7-megawatt solar array installed on parking canopies at Morgan Stanley Wealth Management’s campus in Purchase, N.Y. That project is expected to save the carbon equivalent of burning more than 2.9 million pounds of coal or more than 4,700 barrels of oil, compared to utility power. Morgan Stanley will receive 40% of the electric power generated by the array, and the rest will be offered to the local community.

‍What are the benefits of solar farms?
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Solar farms can impact wildlife habitats in myriad ways, but scientists told Vox in 2021 that it’s not a zero-sum game — they’re looking for ways to prioritize both solar energy and biodiversity. Solar projects can be wildlife corridors and protected habitats for native plants and pollinators, for starters. “Solar can be a net benefit in terms of restoring a native habitat and improving ecosystem services, like storm water control and carbon storage and sequestration,” Leroy Walston, an Argonne National Laboratory landscape ecologist researching the relationship between renewable energy and the environment, told Vox.

Another benefit: Solar farms generate not just electricity but jobs. In fact, a 2023 U.S. Department Energy report touted that solar employs the most workers of any electric power generation technology, with 12,000 new solar jobs in 2022, representing a 3.7 percent growth.

Perhaps the biggest benefit is that solar farms, like residential solar, provide a renewable type of electricity that can reduce or even replace our reliance on electricity derived from fossil fuels. As of the second quarter of 2022, a megawatt of solar electricity could power an average of 173 homes in the United States, according to the Solar Energy Industries Association.

In 2023, solar energy provided 165 billion kilowatt-hours, or 3.9% of the electricity generated by utility-scale facilities in the United States, according to U.S. Energy Information Administration data. In all, renewable energy — which also includes hydro, wind, biomass, and geothermal power — made up 21.4% of that energy production, compared to the 60-percent share generated from fossil fuels.

As the United States works toward a clean energy future —  and as 23 states progress toward their goals of 100% clean energy — you can expect to hear a lot more about solar farms and innovations that allow solar farms to work in harmony with human development and the environment alike.