Clean energy accounted for more than two-thirds of the new US electrical generating capacity added during the first six months of 2022, according to data recently released by the Federal Energy Regulatory Commission (FERC).
Wind (5,722 megawatts) and solar (3,895 MW) provided 67.01% of the 14,352 MW in utility-scale (that is, greater than 1 MW) capacity that came online during the first half of 2022.
Additional capacity was provided by geothermal (26 MW), hydropower (7 MW), and biomass (2 MW). The balance came from natural gas (4,695 MW) and oil (5 MW). No new capacity was reported for 2022 from either nuclear power or coal.
This brings clean energy’s share of total US available installed generating capacity up to 26.74%. To put that in perspective, five years ago, clean energy’s share was 19.7%. Ten years ago, it was 14.76%.
FERC reports that there may be as much as 192,507 MW of new solar capacity on the way, with 66,315 MW classified as “high-probability” additions and no offsetting “retirements.”
The “high-probability” additions alone would nearly double utility-scale solar’s current installed capacity of 74,530 MW, while successful completion of all expected projects would nearly quadruple it.
Notably, FERC’s forecast predates President Joe Biden signing into law the Inflation Reduction Act, and that will likely ramp up solar growth even more.
In addition, new wind capacity by June 2025 could total 70,393 MW, with 17,383 MW being “high probability” and only 158 MW of retirements expected. Thus, installed wind capacity could grow by at least 12%.
“High-probability” generation capacity additions for utility-scale solar and wind combined, minus anticipated retirements, reflect a projected net increase of 83,540 MW over the next three years, or over 2,300 MW per month. That figure does not include new distributed, small-scale solar capacity or additions by hydropower, geothermal, and biomass.
SUN DAY Campaign’s executive director Ken Bossong, who reviewed and reported on the data, said in an emailed statement:
With each new monthly Infrastructure report from FERC, the prospects for renewable sources, especially solar and wind, brighten while those for natural gas, coal, and nuclear power continue to slide. By the end of this decade, the mix of renewable energy sources should constitute the largest share of the nation’s electrical generating capacity.
Companies like BlueWave are betting on it. But the technology has its critics.
In its 150-year history, Paul Knowlton’s farm in Grafton, Mass., has produced vegetables, dairy products, and, most recently, hay. The evolution of the farm’s use turned on changing markets and a variable climate. Recently, however, Mr. Knowlton added a new type of cash crop: solar power.
For Mr. Knowlton, a fifth-generation farmer and the current owner, it was an easy call. He had already installed solar panels to provide electricity for his home and barn. When a real estate agent came knocking to see if he was interested in leasing a small portion of his land for a solar array, “she planted the seed that I could do more,” Mr. Knowlton said.
Mr. Knowlton looked at several companies but was most impressed with BlueWave Solar, a developer in Boston that focuses primarily on solar installations and battery storage, which allows excess electricity to be fed to the power grid. Soon, two small parcels of largely unused land were home to low-to-the-ground panels that produce power. This year, Mr. Knowlton’s farm will go one step further: In a third parcel, solar panels will share space with crops so that both can thrive.
This approach is called agrivoltaics — a portmanteau of agriculture and voltaic cells, which transform solar power into electrical power. Also called dual-use solar, the technology involves adjusting the height of solar panels to as much as 14 feet, as well as adjusting the spacing between them, to accommodate equipment, workers, crops, and grazing animals. The spacing and the angle of the panels allow light to reach the plants below and have the added benefit of shielding those crops from extreme heat.
The electricity generated gets uploaded to the grid, typically through nearby substations. While some of the electricity may find its way to the host farm, the projects are devised to provide power for general use. And such solar installations provide an alternative source of revenue in the form of payments to landowners like Mr. Knowlton or a reduction in lease payments for tenant farmers.
BlueWave has focused primarily on designing the projects, then selling them to companies that build and oversee them. The Grafton project, on Mr. Knowlton’s farm, for example, is now owned by The AES Corporation, an energy company.
“Not only do agrivoltaics advance the clean energy imperative but they are critical to maintaining working farms,” said John DeVillars, one of BlueWave’s three co-founders and the chair of the board of directors.
Dual-use solar became of interest more than a decade ago because “big installations in the middle of nowhere aren’t going to solve all of our energy problems — transporting that energy can be very expensive,” said Greg Barron-Gafford, a biogeographer and an assistant professor at the University of Arizona. Farms in many parts of the country are in peri-urban areas, zones of transition from rural to urban land. Their proximity to high-use metropolitan areas makes open farmland particularly suitable for solar arrays, but in the past, without any coexisting agriculture, that sort of placement can set up a conflict over whether food or energy production should prevail.
In a study by AgriSolar Clearhouse, a new collaboration to connect farmers and other landowners with agrivoltaic technology, the installations were also shown to foster growth by shielding crops from increasing temperatures and aiding with water conservation. While the technology remains in its infancy in the United States compared with countries in Europe, where the technology has been used for over a decade, federal regulators, as well as academics and developers, are working to remedy that disparity.
Early results are promising, said Garrett Nilsen, the acting director of the Solar Energies Technologies Office of the U.S. Department of Energy. “There’s a project in Arizona where they’ve seen a threefold increase in crop yields when they are underneath this kind of system and up to a 50 percent reduction in irrigation requirements” because the panels provide shade, he said. Additionally, the plants under the panels release water into the air, which cools the modules, creating what Mr. Nilsen described as a “symbiotic relationship between the plants and the panels.”
BlueWave’s first project to go live is a 10-acre farm in Rockport, Maine — now owned and operated by Navisun, a solar power producer. Wild blueberry cultivars have been planted below solar panels, which will produce 4.2 megawatts of power; the project is estimated to produce 5,468 megawatt-hours annually — equivalent to the amount of power needed for roughly 500 U.S. households.
Unlike Massachusetts, Maine does not offer significant incentives for the use of solar power, so there was a 10 to 15 percent premium on costs when compared with similar projects, which BlueWave absorbed, Mr. DeVillars said. (That practice is consistent with the company’s status as a so-called B-Corporation, which requires a commitment to social and environmental goals.)
Other players are clearly seeing the potential of agrivoltaics: On May 12, Axium Infrastructure, an investment management firm, announced its acquisition of BlueWave. Trevor Hardy will remain as chief executive and Eric Graber-Lopez will continue as president, while Mr. DeVillars will become chairman emeritus.
Mr. Hardy said that the sale would allow BlueWave to expand so that it will own and operate, not just develop, solar installations and battery storage. Ultimately, he said, the sale “puts us in a stronger place for dual-use.”
“Farmers work on a long-term basis,” he continued. “It’s more compelling to drive up farm roads and sit with the owners at their kitchen tables and say that we develop, own, and operate the installation.” And the technology’s potential goes well beyond blueberries; agricultural uses have included vineyards and shrimp farming.
BlueWave is not the only agrivoltaics developer. According to the Fraunhofer Institute for Solar Energy Systems ISE, based in Germany, five megawatts of power were produced through these systems in 2012; by 2021, 14 gigawatts of power were generated in dual-use systems — roughly equivalent to the electricity necessary for approximately two million U.S. households annually, according to a spokeswoman from the Department of Energy’s technologies office. And the technology is evolving rapidly; in the few years since the installation at Mr. Knowlton’s farm, adjustable panels that can move to maximize the capture of sunlight, for example, have been developed.
“It doesn’t always pay to be a pioneer and it’s very challenging at times,” said Mr. Hardy, who grew up in a South African farming family. Finding suitable sites — where there is sufficient sun and proximity to a substation or other electrical infrastructure — can be difficult. Opposition from neighbors, especially where panels are visible from other homes or even the road, is not uncommon.
Indeed, BlueWave was one of several defendants named in a suit over a proposed plan for agrivoltaics in Northfield, Mass. A state court recently ruled that the neighbor had the standing to challenge the proposed development. One of the plaintiffs, Christopher Kalinowski, said that among his concerns were that his views would be obstructed and that “the area will lose farmland.” (Mr. Hardy declined to comment on the litigation.)
In addition, some chapters of the Audubon nonprofit environmental organization have been vocal about the technology’s potential effect on wildlife. Michelle Manion, the vice president of policy and advocacy for Mass Audubon, said that whileher organization supported renewable energy, including solar within farming operations, “we want to maximize the placement of ground-mounted solar on some of our lands that are the least ecologically sensitive first.”
And there are general concerns that even with dual-use solar panels, arable land may be lost, though BlueWave says that the land can be reverted to pure agriculture uses once the solar leases — typically 20 to 30 years — expire.
But one of the most significant obstacles is cost. The skyrocketing cost of steel has a direct effect on agrivoltaics’ emphasis on raising the panels 10 to 14 feet. “For every foot, you go up you need to go two feet into the foundation,” Mr. Hardy explained. “It’s a challenging industry when you think of what we need to do to reach climate goals. But we’re staying the course.”
Ultimately, though, everything depends on how the crops taste: If flavor or even appearance strays too far from that of traditional produce, the technology will be a hard sell. But in an early study, researchers at the Biosphere 2 Agrivoltaics Learning Lab at the University of Arizona found that tasters preferred the potatoes, basil, and squash grown with agrivoltaics. Beans, however, may take some time: The small sample of tasters preferred the traditionally grown version.
The Stanford panels, which feature a thermoelectric generator that harvests electricity, can only generate 50 milliwatts per square meter at night.
Scientists from Stanford University succeeded in making solar panels that continue to generate a small amount of energy at night, according to research published in the journal Applied Physics Letters earlier this month.
How do the panels work?
While most solar panels produce around 200 watts per square meter during the day, the Stanford panels can only generate 50 milliwatts per square meter at night.
The device, developed by Sid Assawaworrarit, Zunaid Omair, and Shanhui Fana, includes a thermoelectric generator that harvests electricity from the temperature difference between the PV cell and the ambient surrounding.
The thermoelectric generator also provides additional power during the day, according to the research.
The scientists stressed that standard solar panels can only produce power during the day and require substantial additional battery storage systems.
Harnessing the outgoing heat flow
Standard solar panels work by taking heat from the Sun and using the ambient surroundings of Earth as a cold sink and converting solar radiation into electrical power. However, radiative heat also flows from Earth to space, causing radiative cooling from objects. The outgoing heat flow is present both at night and day.
The researchers realized that they could use the outgoing heat flow to produce energy as well.
According to the research, the new device can be used to provide nighttime standby lighting and power in off-grid or mini-grid applications, but can also have a lower maintenance cost compared to battery storage. The team theorized that the cells can be improved to have better performance.