The Rise of Dual-Use Solar

The politics of energy in the US lately seem to have dimmed the immediate-term prospects of solar power. But squint a little and you can see a sunnier vision for this form of renewable energy. In truth, photovoltaic technology continues to grow ever more cost-effective as a means to address not just climate change but energy needs in general. And because demand for solar energy means demand for space to situate solar panels or panel arrays, recent years have seen a rise in innovative dual-use solar projects, which combine space for clean electricity generation with complementary uses.

One prominent—and promising—example is the rise of agrivoltaics: using elevated solar panels on agricultural land, allowing farm animals to graze or crops to grow among panel rows. Globally, the deployment of agrivoltaic projects has grown significantly in recent years, from generating a collective 5 megawatts of peak energy in 2012 to 14 gigawatts in 2021. (For context, one gigawatt is roughly enough to simultaneously power every home in a city the size of San Francisco.)

The strategy caught on first in European and southeast Asian countries with limited arable land, as a means of achieving renewable energy targets without sacrificing agricultural capacity or food security. The concept of combining solar energy generation with agriculture dates back to at least the 1980s, and the term “agrivoltaics” was coined in 2011 by French researcher Christian Dupraz at the Institut National de la Recherche Agronomique (INRAé) in studies exploring the benefits of combined land use.

In Japan, pioneer Akira Nagashima analyzed crop growth below photovoltaic modules within the first research pilot systems in 2004 and promoted the technology as “solar sharing.” Thanks in part to governmental support beginning in 2012, Japan now counts more than 3,000 small-scale agrivoltaic systems. In 2014, China installed the first large-scale agrivoltaic systems and remains the country with the largest installed capacity in the world. In Europe, the first prototype of a suspended mobile solar panel system was built in Austria in 2007. France was the first European country to systematically support agrivoltaics in the late 2010s; Germany, Italy, and others have since developed their own programs.

The US has been slower to adopt the practice, but a map maintained by the National Lab of the Rockies InSPIRE team shows more than 600 such projects around the country today. As recently as ten years ago “there wasn’t a map, and there was none of this happening” in the US, says Matthew Sturchio, a faculty affiliate in ecology at Colorado State University whose research focuses on ecovoltaic projects more broadly. Some of Sturchio’s recent research focused on grassland management in the Front Range of Colorado, finding that shade from raised solar panels can mitigate the effects of chronic aridity, as well as unusually hot and dry seasons. Studies by researchers in Arizona and elsewhere have similarly addressed the role solar can play in addressing arid climate impacts on crops and rangelands.

The configuration of ecovoltaic systems varies based on their goals and context. Some designs feature widely spaced panel rows that allow tractors and farm equipment to operate between them. Others employ elevated mounting structures that raise panels high enough to leave room for grazing livestock or tall crops beneath. Fixed-tilt systems offer simplicity and lower costs, while tracking systems that follow the sun’s path can optimize both energy generation and crop light exposure throughout the day. Research from the University of Arizona found that tomatoes, peppers, and other vegetables grown under solar panels showed increased production compared to traditional full-sun cultivation, while using significantly less water.

The most popular application of agrivoltaics in the US involves grazing livestock beneath and around solar panels. Of 250 or so projects involving livestock in 2025, more than 230 include sheep, according to Inside Climate News (resulting in the irresistible term “lambscaping.”) The American Solar Grazing Association estimates US solar sites now host about 5,000 sheep.

The steady proliferation of dual-use efforts underscores the growing recognition that addressing developing renewable energy is partly a land use issue. “Our responses to climate change, most of them, to some degree implicate land,” notes Patrick Welch, associate director of urban sustainability at the Lincoln Institute, and even in the context of renewables not all those implications are wise. “You see examples of forests being clearcut to then place a large-scale solar farm,” he continues, or solar displacing agricultural areas. “So you’re taking away land that was providing a function.” And those instances can also spark public opposition to renewable projects.

The upshot has been increased emphasis on making the most of land and other surfaces that don’t involve displacement. Welch points to geospatial analysis by the Chesapeake Conservancy’s Conservation Innovation Center (CIC) that concludes that sites like rooftops, parking canopies, industrial lands, and degraded properties could add up to enough space to support Maryland’s renewable energy goals. “Local context matters a lot,” Welch says, “but there are ways to resolve these conflicts over land use that are kind of more win-win.”

That goes beyond traditional agriculture projects. Grassland solar installations can also be havens for pollinators—the bees, butterflies, and other insects essential to agricultural productivity and ecosystem health; even neighboring farms could enjoy improved pollination levels that can boost crop yields. Several US states including Minnesota have developed pollinator-friendly solar standards and incentive programs.

Another dual-use solar application—dubbed “floatovoltaics”—deploys panels on pontoons atop reservoirs, irrigation ponds, and aeration basins at wastewater treatment facilities, generating clean energy without consuming land. The surrounding water cools the panels, which can increase their efficiency by several percentage points compared to ground-mounted systems in hot climates. Simultaneously, the panels shade the water surface, reducing evaporation—a critical benefit in drought-prone regions.

Studies suggest floating solar can reduce reservoir evaporation by 70 percent or more in covered areas, preserving substantial water volumes for irrigation or municipal use. In agricultural contexts, floating solar on irrigation reservoirs allows farmers to generate income from generating electricity while improving water conservation. Japan, South Korea, and China have become global leaders in this technology, with installations ranging from small farm ponds to massive reservoir-scale projects. As the technology matures and costs decline, floating solar is expanding into new markets, particularly in Southeast Asia and South America, where appropriate water bodies are available.

According to market researcher Exactitude Consultancy, the overall global floating-solar market was valued at approximately $8.7 billion in 2025 and is projected to soar to more than $75 billion by 2034. Other estimates vary, but the trend is toward growth. The Asia-Pacific region continues to lead global deployment; Japan makes up about 14 percent of the global market revenue in 2024, and the world’s largest installation is currently the Dezhou Dingzhuang Floating Solar Farm in China, which generates around 550 million kilowatt-hours of electricity per year, enough to power 50,000 homes. Dual-use projects have limits, of course. Agrivoltaic systems typically cost more to construct than conventional ground-mounted solar, requiring specialized mounting structures, increased spacing between panels, and other considerations that complicate design. Agricultural integration can also involve constraints that may reduce overall energy generation compared to single-purpose solar arrays.

Cost remains a challenge for floatovoltaics, too: Analysis suggests that the cost of energy from such systems may be around 20 percent higher than from ground-mounted photovoltaic systems, largely due to specialized flotation equipment. Still, the lower land acquisition costs and higher energy yields from water-cooled panels help offset those costs. And as deployment spreads and the technology matures, the cost premium should continue to decline.

Meanwhile, policy and regulatory frameworks haven’t always kept pace with new technology and new ideas, and adjusting these frameworks to recognize and reward dual-use approaches can be a challenge. But as energy demands continue to grow, and solar remains a key option, the benefits are undeniable. For example, life cycle assessment research focused on grazing has found that agrivoltaics produces 3.9 percent less emissions and 0.5 percent less energy demand compared to conventional photovoltaic systems and sheep grazing separately. “The point of ecovoltaics is looking at where you are in the world, and what is the type of ecosystem service that would be most useful on this landscape,” Sturchio says.

While some funding may be on hold for the moment, the larger trend is clear, he says. “No matter what the social opinion of solar is, it is happening and it is happening in large scale. So we all want to know what the best version of this is, if there’s a best version, what the trade-offs are, what the synergies are.” In Europe and Southeast Asia, some countries may end up using 10 to 20 percent of their agricultural land for dual-use projects.

Technological refinement will likely improve the economics and performance of these solar experiments. Semi-transparent solar panels that allow controlled light transmission, for example, could enable even more flexible agrivoltaic designs. Advances in mounting structures, panel efficiency, and agricultural techniques specifically adapted to solar integration also seem likely.

Politics notwithstanding, climate change will continue to pressure both energy systems and agricultural productivity. Given that dual-use solar projects offer a pathway that addresses both challenges, their future looks bright.

Rob Walker is the author of City Tech: 20 Apps, Ideas, and Innovators Changing the Urban Landscape and The Art of Noticing. More of his writing can be found at robwalker.substack.com.

Lead image: Sheep and solar panels coexist in a field in Germany. Credit: Frederick Doerschem via iStock/Getty Images Plus.