By John Lovett
University of Arkansas Division of Agriculture
Electricity and water don’t usually mix, but technological advancements in floating solar arrays open the potential to generate electricity while decreasing impacts on farm irrigation reservoirs and agricultural land.
Michael Popp with the Arkansas Agricultural Experiment Station is undertaking a new research project to test solar arrays on the reservoir at the Rice Research and Extension Center in Stuttgart.
“The goals are to not convert agricultural land to solar panel use, save irrigation water and create a synergy between utility companies, solar investors, farmers and policymakers,” said Popp, the Harold F. Ohlendorf Professor of Farm Management in the department of agricultural economics and agribusiness for the experiment station and the Dale Bumpers College of Agricultural, Food and Life Sciences at the University of Arkansas.
The experiment station is the research arm of the University of Arkansas Division of Agriculture.
Floating solar systems are also not visually intrusive when compared to traditional land-based photovoltaic systems, Popp said, because the embankments of the reservoir serve as a barrier to block sight of the systems.
Ryan Loy, an assistant professor and extension agricultural economist with the Division of Agriculture, recently joined Popp to talk about the project in an episode of the “Morning Coffee and Ag Markets” podcast for the Fryar Price Risk Management Center of Excellence.
Public perception survey
Popp and his collaborators are currently surveying Mid-South households and farmers on their perceptions of floating solar arrays and their willingness to pay for not diverting agricultural land to solar. The survey is set to expire on May 15.
The survey is available online.
Collaborators on the project, which is funded by Popp’s endowed chair position and the Division of Agriculture, include Chris Henry, professor and water management engineer, and Yi Liang, associate professor emeritus — both with the department of biological and agricultural engineering — and a cadre of graduate and undergraduate honors students.
Anchors aweigh
At the Rice Research and Extension Center, anchors have been placed for buoys to hold the 70-kilowatt, 96-panel floating solar array on about 0.1 acre of a 40-acre reservoir, along with 24 more panels on the reservoir embankment. The panels are expected to be installed in May, Popp said.
Although used in other parts of the nation and world, the research project will help determine economic feasibility within Arkansas, as well as practical operation and maintenance routines of a floating solar array for the unique characteristics of Arkansas. For example, Arkansas’ Delta is situated in the Mississippi Flyway, and Popp would like to see how migratory birds may react to the floating solar array.
The system will also provide a platform for new areas of research for graduate students in agricultural economics and agricultural engineering.
Potential benefits of floating solar
In addition to not taking up farmland for solar energy, Popp said the benefits of floating solar systems include a reduction of water evaporation by 25 to 50 percent, depending on the amount of coverage over the water body.
It remains to be definitively seen on smaller systems, Popp said, but by blocking light on the water, the floating panels may also reduce algal growth that fouls irrigation equipment.
Because floating solar panels are installed at a lesser angle than land-based systems, a 2020 study in Brazil also suggested less area is needed to produce the same amount of electricity.
“Our calculations suggest that of the available surface areas of water and embankments on irrigation reservoirs, it would require approximately 2.2 to 2.6 acres per megawatt,” Popp said.
That’s about half as much as land-based systems, which require about 5.5 to 9 acres per megawatt because of shading issues and the need to manage vegetation.
“Land installations tend to have a larger surface area footprint,” Popp said. “Not only are we not using agricultural land, but we’re also using less surface area per megawatt.”
Driving forces of solar on farmland
Solar land leases have become a financially attractive proposition to farmers in relation to what they could get from leasing it to a tenant farmer, Popp said. Utility-scale solar installations were projected last year to occupy about 0.2 percent of Arkansas’s 13.7 million acres of agricultural land, rising to an estimated 1.7 percent of cropland in select counties.
With preference for land-based solar arrays given to cleared, level and well-drained land, parcels commonly displace cropland near transmission stations but can also be found on marginally productive farmland, Popp said.
A solar land lease can range from about $450 to as much as $2,500 an acre. Comparatively, cash rent per acre for tenant farmers in Arkansas has averaged about $50 an acre for non-irrigated cropland, $150 for irrigated cropland, and $20 for pasture, according to a 2024 report by the U.S. Department of Agriculture’s National Agricultural Statistics Service.
To learn more about ag and food research in Arkansas, visit aaes.uada.edu. Follow the Arkansas Agricultural Experiment Station on LinkedIn and sign up for our monthly newsletter, the Arkansas Agricultural Research Report. To learn more about the Division of Agriculture, visit uada.edu. To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit uaex.uada.edu.
About the Division of Agriculture
The University of Arkansas Division of Agriculture’s mission is to strengthen agriculture, communities, and families by connecting trusted research to the adoption of best practices. Through the Agricultural Experiment Station and the Cooperative Extension Service, the Division of Agriculture conducts research and extension work within the nation’s historic land grant education system.
The Division of Agriculture is one of 20 entities within the University of Arkansas System. It has offices in all 75 counties in Arkansas and faculty on three system campuses.
Pursuant to 7 CFR § 15.3, the University of Arkansas Division of Agriculture offers all its Extension and Research programs and services (including employment) without regard to race, color, sex, national origin, religion, age, disability, marital or veteran status, genetic information, sexual preference, pregnancy or any other legally protected status, and is an equal opportunity institution.
