An Alaska Solar Farm Produces Food, Too

In Alaska, land is easy to come by. But energy and food are not.

So when the largest solar farm in the state, which can power 1,400 homes, was built two years ago, researchers wanted to test whether food could be grown between the arrays. The rows of panels on the 45-acre site are set 50 feet apart, much wider than at lower latitudes, and they collect solar power on both front and back in order to capture the maximum amount of summer sunlight as the sun dances across the horizon all day and all night.

50 States, 50 Fixes is a series about local solutions to environmental problems. More to come this year.

This test case in Houston, Alaska, for combining food farms and solar farms, a practice called agrivoltaics, was designed as a model for other communities seeking energy and food security. Europe, which has ambitious climate goals and limited land, has been exploring high-latitude agrivoltaics in recent decades, but this is the first American project on an industrial-scale solar array.

“The purpose is to study how food and energy can be produced together, in a place where food and energy cost a lot of money,” said Glenna Gannon, an assistant professor at the University of Alaska Fairbanks who led the research. “Self-sufficiency is really important in Alaska.”

The experiment, funded by a $1.3 million grant from the Energy Department, was planned as a three-year project. The researchers received funds for one year of planning and one year of planting, but have not had a response from the federal government regarding money for next year. Similar federal research projects at state universities in Ohio, New Jersey and Arizona, have been paused. The Energy Department did not respond to a request for comment.

Even with only one season of data, the scientists were enthusiastic about what they could see in the rows of vegetables at harvest time.

“The plants that are closer to the panels are more protected,” Ms. Gannon said. “Ones farther away from the solar panels get more solar stress.” Too much sunlight can actually harm plants, and those with some shade can grow larger. At the same time, the solar panels hold heat that can extend the growing season.

The researchers focused on three plants known to grow well in cool Alaskan summers: potatoes, kale and spinach. “Potatoes have historically been a major agricultural crop in Alaska,” Ms. Gannon said.

The crops were planted in June and harvested in September. The research team set up a control plot away from the solar panels, as well as meteorological stations and monitors to track soil moisture and heat, leaf wetness and photosynthesis. Data from the solar cells included voltage, current and the temperature of panels near the crops. The Arctic is warming four times faster than the rest of the globe and the farming season in the north is extending in a way that scientists are just beginning to understand.

For these plants that grow well in shade, the solar panels offer protection from the sun during the long Alaska days.

The crops also provide economic benefits for the owners of the solar array, said Chris Pike, a former research engineer with the Alaska Center for Energy and Power, which is part of the university in Fairbanks. “It’s an income stream because farmers lease the land,” he said. “It also means that solar producers don’t have to remove the vegetation that grows up between rows of solar panels, and that can reduce costs.”

Turning the land cleared for a solar farm into arable land took work, and investment. It was originally part of a wide parcel of community land used for picking wild blueberries and lingonberries, and the land surrounding the solar farm still draws hundreds of locals, who freeze berries for the long Alaska winter.

The Energy Department grant made it possible to drill a well for irrigation, hire the local Knik Tribe to till the land, and bring in many tons of fertilizer.

The crops flourished. At the harvest in September, researchers weighed thousands of pounds of potatoes, kale and spinach, carefully logging each row and reserving specimens for study in the lab.

The bulk of the harvest went into boxes placed right outside of the gates of the solar farm. A note was posted on Facebook, inviting people in the community to help themselves.

Locals swapped kale soup recipes and loaded their cars with the free produce. Kaylene Tomaganuk was driving home from berry picking when she saw the cars lined up near the solar farm. She hopped out to get some free potatoes.

Back in the lab after the harvest, scientists carefully dried and weighed plant samples taken from the field to gauge the effects of proximity to solar panels. They cautioned that one year of data was not enough to draw conclusions. “There is a lot of year-to-year variability,” Ms. Gannon said. “Typically, you want an average of three years.”

Houston, about an hour’s drive from Anchorage, sits nestled between mountain ranges in the vast Matanuska-Susitna Valley, which has long been the agricultural center of Alaska. It was settled in the 1930s, when Franklin D. Roosevelt’s New Deal policies gave land to farmers willing to bring agriculture to the glacial-rich soils of the valley.

Even today, the Mat-Su Valley, as it is commonly called, produces much of the food Alaskans eat that is not brought in from outside the state. But in the last decade as the area’s population has swelled, 11 percent of that farmland has been lost, sold to developers building homes for people who commute to Anchorage for work.

Bill Campbell, a retired scientist and potato specialist for the state of Alaska, said that farms were increasingly under pressure. “Farmland is shrinking, but there’s been a recent movement, in the last five or six years, to protect it and not lose Alaska’s ability to grow its food.”

Energy and agriculture have always been intertwined in Alaska. The Matanuska Electric Association, a cooperative that powers all the homes and businesses in the valley, was founded in the early 1940s by farmers, in part because dairy farmers needed to keep their milk cold.

But Alaska is facing the prospect of an energy crisis, because the local natural gas deposits that power much of the region will be depleted in a few years. That means Alaskans would have to pay for imported gas, or go without power.

Despite this, new renewable energy projects have stalled in the state. Plans to expand the Houston site to generate 30 megawatts, from its current capacity of 8.5 megawatts, and to build a new, larger solar farm on the Kenai Peninsula have been effectively canceled by the investor, CleanCapital of New York.

“We were not able to come to an agreement with the utilities on the power contract,” said Thomas Byrne, the CleanCapital chief executive. “We want power purchasers to pay more; they want to pay less.”

Mr. Byrne recalled that at the 2023 ribbon cutting for the Houston site, which CleanCapital owns and operates, “everyone was excited about building more and more and more, but the cost to build these projects is high.”

Alaska’s darker months do not produce much solar energy. But in early April, when the snow is still deep and the sun returns, solar production jumps as sunlight reflecting on the white snow hits the backside of the panels.

“The bi-facing solar panels are key in Alaska,” said Christie Haupert, a research project manager at the Alaska Center for Energy and Power at the University of Alaska Fairbanks. “Thirty percent of the energy produced in some seasons can come from the back panel.”

Experts say that solar technology is still rapidly advancing as engineers identify new ways to maximize energy generation from the sun. And agrivoltaics is a young science.

“The National Farmers Union annual meeting had packed agrivoltaics sessions for two years in a row, including this March,” said David Gahl, the executive director of Solar and Storage Industries Institute, a nonprofit group that works to expand solar energy. “But we are seeing a focus that shifts from the federal government leading the way to states leading the way.”