How Solar Farming Helps Agriculture

WASHINGTON – For 31 straight days last summer, temperatures in Phoenix reached or exceeded 110 degrees, the longest such streak on record. The searing Arizona heat dehydrates crops and evaporates water that the state must conserve.

One way to solve this problem is to create a shadow.

With solar panels, farmers can protect their crops, save water and lower their energy bills all at the same time – and some are doing just that with the support of federal programs designed to promote this sustainable farming method.

Photovoltaic panels are placed above the crops, harnessing solar energy and providing valuable shade.

“The solar arrays… will help shade and reduce water usage and improve water efficiency, which is very important in places like New Mexico and Arizona,” said Derek Whitelock, supervising agricultural engineer for the U.S. Department of Agriculture. “The plants don’t need as much sun as they do here in the West.”

Three-quarters of Arizona’s water goes to agricultural irrigation, according to the Arizona Department of Water Resources. The Colorado River basin is in the first stage of water scarcity, requiring restrictions on agricultural users. In the face of ongoing drought, farmers are looking for new, sustainable farming methods.

The University of Arizona, in partnership with the U.S. Department of Agriculture, has established an agrophotovoltaic research center to study how solar farms can benefit Arizona.

“We’re saving a lot of water,” said Greg Barron-Gafford, a UArizona professor who led the initiative.

A study by Barron-Gafford found that when irrigated every other day, the plot with the agrivoltaic installation had 15% higher soil moisture than the neighbouring plot without solar panels.

Some plants actually produced more with less water. For example, cowpeas—also known as black-eyed beans—had a higher yield when grown in the shade of solar panels. Full sun required twice as much water, it turned out.

“With agrivoltaics, we’ve been able to get even more bean production because we’re now providing shade, which means the plants are less stressed,” Barron-Gafford said.

The nonprofit Growing Green has built a plot of land for an agrivoltaic installation on the grounds of Spaces of Opportunity, a 19-acre community farm in Phoenix.

His small 4.8-kilowatt system generates about 40% of the farm’s total energy needs, with a projected reduction of 17,000 pounds of carbon per year compared to conventional energy production, said Sarah Bendok, founder of Growing Green, and with more panels, “it can basically power everything on the farm. They have a cold room where they store all the produce they want to store, lighting, bathrooms, basically everything in there.”

“It’s a really great feeling … to create a project that can benefit the community, the crops and the environment as a whole,” she said.

Many federal programs aim to promote sustainable farming practices, especially in conjunction with renewable energy systems. The Rural Energy for America program sent $63 million to Arizona between 2018 and 2022.

REAP provides loans and grants to farmers who invest in clean energy. Funding comes from the Inflation Reduction Act signed by President Joe Biden in August 2022, a major tax reform bill that included incentives for clean energy and climate change mitigation.

Among the many other IRA provisions is a 30% tax credit for farmers who install solar panels.

The Gila River Indian Community began installing solar panels on the Casa Blanca Canal earlier this year, with $5.65 million in federal funding. Nearly 3,000 feet of the canal will be covered, saving water by reducing evaporation — and generating more than 1.31 megawatts of green energy, according to the U.S. Department of the Interior.