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Solar on farmland

June 4, 2025 By EarthWise Leave a Comment

New studies have found that devoting a small percentage of U.S. farmland to producing solar power would benefit both the country’s energy system and its farmers.

Currently, about 46,000 square miles of farmland – about the area of Pennsylvania – is being used to grow corn to make ethanol. One study looked at the impact of using some of this land for solar power instead of corn ethanol.

Not much of all this farmland is close enough to electrical transmission lines to be practical for utility solar power. In fact, only about 1,500 square miles fits the bill. But if even this small fraction of the corn growing land was used instead for solar power, it would generate as much energy each year than from all of the farms growing corn for fuel.

Solar installations on farms are helpful for farmers as well. The land beneath the panels can be used to grow wildflowers that attracts the bees, wasps, and other insects needed to pollinate crops in the nearby fields. In addition, the solar arrays provide a steady income stream for farmers.

In some places, farmers can earn substantially more from leasing their land for solar than from growing crops. But a study of farms in California suggests that the best option is to do both. Farmers who both grow crops and host solar arrays can have more financial security than those who do just one or the other. The income from solar arrays is pretty predictable and is paid throughout the year. Income from crops can drop off from, for example, a seasonal drought, or from extreme weather events.

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To Help Growers and the Grid, Build Solar on Farmland, Research Says

Photo, posted June 9, 2016, courtesy of Matt Lavin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cleaning the grid can create messes

January 9, 2024 By EarthWise Leave a Comment

The electric grid is increasingly embracing renewable energy sources like solar and wind power as well as the energy storage systems that support them. These generation sources differ from traditional sources in that they produce direct current electricity rather than alternating current electricity. Our power grid runs on alternating current. Traditional generators produce alternating current that synchronizes with the grid. Wind and solar power connect to the grid using electronic power converters called inverters that produce the required alternating current.

All of this technical detail is something we don’t pay much attention to, except that the current state of inverter technology can lead to some problems that don’t exist with a fully synchronous power system.

The electric grid frequently experiences disruptive events like trees falling on powerlines, squirrels shorting out substation equipment, and so on. These things normally don’t cause widespread trouble, although there have been notable exceptions such as the massive Northeast blackout of 2003 triggered by an overloaded transmission line drooping onto foliage.

The issue with inverters is that they can shut down in the presence of certain disturbances to the grid. This has happened on a number of occasions and has exposed vulnerabilities that need to be addressed by the industry. Inverter-based resources currently constitute only a relatively small fraction of the grid, but that fraction is growing steadily and can have an increasingly widespread impact. The grid was built predominantly for synchronous generation, and it must be adapted and improved to assure the reliability that is required and expected. It is an issue that can’t be ignored.

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Renewables are cleaning the grid. They’re also messing it up

Photo, posted July 5, 2017, courtesy of Sue Thompson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar Parking Lots In France | Earth Wise

January 6, 2023 By EarthWise Leave a Comment

France has passed legislation that will require all parking lots with more than 80 spaces to be covered over by solar panels. This is part of a broader effort to put solar panels on vacant lots, empty land alongside roadways and train tracks, and even some farmland. The overall program would add 11 gigawatts of solar power to the French electricity grid.

The legislation applies to both new and existing parking lots. Owners of parking lots with more than 400 spaces would have 3 years to comply, while owners of lots with 80 to 400 spaces would have five years.

To produce 11 gigawatts of solar output, about half a percent of France’s urban land would need to be covered with solar panels. This is quite a bit, but not an insurmountable obstacle. Parking lots, however, could only provide a fraction of what is needed. It would take something like 8 million parking spaces covered with solar panels to produce that much power. That is probably at least twice as many as France has.

Several countries, most notably Germany, already have mandates for new construction to incorporate renewable energy. This includes solar panels, biomass boilers, heat pumps, and wind turbines. Many parking lots in southern Europe already have sunshades over them, which would make it pretty easy to install solar panels. This is much rarer in cooler countries.

France is pursuing this policy to reduce its dependence on nuclear power, which currently provides 70% of the country’s electricity. Apart from the general trend of opposition to nuclear power, reliance upon it during increasingly common droughts is problematic as the power plants require significant amounts of water to operate.

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France’s plan for solar panels on all car parks is just the start of an urban renewable revolution

Photo, posted February 11, 2008, courtesy of Armando Jimenez / U.S. Army Environmental Command via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.