Iowa experiment tests potential to pair solar with carbon sequestration

As thousands of acres of Iowa farmland are eyed as possible sites for solar farms, a research project is getting underway to explore a new crop that could co-exist with this burgeoning source of power: carbon sequestration. The state’s economic development office last month awarded $297,000 to an environmental consultant to create a business model “for monetizing carbon capture on solar energy farms.”

Although solar energy production and “carbon farming” exist independently, the consultant, Mike Fisher, said he didn’t think they’ve been combined, as he has proposed. He will test his theory that the right combination of crops could stash significant amounts of carbon in the ground while enhancing the soil’s fertility. Both the landowner and the solar developer could benefit, he said, from the sale of credits for the sequestered carbon and the enhancements to the soil. 

The most common Midwestern crops — corn and soybeans — don’t sequester much carbon because they put most of their energy into producing above-ground “fruits,” said Randy Jackson, an agronomy professor at the University of Wisconsin. Perennials, which plow much more of their energy into roots, stash more carbon as a result. Pasture grasses, such as brome, direct carbon into just the top 12 inches or so, Jackson said.