Geothermal Greenhouses Could Bring Citrus Groves to the Midwest

Citrus groves are the stuff of dreams for this midwestern lady! We’re lucky to have some lovely peaches and cherries come summer, but oranges and lemons? Not a chance. Brutal winters and cold temperatures just don’t fit the bill for a juicy grapefruit to roll from the tree to my bowl. But thanks to the efficient nature of geothermal greenhouses, that could soon change!

Greenhouses are a great idea when it comes to extending a crop’s growing season, but they’re not entirely without fault. Of course, an obvious perk of eating locally is the reduction in resources required to produce said produce. But greenhouses, unfortunately, can have monstrous bills when it comes to maintaining an acceptable temperature for growth — a fact which is exaggerated when the fruits and vegetables in question prefer warmer temperatures.

So, clever farmers began to wonder: Why not tap into a free and abundant source of heat — the Earth? Twenty years ago, Russ Finch designed and built an incredible greenhouse that does just that. The plans include a foundation that sits four feet below ground level, a roof that slants toward the sun, and a series of plastic tubes.

Thanks to the sunlight, his Greenhouse in the Snow reaches temperatures well into the 80s during the day. But at night, the temperature is only kept above dangerous levels, thanks to a smart system of plastic tubes buried underground. Air circulates from the greenhouse, through the soil, and back again — eradicating the need for any external heaters. Finch says this system keeps his energy bill down to an unbelievable $1 a day!

His greenhouse, located in Nebraska, is brimming with lemons, oranges, figs, and grapes. He even sells the construction plans for those who might be interested in building their own. Unfortunately, the green thumb is not included.

→ Read more: Citrus In The Snow: Geothermal Greenhouses Grow Local Produce In Winter from The Salt, NPR