This Geothermal Greenhouse Grows Oranges in the Snow

This man has figured out how to harness the heat of the Earth to grow citrus in the Midwest all year long

A former mailman has figured out how to grow citrus in Nebraska, all year long, with his specially designed geothermal greenhouse.

Typically, it’s impossible to find local produce in the northern half of the country this time of year, but a man named Russ Finch grows hundreds of pounds of fruit each year in his “Greenhouse in the Snow.”

Historically, the problem with greenhouses is they require a lot of energy to heat. While the sun keeps them hot during the day, electricity or gas are required to keep plants from freezing at night.

But Finch’s geothermal greenhouse uses the free heat provided by the earth to keep his fruits and veggies warm.

His “Greenhouse in the Snow” is fashioned after a “walipini,” or pit greenhouse. It’s floor is  4 feet below the Earth’s surface with a roof slanted toward the south to catch as much sun as possible.

The temperature inside can reach well into the 80s during the day, but drops dramatically at night. That’s when Finch relies on geothermal heat.

Instead of propane or electric heaters, warm air blows out of perforated plastic tubing that is partially buried underground. The air is moved by a single fan.

“All we try to do is keep it above 28 degrees in the winter,” Finch told NPR. “We have no backup system for heat. The only heat source is the Earth’s heat, at 52 degrees at 8-foot deep.”

The system is so self-sufficient, Finch has got his energy costs down to about $1 a day, for a green house that produces hundreds of pounds of fruit each year.

“There have been hardly any successful 12-month greenhouses on the northern High Plains because of the weather,” he says. “The cost of energy is too high for it. But by tapping into the Earth’s heat, we’ve been able to drastically reduce the cost.”

In the video above, Finch boasts about his juicy Valencia oranges.

“These are the trees they’re losing in Florida now, because of the greening disease,” he says.

“We can grow them cheaper on cheaper land … without the transportation costs.

Finch makes some of his living selling fruit at local farmers markets, but his main business is selling the design for his greenhouse. So far, 17 of them have been built in the U.S. and Canada. One of those is at a high school in Nebraska, where students grow tomatoes, cucumbers and other vegetables to serve in school lunches.