Pennsylvania greenhouse stays warm by storing heat underground

Summary

Podcast Summary: Climate Connections

Episode: Pennsylvania greenhouse stays warm by storing heat underground
Date: May 15, 2026
Host: Dr. Anthony Leiserowitz (Yale Center for Environmental Communication)

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Overview

This episode of Climate Connections spotlights an innovative heating method for greenhouses designed to be both cost-efficient and climate-friendly. Host Dr. Anthony Leiserowitz explores how a Pennsylvania farmer, Tim Clymer, uses an underground "climate battery" system to store and reuse heat, reducing reliance on fossil fuels and cutting greenhouse gas emissions. The episode serves as both a practical solution for cold weather farming and an inspiring example of climate-conscious agriculture.

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Key Discussion Points & Insights

Traditional Greenhouse Heating and Its Drawbacks

• Problem Identified: Many greenhouses in colder climates are heated by burning propane, which is expensive and emits greenhouse gases.
• Climate Impact: These fossil fuel systems contribute to global warming, an issue Tim Clymer is keenly aware of.
  • Quote: “I see the exhaust coming out there, and I know how much fuel they're burning through.”
    — Tim Clymer, 00:24

The “Climate Battery” Greenhouse Solution

• How it Works:
  • On sunny days, fans circulate warm air from the greenhouse into underground tubing, heating up the soil.
  • When outdoor temperatures drop, the system reverses: fans pull the stored heat from the soil back into the greenhouse, keeping it warm.
• Thermal Storage Explained:
  • Soil around the tubing acts as a large battery, but for heat instead of electricity.
  • Quote: “We're using the soil as a big thermal battery, so regular batteries store electrical energy. We're storing heat energy in the soil.”
    — Tim Clymer, 00:49

Real World Results & Expansion of the Idea

• Long-Term Use: Tim Clymer built his climate battery greenhouse nine years ago and has had continued success.
• Crops Grown: The system supports crops such as figs, Meyer lemons, satsuma mandarins, and other citrus fruits that typically require warm climates.
• Scaling the Solution:
  • Clymer’s success led him to start a greenhouse design and consulting company, aiming to help more farmers adopt this low-carbon heating method.
  • Mission: Sharing his experience to encourage widespread adoption of climate-friendly agricultural innovations.

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Notable Quotes & Memorable Moments

• On Observing Conventional Greenhouses:
  "I see the exhaust coming out there, and I know how much fuel they're burning through."
  — Tim Clymer, 00:24

• Explaining the System:
  "We're using the soil as a big thermal battery, so regular batteries store electrical energy. We're storing heat energy in the soil."
  — Tim Clymer, 00:49

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Important Segments & Timestamps

• [00:01] Introduction — Context for greenhouse heating and climate issues.
• [00:24] Tim Clymer discusses the problem with traditional greenhouses.
• [00:29] Description of the underground climate battery system.
• [00:49] Explanation of the thermal storage concept.
• [00:59] Discussion of crops grown and Clymer’s outreach to other farmers.

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Takeaway

This episode highlights an actionable, hopeful step in making agriculture more sustainable. Tim Clymer’s climate battery greenhouse model demonstrates how innovation can help both the environment and farmers’ bottom lines, showing listeners that practical climate solutions are within reach.

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For more stories and solutions in climate action, visit climateconnections.org.

Transcript

[A]

I'm Dr. Anthony Liesiewicz, and this is Climate Connections. Heated greenhouses let farmers grow some crops year round, even in cold climates. But oftentimes the heat comes from burning propane, which is expensive and warms the climate. Tim Clymer, co owner of Threefold Farm in Pennsylvania, says he'll sometimes drive by a commercial greenhouse.

[B]

I see the exhaust coming out there, and I know how much fuel they're burning through.

[A]

So he built what he calls a climate battery greenhouse instead. On warm, sunny days, when the greenhouse naturally heats up, fans blow warm air into a network of underground tubes that heat the soil around them. Then, when it's cold, the system works in reverse. Fans draw the heat out of the earth and back into the greenhouse.

[B]

We're using the soil as a big thermal battery, so regular batteries store electrical energy. We're storing heat energy in the soil.

[A]

Limer built his greenhouse nine years ago and uses it to grow figs, Meyer lemons, satsuma, mandarins, and other citrus fruits. He also started a company that sells greenhouse design plants and consults with other farmers to share what he's learned so more farmers can invest in this approach for heating greenhouses without heating the climate. Climate Connections is produced by the Yale center for Environmental Communication. To learn more about climate change, visit climateconnections.org.