Use of Underground Air for a Heating and Cooling Energy Source on Jeju Volcanic Island of Korea

Underground air on Jeju Volcanic Island, Korea, offers a stable and energy-efficient alternative for heating and cooling, with temperatures ranging from 15°C to 19°C (median 17°C) year-round. This stability contrasts sharply with ambient air temperature fluctuations and leverages the island's abundant vesicular basalts, which facilitate underground air extraction. As of 2007, 63 such systems were in operation, primarily serving greenhouses where they significantly reduced energy costs and boosted crop production due to the high CO₂ content in the extracted air. Despite these advantages, challenges remain, including public concerns about groundwater contamination from boreholes and a lack of standardized regulations or technical expertise for optimal system design. While underground air systems show promise as a renewable energy source, their sustainable adoption hinges on addressing these issues.

Lee, J.-Y., & Choi, H.-M. (2012). Use of Underground Air for a Heating and Cooling Energy Source on Jeju Volcanic Island of Korea. International Journal of Green Energy, 9(7), 597–611. https://doi.org/10.1080/15435075.2011.625584