Geoenergy for heating and cooling buildings

Using the earth as a thermal battery

Challenge

The carbon footprint of heating and cooling buildings, campuses, complexes, and more

The buildings where we live and work account for 39% of global energy-related carbon emissions.* Of this, a projected 15% come from heating and cooling buildings.** That’s about 6 gigatons of CO₂ annually. Today, fossil fuels are predominantly used for heating, but they significantly increase our carbon footprint. And hotter global temperatures, successive heat waves, and increased development in hot-climate countries are teeing up building cooling efforts for accelerated growth. So how can we measurably reduce the carbon footprint of heating and cooling buildings at scale?

*World Green Building Council, "Bringing embodied carbon upfront"
**World Economic Forum, "How to heat up - and cool down - climate innovation"

Photo peeking through back of open staircase in office building, two people walking up stairs

Solution

Using the earth as a thermal battery

About 70% of the thermal energy a building needs is actually available tens of meters below it—in the ground.

Unlike air temperature, ground temperature remains constant all year long. In the winter, heat can be extracted from the ground and supplied to the building, campus, facility, or neighborhood with the use of a heat pump system that lifts the temperature to match the requirements. In the summer, the building, campus, facility, or neighborhood can be cooled, and the extracted heat is returned to the ground.

The ground is then used as a renewable, local, and resilient thermal battery—transferring stored heat from the soil to the surface when it’s cold outside and then reversing the process when it’s hot. We call this geoenergy, a form of shallow geothermal energy.

An industry poised for growth

Typical geoenergy systems use a ground-source heat pump (GSHP) in which an underground heat exchanger circulates fluid through shallow, closed-loop wells. At the surface, a heat pump provides hot water for space heating or chilled water for cooling. Ground-source heat pumps are gaining traction, with the potential to reduce global carbon emissions by at least 500 million metric tons in 2030. With more than one‐sixth of global natural gas demand used for heating in buildings,* geoenergy is poised for growth as a more sustainable way to generate both heating and cooling.

*IEA (2022), The Future of Heat Pumps, IEA, Paris

Geothermal heat pumps use the constant underground temperatures as thermal storage to exchange temperatures efficiently, heating buildings in the winter (left) and cooling them in the summer (right). The earth plays the role of a thermal battery.

Outdoor seating area with central glass pyramid showing Celsius Energy geoenergy installation underground

Our approach

Reducing emissions takes a solution that is not only available to new constructions but also supports existing construction and renovations. Our Celsius Energy™ solution for heating and cooling buildings and campuses supports new and existing constructions. And leveraging SLB's extensive knowledge of the subsurface and automated technology, we help meet global goals for reduced emissions.

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