The world needs more sustainable solutions for heating and cooling that reduce energy consumption and CO2 emissions. Part of the solution could come from ‘geoenergy’ or shallow geothermal heating and cooling technologies, which use the Earth as a type of thermal battery.
Related: Energy explained: What is geoenergy?
Cindy Demichel, geoenergy expert and CEO of geoenergy solutions provider, Celsius Energy, breaks down this decarbonized heating and cooling alternative, touching on common misconceptions in the market today and the long-term economic benefits of geoenergy.
To understand how geoenergy works, you need to know a little about how the Earth works. All year round, the soil temperature tens of meters below ground is relatively constant. What this means is the soil temperature is typically warmer than the air temperature in the winter and then cooler during warmer months. Geoenergy installations—which use a ground source heat pump (GSHP)—transfer stored heat from the soil to the surface when it’s cold outside and then reverse the process when it’s hot.
Ground source heat pumps have been around for a long time. Today, there are wide range of GSHP solutions; however, they represent a relatively small percentage of the global thermal comfort market. There are a few reasons for this. One is many building owners, real estate managers or municipalities are simply unaware about the technology and its benefits. There are also misconceptions that the costs of such installations are too high or that they aren’t a feasible option for existing buildings due to the typically large surface footprint requirement.
It really depends on the type of solution you choose. There are several options out there, including closed- and open-loop systems, which require an individual needs-based evaluation. The main benefits, however, are long-term cost savings and carbon footprint reduction. Geoenergy is also locally sourced, which is an increasingly important consideration for building owners and municipalities alike as concerns continue to mount over energy access and energy security, particularly in Europe.
I can’t speak for every geoenergy installation, but I can share Celsius Energy’s results. On a recent installation, we reduced building greenhouse gas emissions by 87.5 percent, energy consumption by 74 percent, and operational costs by 40 percent while covering 100 percent of heating and cooling needs. While upfront costs of geoenergy installations seem higher when compared to traditional heating, ventilation and air conditioning (HVAC) solutions, we expect most of our customers to realize a return on investment within 8–15 years. In addition to being a far more sustainable solution that’s better for our planet, the improved efficiency can also help safeguard from volatility in energy commodity markets. Once connected to geoenergy, a building divides by four its dependence on energy market fluctuations.
I would say it’s the installation designs that have evolved the most in recent years. Just a few years ago, geoenergy installations required a large surface footprint requirement. Today, there are several outside-of-the-box installation designs that are changing that. Our solution, for example, uses a pyramid-shaped design that locates the ground heat exchangers at a common surface position but extends them directionally in the subsurface. This results in a permanent surface allocation of less than two standard parking spaces. The small surface footprint preserves available real estate for future construction, enables other construction efforts at the same time and reduces connective piping requirements by up to 70 percent.
Over the years, digital technologies have become more advanced and today you see more companies in this space using digital across their process and in their final installations. We use digital at every step of our process, from dimensioning the future installation to drilling the inclined heat exchangers. Once operational, our solution uses a digital control system to minimize electricity consumption by optimizing the operation of the subsurface. This does a lot to enhance overall system performance and reduce maintenance, which has a significant impact on a building’s total opex costs over its lifetime.
Supportive policies are either in place or on the horizon for end users and decision makers in this space to embrace geoenergy solutions for heating and cooling. Today, the markets we see creating supportive policies are concentrated in Europe and North America, including the U.S. and Canada. I believe very strongly in the power of technology innovation to reduce the impact of climate change on our society. For me, the greatest enablers in this space are advocacy, supportive policies and continuous education. What excites me the most is these solutions exist today. Now it’s time to make these projects happen at scale.