The Differences Between GeoExchange and Geothermal Power Generation
The retrieval of energy from the earth’s core is still a relatively youthful concept, with many people in the US encountering this terminology for the first time. As an expert in heat transfer for ‘geothermal’ applications, CORECHEM is seeking to explain the differences between GeoExchange and geothermal power generation. Our latest learning resource contains everything you need to know, removing the common confusion around these terms.
The terms ‘geothermal’ and ‘GeoExchange’ sound very similar, and these processes do hold some similarities. These similarities often lead to confusion to those both inside and outside of the industry, with the term ‘geothermal energy’ pointing to an incredibly broad range of technologies, ranging from the drilling of deep wells to utilizing the residual hot brine created by geothermal power generation.
Geothermal Power Generation vs GeoExchange
As we’ve already touched upon, the term ‘geothermal’ is used ambiguously and is often used to discuss varying types of systems under the same term. This widespread confusion of terms has been highlighted by industry leaders as one of the key challenges and obstacles to growth the sector has faced over recent decades. This was highlighted as recently as 2022, with geologist Catherine Hickson of Geothermal Canada describing it as one of the biggest problems she has faced across her 40-year career.
In order to understand the differences, it is essential to understand each term individually. Let’s begin by looking at Geo-Exchange in close detail.
What is Geo-Exchange?
At its core, Geo-Exchange entails a loop field of pipes installed either by drillingboreholes up to 500 feet, or by trenching and placing horizontal pipelines at a depth of approximately 6-10 feet. This taps into the earth as a reservoir of thermal energy maintained by solar heat, which remains nearly constant throughout all seasons of the year. An environmentally-safe Heat Transfer Fluid (such as the GlycoChill+ products manufactured by CORECHEM) is circulated through the loop field, allowing us to tap into that thermal energy, using it to heat and cool buildings throughout the USA and beyond.
Heat Transfer Fluids are pumped through the ground and processed – or cooled – through a system called a heat exchanger. Geo-Exchange systems are commonly referred to by other names, including Geothermal Heat Pumps (GHPs), Ground Source Heat Pumps (GSHPs), earth-energy systems, and earth-coupled systems, which can add to the confusion around the understanding of the concept.
The most important fact to bear in mind around Geo-Exchange is that it isn’t an energy source, but a means to transfer thermal energy sources from the ground at relatively shallow depths. The systems use a hydronic ground-source heat pump to transfer the building heat to or from the loop field.
What is Geothermal Power Generation?
Unlike the temperature moderator, Geo-Exchange, geothermal power generation is a positive thermal source through which renewable power can be extracted. This energy source conducts non-stop from the earth’s core to the surface, with various places within the earth’s crust heating rock and water to temperatures as high as 370°C.
The heat energy is extracted in the form of hot water or steam to generate electricity. Cost-effective, reliable, environmentally-friendly, and sustainable, this energy is often accessed using deep production wells, where water from within its rock is pumped to the surface, with its heat used to power turbines. In most cases, geothermal plants use dozens of these production wells.
Across the United States, geothermal energy has been highlighted as one of the key ways that industries can transition towards a cleaner, greener, more sustainable future. Currently, the US leads the world in geothermal electricity generation, with geothermal power plants in operation across seven states producing approximately 17 billion kilowatthours towards utility-scale electricity generation.
Geothermal & Geo-Exchange: The Role of Heat Transfer Fluids
Whilst there are many similarities between the concepts of geothermal power generation and Geo-Exchange, one of the key differences is their reliance on high-performance Heat Transfer Fluids. Only Geo-Exchange systems use heat transfer fluids. Here at CORECHEM, we’re passionate in our belief that biobased Heat Transfer Fluids can help validate Geo-Exchange as the most sustainable process for building climate control.
That’s where our GlycoChill+P Series comes into play. This exclusive line of Heat Transfer Fluids – including GlycoChill+ P200HD and GlycoChill+ P200FG have been engineered to enhance sustainability at the heart of geothermal hydronic systems.
As the world faces growing concerns over resource scarcity, products with USDA Certified Biobased content contribute to reducing our dependence on non-renewable synthetic or petrochemical resources, fostering long-term resource sustainability. The biodegradability of these products also demonstrates our commitment to protecting our aquifers and environment. To find out more, simply reach out to one of our chemical experts.
CORECHEM: Your Geothermal Partner
If you’re a decision-maker with responsibility over any Geo-Exchange systems, we’d like to talk to you about how our Heat Transfer Fluids can provide significant benefits. To get started, browse our full selection or contact us to discuss your unique operational requirements.
