How does geothermal installation work?

Geothermal energy projects – which you may also have heard of referred to as ground source heat pumps – are becoming increasingly common. As we enter a context in which energy instabilities are becoming more and more prominent, these renewable heating systems will only grow in popularity, but how do they actually work?

In this article, we take a closer look at how the geothermal installation process goes, from an initial assessment of energy needs to the final stages of system integration.

Assessing energy needs

Before a geothermal energy project can begin, a thorough assessment of the client’s energy needs will need to be completed. 

Most geothermal energy systems are used to heat properties – in these situations, the assessment will look at the size of the property, its energy efficiency rating, and the average annual external temperatures. 

This assessment will provide a much clearer understanding of how much energy the geothermal system will need to produce. 

Geological survey

Next, a geological survey will need to be carried out. During this survey, a specialist will be able to assess what material (clay, granite, limestone, etc.) will need to be drilled through, the stability of that material, and any potential complications or environmental issues that might arise. 

The findings of this survey will provide the rest of the information necessary to understand what kind of hole will need to be drilled.

Drilling

Once the requirements of the property and the geothermal potential of the ground below have been understood, the drilling can begin. A drilling rig will be brought to the site along with a team of competent technicians. 

This rig will be able to drill at a rate of roughly 50-100 vertical metres per day, meaning that most projects should be completed in between 1 and 3 days. 

Loop installation

Once the borehole has been drilled, the next step will be to install the loop. This essentially consists of two long plastic pipes that are connected at the bottom, and once it has been placed in the borehole, the surrounding space will be filled with grout. 

The loop can then be filled with a water/antifreeze mixture, which can be pumped through the system to bring up some of that heat trapped in the Earth’s crust.

System integration

The final stage will be to integrate that geothermal borehole and loop into a heating or, in some cases, electricity generation system. In most cases, these kinds of projects are used for heating, in which case, the loop will be connected to a heat exchange system. 

This essentially magnifies the temperature of the liquid that was brought up in the loop, transferring that heat into water from the mains system that can then be used to heat a property or run through the taps. 

Geothermal installation can be quite expensive and complex compared to more conventional energy and heating systems, but the medium to long-term benefits are profound. It’s worth at least having a survey conducted to see if one of these systems could suit your property, so that you can make an informed decision.