Can Geothermal Drilling Be Done in Winter?

You’ll likely have noticed, walking around on a frosty winter morning, that soil can become much harder during the cold winter months. While it might be intuitive to think that this would limit geothermal drilling, in the UK at least, it has limited impact on the drilling itself. 

Below, we’ll go through some of the details on this topic, including some aspects of planning that might need to be altered slightly to mitigate the risks posed by colder weather. 

Why winter conditions don’t affect drilling

Boreholes can be drilled through granite, limestone, clay, and a range of other substances. Some of these will be slightly harder at the surface during winter than summer, but not harder than granite or other similar rocks.

More than that, though, one of the whole points of geothermal drilling projects is that you’re able to access ground which remains a stable temperature year-round. Even just a few metres down, you’ll typically find that there’s minimal variation between the coldest and warmest months of the year, especially in areas like the UK. 

What might be impacted?

There are, however, a few areas that might be impacted by winter conditions. 

Access conditions

In rural locations, winter weather might mean that the paths and fields that need to be traversed to access the site are a lot muddier and slippier. This won’t generally mean that it’s impossible to carry out winter projects, but it can mean that some additional precautionary measures are necessary. 

Grout

Once the borehole has been drilled, the gap between the hole itself and the ground loop will need to be sealed with grout. It’s important that the grout provides a strong thermal connection, so that the loop can effectively bring heat up from deep in the ground. 

Most grouting materials will need to be within a certain temperature range to ensure they set properly. During prolonged cold spells, this can mean that extra measures might need to be put in place to ensure this is managed effectively. 

Pipework installation

The liquid inside the pipes will be a mixture of antifreeze and water, which means it won’t freeze in any commonly seen UK winter temperatures. However, installing the pipes can be difficult when it’s very cold, especially if it’s also quite wet. This shouldn’t result in any insurmountable issues, but could delay things slightly. 

Optimising working conditions

In most cases, cold, wet weather conditions can be worked around, but they won’t necessarily be the best conditions for geothermal drilling projects to be completed in. 

The contractor you’re considering engaging will be able to provide you with more information pertaining to suitable working conditions, which will also in part be determined by the site itself and any access considerations.

As you can see, geothermal drilling projects can basically be completed year-round. There are a range of factors that weather conditions can have a slight impact on, some of which will depend on the site itself, and you will ultimately have to defer to the expertise of the team that will actually be planning and completing the drilling on when will be best.