Powering ahead with innovative geothermal energy trial

Date Added: 30/11/2021

As temperatures begin to drop and the winter maintenance season starts, we are well prepared with a new geothermal energy system helping keep our vehicles on the roads.

As part of the £22.9m ADEPT SMART Places Live Labs programme funded by the Department for Transport, five geothermic probes have been installed 150 metres into the ground. This solution was implemented by engineering contractor Eurovia UK – as part of their exciting ‘Power Road’ technology.

When it’s warm, the car park surface heats up. Tubes just below the surface filled with a special liquid capture this warmth as heat energy. This energy is then transferred to the geothermal probes where it can be stored in an on-site storage unit to keep its heat for several months.

The geothermic probes combined with a heat pump respond when the temperature drops to freezing. Similar to underfloor heating, the car park is heated from underneath the surface to prevent ice forming or snow settling. This means there is no need to grit the car park, and vehicles can continue to operate, saving both time and money.

Any excess energy can also be used for other purposes. In this instance, we will use the surplus energy to heat the depot building, saving on energy costs.

This initiative is one of our ADEPT Live Labs trials, where three renewable energy projects have been piloted. The three schemes focus on capturing and reusing solar, kinetic and thermal energy.

Rainwater harvesting
We have also been working on an exciting piece of innovation which helps with its gritting runs and has considerable sustainability benefits.

A rainwater harvesting system at the Thorn Turn depot collects rainwater that would otherwise flow down gutters into the drain. The collected water is stored in a 15,000 litre tank and used for a pre-wet solution which enables the gritting salt to spread more accurately and stick better to the road surface.

The system was first used in January 2021 throughout last winter’s gritting season. It's led to a reduction in the amount of salt and fresh water being used, which is an added benefit to the environment and saves money.

Following the successful trial, we installed a smaller, 1,000-litre, rainwater harvesting system at our Sandy highways depot in April. The rainwater collected is used to clean vehicles and equipment and in our highway maintenance programme such as to mix with asphalt and other materials.