A successful geothermal project: the keys to success

A well-designed geothermal installation is simple, reliable and very comfortable. As with any technical project, however, certain steps are decisive for the final result. From defining your needs to choosing your partners, here are the main points to get right.

1. Clarifying needs: heating, cooling, hot water

The first step is to define clearly what you expect from the installation:

• heating only;
• heating + cooling (geocooling);
• heating + domestic hot water;
• or all three.

This makes it possible to size the heat pump output, the storage volume (buffer tank, hot water cylinder) and the borehole field correctly.

2. Proper sizing, without oversizing the heat pump

An oversized heat pump often causes problems in use: short cycling, frequent stops and starts, lower efficiency and premature wear. A correctly sized heat pump, by contrast, runs longer at part load, with a better COP and more stable comfort.

The "heat pump + storage tank" pair is essential:

• the heat pump supplies the power,
• the tank absorbs variations in demand and lets the system run at the best moment (for example when solar panels are producing).

In most standard residential and commercial projects, a well-sized geothermal installation covers the full heating demand, with no need for a fossil-fuel back-up system.

3. Keeping the plant room simple

Modern water-to-water geothermal heat pumps are compact units, often fully integrated (pumps, heat exchangers, controls, etc.), that take up barely more space than a large fridge. In many cases the plant room needed is simpler and cleaner than a traditional boiler room: no chimney, no burner, no fuel storage.

Even in existing buildings, geothermal usually fits in well: the boiler is replaced by a heat pump, a buffer tank is added, and the controls and emitters are adapted if necessary.

4. Building the storage tank into the design

Adding a storage tank to the system is often an excellent idea. It makes it possible to:

• optimise the heat pump's operation (fewer starts, better efficiency);
• smooth out the building's power demand;
• make the most of solar PV, by heating water when electricity production is at its peak.

This tank is a central part of a simple, robust and efficient installation.

5. Pairing geothermal with solar PV

Geothermal is a 100 % electric system. Combined with solar panels, it cuts the energy bill dramatically. In practice, a large share of the electricity used by the heat pump can be covered by solar production, especially if the controls are set to favour operation during sunny hours.

Here again, the storage tank plays a key role: it "stores" the surplus electricity produced at midday as heat, to release it in the evening or the next day.

6. Geothermal, radiators and renovation: a good combination

A stubborn myth holds that geothermal only works with low-temperature underfloor heating. In reality, in many existing buildings, radiators are oversized for today's needs (better insulation, new windows, etc.).

By adjusting the controls and working with slightly lower temperatures, it is often possible to supply an existing radiator network with a geothermal heat pump while keeping good efficiency.

In renovation, geothermal therefore adapts very well, without necessarily having to start again from scratch.

7. Very wide geothermal potential in Belgium

Belgium's subsurface offers excellent geothermal potential across the vast majority of the country. In most projects, vertical probes can be drilled deep enough to supply an efficient heat pump.

WellDoneDrill assesses the feasibility of each project and tells you transparently whether geothermal is technically possible on your site.

8. Working with the right partners

The success of a geothermal project depends on good coordination between:

• the driller (probes and boreholes);
• the installer of the heat pump and hydraulic equipment;
• the engineering firm or engineer responsible for overall sizing;
• the architect or project owner.

WellDoneDrill acts as a specialist partner for drilling and probes, working closely with the other parties. The aim is for geothermal to be a simple, clear and efficient solution for the end client, with no unnecessary complexity.

In short, a successful geothermal installation is above all a well-prepared one: clearly defined needs, proper sizing, smart integration into the building, possible pairing with solar PV and experienced partners. On that basis, geothermal becomes a technology that is easy to run day to day, while delivering comfort and performance that are hard to match.