One borehole. One closed loop.
The NotusPiD system is a coaxial heat exchanger installed in a single deep well. It exchanges heat with the rock instead of producing water from it — which is why it does not need an aquifer, a second well or reinjection.
How it works
Four steps, and none of them depend on finding water underground.
One well
A single borehole is drilled to the depth the demand requires. Nothing is produced from the formation, so permeability, porosity and the presence of an aquifer stop being the deciding factors.
A coaxial heat exchanger
A production string is installed inside the casing. The annulus carries cold fluid down; the insulated centre brings the warmed fluid back up. The working fluid never meets the formation.
Circulation
A pump keeps the fluid moving. Heat passes from the rock through the steel into the fluid along the whole length of the well. Nothing is taken out of the ground and nothing is injected into it.
Delivery
At surface the heat goes through a heat exchanger into the building, the district network or the process. A heat pump lifts the temperature further where the application asks for it.
Why one well instead of two
It is not a detail of the design. It decides where geothermal energy can be built at all.
A conventional doublet
Two wells. Hot water is produced from a permeable layer and pumped back into the ground through the second well. It needs an aquifer with proven flow, it stands or falls with reinjection, and it only becomes viable above a certain project size.
A NotusPiD single well
One well. A closed loop: no production, no reinjection, no water chemistry. It works in any formation that is warm enough, the subsurface risk is limited to temperature rather than flow, and it scales from a single building upward.
What sets the yield
The output of a single well is engineered, not discovered. Four variables decide it, and three of them are ours to choose.
Curious what one well would deliver at your site? Send us the location and the load: info@notuspid.nl
Depth and rock temperature
Every extra hundred metres adds temperature. The depth is chosen from the supply temperature the application needs — not the other way round.
Thermal conductivity of the rock
How fast the formation hands its heat to the well. It is measurable and it can be modelled before the design is fixed.
Flow rate and return temperature
Two variables you control at surface. Together with depth they set the power and the annual yield of the well.
Recovery
Because nothing is produced, the rock around the well recharges by conduction. Where the site also needs cooling, summer and winter can be balanced against each other by design.