Advantages
Documented
Performance Advantages
Key figures based on field results from reference projects and simulation-supported forecasts in partnership with Transflow GmbH
more heat extraction
Higher Thermal Extraction Capacity
The enlarged heat transfer surface through 10 concentric outer pipes increases heat extraction per borehole metre by up to 35 %. Same thermal performance at shorter borehole depth — or higher performance at the same depth.
more heat output (sim.)
More Capacity — in Both Directions
The enlarged heat transfer surface works bidirectionally: more heat extraction in winter, better regeneration in summer. The 100-year simulation shows 673.3 MWh/a heat output vs. 507.1 MWh/a (DU-100) at 91.9 % regeneration efficiency.
cost advantage per 100 m borehole
Economic Advantage per Borehole Metre
Compared to a conventional double-U-tube probe, the Multi-U-Tube Probe achieves a calculated cost advantage of up to 1,700 € at equivalent thermal extraction capacity. This primarily results from significantly reduced borehole depth at identical energy yield.
measurement-based
Documented Field Measurement Data
All performance data is backed by measurement series from reference projects: temperature profiles, flow rates, pressure losses, seasonal extraction capacities. No extrapolation from laboratory conditions.
View production line →numerical simulation
Bridging to Standard Planning Tools
Since standard BHE planning tools could not capture the specific performance advantages of the MU probe, the numerical simulation software ModThermWg (Transflow GmbH, Freiberg) was optimised in close collaboration with us. This finite-difference model creates the necessary, well-founded data basis to accurately represent our technology and transfer it into common planning tools.
What the Reference Projects Prove
Technical Functionality
The Multi-U-Tube Probe operates in continuous duty without degradation of thermal performance. No material failure, no pressure loss increase above reference values.
Superior Heat Transfer
Measurement data confirms the theoretically calculated superiority over double-U-tube probes under real field conditions.
Ground Compatibility
No negative impact on the thermal equilibrium of the surrounding ground. Regeneration rates within standard range.
Production Readiness
All component geometries and manufacturing parameters are documented and prepared for industrial series production.
Direct Comparison: MU Probe vs. Double-U-Tube
| Criterion | MU probe | Double-U-tube |
|---|---|---|
| Heat transfer surface | +30–35 % | Reference (100 %) |
| Heat extraction per metre | Significantly higher | Standard |
| Grouting thermal cond. (rec.) | 1.4 W/(mK) | 2.4 W/(mK) |
| Cost advantage per 100 m | up to −1,700 EUR (estimate) | 0 |
| Borehole diameter | 150–190 mm | 120–150 mm |
| Material standard | PE100 / PE100 RC | PE100 / PE100 RC |
| Field validation | Yes — reference projects | Long-established |
| Installation effort | Standard drilling rigs | Standard drilling rigs |
| Heating capacity (100y sim.) | 257.2 kW | 190.1 kW |
| Heat output (100y sim.) | 673.3 MWh/a | 507.1 MWh/a |
| Cooling capacity (100y sim.) | 287.7 kW | 220.9 kW |
| SCOP heating | 4.14 | 4.16 |
| SCOP heating + cooling | 7.20 | 7.03 |
| Regen. efficiency | 91.9 % | 92.0 % |
Rows marked "100y sim." are based on the 100-year simulation (25×4 probe field). Source: GeoTherm 2026.
Learn more
From Vision to Innovation Product
Depending on the project framework — depth limitations, probe field dimensioning, regeneration concept — the weightings shift. We are happy to discuss details and project-specific considerations with you.