The project investigated a novel insulated‑glass flat‑plate solar collector prototype and its integration into a free‑field solar‑thermal plant. The core of the study was the validation of the CARNOT simulation model against measured data from both a rooftop reference plant and a newly installed pilot plant. The pilot plant, covering 124 m² and positioned at a 35° southward tilt, operated between 16 March 2024 and 5 May 2024. During this 53‑day monitoring period the collector delivered a solar yield of 36.92 kWh m⁻² a⁻¹, a system utilisation of 17.71 % and a solar coverage of 1.02 %. The simulation reproduced these figures with a deviation of only 0.14 % for the yield, 0.02 percentage points for utilisation and 0.10 percentage points for coverage, confirming the model’s validity for further scenario analysis.

The annual energy output of the pilot plant, extrapolated from the validated simulation, was calculated to be approximately 161 kWh m⁻² a⁻¹. This value is markedly lower than the manufacturer’s pre‑installation estimate of 238.4 kWh m⁻² a⁻¹, largely because the plant operated with higher feed‑water temperatures than assumed in the simulation. The reference plant’s measured yield of 124.8 kWh m⁻² a⁻¹ matched the simulation (125.4 kWh m⁻² a⁻¹) within 0.48 %. These results highlight the importance of accurate temperature control and suggest optimisation potential in the plant’s regulation strategy.

A comprehensive techno‑economic assessment was performed using a 20‑year horizon. Key assumptions included a corporate tax rate of 15.825 % plus a 5.5 % solidarity surcharge, an average inflation of 1.88 %, a nominal interest rate of 2.08 % and a discount rate of 0.17 % derived from Fischer’s methodology. The cost of auxiliary electricity was set at 91.1 €/MWh, and the life spans of collectors and mounting systems were 20 years, while the thermal storage and piping were assumed to last 25 years and the control system 10 years. Operating costs were estimated at 0.75 % of the investment, with linear depreciation applied. A degradation factor of 0.2 % per year for solar yield and an additional 0.067 % per year for argon loss in the insulated glass were incorporated. These parameters fed into cost equations that relate specific costs to collector field size, enabling a direct comparison between the reference and pilot configurations.

The pilot plant’s performance, while lower than the manufacturer’s prediction, demonstrates the feasibility of the insulated‑glass concept and provides a solid data set for refining control algorithms and improving thermal efficiency. The validated CARNOT model now serves as a reliable tool for exploring design variations, scaling strategies, and economic scenarios. The project’s monitoring phase, spanning just over eight weeks, underscores the importance of long‑term data collection for accurate performance assessment. Although the report does not detail the full consortium, it indicates that the work was carried out by a collaboration of academic researchers and industry partners, with the pilot installation and data acquisition coordinated by the project team during the specified timeframe.