Development and evaluation of an uncovered modular photovoltaic-thermal collector based on a mounting system with integrated construction

Dr.-Ing. Federico Giovannetti
Tel.: +49 (0)5151-999 501

Dachintegrierter BIPV(T)-Prototyp
Roof-integrated BIPV(T) prototype
Anordnung der BIPV(T)-Versuchanlage
Anordnung der BIPV(T)-Versuchanlage
SolarHybrid Optimierung der Neuentwicklung durch numerische Modellierung

Optimization based on numerical modelling

Photovoltaic-thermal (PVT) collectors allow for an efficient use of roof space through the simultaneous conversion of solar radiation into useful heat and electricity. In addition, hybrid collectors offer the advantage of a uniform architectural appearance. Optimizing a novel roof-integrated, uncovered PVT collector at the ISFH, these aspects are essential. The fluid-flow heat exchanger made of extruded aluminium forms the self-supporting mounting system for PV modules and, at the same time, makes the roof cladding in conjunction with crystalline or thin-film modules. The fluid channels are integrated directly into the profile. This simplifies the design and requires only a small number of components. Furthermore, the modules are clamped onto the aluminium profiles without the use of adhesives. Thereby, we simplify the installation of the collector increase the usability and reduce the energy costs. The collector has been optimized with regard to heat transport and ease of installation in cooperation with the architecture and planning office Grobe Passivhaus GmbH and the manufacturer and developer Elodrive GmbH.

On a test roof of the ISFH we installed a 20 m2 prototype (including 14 m2 PVT) for performance measurements and usability tests. Figure 1 shows the prototype on the wooden roof substructure specially constructed for authentic measurement results. The system is connected to a heat pump system and is operated with a 30% ethylene glycol mixture in order to adjust low collector inlet temperatures. In addition to the sensors required for power measurements, numerous temperature sensors on the collector and roof surfaces as well as measuring equipment for the recording of electrical string voltages and currents were installed.

Using numerical modelling, the heat transport through the continuous casting profile is optimized to the greatest possible extent. Based on the same method, we classified the thermal connection between PV cells and heat exchangers prevailing on the installed prototype. Due to insignificant air inclusions, the detachable connection shows nearly optimal thermal bonding and high thermal efficiencies in measurements and simulations.

Industrial partners

Elodrive GmbH, Nussbaumweg 23, 51503 Rösrath

Logo Elodrive GmbH
Architektur- und TGA-Planungsbüro Carsten Grobe Passivhaus,
Boulevard der EU 7, 30539 Hannover
Logo Büro Grobe

Duration of the project

01.04.2015 – 14.09.2017


The project “ModulTech – Solarhybrid” underlying this publication is funded by the German Federal Ministry of Economy and Energy (reference number 16KN041920) based on a decision of the German Parliament. The authors alone are responsible for the content of this publication.

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