The TPedge concept reduces the material and production costs of PV modules, since encapsulation foils and the lamination process are no longer needed. At the same time, the aging stability of the PV module increases appreciably. In cooperation with its partners the Fraunhofer ISE has developed processes so that the innovative PV modules can be manufactured on an industrial scale.
TPedge modules are edge-sealed, double-glass PV modules, similar in construction to insulating glass windows. The solar cells are fixed in the gas-filled space between the two glass panes with special adhesive pins. The TPedge module forgoes the conventional encapsulation foils as well as the traditional module frame. This not only saves material costs but also avoids the time-consuming lamination process. In the project “TPedge – Development of a Technology for Edge-Sealed Solar PV Modules,” Fraunhofer ISE and the company Bystronic glass together developed processes for the industrial production of novel solar module concepts.
At the PV Module-TEC (Module Technology Center) at Fraunhofer ISE, the researchers put automated production systems into operation with which they were able to produce numerous prototypes with different setups. As a next step, the industrial production processes were developed further and optimized. The results show that the specific module costs of the TPedge concept are approximately 2 percent less than the conventional glass-foil-laminate concept
The Prototypes underwent many tests based on the standards IEC 61730 and 61215. Fraunhofer ISE states that these tests confirm the high reliability and technical maturity of the TPedgde module concept. In the humidity-heat test various TPedge modules showed now change to the initial values measured before after being subjected to a relative humidity of 85 % at a temperature of 85°C over 4000 hours. Conventional module concepts demonstrated, in part, large degradation effects after undergoing the same test. The prototypes also had to face mechanical testing. The tested modules successfully passed the tests in which pressure loads up to 5400 Pa were applied to the modules in different mounting configurations. In the procedure, large hail stones of 25 mm diameter were also aimed at especially critical parts of the module, for example, the glass edges. The modules passed the hail tests without being damaged and could be used further in the following tests.
The project “TPedge” started at the beginning of 2013 and was funded by the German Federal Ministry for Economic Affairs and Energy (BMWi). Fraunhofer ISE and its project partner Bystronic glass developed the TPedge module technology and the possibilities for industrial production followed. Fraunhofer ISE has installed 70 TPedge modules on the façade of one of its lab buildings; these have been operating in a field test for three years now. Further research explores promising approaches to increase the module power and addresses the particular suitability of this technology for building-integrated photovoltaics. An industrial implementation of this technology is a future aim and partners are being sought.
Philipp Kronsbein / Fraunhofer ISE