The optical and electrical losses have so far led to a PV module producing less electricity than its cells would produce althogether. It is precisely these losses that the Fraunhofer Institute for Solar Energy Systems ISE and the Fraunhofer Center for Silicon Photovoltaics CSP are seeking to reduce in the collaborative research project CTM100+ with twelve partners from industry.

By optimising the processes in the module and by directing the sunlight more effectively into the cells, the ratio of the module output to the total amount of cell power of all individual cell outputs – in short, CTM (cell-to-module) – is to be increased. The aim is to produce a module that provides over 100% of the cumulative cell power. In this project, the interaction between different designs and material combinations of PV modules was investigated in more depth. Based on this, the Fraunhofer institutes involved produced new, optimised modules. Their performance was then jointly evaluated with experts from industry from the perspective of the level of CTM achieved. The results are impressive: within the scope of the project it was possible to produce half-cell modules with a CTM of 104%.

To measure the output of the test cells and modules, the researchers used advanced software from Fraunhofer ISE. The software measures optical, electrical and geometric cell and module losses and enables the CTM to be determined. This means the influence of individual components and materials on the module performance can be determined on a computer before they are installed.

The project CTM100+ will continue to receive funding from the Federal Ministry for Economic Affairs and Energy (BMWi) within the scope of the sixth energy research programme until March 2019.