Here, Opvius is offering no ordinary PV product, but a shapeable, solar-active surface that refines customer applications. This is a decisive factor in the implementation of projects in the Building Integrated Photovoltaics (BIPV) segment and is also finding increasing recognition in the automotive segment.
Furthermore, OPV has a series of technical features that also set it apart from hitherto technologies: Apart from a positive temperature coefficient – which allows increasing efficiency at rising temperatures – and an excellent energy yield under less than optimal angles of radiation, it is the excellent diffusion and low-light behavior that is the hallmark of OPV modules. Whether in the morning or evening, cloudy and rainy weather, in shadow or in artificial lighting, the energy yield remains significantly high.
However, the past has shown that the quality of low-light was subjected to strong fluctuations, even within the same production batch, thus causing low yields and making industrial applications difficult. Now, an internal research and development project has demonstrated that efficient energy extraction by OPV modules under low light is directly associated with leakage current or so-called shunt resistance. It has also shown that module performance under low light diminishes disproportionately as leakage current increases.
Nevertheless, these features are not generally connected with the general capacity measured under standard test conditions (STC). Rather, when there is a great amount of leakage current, capacity sinks as the light intensity diminishes, but this does not necessarily lead to a conspicuity in the “STC” capacity. This also means that a large strewing of leakage current results in a lower yield of module production if one takes low light into account as a quality feature. In the end, such a restriction on yield leads to reduced applicability in the low-light segment and makes commercial applications in this environment difficult.
As a result of the Opvius investigations, the performance of OPV modules under low light has been improved and the strewing of properties has been clearly reduced.
“As a result of the optimization of our production processes and continuing to use all our standard materials, we have succeeded in restructuring production so that virtually all the modules in a manufacturing batch demonstrate identical and also lower leakage current. Thus with a lower light intensity of just 100 lux, we can theoretically still guarantee the highest possible voltage,” explains Dr. Sebastian Meier, head of Research & Development at Opvius.
“This result is attributable to a number of adaptations along our entire process chain. The fact that we have optimized the manufacturing process of all the modules in a given batch is of great interest because the yield regarding low light requirements can be clearly improved.”
100 lux corresponds to an extremely low-light scenario. For instance, Directive “ASR A3.4 Lighting” by the Federal Institute for Occupational Safety and Health calls for a minimum light intensity of 200 lux in offices and office-type environments, depending on the type of activity.
Hermann Issa, Senior Director Business Development & Sales at Opvius, adds: “Now, even in extremely low light, our modules generate sufficient power to supply small electronic components. Therefore, with their easy integration, OPV solutions are also attractive in the context of the Internet of Things (IoT), where millions of small and tiny devices, such as sensors and transmitters, are linked and can communicate with each other. Energy-independent operation, making disposable batteries superfluous, not only reduces the strain on the environment, but also saves the considerable costs of service and repairs.”
Naturally, this further development also has a generally positive impact on all areas where Opvius OPV solutions are applied. OPV modules also prove their worth in outdoor use when the level of light radiation is low, for example in shadow or at sunrise or sunset. Last but not least, this optimization offers new possibilities in the “consumer electronics” and “wearables” segments.