performance analysis for semi-transparent PV modules

Solar photovoltaics (PV) come in a variety of new formats and materials that allow for a whole range of new and exciting applications. In this project the partnership aims to thoroughly measure the relevant parameters of one type of these new PV embodiments -- a semi-transparent module -- that has applications in building integrated PV (BIPV). The potential for this PV type to clad our tall steel and glass buildings in cities is huge, bringing renewable energy to where it is needed and away from our rural areas.

Silicon based PV, like the panels we regularly see on rooftops and in fields, are well understood from multiple viewpoints; location based performance, inefficiencies due to angle of installation, prediction of annual power yield and many more criteria. As a result of this good work anyone interested in deploying a PV system can use the resources available online to assess the impact a PV system will make on their energy profile. The same is true for comparing different types of silicon based PV as researchers or developers of new embodiments can highlight the up and downsides of a particular system.

Polysolar Ltd are specialist in BIPV with a deep interest in semi-transparency using our cadmium telluride (CdTe) PV technology which gives a neutral tint to the glass thus reducing glare and intensity inside the room. However, the deployment for this type of glass is not as well understood due to multiple factors like internal reflection, vertical orientation and illumination from the rear (non-active) side. To this end, when we predict power output it may not be as accurate as we wish which can lead to clients being disappointed and discouraged from purchasing and including this vital technology in their next construction project.

The National Physical Laboratory, NPL, are experts in measurements and have been involved with PV for many years developing standards and methodologies for testing to ensure all technologies are compared fairly. Their capabilities will define the experiments required to determine which factors influence the performance for these CdTe PV panels in relevant scenarios, leading to more accurate predictions of performance. This will increase the confidence in the technology and support its uptake.