International consortium carries out PV performance R&D project

Performance Plus, a research and development project aimed at improving the performance and lifetime of PV installations and financed by the European Commission is showing results.

An international collaboration between market, industry and research, the Performance Plus project is headed by Brussels-based renewable energy consultancy 3E. Leading partners include Italian R&D company Alitec, Belgian research center imec, Belgian university KU Leuven, the University of Applied Sciences of Southern Switzerland (SUPSI), the University of Oldenburg in Germany and the Austrian Institute of Technology (AIT).

As part of the project, researchers are developing a series of tools, models and hardware with the goal of making PV systems more reliable and cost-effective and improving their overall performance.

Among the project’s initial findings was that power generation forecasts of PV installations on variable weather days can be brought down to an accuracy of about 4% instead of the current 10% by combining new modeling concepts with improved weather forecast, as shown by imec.

Spatially and temporally highly variable surface solar irradiance caused by broken cloud conditions was analyzed and forecasted by means of a ground-based sky camera. Oldenburg University processed sky images to extract the cloud distribution and their motion as well as the resulting surface shadow and solar irradiance fields.

Other tools, models and hardware developed for the project include a flexible inverter model developed by AIT that is able to precisely predict the performance of a wide range of PV inverters; a Model-Predictive Control (MPC) framework developed by KU Leuven that allows control of the PV plant together with other systems on the site, taking into account weather forecasts, variable tariffs, energy efficiency and peak loads in order to optimize the power injection to the grid over time; and the ESA sensor prototype, designed and built by Alitec, which is able to measure both direct and indirect solar irradiation.

3E developed a web-based tool for financial optimization of PV systems as well as an automated health scan procedure for fault recognition from operational PV system monitoring data.

SUPSI developed new test procedures to improve the accuracy of PV measurements that take into account separately the contribution of all possible causes of energy losses and under-performance, optical, mechanical, potential induced degradation (PID) and other degradation effects.

The project team also published best practice guidelines for uncertainty in PV modeling and monitoring of grid-connected PV systems. The guidelines will support PV project developers and investors with managing the financial risks.

The models and tools are currently being tested in the field. Working with a user group composed of seven large portfolio owners and EPC and O&M contractors, the consortium has access to 25 PV systems, ranging from small residential to large utility-scale PV systems across Europe. Final versions will be presented in October.

The project is financed by the European Commission under its 7th Framework Programme.