The technical advances in the photovoltaic industry continue unabated. As a result of technical developments, the prices for modules, energy storage devices and inverters have fallen continuously. Although this has also been accompanied by a corresponding fall in the production costs for sustainably generated solar electricity, a critical point still remains which could significantly influence the success of a solar energy project, namely a reliable yield forecast for the expected output. If, for example, the calculated yield is 10% lower, this could already cause financial difficulties in a low profit margin market.

It is therefore necessary to continue to improve the existing models for forecasting the yield of PV parks. This issue has been addressed by a group of three research institutions and one company in order to achieve greater reliability and to develop new business models. The aim of the SOLREV project is therefore to investigate and evaluate different models in order to provide radiation data and their projections. Ultimately, the aim will be to advance the integration of renewable energies into the grid and to ensure that solar power plants can provide a stable and predictable yield long-term. Current forecasts are based on ground measurements, satellite data and weather models.

The economic value of these forecasts will be analysed and quantified in case studies. In addition, a benchmark system will be developed for the various forecast models which will provide information on the quality of the forecasts. In order to do this, large-data series of forecasts will be compared with the measurements taken. This will also involve the use of artificial intelligence. In collaboration with large-scale German network operators the validity of the improved forecast models will then be tested. In addition to developing suitable software, the research-based companies and institutions will be contributing to the work of the IEA working groups. For Task Group 16 ‒ Photovoltaic Power Systems Programme ‒ a handbook of best practices will be put together which will also include the German experiences.

The research project is being funded by the Federal Ministry for Economy and Energy and will run from 2019-2023.