IMPACT OF GLOBAL IRRADIATION DATA WITH DIFFERENT CHARACTERISTICS ON THE PERFORMANCE RATIO AND THE EXPECTED ENERGY OUTPUT OF PHOTOVOLTAIC POWER STATIONS

摘要

For the purpose of assessing the expected energy output of Photovoltaic (PV) Power Stations, several calculation programs are in use. They all aim to describe the energetic losses which arise from the chosen system configuration and the technical properties of the components used and intend to generate reliable Performance Ratio (PR) values.However, assessing the PR is just half of the challenges, which have to be addressed within an Energy Yield Assessment. Determining the site-specific, meteorological conditions – appropriate for the period of operation considered – could be the even more difficult task. Besides deviations between long-term datasets from different sources, as governed by long-term variations, the characteristics of the data available may lead to significant varying results, too.The present work uses irradiation data from several sources and two different calculation programs to focus on the impact these differences induce with regard to the Performance Ratio calculated and the energy output expected for a given PV Power Station. It highlights that the main reason for the resulting energy output differences can be found in the long-term global irradiation data applied. Furthermore, as a consequence, it demonstrates that consideration of long-term variations of annual global irradiation is of great significance for reliable Energy Yield Assessments.