EirGrid's Met Mast and Alternatives Study

The current grid code in Ireland requires wind farms to deliver meteorological data to the two transmission system operators, EirGrid and SONI. For wind farms greater than 10 MW in size it is obligatory to submit four meteorological data signals: wind speed, wind direction, air temperature and air pressure. The data is collected within EirGrid and SONI and thereafter used in the wind power forecast process. The wind speed signal is the most important variable as it helps in the detection of high-speed shut down events. The importance of accurate on-site measured wind speed signals increases as a function of the installed wind capacity. Since wind farms have been installed with varying technologies over the past 20 years, the system does not have a single point of failure. The lack of uniformity has been found to be both a handling challenge and reliability strength. In order to investigate the future compatibility of the current quality of met data and to verify, whether and which types of new technology may be an acceptable source of meteorological data to be delivered to the TSOs, a study has been carried out. The study verified whether the quality of meteorological data is sufficient and reliable enough for the 2030 penetration targets set by the Irish government. This paper will describe the methods used to verify the quality of meteorological data signals, along with the various types of meteorological measurements that were found to be acceptable under varying conditions. We will also present a number of recommendations based on the findings of the study, and discuss how these recommendations are being implemented by EirGrid.