The matter raised by the Deputy is an operational matter for EirGrid, the transmission system operator. It is clear that the underlying issue is a concept known in the energy sector as "dispatch-down" of renewable energy. This term refers to the amount of renewable energy that is available but cannot be used by the energy system. This is because of broad power system limitations, known as curtailments, or local network limitations, known as constraints.
EirGrid prepares an annual report outlining the levels of dispatch-down of renewable energy on the island of Ireland. The latest such report can be found here: http://www.eirgridgroup.com/site-files/library/EirGrid/Annual-Renewable-Constraint-and-Curtailment-Report-2020.pdf.
Dispatch-down is regrettable and EirGrid strives to address the system limitations that cause it. They have a number of measures in place that seek to limit the amount of dispatch down and they continue to evolve them further in line with European policy such as the Clean Energy Package. Such measures include the DS3 programme of system services. Investing in and strengthening the electricity grid network, as well as increasing storage, are also critical to minimising the levels of renewable energy sources that are curtailed or constrained down. In addition, the Climate Action Plan 2021 includes a number of actions to address storage policy and higher levels of renewable electricity on the network. My own Department will publish a storage consultation later this year leading to the development of a national storage policy next year.
The Department is not aware of the specific details referred to by the Deputy but I have instructed my officials to ask EirGrid to review the matter.