STATCOM systems stabilise the grid by absorbing or feeding voltage-supporting reactive power, reducing the risk of voltage drops and blackouts.
Siemens Energy will design, build and provide five-year maintenance through the contracts, building the three projects concurrently.
The projects are predicted to take two years to complete.
Dave Dwyer, Networks Project Manager, Engineering and Major Projects at ESB, said: “These are the very first STATCOMs to be deployed by ESB Networks on the Transmission System and we are delighted to work with Siemens Energy on this project.
“These projects will make a significant contribution to meeting Ireland’s ambitious renewables targets and help decarbonise the electricity grid as a whole.”