The company will design and build ESB’s substations and service them under a five-year maintenance package.
The substations will be built at Ballyvouskill in County Cork, Ballynahulla in County Kerry, and Thurles in County Tipperary.
Construction works will begin in the coming months, with completion expected in 2023.
Siemens Energy Ireland managing director Nick O’ Mahony said: “Across the world, we have vast experience in helping grid operators strengthen grid resilience.
“These projects, combined with the recent synchronous condenser project at Moneypoint, will play a vital role in keeping the lights on across Ireland.”
As lead contractor, the company will partner with local contractors to carry out required civil works.
The three projects are expected to create almost 100 local jobs.
Siemens Energy said that many large power plants, which produce reactive power, are being decommissioned and replaced with renewable generation, with energy transition taking place swiftly.
Because of this, grid operators across the globe are building static synchronous compensator (STATCOM) systems, which help keep the power grid stable despite inconsistent power supplies from renewable and distributed energy sources.
ESB Engineering and Major Projects networks project manager Dave Dwyer 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.”
Earlier this month, Siemens Energy reported a moderate decrease in revenue by 4.4% to €6.5bn for the second quarter of the year.
The company’s revenue was €6.78bn in the same quarter of last year.