The victim was an employee of Bord na Mona, who supply fuel to the ESB plant.
It is understood the accident happened in an area where peat is unloaded from trains that supply the power station.
Bord na Mona issued a statement confirming the tragic accident at the power station.
"The company have been working with the emergency services through the night and have already informed the Health & Safety Authority," the statement said.
"Bord na Mona have also begun an internal inquiry into the circumstances of the man's death. Our deepest sympathies go to his family at this difficult time," it added.
The ESB described the incident as a tragic accident but could not comment further.
The gardai and the HSA will carry out separate investigations into the circumstances surrounding the man's death.
The 100 megawatt Lough Ree power plant was commissioned in 2004 as a peat burning generating station located on the banks of the River Shannon.
It is the third largest peat-fired power station in the country and has a 15-year contract to burn peat supplied by Bord Na Mona.
It was constructed as a replacement to the ageing 85MW Lanesboro Power Station. The new plant allowed ESB to reduce gas and dust emissions.