A consortium led by UK utility Centrica has finalised a deal to buy the energy business, with Brookfield acquiring the wind business.
The Canadian firm said that it expects the onshore portfolio, all in Ireland, to exceed 500MW by the end of the year.
The company said the acquisition represents its first renewable investment in Europe and will provide it "with an established platform from which to grow the business through continued acquisition and development".
Centrica and Icon Infrastructure will take on the rest of the business, which includes gas power stations and a gas and electricity supply network with around 650,000 customers.
The deal is expected to be completed in the second quarter of this year and is still subject to regulatory approval.