A Dublin-based energy firm has announced that it will begin selling electricity to households in Northern Ireland from next month.
Airtricity will be the first company to compete with NIE Energy in the domestic electricity market.
The company says that its entry into the NI market will create 75 jobs, a number that it believes will rise as its business grows.
It is expected that it will intially undercut prices by about 14%.
The discount is expected to stay in place for at least 12 months and will cut the average household bill from £500 to £430.
Energy companies based in Ireland operate both north and south of the border under different guises.
However, Airtricity's entry into the market in Northern Ireland means that for the first time, domestic customers throughout the island will be able to buy the same brand of electricity.
Airtricity managing director Kevin Greenhorn said it was "fantastic news" for the consumer.
"Consumers want competition as it will not only drive down their energy costs but also provide families across Northern Ireland with the real choice and real savings in their electricity supply that they have been anticipating for so long," he added.
A spokesperson for NIE said that it recognised a new entrant to the domestic market gave customers more choice.
The spokesperson added: "We have been preparing for a more competitive environment for some time. Last year we reduced our prices by 15% and we are due to make another pricing announcement within the next few months."
Meanwhile, Energy Minister Arlene Foster has welcomed the announcement by Airtricity.
The minister said that it "is proof that the Single Electricity Market has delivered transparency and increased electricity supply competition for domestic customers in Northern Ireland".
"Customers will be able to compare electricity costs and levels of service being offered before choosing their electricity supplier."
The chief executive of the Consumer Council, Antoinette McKeown, said the announcement was "good news".
She added: "The Consumer Council hopes that this competition will bring lower prices, which will in turn help tackle our unacceptable levels of fuel poverty in Northern Ireland, with one household in two currently struggling to pay its energy bills."
The move has also been welcomed by the chief executive of the utility regulator, Iain Osborne.
"Consumers have told us that they want a choice of electricity supplier and we have worked vigorously with potential suppliers to make this happen," he said.
"As a regulator, we will carry on with our work to protect the interests of consumers by continuing to control the prices of NIE Energy and ensuring all suppliers provide a quality standard of service."