The boilers fed steam to four turbo-alternators:[4] Condenser cooling water, 6.09 million gallons per hour (7.69 m3/s) was drawn from the sea.

Supplying all of Belfast and most of the eastern half of the province, Northern Ireland was effectively brought to a standstill when the mainly Protestant workers of the plant were persuaded to join the strike.

In 1992 the four power stations at Belfast Harbour, Ballylumford, Derry (Coolkeeragh) and Carrickfergus (Kilroot) were demerged and sold.

In 1993 the remainder of NIE (transmission, supply and retail businesses) was privatised as Northern Ireland Electricity plc.

As a result, Northern Ireland Electricity sold the Ballylumford site to Premier Power, a subsidiary of British Gas.

On 12 August 2010, the AES Corporation announced that its subsidiary, AES Ballylumford Holdings Limited, had acquired Premier Power Limited (PPL) from BG Energy Holdings through an all-cash transaction for £102 million (approximately $160 million), which included purchase price and working capital adjustment.

[8] Ultimately Kilroot was retained, but the "B" station (which had gradually decommissioned most of the six generators due to emissions requirements) finally closed in 2018.

[9] In April 2019 AES Corporation has agreed to sell Ballylumford to EP UK Investments, a subsidiary of Energetický a průmyslový holding.