Several agencies have been shortlisted for the consumer and corporate account, which has been held by Golin for four years.
The review is being led by npower's newly promoted head of PR, Zoe Melarkey, and Ingenuity has been involved in selecting agencies for pitches, which PRWeek understands will be held shortly.
The PR roster that had been in place prior to Golin's 2013 appointment was worth about £1m annually.
That appointment followed the hiring of E.ON's Guy Esnouf as external comms director, and npower finishing bottom of consumer group Which?'s annual energy satisfaction survey for the second consecutive year. The firm again occupies that position in the 2017 iteration of the survey.
The new review comes at a time when the energy industry is again a political hot potato, with Prime Minister Theresa May recently indicating her preference for a firmer cap on energy pricing than had been expected by some.
Exclusive: Theresa May risks Tory backlash as she unveils energy price cap for 18 million households https://t.co/s5JI7BNZmm— The Telegraph (@Telegraph) October 12, 2017
Golin also recently lost its consumer PR brief with Sainsbury's.
Also this year, the agency's London office won new briefs with Premier Inn and chocolate brand Green & Black's, and its executive creative director, Charlie Coney, relocated to Golin's Los Angeles office.