The work, which is set to be carried out by SSE, will take place from 8th February, and are expected to take five weeks.
The first phase starts in Tower Street, heading down Jewry Street towards St Peters Church, while the second phase of the work will work begin on the opposite side of Jewry Street outside St Peters Church, heading towards The Old Gaolhouse.
Steve Brine visited the SSE depot in the New Forest in January to see their winter planning in action and was fully briefed on the city centre work they are committed to. He said: "Concerns around power supply in this part of town have plagued businesses for many years so I've been clear with SSE we need robust action, and investment, to safeguard the supply.
"It's taken a while, and there will be some real disruption while the work is carried out, but this is welcome and will make a tangible difference."
Pictured; Steve examines a model which demonstrates how our electricity supply works, during a visit to SSE in January