Upgrade works will include a new substation and a Thames tunnel.

Electricity supplier EDF Energy is to spend £2bn upgrading London’s electricity networks over the next five years.

Beginning next month, the utility company, owned by French electricity giant EDF, will spend £400m in London and the South East.

Vincent de Rivaz, the chief executive of EDF Energy told The Times: “Some of our networks are over 40 years old. We will be embarking on the biggest investment for a generation to increase quantity, quality and security of supply.”

EDF Energy will spend £20m on a tunnel under the Thames and a new primary substation will be built behind the Tate Modern art gallery.

The remainder of the £2bn boost will be spent on replacing high-voltage equipment at substations in north and South West London and towards the cost of trimming trees close to power lines.