London electricity substations need revamping to the tune of £210 million, according to the Mayor Boris Johnson.

Declaring a “real wake-up call”about the needs of the capital yesterday he said its population is forecast to rise 37% to more than 11 million people over the next half a century.

Launching a London Infrastructure Plan 2050, he claimed demand on energy supplies is set to increase by 20% during a period where demand on electricity supplies is forecast to more than double.

Meanwhile Thames Water reckons demand for water could exceed supply by 10% in London by 2025, he said.

A short term investment of £210m on electricity substations is required but in the long term, Mr Johnson said changes to the regulatory regime must be considered as well as plans to supply a quarter of London’s energy from local sources and exploit the capital’s waste heat resource.