There was confusion yesterday as the Mayor of London, Boris Johnson announced the establishment of a green technology fund for the capital.

Initially, Johnson told the BASELondon sustainability conference in London: “We are setting up a half a billion-pound green fund to leverage new green technology in the city.”

However, when answering a question in the audience, Johnson said that the green fund would have “£100 million from the London Development Agency (LDA) to leverage in more investment in the private sector”.

A spokesperson for the LDA confirmed the latter figure, and added: “If we can attract investment up to half a billion pounds that would be great.”

In his speech outlining his plans to make London “the low carbon capital of the world”, the mayor referred to a range of transport initiatives, including Transport For London’s plans reduce energy consumption by putting LEDs in traffic lights, and encouraged the use of electric vehicles.

To this end, Johnson said: “We are working with the supermarkets to put charging points [for electric vehicles] in the car parks.”

Other initiatives Johnson launched include the setting up of a “Green Enterprise District” based in Thames Gateway in East London. It aims to attract green companies, jobs and innovation to the area. Siemens has kicked off the initiative by announcing a plan to invest £30 million in a new sustainable building in the area, comprising an exhibition and conference centre with a 300-seat auditorium. The new 'Siemens Pavillion' is set to be built and operational by early 2012.

According to the LDA, London generates around 47.5 million tonnes of CO2 a year, which the Mayor of London aims to reduce by 60 percent by 2025 compared to 1990 levels. The green technology investment fund of £100 million will be divided into three tranches, covering waste and recycling infrastructure, decentralised energy and energy efficiency.

Johnson recently promised that "every lampost and every bus stop will one day very soon, and before the 2012 Olympics, be wi-fi enabled".