Boris plugs the Renault Fluence Z.E. at EcoVelocity

Can anything upstage London's ebullient Mayor, Boris Johnson? He was active on both sides of the Thames yesterday, with wheelchair tennis in Trafalgar Square and a test drive of Renault's Fluence Z.E. saloon at Battersea Power Station.

London's great white elephant (I mean the Power Station) was hosting Boris and EcoVelocity 2011, the Low Carbon Motor Festival. UK consumers got their first sight of the 100 per cent electric Fluence Z.E when the Mayor took part in the opening parade of electric and low-carbon vehicles.

Swapping his usual bicycle for something with a more 21st-century profile, Boris said: "I was delighted to try out one of Renault's electric vehicles and glide it silently around the EcoVelocity test track." It seems unlikely that Boris would do anything quietly, so perhaps Renault's stylish 5-seater has more going for it than I realised.

The four-door Fluence Z.E will go on sale in the UK in the first half of 2012. (Just in time for those Olympic traffic jams.) It will be priced from £17,850 on the road -- that takes account of the generous deduction of £5,000 for the government's Plug-In Car Grant. That scheme runs until 31 March 2012 and also covers vehicles like the Vauxhall Ampera, Chevrolet Volt and Toyota Prius Plug-In.

An extra financial incentive for Fluence Z.E buyers is that they will be hiring rather than purchasing the vehicle's lithium-ion battery. So, for £69.60 per month (including VAT) you can banish your fears of battery longevity and replacement costs.

Renault's vision for an electric vehicle future also includes the two-seater Twizy, priced at a competitive £6,690 and an electric van, the Kangoo Van Z.E.

Not content with covering the Capital with bike stands, Boris is also firmly behind the Source London network, which aims to provide a membership scheme with 1300 charge points in place by 2013.

EcoVelocity 2011 will run from 8-11 September -- unless those "range anxiety" fears prove valid and it runs out of juice.