Business Green: Two years in the making, green energy provider Ecotricity will today unveil a 170mph electric sports car, ahead of a crack at the British electric car land speed record in 2011. Chief executive Dale Vince will debut the car, dubbed the Nemesis and powered solely by wind energy from the company’s 51 UK turbines, at today’s RAC Brighton to London Future Car Challenge. Nemesis has been something of an obsession for Vince, who commissioned the car to “blow the socks off Jeremy Clarkson and smash…