Don't forget to discuss..
what fuel will be used. I notice that you use the word "drive" in "drive our cars" and not "fuel our cars" i.e. get the energy to the wheels. Remember that electricity and hydrogen are not "fuels" - there are no hydrogen collectors or electricity mines. Hydrogen is currently mostly obtained from non-renewable sources (hydrocarbons) so it's use in cars is simply moving greenhouse gas emission elsewhere. Someone needs to calculate just how much more electricity the UK will need to eliminate oil consumption. Currently we consume around 70 million metric tonnes of oil per year (2016) for all uses (dunno how much in vehicles). According to www.unitjuggler.com that equates to around 850,000 Gigawatt hours in comparison with about 360,000 Gigawatt hours of electricity generated in 2016 (admittedly around 10% of that from oil). They could be powered by wind turbines i.e. using wind as the fuel. At around 6 gigawatt hour per year each I suppose we will only need around 150,000 more wind turbines added to the 8500 we already have. This is not a highly researched observation, just 15 minutes with Wikipedia and other public sources. ANY conference on replacing oil consumption in favour of carrying some other energy by electricity should have this calculation done with considerably better accuracy.