From Hammond's speech to the Tory Conference:
….. let’s not forget that over 80% of all journeys are undertaken by car ... Clearly, while motoring was synonymous with carbon production, it couldn’t be a major part of Britain’s future transport plans.
But the idea that the only solution is to force people out of their cars is pessimistic, outdated, Labour dogma. This Government is supporting the ultra-low emissions technologies that will see the carbon output of cars plummet over the next two decades.
Drawing fuel, not from petrol pumps, but from an electricity grid which Chris Huhne is determined to make one of the greenest in Europe. The Coalition has signaled its commitment to de-carbonising motoring by confirming, ahead of the spending review, grants for R&D and generous consumer incentives for every ultra-low emission car sold.
So motoring can again become part of our future transport planning, as the greening of the car saves it from extinction and that means we can end Labour’s indiscriminate war on the motorist as we focus on the real enemies – carbon and congestion.”
Let's look at the feasibility of replacing some or all fossil-fuelled cars with electric cars.
The electric Nissan Leaf has a 24KWh battery pack, which the manufacturers claim gives a 100-mile range. Let's say the owner drives 12,000 miles a year, which in the UK is average. . Over a year the car will consume 2880KWh, that is, 2.88MWh. As Hammond says, we're not "forcing people out of their cars", which means we need to assume mileages stay as the are currently, if they don't actually increase.
So every million electric cars will consume 2.88TWh.
How many cars are there in the UK? Around about 30M.
So the power you would need to enable those cars to drive 12000 miles a year each would be 86TWh.
The annual electrical energy used in the UK is currently around 360 TWh. To produce 86TWh using renewables, you would need approximately 30,000 1MW turbines. Currently, the UK is aiming to increase the percentage of electricity generated from renewables from 2% to 15% by 2020. 86TWh is nearly twice as much additional renewable gneeration capacity. (I'm ignoring transmission losses here.)
So to power the existing UK car fleet based on current mileages would require an increase in generating capacity of 24%. However, I've not taken into account commercial vehicles, which would up the total considerably - cars only represent 55% of UK transport-related carbon emissions. I've also not taken into account the charge efficiency. Not all the energy you put into charging a battery ends up as stored electrical energy, so this puts the total up further still.
Bear in mind that this required increase in generating capacity is taking place against a backdrop of decarbonizing electricity generation. There's no point in replacing petrol cars with electric cars if the electricity is fossil-fuel-generated. Fossil-fuelled power stations must therefore close, and this capacity will need to be replaced by renewables or nuclear. It is also likely that oil and gas as heating fuels will be partly replaced by electricity. While this may be offset by better home insulation, it's unclear what the net effect on electricity demand will be. Higher summer temperatures may increase the use of air-conditioning, which will inflate electricity demand.
This really is desperate stuff from Hammond. He's already demonstrated that he doesn't understand transport, he also clearly doesn't understand the laws of physics. The idea that we can continue to drive the same amount of miles as we do today is somewhat beyond believable. To base a whole transport policy on such fantasy runs the risk of breaking the whole economy. If we don't start to give the signals now that both businesses and individuals must drive fewer miles - massively fewer miles - we'll have a country that is totally dependent on cheap energy just at the point when energy becomes expensive. We'll face an energy deficit. Unlike a fiscal deficit, you can't live beyond your energy means - you cannot 'borrow' energy and pay it back in the distant future.
See also this piece from the admirable Lo Fidelity Bicycle Club.