Some good points and concerns Richard, however lets see if we can talk you around with a bit more analysis and number crunching.
RichardW wrote:We don't have enough generating capacity to keep the lights on at present - there is no room for loads of electric cars.
Lets crunch some numbers to see how much electricity use it would take if I was to start driving a Tesla Model S tomorrow - which as electric cars go is a big heavy car and therefore has a relatively low miles per kWh figure compared to a smaller car.
It averages about 3 miles per kWh and I'm currently doing about 300 miles a month. Our current existing electricity usage (thanks to a loop energy monitor) is approximately 320kWh per month, I say approximately as I haven't had loop a full month yet.
Charging the car at home would use 100kWh per month, requiring me to charge the car at least once a month and increase my monthly electricity use to 420kW/hour - a 37.5% increase, which is quite significant but not earth shattering in the big picture. At our current rate of 12.8p per kW/hour this electricity would cost me £12.80, however this would be in lieu of about £90 worth of petrol.
If I had dual rate electricity I could set the car to charge off peak during the night at roughly half the cost again and help to avoid overloading of the grid during peak hours. I would wager that if everyone charging their EV's did so during off peak times like the middle of the night the current grid could cope as is, as it is underutilised in the off peak hours, not to mention that everyone is not going to suddenly switch over to EV's at once - it will be a gradual process that gives time for the electricity grid to keep up.
Also smaller cars like the Tesla Model 3, Chevy Bolt etc should do significantly better miles per kWh than a big heavy Model S.
So I don't see the ability of the electricity grid to keep up as a significant hurdle. As far as generation capacity goes - if you're not burning all that oil as refined petrol and diesel then (short term) you can burn it to generate the required electricity needed for the EV's while renewable sources are built out, which segways nicely into your next point...
They only 'move' the pollution from the car to power station in any case (unless its' running on renewables, but they're not very consistent!) - but I can see there are advantages to this from City air quality point of view.
This is a massive but often quoted fallacy - that you're only shifting the pollution and problem upstream to the power stations which are "probably" burning coal or other polluting fuel source. There are multiple solid points against this line of argument that I can think of just of the top of my head, so here goes:
1) This argument assumes that power generation continues to rely on nuclear and fossil fuels in the same mix as today. When vehicles are widely electrified there is much more incentive to build more renewable resources like wind farms because then these sources of energy can power the nation's transportation. Fossil fuels can be (temporarily) burnt to provide electricity to power EV's during a transition period, but renewable energy generation cannot be used to create fossil fuels to power diesel/petrol vehicles. (Ignoring the electricity used in the cracking and refining process - but electricity alone doesn't get you petrol and diesel out of thin air) So the transition to more renewable's will follow car electrification rather than preceding it.
2) This argument completely and utterly ignores the fantastically higher efficiency of an AC induction motor vs an internal combustion engine and conventional gearbox. I could write a whole article on this point alone.
The best state of the art 60MPG diesel engines today mated with a manual gearbox will get you AT MOST 30-35% efficiency from chemical energy in the fuel to wheel horsepower. And this is over a narrow set of "optimal" driving conditions, eg constant low speed in top gear. (about 40mph) As soon as you accelerate hard efficiency goes way down. As soon as you use lower gears efficiency goes way down because your engine RPM is high relative to the road speed. As soon as you sit idling in a traffic jam or at a stop light your efficiency goes down to ZERO percent. Every time you press the brake pedal to slow down in stop start traffic energy is thrown away. Add an automatic gearbox in place of a carefully driven manual and efficiency goes way down especially in stop start traffic.
In short even 30% is a fairy tale figure - average efficiency over typical driving is probably more like 10-15% when idling, stopping and starting, accelerating and use of low gears is taken into account. But lets just pretend for a moment that it is 30%.
Contrast this to an AC induction motor as used in a Tesla - which has over 90% efficiency under almost all load conditions with very little change in efficiency from slow speeds to fast or low loads to heavy acceleration. That's at least 3x the best efficiency a diesel can give you right there. Battery charge to discharge losses I believe are under 20% so the majority of the energy you charge with does reach the motor. Now factor in regenerative braking, which can be over 80% efficient at recovering kinetic energy to charge the batteries, with a maximum of approximately 50kW of instantaneous regeneration ability on a Model S. It's perfectly feasible to drive the car without even pressing the brake pedal regeneration is so good. Regeneration will further contribute to effective efficiency versus a car where braking energy is thrown away.
In short the total amount of energy provided by the power station to do the same number of miles is 3x less - so even if the power station was just burning petrol or diesel straight away you've reduced your emissions by a factor of 3x - which is not to be sneezed at. But it gets even better...
The 30% efficiency figure of a diesel car could only be achieved under ideal driving conditions - eg not very often. But a stationary generator in a power plant doesn't have to worry about starting and running cold, operating under widely different loads and engine RPM etc..It also doesn't have to be designed to be light, compact and cheap. It can be designed to run at a specific optimal RPM, with an optimal load and be designed to be very efficient there. It turns out that a fossil fuel stationary generator can reach efficiencies of up to about 60% due to being optimised for such a specific operating condition.
So you have a further 2x improvement in the use of fossil fuel by burning it in a large, specially designed stationary engine instead of in millions of car engines. So now we have a 6x improvement in fuel use over just burning the fossil fuel in a diesel car and probably 12x over a petrol car.
As far as pollution goes - its far easier to control pollution from a large power plant sized stationary generator that is under proper controls and regulations than it is to control the pollution from millions of individual car engines. A good example is a catalytic converter in a car - an ingenious invention that has done a massive amount towards reducing pollution, with one major flaw - it doesn't do anything until it warms up... so while the emissions from my Xantia are very low when hot, the first few minutes of driving have high emissions due to the cold cat. In a car that does lots of small trips this is a major issue.
Also cars frequently have faults like faulty coil packs that cause high emissions, how many of these go unnoticed until the MOT failure a year later, meanwhile pumping out extra pollutants unchallenged.
A stationary engine can be running all the time with an always warmed up and much more sophisticated catalytic converter and emissions control system. So even if it burned the same amount of fuel (instead of 1/6th) the pollution would still be less.
Yet another gain is you don't have to burn diesel to drive a fuel tanker that is carting thousands of gallons of fuel to service stations...once the electricity infrastructure is in place, you can "transport" that electric energy across the country essentially for free, rather than transporting physical fuel.
In short, centralising the burning of fossil fuels to generate electricity for EV's improves efficiency and reduces emissions dramatically compared to spreading it across millions of potentially poorly maintained (de-FAP'ed anyone ?) vehicles, even if more renewable sources were not added.
So I completely refute the notion that electric cars only push the problem further upstream, even in the short term.
However, the biggest bar is cost. Only a very few people are going to fork out £25 grand for a 70 BHP supermini, with a range of only 100 miles or so, that is going to save them maybe £100 / year in fuel costs (or alternatively over £100k for a Tesla with a decent range).
And once a move is made to E-cars, and the dino fuel tax starts to dry up (which is what makes it 'expensive'), HMG is going to start looking elsewhere. Oh, electric cars, they must need a 'fuel' tax.....!
I do 15k miles a year, for a current cost of £1700 diesel - even if I saved 80% of this, it's going to take a loooooong time to re-coup the cost of an E-car. And I'm not sure it would manage the 60 mile round trip in deepest darkest cold wet Scottish winter.
I still need a lot of convincing!! Although I'd jump at a Tesla if I had £100k burning a hole in my pocket. Sadly, I don't....
I don't know where you're getting 70BHP from for £25k
I don't want to be a Tesla fanboy but I'm pretty familiar with their tech and not that familiar with most other brands.. but the Model S is an expensive car competing with high end luxury cars - not something you or I would ever afford...
It's also a bit big physically for the UK market - its a full foot wider than my Xantia so it wouldn't even get through my gate, let alone fit in Asda car parks!
But take the smaller Model 3, due in 2018. Entry level price is said to be $35,000 US, so lets be pessimistic and call that £35,000 as well. For this you get a car with 215 miles of range and a 0-60Mph time of less than 6 seconds. It will probably still weigh about 1800-1900Kg (vs the Model S's 2400Kg) so to do that sort of time its going to be at least 250-300bhp. (The top of the line AWD Model S is 770bhp) For acceleration even the entry level Model 3 will kick my Xantia V6's arse and do it with a fraction of the running costs. It won't be any 70bhp slouch that's for sure...
It would have absolutely no trouble doing your 60 mile daily commute with a top up each day or a full charge every 3-4 days.
As for recouping the cost of the car - I could apply exactly the same argument to replacing my £500 20 year old gas guzzling but otherwise seemingly reliable Xantia V6 with a brand new £25,000 diesel car. As I do only 6000 miles per year in terms of ROI it would be a massive loss that probably wouldn't ever pay itself back even if I ignored financing costs - I'd get 2-3x the MPG but it would never come close to offsetting the purchase price of the car. Comparing a brand new electric car (even at £35k) against our old petrols and diesels on a ROI basis is just as unfair a comparison.
But take that £35k electric car and buy it when it is £5000 and 10 years old and still uses a tiny fraction of the energy of a diesel, and now you have a no brainer, especially when diesels will be outlawed in many large cities by then...
People like us just need to wait patiently until cars like the Model 3 are well into the second hand market, by that time the economics of switching will be undeniable.