The power companies are going to love that!
I couldn't resist whipping out Google and the calculator and doing a rough feasibility study.
Looking at electric car stories, the first thing journalists and reviewers look at is the speed and range in miles per charge (mpc) of a vehicle, but the total energy of charge (kWh) is at least as important as it gives you an indication of how much juice it's going to be pulling out of the grid for how long.
I decided to grab 80 km (50 miles) as my benchmark for the daily use made of a car in our societies.
Some examples...
Bubble cars - the Zap range of bubble cars and mini trucks which do 40 km on 4.75 kWh, which we could say would be 80 km on 9.5 kWh if they had bigger batteries.
Sedans - there's a DIY-job electric car on How Stuff Works, the claim is it needs 12 kWh for 80 km.
Trucks - Ford Ranger EV (pick-up) works out as 17.7 kWh for 80 km.
Future stuff - GM's Volt concept car needs 12 kWh for 80km, though its range is shorter and capacity lower. Recharge time is given as 6 - 6.5 hours.
For the sake of convenience, let's say the current generation of cars needs 6 hours to fully recharge and needs a 12 kWh charge every day, with light trucks needing 18 kWh. A car or a truck therefore places a 2 kW or 3 kW electrical load respectively, for 6 hours, which is akin to keeping a kettle on the boil for that long.
There are 32m cars in the UK and not all see daily use, so assuming only 10m were plugged into the grid at the end of rush hour, the additional load would be 20-30 GW.
Here is a demand profile, 60 GW winter peak and installed generating capacity is 79 GW. As you can imagine, the demand surge at the end of a working day is going to look like
a break during/after a major televised sporting event. That's difficult enough to manage, they are considered exceptional events on the system and the response is choreographed weeks in advance, every gas turbine and every bit of pumped storage is on standby and waiting for the signal when they take place. Making it the norm? Increasing the swing from < 3 GW to up to 30 GW? And extending the moment for hours? Ouch.
Even assuming some sort of timer device ensures the cars only recharge at a random spread of hours between 22:00 and 06:00, when demand falls off to baseload (plus that would be incompatible with some people's schedules), it would still require an expansion of availability of quick-response generating capacity (ie CCGTs) and scheduling coal-fired plants to run longer.
So how much of your country's coal and natural gas do you want to waste on personal motoring?
Aside from longer uptimes and increased coal / natural gas usage, the other major change would simply be
more of everything, expanding installed generating capacity by a third and making corresponding changes to existing transmission and distribution infrastructure. Do not underestimate how far-reaching the impact on the existing asset base would be. The value of power system assets in the UK alone is around £80 bn. Upgrades would cost each car owner £2500 just for the network hardware; if you include construction costs, that figure swells. Need I add which way the estimates will go if you factor in rising commodity prices as energy gets more expensive?
They could make the batteries twice as efficient and we're still talking tens of GW of additional electrical load in large industrialised countries, and reworking of existing infrastructure.
I will assume the issue of switched-mode power supplies and feeding harmonics into the system has been solved on-board. Otherwise that's another nail in the coffin.
I also considered the personal financial costs. My 40 mpg car does 660 km on a single £44 tank of fuel. From my domestic electricity bill, running a plug-in electric car the same distance would cost only £10. But the former figure includes the cost of appropriate supply infrastructure - the filling stations are already there for everyone. It makes economic sense to go electric so long as the parasites leeching off the network are few in number, but if everyone does it, I would have to pay the £2500 for network expansion / replacement as detailed above, plus the same again in manpower costs, through rising electricity bills. Over a 100,000 km lifetime of the car, that would come to an additional charge of £33 for the same 660 km in journeys, a total of £43. Compare that to my £44 tank of fuel. If everyone switched at today's oil prices, I would be financially no better off than if I stuck to petroleum.
That's no coincidence. The electricity networks aren't built with plug-in electric cars in mind, so if you want all the functionality of the petroleum distribution system in electric form, you are going to have to fork out the same cash. Your share of the cost of total asset replacement is as reasonable a rule of thumb as any.
To summarise, electric cars only work if a minority has them, and that minority is so small as to have a negligible impact on electricity networks, thus not necessitating any changes or expansion. Otherwise, you are in exactly the same boat, only you are burning coal and gas in vastly increased quantities.
Personal motoring is going to die post-peak, a wholesale conversion from petroleum to plug-in whatever is not possible unless the electricity is generated renewably off-grid, and the car manufacturers are only talking up mass ownership because no-one is going to buy them otherwise, for fear of limited product support.
The real technological bottleneck is not what's in the car. The true cost of ownership actually rises with more widespread use.