Gas-powered vehicles remain essential to driving equation
Super-fast recharging stations on highways just don’t make cents, writes David Booth.
Anyone who tells you the electric car in your future will be just as convenient as the gasoline-fuelled vehicle you’re driving now is lying. If not overtly, then at least by omission.
Nor can they plead ignorance: the calculations required to reach this conclusion are hardly the stuff of graduate-level physics. Judging from the experts I’ve spoken with, plenty have been the warnings proffered to the politicians, policy-makers and futurists advocating an all-battery-powered future.
Now before you go all Tesla on me and start putting angry pen to paper, let me first give credit where credit is due. In an emissions-free automotive world, the electric vehicle is king of the inner-city commute. The ability to recharge at home — during off-hours, minimizing the load on our grids — is convenient. Their torquey motors are perfect for the point and shoot of inner-city traffic, and their range more than ample for 90 per cent of commuters.
I also trust battery technology will get lighter and more dense, so the 100+ kWh batteries of the future won’t all weigh a thousand pounds. Nor is the tired old bugbear — “all that electricity is being generated by coal” — likely to be a problem in 20 or 30 years, the cost of renewables hopefully coming down to a manageable level.
Instead, the problem for our all-electric future — now California is said to be following France and England’s banning of the internal combustion engine — is one of power transmission. More specifically, as one industry expert summed up the situation, “the bottleneck (clouding the future of the electric vehicle) is local distribution.”
That bottleneck is going to be the highway service stations required to service North America’s 300 million now-electric cars when we don’t have access to the convenience of our home chargers.
Consider the following scenario: on Labour Day weekend, like so many holiday weekends, pretty much every fuel pump on the side of my most frequently travelled highway — Ontario’s 401 — was, er, pumping nonstop.
That, for anyone thinking of following along with my calculus, is a station roughly every 80 kilometres, each with up to 16 pumps, each capable of pumping about 30 litres of gasoline in a minute. In other words, discounting credit card transaction and unscrewing of gas cap, even the most ardent gas-guzzler can take in enough fossil fuel for 500 kilometres of driving in about two minutes.
Now consider this: An EV that can guarantee 500 km requires at least 100 kilowatt hours of battery. Do the math and a similar two-minute recharge would require three megawatts. That, for those who don’t have an electrical engineering degree, is 3,000 kilowatts (3MW) of power.
Now for some perspective. Today’s fast chargers boast about 50 kW. Yes, that’s essentially 1/60th of the charging capacity required to match the refuelling rate of a gas-powered car. Serving the same number of cars could, then, require as many as 960 charging stations (and the cars would still have to sit there for two hours to fully charge).
But, isn’t Porsche promising a 20-minute charge for 400 km of range, you ask? Doesn’t that mean we’ll soon see EVs capable of matching those two-minute recharges?
Well, yes, Porsche is making just such a promise. Unfortunately, that would seem to be the practical limit of how fast we’re going to be able to recharge these electrical behemoths. The 350kW rechargers required for those promised 20-minute refuelling is likely the upper limit of the equipment we humans will ever be allowed to handle. These 350kW rechargers generate so much heat that the cables carrying all that current need to be liquid cooled. Anything that can recharge our batteries faster than 20 minutes will have to be automated, i.e., phantasmagorically expensive.
How expensive? As I mentioned, you’ll need about 60 50kW rechargers to replace one fuel pump; about eight of the 350kW variety. That, as I mentioned, would mean 960 of the low-powered 50kW units at each rest stop, or 128 of the high-tech 350kW versions.
Have I mentioned that even those low-powered 50kW fast chargers cost about $40,000 each? A 350kW item will be about $200,000. Faster-charging automated versions would cost upward of $500,000 each. In other words, each and every roadside station will cost somewhere between $25 and $40 million in recharging equipment alone.
They’ll also need somewhere between 30MW to 40MW of power. Thirty megawatts, for perspective, is enough to power about 20,000 homes, or about the same amount of electricity as a city with a population of 75,000. Oh, and by the way, all that electricity, unlike off-hour, home recharging, happens during peak-usage daylight hours.
All that extra power, at least for intra-city travel, will have to come from new — not existing — sources. At the most optimistic prices posited for the future cost of solar panels — about a buck a watt — that’s another $30 million to $40 million. Just as further reminder, that’s for each roadside station.
And for those thinking there may be some breakthrough in the future that will allow faster recharging, know that while battery technology is still in its infancy, electricity generation is a mature technology and the laws of power transmission are likely to remain immutable.
So I will ask the same question I raised in the first part of this inconvenient truth series: If we can reduce 75 per cent of greenhouse gas emissions by banning gasoline in urban centres, but allowing it for inter-city travel, why are we going through the trials and tribulations of rebuilding a refuelling infrastructure that already serves us so well?