Motor Mouth: More inconvenient truths on banning gas engines
High-speed EV recharging stations on highways sound great – until you hear how much they would cost
Anyone who tells you that the
electric car in your future will be just as convenient as the
gasoline-fueled vehicle you’re currently driving is lying. If not
overtly, then at least by omission. Nor can they plead ignorance, the
calculations required to reach this conclusion hardly the stuff of
graduate-level physics. Indeed, 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 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
perfect for the point and shoot of inner-city traffic, and their range
more than what is needed by 90 per cent of commuters. I also trust that
battery technology will get lighter and more energy dense so the 100+
kilowatt-hour 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.
Consider the following scenario: last Labour
Day weekend, like so many holiday weekends, pretty much every fuel pump
on the side of Ontario’s 401 was, er, pumping non-stop. That, for
anyone thinking of following along with my calculus, is a station every
80 kilometres, each with up to 16 pumps. More importantly, each of those
is 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.
But consider this: an EV that can guarantee
500 klicks 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.
Now for some perspective: current fast
chargers boast about 50kW. Yes, essentially 1/60th of the charging
capacity required to match the refueling rate of an everyday gas-powered
car. If you’re reaching for your calculator, I’ll save you the trouble:
Serving the same number of cars could theoretically require as many as
960 charging stations (and they’d still have to sit there for two hours
to fully charge).
But isn’t Porsche promising a 20-minute
charge for 400 kilometres 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, however, that would seem to be the practical
limit of how fast we’re going to be able to recharge these electrical
behemoths. Indeed, The 350kW rechargers required for those promised
20-minute refueling is, according to the experts I spoke with, likely
the upper limit of the equipment we humans will ever be allowed to
handle. In fact, these 350kW rechargers generate so much heat, their
amperage is so incredibly high, that the cables carrying all that
current need to be liquid cooled. And 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 for every pump. That, as I mentioned, would mean 960 of
the low-powered 50kW units at each rest stop and 128 of the high-tech
350kW versions. Have I mentioned that even those low-powered 50kW fast
chargers cost about $40,000 apiece? One of those faster-charging 350kW
items? About two hundred large. Faster-charging automated versions would
cost upward of a half-million each.
Even a more conservative estimate taxes
one’s calculator. Factoring in the aforementioned credit card
transaction and washing of windshield that might extend gasoline
refueling to five minutes, it would still require 600 of those 50kW
chargers for a roadside station to service the 2,000 cars those gas
pumps could service in a busy 12-hour period. Even that conservative
estimate would require a $24-million investment just for the cheapest
rechargers.
They’d also need about 30 megawatts of
power. For those thinking that’s a sh%$-load of electricity, you’re
right. Thirty megawatts, for perspective, is enough to power about
20,000 homes. In other words, powering these service stations of the
future will require about the same amount of electricity as a city of
75,000. Oh, and by the way, all that electricity, unlike off-hour home
recharging, happens during peak-usage daylight hours.
In other words, 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. If you
want to go the windmill route, you’ll need 10 of them, each costing
roughly $4 million. Just as further reminder, that’s for each and every
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 in its infancy, electricity generation is a mature
technology and the laws of power transmission are likely to remain
pretty much immutable.
Lastly, I’d like to mention that so
outrageous were the numbers these calculations generated I felt obliged
to contact numerous experts in the field to check my calculus. To a
person, these experts — infrastructure engineers, EV prototype designers
and the heads of entire EV programs — didn’t know how, indeed if, the
problem of recharging an entire fleet of battery-powered cars could be
solved. Most said that some form of range extension would be a far more
practical solution.
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 internal combusting for inter-city travel (as is
possible today with extended-range EVs), why, again, are we going
through the trials and tribulations of rebuilding a refueling
infrastructure that already serves us so well?
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