It is fun to think about how machines might work in the future. I will let
someone else work out the kilowatt hour and amperage details. Here are some
other ideas about this subject.
OrionWorks wrote:
I seem to recall Mike Carrell once cautioning the Vort readership of the
fact that there is a practical limit as to how fast batteries can be
recharged. Pushing too much juice within a finite amount of time could
cause our auto batteries to vaporize.
The latest Japanese electric car prototypes can be recharged 90% in five
minutes. I gather that a 15 minute charging time will be possible without
undue stress or heat.
I do not recall Mike Carrell describing exploding batteries, but I recall
that he pointed out that a highway charging station that handles a dozen
automobiles would draw a terrific surge of power. I have an idea about that.
When millions of electric cars are manufactured, the price of batteries
will fall, and reliability and capacity will increase. A charging station
may be equipped with a large "battery of batteries" to act as a buffer.
Power companies use giant batteries now for load balancing. Power companies
may even want to make arrangements with highway charging stations to have
the stations act as load balancers, feeding power back into the system on
demand.
So I was thinking to myself, you drive into a power station and electricity
is transferred from a stationary battery to your car battery. On the face
of it, it would make more sense to simply swap out the batteries. Put a
fully charged battery in your car, and leave the discharged one behind to
be recharged at leisure. This scheme has been proposed many times since the
1960s, and I have often mentioned it here. I recall a drawing in Life
Magazine (or Popular Mechanics) showing life in the future, with a forklift
removing a tray of batteries from a car, swapping them out for a new set.
Mike Carrell thought this would be impractical because of ownership issues:
Who would own the battery? Who is responsible for defects? What do you do
with old batteries?
I think this scheme might work if batteries are treated the way barbecue
grill propane gas tanks are today. You would rent them. They would belong
to the power company, or possibly to the power station chain. But you could
rent a battery at QTrip and return it to BP Power, and no one would care.
They would have elaborate electronic bookkeeping to keep track of
batteries, with barcodes and RFID tags. This is what is done on railroads,
where freight cars from different railway lines and private corporations
are mixed up together to form a train. A car from the Union Pacific
Railroad might spend months on a Southern Railway line.
But anyway, let us assume people do not want to do this. Or assume it is
mechanically unwieldy to change out the battery pack. Even in that case,
after you recharge, it would be nice to drive off carrying one of those
large, fresh stationary batteries from the charging station. That would
extend the range of your car. And why not? Maybe the charge station can
offer something like a small U-Haul trailer, that you attach to the back of
your car and pull along. The trailer would contain a huge battery, or
perhaps a 20 kW gasoline-powered generator. In other words, you would
temporarily convert the car into a hybrid. When you reach the end of the
trip, you pull into another U-Haul Power Supply dealer and return the unit.
This would reduce the efficiency of the car but it would greatly extend the
range.
Even if gasoline costs $10 per gallon it might be worth it to use it to use
a gasoline generator U-Haul Power Supply on rare occasions when you take
very long trips. After all, gasoline will not run out completely worldwide,
and we can always synthesize it or use biofuels. If gasoline is only used
on long trips with the U-haul power supply, only a little would be consumed.
For many years, people have been saying that electric cars are not
practical in the US because consumers are used to having a 500 mile range,
or they are used to refilling quickly, or for various other reasons. Much
of this boils down to attitude, expectation, and what you are used to. For
example, Americans are used to leaving on a trip whenever they feel like
it, without a schedule. They might find it annoying to travel by railroad
in Japan, where you have to arrive at the station on time or you miss the
train. On the other hand, I find it annoying to be delayed by a traffic jam
on a highway. I prefer predictable travel, when you know the arrival time
and you can make plans. Delays are rare on a Japanese railroad. (I recall
only one serious delay, when a kid got a kite tangled in the overhead wire
on the Shinkansen. The kid was fine.) Problems that you are used to, such
as traffic jams, do not bother you, whereas you notice novel limitations
and problems, such as having to abide by someone else's schedule. In the
case of an electric car, you will notice having to wait 15 minutes for the
car to fully recharge. If we had been using electric cars for decades, we
would hardly notice this delay, and it would not bother us any more than it
bothers me to wait on a railroad platform when I arrive 15 minutes before
departure time. We might even feel that gasoline-powered cars refill too
quickly, which does not give you enough time to go to the bathroom or get
some exercise.
OrionWorks wonders:
I'm also curious as to how efficient the recharging process itself is. How
much energy is simply lost as unrecoverable heat?
Circa 1990 it was ~30% and it is probably ~20% with advanced batteries
today. See p. 16 of this document:
http://lenr-canr.org/EnergyOverview.pdf
- Jed
