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Competent
and committed people are organizing the first major high level
electric racing series. They have the right contacts, deep
pockets, excellent partners and skilled Media relations. What
factor are they missing?
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To
be successful, the series needs to be designed from the start
to provide exciting competitive racing, which will attract fans,
at a cost proportional to the rewards that attract teams.
Formula
E is not designing the series. They do not have a vision of
what the series should look like that they are working towards.
Instead the series is evolving based on poor choices made
on marketing goals. These choices have created technical flaws
that could kill Formula E.
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The
first bad decision is the chassis.
The
top racing series in the world is Formula 1. They run winged,
open wheeled, single seaters. Formula E's goal is to be the
top electric racing series in the world, so for marketing
reasons, their vehicle of choice is a winged, open wheeled,
single seater.
The
high drag, winged, open wheel, single seater is a terrible
choice for an electric race car. It can go fast, but not far
(see: "Doing
the Math" for a more detailed explanation).
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The
extreme range limitation of the high drag, open wheel design
leads to questionable decision number two.
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Aero drag increases by the square of speed. This means power
usage goes up exponential the higher the top speed. If the
Formula E cars run on tracks with high top speeds (Le Mans,
Silverstone, Daytona), their run time will be extremely short.
Conversely, if they are run on tight, twisty tracks like Monaco,
they should be able to run longer. So the decision has been
made to run all Formula E races on tight, temporary street
courses, set up in city centers.
From
the marketing perspective, this ties in nicely with the concept
of electric cars as city cars. Short commutes. Limited speeds.
No exhaust when stuck in traffic.
The
negative impact of this decision is that the races become
expensive to hold. These cars are fast and powerful. The organizers
must earn enough money to pay for building a safe temporary
track on city streets and pulling it down again. Teams must
budget for the additional crash damage that comes from racing
on a cement barrier lined track. This means the series will
need to be very successful to cover the extra cost.
The
decision to run on temporary street courses creates the next
problem. To justify the high ticket prices the promoter must
charge to pay for the track, the series needs to provide a
full day's experience. The marketing people decided that means
the Formula E's main event needs to be at least 1 hour long.
Since, at racing speeds, the Formula E cars can only run 20
to 25 minutes, this presents a problem.
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So
Formula E must choose from three options. Working out a way
to fast charge batteries during a fast pit stop presents huge
technical challenges and no guarantees. Allowing battery pack
swaps during pit stops would require a complete redesign of
the car, would add weight and would need a FIA safety study
before it could be sanctioned. The easiest choice to implement
and the one that should not delay the series is to require
the drivers to come into the pits and change to a second car.
This
is kind of a disaster from the marketing point of view. 'Electric
cars, one is never enough!' is not the sort of slogan that
will build the market.
This
is kind of a disaster from the financial side as well. Teams
now must get and service two cars per driver. More equipment
to maintain. More equipment to transport. More expense.
Formula E management tries to put the best face on it, promising
the car swap will add excitement to the race. This is a feature,
not a flaw?
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This
has not been thought through. To operate a modern race car
with its high G forces, the driver needs to be strapped tightly
in place. The standard is 6 belts (between the legs, across
the waist, over the shoulders). A safety neck brace must be
fitted properly under the shoulder belts while attached to
the helmet. Finally, a neck brace/ arm restraint snaps around
the driver. It is difficult to do this even in the calm before
a race. It will be a clear safety hazard to ask a driver to
do this under the pressure of competition. Drivers take chances
to win. How does the sanctioning organization police the car
changes so that no driver is going out with his belts not
properly secured?
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It
gets worse. The second car will run out of power 40 to 50
minutes into the race. So Formula E announces the teams will
need to recharge the first car and do a second pit stop to
swap back to the first car to finish the race.
At
this point, it is clear that the people at Formula E have
not thought through the ramifications of this decision either.
A basic understanding of battery technology helps.
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The
Formula E prototype uses SAFT lithium ion VL41m cells. While
the final brand might change, these are fairly representative
of the technology available.
SAFT
specifies that the cells are capable of a 3C continuous discharge
rate. That means they can be fully discharged in 1/3 of an
hour and still meet their published specification. Right at
the limit for a twenty minute race, but OK.
This
limit is due to heat. Discharge the batteries too quickly,
they get too hot. Too hot batteries fail sooner.
The
normal battery rating test procedure is to discharge a single
cell, starting at a standard temperature and in still air.
The
Formula E's battery pack consists of 200 tightly packed cells,
which will all generate heat as they discharge. To overcome
the heat, the pack will need to be actively cooled. Battery
pack cooling is a challenging part of the electric race car
design.
SAFT
also specifies that the maximum continuous recharge rate is
1C. That means the batteries can be charged at a rate that
will recharge them in an hour (they cannot actual be fully
charged in an hour but let us ignore this for the moment).
This latest decision by Formula E requires that the batteries
will be discharged at very close to their maximum rate for
20 minutes and then immediately recharged at 3 times the allowed
rate.
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This
is a technological problem and given enough time and money,
it can be solved. But first someone needs to design and build
and put into production a 90 kW fast charger. At the moment,
there is no unit capable of providing a twenty minute recharge.
Which
brings us to the final problem. When someone develops and
build a 90 kW fast charger, where will the teams plug it in?
If Formula E attracts a full field of 20 cars, there will
be a sudden load of 1,771 kW. This is almost 2 megaWatts.
Roughly equivalent to adding the load of about 1,200 households
to the grid.
The
local power utility will need to add this capacity for use
one day a year. This means power source, transmission lines
and outlets or risk the race blacking out the city. This will
not be cheap. This needs to be negotiated for each city. This
needs to be built and tested before the race. This will not
happen in all ten cities.
So
instead, each car will need its own 90 kW generator. These
cost around $50,000 US and weigh around 8,000 lbs (3,629 Kgs.).
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To
sum it up, from a team manager's point of view:- Budget for
four cars (five for redundancy). The value of these cars goes
to zero if the series fails. Budget for two prototype fast
chargers (three for redundancy). Two $50,000 generators (three
for redundancy). Budget for ten street races worth of spare
parts. Battery budget is a giant unknown. Batteries are currently
the most expensive part of an electric vehicle and no one
has any idea how long they will last or how many will be needed.
Crew wise - two drivers; enough mechanics to service four
race cars; specialists to run and service the generators,
chargers and battery packs; plus the usual DAQ, tire guys,
and truck drivers. Finally, add on the cost of transporting
all this gear and all these people around the world.
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Formula
E Holdings will need to have very deep pockets to put together
an attractive enough rewards package (appearance fee, prize
money, sponsor exposure) to make this a viable risk for any
race team.
The
races will need to provide an amazing spectacle that catches
on immediately with the public to generate enough money to
pay for all this. It is difficult to imagine how long pit
stops and cars rolling to a stop with multiple battery failures
will provide this.
The
only bright spot is that if this series as currently conceived
ever happens, it will negate the electric racing naysayers'
pet complaint. One third of the way into the race, when the
twenty 90 kW generators lined up behind pit lane go to full
power, the earth will shake. And nobody will miss the roar
of the internal combustion engine.
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