How Fuel Cell Vehicles Work
Do
you know what a fuel cell is and how it functions? Below we’ll post a
101-level primer and we’re doing so because, well, everyone else is
preparing for fuel cell vehicles (FCVs), so ready or not, here they
come!
You may have noticed an increase in fuel cell news as automakers
publicly or behind-the-scenes work toward a “2015” timeframe in America
to begin launching FCVs in earnest.
Presently federal and state government agencies, advocacy groups,
and industries are working on details not least of which is developing
cars and adding refilling stations to the mere 10 stations now in the
U.S. – not to mention devising a way to charge customers for hydrogen by
the kilogram.
Honda FCEV concept at the LA Auto Show.
To date, leases of the comparative handful of FCVs on the road
include the hydrogen’s cost in the payment, thus bypassing that sticky
problem for cars that get somewhere around 70 mpg equivalent.
Hyundai will be next to not wait for a per-unit H2 price, and is planning a lease program for its ix35 in Southern California to begin next spring. This will precede Toyota’s first sedan
to be launched for 2015 as well as Honda’s next generation follow-up to
its essentially sidelined FCX Clarity promised for the same timeframe.
Ford, Daimler, and Nissan are working on a new car for you.
Beyond that, Nissan, Mercedes-Benz, and Ford have signed a collaborative agreement
to co-develop cars to be respectively badged and individualized to each
maker. The tentative timeframe for the Nissan/M-B/FoMoCo effort is
2017. And then you have Daimler, which has been showcasing its work for
years, and says it too shall be in the FCV production business (finally)
by 2017.
BMW is also working with Toyota, and is expected to have a FC car ASAP as well, and let’s not forget the early pioneer, General Motors.
GM has announced nothing for production, but is yet working on and
was talking up FCVs prior to being sidetracked by the Volt, a
bankruptcy, and other details. Don’t be surprised if we hear of a car
from GM in 2015-2017.
Volkswagen is the notable hold-out, at least officially. Its CEO
Martin Winterkorn has pointed to huge cost and infrastructural hurdles
as though he is describing the emperor’s new clothes – and for all
anyone has yet proven unequivocally, he may well be.
VW’s media people repeat what their chief says – and despite what sister company Audi has said
– but the VW Group is working away at the task nonetheless, and we hear
it intends to be in on the fuel cell market as soon as feasible,
regardless.
Graphic courtesy of GM.
As a sign of their intent, most of these OEMs are now members of the California Fuel Cell Partnership including Chrysler, Daimler, General Motors, Honda, Hyundai, Honda, Hyundai, Nissan, and Volkswagen!
California is of course the epicenter, followed by eight other states thus far following its lead, and having signed a pact to make happen what skeptics say is nigh to impossible.
Without touching on the viability question, we thought we’d lay out the simplified primer on how fuel cells work.
We’ve linked to other resources, but want this to be a reference in
its own right to at least highlight what all the hype – or is that hope?
– is about.
How a Fuel Cell Works
Graphic courtesy of Calif. Fuel Cell Partnership.
Common to all the automakers in question – and bus makers also
operating now – is the underlying technology: a proton exchange
membrane, or PEM.
This basic design has been around for years, and the costs have come down as efficiencies have gone up.
In simplified terms, a PEM fuel cell is two electrodes — the anode
and the cathode — separated by a catalyst-coated membrane. Platinum is
typically used as the catalyst which sounds expensive – and is – but at
this point the quantity required equal to or less than the quantity used
in catalysts for “clean diesel” engines.
Graphic courtesy of Calif. Fuel Cell Partnership.
PEMs take in gaseous hydrogen – produced from a variety of methods –
and produce electrical energy. They’re assembled into a fuel cell stack
which is comprised of many PEM fuel cells stacked like slices in a loaf
of bread.
Fuel cell vehicles are all-electric, but unlike an electric car with a chemical battery, they are refilled not recharged.
Electrical energy generated by the fuel cell stack is sent to a power
module and this in turn powers an electric motor which turns the
wheels.
Also energized by the power module are on-board devices and accessories, including A/C and sound system.
A high-voltage battery such as a regular full hybrid would use is also tied in to provide extra torque when needed.
The design in a nutshell is a lot like a regular hybrid, and by
definition, is a hybrid – being that two motive power source are
utilized.
Toyota explains its FCV as being “just like a Prius” except you
delete the gas engine, and replace with the FC stack. It’s so like a
Prius, in fact, Toyota is kicking around the idea of merging its 2015 car into the Prius family line.