Vehicle manufacturers expect that the first mass-produced
hydrogen-powered fuel cell cars are likely to roll off production
lines in 2015. While they are expected to be lower-carbon
than cars using internal combustion engines, they will also be more
costly. Reducing the price of these cars is therefore deemed
critical. UK-based ITM Power's technology could potentially provide
an important part of the answer.
One of the most important factors for bringing down the cost of
a fuel cell is increasing its power density - the amount of power
produced for the size of the fuel cell. ITM Power has
published figures showing what it believes is the highest ever
polymer fuel cell power density using hydrogen as the fuel and
ordinary air, rather than pure oxygen. Polymer fuel cells are
seen as particularly suited to use in cars as they run at lower
temperatures than other fuel cell types and are relatively
lightweight and compact. The more power you can generate per
cm2, the smaller the fuel cell can be and the power
versus weight ratio is considered of paramount importance in
cars.
About ITM Power
- Founded in 2000
- Floated on the AIM stock exchange in 2004, secondary placement
in 2006
- 62 employees
- Based in Sheffield, UK
- Manufactures electrolysers which generate 'clean' hydrogen
Simon Bourne, CTO of ITM Power, explains: "We are basically
attempting to squeeze more power out of the fuel cell than anyone
else. If successful, we can cut the size of the fuel cells
needed to power the car and so reduce the cost of the overall
system."
ITM Power is now aiming for its technology to be included in the
second generation of hydrogen-powered cars expected to be launched
in 2017-2018. To help support the development of potential
technologies, and as part of its Polymer Fuel Cell Challenge (under
which the Carbon Trust is supporting a number of selected
companies) the Carbon Trust is supporting ITM Power to develop its
technology and intends to provide high level introductions to key
players in the automotive sector.
How it works
When oxygen and hydrogen are exposed to each other they react,
generating the power in a fuel cell. All fuel cells contain a
membrane which sits between the oxygen and hydrogen and manages
this reaction. ITM Power has developed an ultra-efficient
membrane which it claims enables more power to be generated per
cm2 than any other. ITM Power is a provider of
electrolysers (a device for generating hydrogen from electricity)
and originally developed the new membrane for that purpose.
As an electrolyser is effectively doing the reverse of a fuel cell,
the membrane technology works just as well in a fuel cell.
How the technology can reduce costs - the
science
The automotive industry is targeting fuel cell technology that
can generate one watt of electricity per cm2 of
membrane. ITM Power has tested its membrane under laboratory
conditions, and its results show it as achieving a 2.1 watts per
cm2. The average car has a power output of 80
kilowatts, equivalent to about 40 electric kettles. The more power
per cm2, the fewer fuel cells you need to meet this
power requirement and so the cheaper the overall system. At one
watt per cm2 you need to fit 8 m2 of membrane
into every vehicle in a series of cells compressed together to form
a stack - but the ITM Power membrane would need less than half the
area and hence less than half the number of cells.
ITM Power's membrane technology is also
made from hydrocarbons which are less costly than conventional
membranes and can be easily mass produced in casts.
Conventional membranes are commonly made from fluorocarbons using
expensive chemicals.
The preliminary results of a cost analysis commissioned by the
Carbon Trust, and based on information provided solely by ITM
Power, are shown Figure 1. These results, based on the data
published by ITM, indicate that ITM's technology has the potential,
assuming that the significant technological hurdles can be
overcome, to reduce the cost of a fuel cell from the current
projected industry average of 50$/kilowatt to 35$/kilowatt by the
year 2030. According to analysis by the Carbon Trust, a cost of
below $36/KW is where future FCVs are expected to be able to
compete with internal combustion engine cars at mass-manufactured
volumes on a total cost of ownership basis.
Figure 1 - Cost reduction potential
of a polymer fuel cell system using an ITM Power membrane