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March 2017
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MechChem Africa
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Innovative engineering
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A 2.2 MW fuel cell came online at a regional high school is in
Connecticut in January 2017. The fuel cell is linked to a microgrid
and will power the school during a prolonged power outage. Waste
heat from the fuel cell will also be used to heat the high school.
The company has invested over
R100-million in energy conserva-
tionprogrammes andwill continue
to work with Eskom while par-
ticipating in various demand-side
management programmes.
“Fulfilling a prominent role in
developing the nascent fuel cell
industry in South Africa is part
of Implats’ strategic objective to
demonstrate responsible stew-
ardship of our mineral and energy
resources,” says Smith.
Doosan’s PureCell 400
The scalable Doosan PureCell
®
400 can generate up to 440 kW of clean elec-
tricity when new, reducing to 400 kW after ten
years of use. In addition, the system produces
nearly 500 kW of useable heat. The PureCell is
designed to be powered by natural gas rather
than hydrogen, which means it cannot make
the claim that only water vapour is emitted. But
it also means that it is ideal for fuelling from a
piped gas supply.
Doosan uses phosphoric acid fuel cells with
highly concentrated pure liquid phosphoric acid
(H
3
PO
4
) as the electrolyte, which is saturated
in a silicon carbide matrix (SiC). The electrodes
are made of carbon paper coated with a finely
dispersed platinum catalyst – hence Implats’
long-term interest.
The operating temperature range is about
150 to210 °C, creating theopportunity toutilise
the ‘waste’ heat for combined heat and power
applications. When the heat can be gainfully
used, Doosan claims an operating efficiency of
up to 90%.
Reliability wise, a remarkable 98% uptime
across the fuel cell stack life of ten years is
being reported. So not only do these fuel cells
run cleaner and more efficiently, as a power
generation alternative they are more reliable
than nearly all other alternatives.
The costs? Doosan claims a generation cost
of 14 to 15 US-cents per kWh, which is within
the range being reported in theDecember 2016
version of Lazard’s Levelised Cost of Energy
(LCOE) Analysis – US$119-$182 per MWh or
11.9 to 25 UC-cents per kWh. The Lazard LCOE
range for nuclear power in the USA is not that
much cheaper: $97 to $136 per MWh.
Hybrid renewable and fuel cell
solutions?
Arguments against renewable energy genera-
tion from solar PV and wind generation are no
longer restricted to costs. For PV systems, cost
parity is alreadybeing claimed for someprojects.
But their intermittent nature means that either
storage solutions are necessary or renewable
systems need to be coupled with traditional
generation for continuity of supply – at night or
when the wind drops.
For distributed solutions such as mi-
crogrids, therefore, gas or diesel generators
are often coupled with PV, wind or hydro
plants to ensure continuity of supply regard-
less of the available sunshine, wind or water
flow.
Fuel cells, which are already being widely
used as backup power for cell phone towers
and data centres, offer an ideal alternative
to gensets for these distributed microgrid
applications. They can be brought online
quicklyandregulatedtosupplythegeneration
shortfall whendemandexceeds that available
from renewable energy plants.
A PV system coupled with a fuel cell could
well offer an ideal hybrid clean generation
solution, one that is not far away for grid-
cost parity and without the disadvantages of
intermittency.
The rise of FCEVs
At a factory in Michigan in the US, General
Motors and Honda plan to invest US$85-
million to build hydrogen fuel cell stacks for
the next-generation fuel cell electric vehicles
(FCEVs). The joint venture, Fuel Cell System
Manufacturing, will begin producing the fuel
cell systems in around 2020 out of GM’s
BrownstownTownshipplant southofDetroit,
which currently produces battery packs for
hybrid and electric vehicles.
GM and Honda say that cooperating on
developing fuel cells will slash costs and
boost efficiencies. The goal is lighter, smaller,
more powerful and less costly stacks that use
hydrogen as the fuel to produce electricity to
power cars.
Fuel cells “are not a science project any-
more,” saysGMexecutivevicepresidentMark
Reuss, which is clear from the success of the
Honda Clarity and the Toyota Mirai.
In the fuel cell electric vehicle (FCEV) the
drive train is 100% electric, with the fuel cell
and its hydrogen fuel tank replacing the Li-ion
battery pack used in electric vehicles.
Clearly, the hydrogen-refuelling infra-
structure is a huge hurdle, but even this is not
that far away.
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