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BOULDER, Colorado, US, November 29, 2006
(Refocus Weekly)
Wind turbines could produce hydrogen that would
cost less than US$3 a kilogram delivered, according to a report
prepared for the U.S. Department of Energy.
Hydrogen can be produced at a wind turbine site for $5.55 / kg in
the near term to $2.27 / kg in the long term, explains ‘Wind Energy
& Production of Hydrogen & Electricity - Opportunities for Renewable
Hydrogen’ prepared by J Levene for DOE’s National Renewable Energy
Laboratory. A second analysis examined if wind could produce
hydrogen in a distributed fashion, where a windfarm signals a
remotely located electrolyzer that would allow the electrolyzer to
run only when the wind is blowing.
Hydrogen can be produced from a variety of renewable sources of
energy, and the assessment for wind/hydrogen/electricity systems at
both central and distributed scales “provides insight into
opportunities for renewable hydrogen as well as research priorities
for this hydrogen production pathway,” the report explains. The
research was initiated by Xcel Energy to determine if hydrogen could
be economically produced via wind power for transportation fuel use.
An advantage of the distributed fashion is that signals from many
different windfarms could be used, which would increase the capacity
factor and decrease the cost of the hydrogen production system. The
second study estimates that hydrogen could be produced at the point
of use for prices ranging from $4.03 / kg in the near term to $2.33
/ kg in the long term, and this approach could minimize delivery
costs if the electrolyzer was located at the filling station.
“Both analyses reveal that in order to optimize the production of
hydrogen from wind, the electricity and hydrogen production needs to
be examined as an integrated system,” it explains, noting that NREL
researchers are working to build renewable hydrogen from wind into
“a viable production method for transportation fuel in the future.”
Electrolysis (production of hydrogen from water) requires 39 kWh of
electricity to produce each kilogram of hydrogen at 25°C. Each
kilogram of hydrogen has the same energy content as one gallon of
gasoline for transportation applications, it explains.
DOE’s Hydrogen, Fuel Cells & Infrastructure Technologies (HFC&IT)
program has a 2015 goal of delivering hydrogen at $2 to $3 per kg,
with a goal for delivery and dispensing of $1 per kg for delivery.
In the first scenario, the report says hydrogen must be produced for
$1 to $2 while, for the second, hydrogen must be produced for $2 to
$3 per kg since delivery charges are eliminated.
The long term prices for wind-produced hydrogen are $2.70 to $2.27 /
kg which, when added to delivery costs, are slightly higher than DOE
targets and the first case “appears to only be economic for a small
scale niche market with good wind or subsidies that help to drive
the cost below $3/kg,” it explains. If system costs can be reduced
$0.27 to $0.70 per kg, “wind hydrogen may be produced and delivered
for less than the DOE cost target.”
In the near and mid term, “hydrogen can be produced at the point of
use for less than the cost of producing hydrogen at the windfarm,”
it concludes, because the capacity factors of the electrolyzers are
higher in the distributed scenario than in the on-site case. The
aggregate wind signal helps level the peaks and valleys of
intermittent wind energy, boosting the capacity factor for the
electrolyzer from 81% to 90%.
“Hydrogen produced from wind electricity appears to have potential
to meet the DOE HFC&IT program goals,” it concludes. “If aggregate
wind electricity is available at the filling station for $0.038 /
kWh, it is possible for production, compression and storage to cost
below the target of $2 to $3 / kg delivered hydrogen.”
“Hydrogen production at the wind site makes fiscal sense if cost
reductions offset delivery cost, and cost reductions need to be
between $0.27 and $0.70 / kilogram to meet the DOE HFC&IT cost
targets,” it adds. “Researchers at NREL are working to determine if
optimized hydrogen/electricity production applications can help
improve the efficiency and costs of renewable hydrogen production
systems.”
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