POWER July 2014 - 12

3. Floating through. The current 2-MW WindFloat prototype off the coast of Aguçadoura,
Portugal, could be expanded to five platforms. A final build-out phase is planned to have a capacity
of 150 MW. Courtesy: Principle Power
deployed a full-scale 2-MW prototype
WindFloat turbine off the coast of Aguçadoura,
Portugal (Figure 3), a system that
has since produced more than 9 GWh delivered
by subsea cable to the local grid.
Japan also has two experimental floating
2-MW Hitachi turbines and plans to put a
new Mitsubishi 7-MW turbine on a semisubmersible
platform this year.
Among notable floating projects proposed
are Principle Power and Deepwater
Wind's five floating platforms, each with
a 6-MW turbine, off Coos Bay in southern
Oregon, and Statoil's proposed 30-MW
venture planned for the Buchan Deep site,
about 19 miles off Peterhead in Scotland.
The European Commission has also awarded
funding to Principle Power to build a
27-MW second phase consisting of five
WindFloat platforms developed by Principle
Power, with a final build-out phase
that could have a capacity of 150 MW.
" However, the costs for the initial proj4.
Novel development. EnerVault connected its unique iron-chromium redox flow battery
to the grid this May. Courtesy: Government Contractors Network
ects are very high, and as with any new
technology configuration, years of testing
will be required to understand how reliable
and economical the technology can be, "
cautions Steve Sawyer, secretary-general
for the Global Wind Energy Council. " And
then the challenge will be the same as for
the current round of offshore deployment,
that is to say how to get the scale-up required
to make the economics work. "
of Stonehaven, in waters that are about
60 meters (m) to 80 m deep. Kincardine
wants to begin construction in the second
quarter of 2016 to have the wind farm operating
by the end of 2017.
Several developers have proposed floating
offshore wind arrays off the coasts of
the UK, Norway, Denmark, Portugal, and
the U.S., touting the use of semi-submersible
platforms as a means to cut construction
and installation costs, because they
remove the need for costly foundations.
Floating offshore wind turbines can also
be located in deeper waters and take ad12
vantage
of stronger winds.
According to Navigant Consulting, 1.7
GW of offshore capacity was installed in
2013 worldwide-mostly in Europe-
bringing the total capacity to 7 GW. New
and expanding projects are likely to contribute
a record-setting 2.2 GW in 2014
alone, mostly in Germany and the UK.
" Globally, offshore wind projects continue
to trend further from shore into increasingly
deeper waters, " explained Bruce
Hamilton, who directs research at Navigant's
energy arm, this May.
Hamilton noted that Principle Power
www.powermag.com
Grid-Scale Iron-Chromium
Redox Flow Battery
Connected
One of the world's first grid-scale ironchromium
redox flow batteries was interconnected
this May to the distribution
grid. The EnerVault Turlock, which its
developer EnerVault says is a 250-kW,
1-MWh battery grid-scale energy storage
system, will be charged by a 150-kW dualaxis
tracking solar photovoltaic system in
an almond orchard in California's Central
Valley, will power a 260-kW irrigation
pump, and will inject energy back into the
grid during peak times (Figure 4).
According to the Energy Storage Association
(ESA), iron-chromium flow batteries,
pioneered and studied extensively by NASA
in the 1970s and 1980s, are essentially redox
flow batteries-a class of electrochemical
energy storage devices that employ
reduction and oxidation reactions to store
energy in liquid electrolyte solutions, which
flow through a battery of electrochemical
cells during charge and discharge.
That means, unlike other types of batteries,
which are packaged in small modules,
iron-chromium flow batteries consist
POWER | July 2014

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POWER July 2014

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