Port Allen Solar Array Ready to Shine - Kauai Island Utility ...

By Jim Kelly
Three Big Solar Projects
Set to Power Kaua‘i by 2014
PV, batteries to provide 50 percent of daytime electrical demand
On a clear afternoon three years from now,
energy generated by the sun will be providing at
least half of the power used on Kauaʻi. Traffic
lights, water heaters, air conditioners, irrigation
pumps, desktop computers, washing machines,
cash registers and industrial conveyors across
Kauaʻi will be powered not just by oil­fired
generators, but also by the sun.
The first of three utility­scale photovoltaic (PV)
projects on Kauaʻi will begin supplying power to
the grid in December. Alexander & Baldwin’s solar
array at Port Allen will provide 6 megawatts of
power to KIUC at a cost well below the price of
using oil.
The solar array is adjacent to KIUC’s Port Allen
generating station. As part of the project, KIUC has
installed two, 1.5­MW battery energy storage
systems to help provide stability on the grid.
As the first large­scale solar project to come
online on Kauaʻi, the Port Allen array will provide
valuable hands­on experience to KIUC engineers
Jon Yoshimura of SolarCity, Brad Rockwell of KIUC and Michael Tresler of Grove Farm at the
site of the proposed KIUC solar project near Koloa.
and operators who are charged with keeping the
system running at peak efficiency, with the load
balanced between solar and traditional
generation.
Engineers will closely observe how the system
responds when clouds diminish the output of the
solar panels. It takes only a few seconds for the
output of a panel to go from 90 percent of
capacity to less than 10 percent, then to bounce
back up to 70 percent.
The battery system reacts within milliseconds,
kicking in reserve power to “smooth” the load and
then backing off when the sky clears.
No other utility in the United States will have as
much solar on its system, so there is no playbook
for KIUC’s engineers to follow.
“It’s definitely a learning process, but we’re
confident,” said John Cox, KIUC’s senior engineer.
He points out KIUC engineers have been familiar
with the challenges of “variable generation” for
years as more PV has come online. PV now
accounts for 5 percent of the power produced
during the day.
The observations of how the new Port Allen
system and its batteries work will be even more
important as two larger solar arrays are built
during the next two years.
In October, KIUC announced it will build a $40
million solar facility that will generate 12 MW of
power, about 6 percent of Kauaʻi’s daily energy
needs.
The PV project will be built on 67 acres KIUC is
leasing from Līhu`e­based Grove Farm Co. Inc.
near Koloa. Construction is expected to begin
early next year, with completion set for 2014.
When completed, these projects will generate
30 MW during the day, enough power to meet
about 50 percent of Kauaʻi’s daytime electrical
demand of about 65 MW.