CALIFORNIA NEWS
WORLD-GENERATION MAY/JUNE 2015 V.27 #2
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Protec is considered a global leader in
the design and manufacturing of fiber
reinforced plastic pressure vessels for
membrane filtration systems. It has sales
offices in Vista, California, Tokyo and
Munguia, Spain. Dow’s reverse osmosis
membranes will work with the pressure
vessels to squeeze out the salts of the
Pacific Ocean seawater. This portion of its
business is located in Edina, Minnesota
and in Saudi Arabia.
REDUCE OVERGENERATION WITH
DESALINATION?
What is over-generation? As dis-
cussed earlier, it occurs when more elec-
tricity is supplied than is needed during
certain hours of the day. It is not an issue
at the moment but it will grow as more
intermittent renewable resources, such as
wind and solar, come online to meet the
state requirements for 30% renewables by
2020 and 50% renewables by 2030.
Cal-ISO has demonstrated its chal-
lenge with its Duck Chart. In the morn-
ing when everyone is getting ready for
work electricity usage ramps up, then dips
and ramps up again in the late afternoon
when electricity users arrive home and
turn on appliances. In the chart, the belly
of the duck gets deeper in the afternoons
as more renewables come online in the
years leading up to 2020 reflecting the dif-
ference between over-generation and lack
of demand.
Cal-ISO’s job is to use flexible genera-
tion resources that can meet short, steep
ramps. But until technology is developed
to ramp wind and solar up and down, gas-
fired plants must do that job.
The Independent Energy Producers
Association has come up with an intrigu-
ing idea in the brief it contributed to the
CEC’s 2015 Independent Energy Policy
Report docket in April. IEP suggested
that repurposing clean energy into other
sectors of the economy will allow for
expansion while displacing direct petro-
leum use (with clean alternative fuels)
and creating new sources of local water.
In particular, IEP argued that
renewable energy could be considered as
a critical power source for expanding
California’s water supply infrastructure in
the form of desalination plants. It
suggested that 15 desalination plants
would absorb over 30% of the over-
generation forecast to occur by 2030
under the 50% renewable requirement.
These plants would supply additional
water to meet 12% of the state’s current
public water demand and meet 3% of
current irrigation needs.
However, this intriguing suggestion is
not on the radar of either SDG&E or Cal-
ISO. SDG&E will be adding the Carlsbad
desalination plant as a customer and
would not be able to separate out the wind
and solar generation being supplied to its
grid in order to direct it to the desalina-
tion plant. Furthermore, Cal-ISO has con-
trol of the state’s grids and manages the
power on a macro level.
To implement IEP’s idea would
require siting renewable resources near
or adjacent to the desalination plants
which would require being close to salty
or brackish water sources. Perhaps off-
shore wind projects, such as those being
developed off the east coast, could be built
along the California coast near the
Carlsbad desalination plant now under
construction and the Huntington Beach
plant being planned.
In its 2007 environmental impact state-
ment, Poseidon contemplated installing a
solar system on the roof of Carlsbad’s
main desalination plant building which
would generate approximately 777 MWh/
year, about 0.3% of the plant’s projected
annual electrical need of 274,400 MWh/
year. There is currently no mention of a
plan to install such a solar system.
Santa Barbara is brushing off and
updating the desalination plant it built
during the last drought and promptly shut
down when the rains came. Other cities
along the California coast have contem-
plated building desalination plants but
dropped the plans after analyzing the
large costs to develop them. Perhaps if
the drought persists for a few more years,
new interest will emerge and developers
will venture to propose partnerships for
off-shore wind projects near the planned
sites for desalination projects. It is a pro-
voking thought.
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