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As Almond Facts went to press, the power supply and
cost scenarios for California almond growers remained
unclear. Some progress had been made on rate structures,
but not on significant new sources of power or on the
question of prior notice of power interruptions. What
is certain is that electric power will cost vastly more
(double, triple or more) than in years past and frequently
will be unavailable during periods of peak demand.
Power interruptions will most likely occur during peak-use
hours - noon to 6 p.m. - and last from one to two hours.
Predictions of the number of blackouts to expect this
summer continue to increase. Some recent estimates go
as high as one thousand hours and 34 days of blackouts.
The prospect of having an unannounced blackout during
an irrigation cycle or at harvest when huller/shellers
are running around the clock is unsettling to say the
least. Unexpected power interruptions could wreak havoc
with such operations, waste large amounts of water and
product, and add more costs to growers' shrinking bottom
line.
While there's little that an individual grower can do
to prepare for unannounced blackouts, he can take steps
to minimize his power consumption or cost of power.
Some experts on the subject have shared some tips on
what you can do to help ease the pain this summer.
Tto Options
There's no in-between. The laws of physics are firm
on this. According to Wateright (a web site of CSU Fresno's
Center for Irrigation Technology), to reduce energy
use, you must either reduce the kilowatt-hours required
to pump each acre-foot of water or reduce the number
of acre-feet pumped. In other words, to use less energy,
your irrigation system or plant operation must run less
or more efficiently. But begin your quest for lower
power costs by making sure you are on the right rate
schedule.
Get Right Rate
Are you paying the lowest possible rate(s) for your
electric power usage? Agricultural users have a variety
of options based on horsepower requirements as well
as operating hours, days and seasons. Time-of-use schedules
can save you money if you have the flexibility to pump
during non-peak periods. The CPUC announced new base
rates on May 14 that will have rippled through power
suppliers' rate schedules by the time you read this.
If you haven't already, check with your supplier to
make sure you are being billed on the lowest possible
rate for your usage and to see if you can adjust your
peak usage to a better rate schedule.
Reschedule Operations
Many growers don't have the option of limiting their
pumping or hulling/shelling to off-peak periods, but
if you do, avoid the noon to six p.m. time slot to ease
the load and save some money. The California Energy
Commission (CEC) advises signing up for Time of Use
rates with your utility company to lower your costs
and, perhaps, avoid power interruptions. The likelihood
of blackouts occurring during peak times is higher than
during off-peak periods.
You'll need to calculate whether or not your pump and
irrigation system can deliver the water your orchard
needs in 18 instead of 24 hours. If it can, you are
a candidate for off-peak scheduling. Also, if you can
operate your huller/sheller during off-peak hours and
still get the job done, you could schedule operations
between 6 p.m. and noon the following day and reduce
your likelihood of an unplanned shutdown due to a blackout.
Tune Up Pumps - Inefficient pumps and motors waste
money.
Tim Jacobsen of the Center for Irrigation Technology
strongly advises conducting a head-works or pumping
station audit. He points out that PG&E has discontinued
its pump testing service, but your local pump company
can test your equipment for you or tell you who can.
A pump test is nothing more than a comparison between
how much energy your pumping plant is using and how
much it is producing, Wateright explains. In an electric-powered
plant, the "wire-to-water" efficiency compares
how much electric energy is being consumed to the water
flow and pressure produced.
When your pump is tested, Jacobsen says, and the technician
finds it running at less-than-rated efficiency, "the
technician will loosen the nut on top and re-set the
impellers. This brings the pump back into tolerance.
It will increase the amount of water the pump produces
and the load will go way up, but the pump is running
more efficiently, which saves power." The cost
of this test runs around $50 to $60, he says, but can
soon pay for itself in less power consumption.
The CEC recommends adjusting the impeller on pumps
that test between 55 and 60 percent efficiency. Pumps
that rate between 50 and 55 percent efficiency should
have their impeller adjusted, but if that doesn't improve
their efficiency, the pump should be repaired or replaced.
Pumps with less than 50 percent efficiency should be
repaired or replaced.
According to Wateright, one factor to consider when
interpreting the results of a pump test is how representative
the operating conditions were. Was the pump operating
under normal conditions when the test was performed?
If on a water well, was the water table lower than normal?
If so, the pump will not be as efficient.
Motor efficiency has improved greatly in recent years.
The CEC suggests buying the new energy-efficient models
when replacing a standard motor. At today's electric
rates, the new motor will soon pay for itself.
If you operate a deep well with frequent startups on
a Time of Use rate schedule, the CEC points out that
you can reduce power consumption by installing variable
speed drive controllers.
Check the System
An efficient irrigation system saves money. By maximizing
its efficiency you minimize the run time and, therefore,
the amount of power consumed, says Jacobsen.
"When testing your irrigation system, make sure
the pressure regulator valve is set correctly,"
Jacobsen says. "If you have a micro-irrigation
system, make sure that the filter station is backwashing
as often as it should and that the pressure loss over
the filters is correct." Jacobsen says that the
pressure loss should be only a pound or two. More loss
than that means the system is not cleaning itself often
enough.
"Check every point where there might be a pressure
loss. When you find a drop in pressure, make sure you
know why it is less and if it is appropriate for that
piece of equipment," he adds.
Sources of Information
For details on how you can calculate your energy requirements
and costs, options for reducing energy use and cost,
and much more, visit the Wateright web site at www.wateright.org.
For energy advisories, visit PG&E at www.pge.com
or the Association of California Water Agencies at www.acwanet.com,
or the California Farm Bureau at www.cfbf.com.
And that's just the beginning. Each site has links to
other agencies or associations that offer an abundance
of information
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