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If you are like most people, you might be surprised
to learn how much of your electric bill is created
by your usage of lights. Each light taken by itself
is not a big user of electricity, but often the
shear number of lights and the tremendous amount of
time they are left on make a big dent in your
pocketbook.
This chart is derived from a benchmarking database
published by the U.S. Department of Energy. It
shows the average breakdown (mbtu) of electricity
usage for a commercial facility meeting these
criteria: (i) professional office building (ii)
100,000 - 200,000 square feet (iii) built 1990 -
1992 and (iv) located in the Midwest. You can see
that in these facilities lighting accounts for
approximately 1/2 of their total electric usage.
A lighting improvement program can often pay for
itself in energy savings within 2 years. Moreover,
certain inefficient bulbs and ballasts are no longer
being produced and their sale will soon be
prohibited. Cost effective lighting projects include:
Please contact Independent Energy to learn how we can help you determine what lighting is costing you, what can be done, and how much you stand to save. We are a proud partner in the U.S. EPA's Energy Star Program. |
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In many applications motors are operated at
constant
speed and some other means of varying the process
flow are used. For example, a production line might
employ a gear reduction technique, and the flow of
fluid or air from a motor-driven pump or fan might
be restricted or recirculated with flow control
valves. In each of these applications there could
be a better solution. Variable speed drives (VSD) are
electrical devices installed just upstream of
electric motors. Sensors in the production flow
process send signals to the VSD when they sense a
need to speed things up or slow them down. When the
VSD receives this signal it adjusts the frequency of the
electricity being sent to the motor. In alternating
current motors the voltage and frequency are
proportional to each other. For example. A 480 VAC
motor operating at a frequency of 60 Hz. will
operate at 240 volts if the frequency is reduced
to 30 Hz. And if we lower the voltage at which a motor
operates, we lower the power it consumes and the
money it costs to operate. Of course, there are
practical operating limits within which a motor can
run safely, but the example illustrates the point
we wish to make.
Let's take a look at the benefits of matching air
flow in a ventilation system to a particular need. If we have a 3-phase
motor and fan combination
operating at 100 percent flow rate, and utilizing
dampers to redirect unneeded air flow, we are using
the maximum amount of electricity possible. If we
modify that system by installing a zonal temperature
sensor and a VSD, we can match the airflow to the
desired temperature. Let's assume that we can
reduce the overall motor/fan speed and resultant air
flow to 80 percent and achieve the desired cooling.
That 20 percent reduction in air flow does not
result in 20 reduction in electric use. The
reduction in electricity turns out to be a whopping
49 percent! The 49 percent reduction results
because we are saving electricity on each of three
phases: 0.8 x 0.8 x 0.8 = 51 percent of original
electric use or a 49 percent power reduction. VSD
are very common in commercial and industrial
facilities, but need to be installed with care. Please contact Independent
Energy Consultants to
learn more about how we can help you identify
equipment and systems that may be ripe for energy
efficiency improvements.
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