Page 9 - May-June 2017 Vol. 35 No.1

“denitrifies” the effluent is a key process TVA Comprehensive Service Demand Graph. This plant had an Off/On aeration cycle, then added other
in keeping effluent total nitrogen at a low equipment that resulted in a peak demand of 95kW.
level. This would be half of the nutrient-
removal requirement that TDEC is been extreme. Some systems already There are many options available to
beginning to add to discharge permits. had implemented our most common managers and plant operators when
recommendations, others embraced seeking assistance or guidance for energy
In water and wastewater systems, recommendations quickly and others, savings. Some were mentioned and
pumping costs can be significant. though in the program, effectively did not others can be located by doing internet
Matching usage and electrical billing participate. These are cultural differences. searches. Generally the process begins
data can often be helpful. A recent TN Utilities with key persons who had with an evaluation of the detailed electric
Partnership system lowers the demand previously worked in manufacturing and billing statements and comparing them
charges by using one high-service pump experienced, firsthand, the competition to plant operational data. The process
for longer hours instead of two pumps of the marketplace were always far ahead is somewhat like a treasure hunt, sifting
for a short time. Also, matching the in finding and embracing energy-savings through the data looking for savings in
pump and motor to the load is critically measures. energy and dollars.
important for economy but is often a
challenge in design when current water
flow is far smaller than future flows are
expected to be. For pumps and motors
that operate 24/7, the use of premium
efficiency motors is worth the added cost.
The Department of Energy Pump System
Assessment Tool is also an excellent
way to evaluate pumps and motors and
is available at https://www.energy.gov/
eere/amo/articles/pumping-system-
assessment-tool.

Energy-Efficiency Culture

Over the past six years, the TN
Partnership has worked with almost 40
utilities. The cultural differences have

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