Page 8 - May-June 2017 Vol. 35 No.1
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STATEWIDE By Brett Ward
Water and Wastewater System
Energy Savings
Electrical savings of tens of thousands provide electrical demand graphs, which guidance, and most are very familiar
of dollars, sometimes up to 30 percent, can be very helpful in managing demand with water and wastewater plants and
have been achieved through simple charges. Contact your local power the various processes. A recent TN
operational changes at wastewater plants. company for details. Partnership city is using a local electrician
Quick and dramatic results don’t always to slowly upgrade facility lighting to LED
happen, but you don’t know until you Energy Service Companies fixtures. Sometimes utility staff persons
begin to ask questions and dig into the also have the skills to provide these types
electrical, operational and design details. Energy Service Companies are very of upgrades.
For Tennessee water and wastewater active within the state. They generally take
utilities there are several options for a citywide look at all electrical loads and Plant Operations
assistance in evaluating water and will bundle high return on investment and
wastewater energy usage. low ROI upgrades to make an economical Energy conservation, sustainability and
• Tennessee Water & Wastewater Energy project. The ESCO fees and all upgrades stewardship have all become popular
are financed from the electrical savings. buzzwords for any enterprise that uses
Efficiency Partnership MTAS would recommend that the electrical equipment. It is often cited that
• Comprehensive Services from TVA Qualifications-Based Selection process 35 percent of a city’s energy usage occurs
be used when choosing an ESCO. Most at water- and wastewater-treatment
through your local power company ESCOs also sell electrical equipment, so plants, so these facilities generally get
• Energy service companies many of their recommendations involve a lot of attention. For water plants,
• EnerNOC upgrading that equipment. It is good pumping is generally the largest power-
• Consulting engineers to choose a contractor who is qualified using activity, but water must be pumped,
• Self-audits to evaluate plant processes, pumps and in wastewater plants, aeration is
and motors, as well as the electrical the largest power-consuming activity.
Tennessee Water and Wastewater equipment. See www.naesco.org for more Knowing and understanding these
Energy Efficiency Partnership information. processes and the details of electrical
billing will help diligent managers
This group began in 2011 as a EnerNOC and operators fulfill their missions as
cooperative effort between TDEC, Region economically as possible. See MTAS
4-EPA, TVA, the University of Memphis EnerNOC is a third-party contractor guidance material on understanding
and the Municipal Technical Advisory who works within the TVA system to the commercial electrical bill at
Service. The Partnership provides no- assist in lowering the peak electrical http://www.mtas.tennessee.edu. View
cost technical assistance to water and demand. Many industries and public several documents under “Links for City
wastewater plants and has averaged a 19 utilities already contract with them. They Officials, Sewer, Energy and Electricity
percent savings through several rounds of pay a modest monthly fee plus additional Resources.”
projects. The assistance includes training monies when the facility makes a demand
for staff and an on-site audit conducted by response. During peak demand times Wastewater plants often have two
Dr. Larry Moore from the University of such as hot summer afternoons or cold types of “low-hanging fruit” just ripe for
Memphis and Brett Ward, UT-MTAS. For winter mornings, EnerNOC will request the energy-conservation picking. The
more information, contact Ben Bolton at that the electrical demand be lowered. discharge of nitrate, either in the plant
ben.bolton@tn.gov or (615) 532-8798. A response is not mandatory, but if the effluent or digested sludge, represents
plant rarely fulfills its demand response potential savings, but the facility must
Comprehensive Services they will eventually end the contract. have the capacity and staff must have
In addition to the fees paid, one of the the understanding of how to “denitrify”
Most local power companies most useful benefits of EnerNOC is the those processes to achieve the savings.
participate with TVA in a program called software they will install on an on-site Many plants also operate their biological
Comprehensive Services. This program, computer that gives an ongoing graph treatment units at far too high a dissolved
paid for by the local power company, of electrical demand. This real-time tool oxygen level and also too high a “sludge
provides engineering and technical can be very helpful in understanding and age” than is needed for meeting permit
assistance to commercial and industrial thereby managing your facility’s electrical requirements, but there are often local
customers. The program can include demand. For more information, see reasons for these high operational levels.
HVAC and lighting recommendations, https://www.enernoc.com. Contractors who focus on equipment
infrared scans, ultrasonic testing, only often miss these areas of low-
metering equipment to gather data, power Other Options hanging fruit. It should be noted that
analysis and demand-side management. operating a wastewater plant so that it
Projects often document and recommend Many consulting engineers can also
solutions for low power factor and can provide excellent energy audits and
8 TPW May/June 2017
