Looking for a simple way to reduce cost of operation?  Have you viewed your energy bill, lately?

The cost of energy has been skyrocketing.  Water and wastewater utilities are becoming aware of the large cost of energy bills as part of their bottom line.  Much of the cost of energy at these utilities is directly related to electric motors.

Here are statistics from the Department of Energy (DOE):

• Nearly 25% of all of the nation’s electricity demand comes from industrial motor systems
• Over 50% of pump “life-cycle-costs” result from energy and maintenance expense
• Less than 15% of pump “life-cycle-costs” are initial purchase costs
• Energy savings of 20% or more are possible with systems optimization

In addition, power and efficiency levels are defined – allowing comparison to published data for the pumps as installed.  It’s like having the DNA for pump/motor combinations in actual field conditions.  And, the data is now available for comparison to future measured values – tracking performance in a scientific approach to optimizing performance.

In addition to awareness of power consumption, operators/owners of utilities need to be aware of the quality of the power they are buying.  Quality of electric power includes variation in power across the legs of three phase lines and variation in the quantity of variability in the sine wave being provided (sometimes containing harmonic variations).  The consumer of electric power rarely knows the quality of power being purchased at his metered location.  The quality of power being provided will directly affect the life span and operating characteristics of machinery being operated in the consumer’s plant.

Fortunately, there are simple instruments which a consumer of electricity can use to make quality and quantity checks for the power being purchased. I recently had the opportunity to borrow a “power pad” by Rockwell Automation/Allen Bradley in conjunction with a pump station audit for the City of Mequon, WI. PowerPad offers a wide assortment of measurement parameters in one compact device. It can determine both quality and quantity of power being provided to the end user and provides both qualitative and quantitative metrics to offer ways to improve upon the effective use of power while minimizing consumption by measuring and reporting. A photo of a typical field set up – with laptop, PowerPad and whiteboard at Mequon is depicted in the photo at left.

City of Mequon, Wis. Pioneers in Defining Pumping Station Performance Metrics

The city of Mequon, WI – home of Allen Bradley’s Drives and systems division – elected to be pro-active in their defining the metrics of performance for their 21 wastewater pumping stations.  As part of their “metrics” project, they asked their consultant to provide energy consumption values for the pumps at their main pumping stations.  The Rockwell PowerPad portable power monitor was the perfect solution to their needs.  Each pump was run at design flow conditions and power curves were produced (an example of power/watts vs time for one pump cycle is shown in the graph) which defined energy consumption for the design conditions.

Thanks to Sean Schmelzer, P.E., Rockwell Automation, Allen Bradley Division for providing the PowerPad for this study at no cost.

Fred Schneeberg, Mequon Utilities Superintendent, for helping us through our first official pump station audit.

David Rice, Electrical Engineer, Port Washington, Wis. for sorting through the hardware and software to refine the field data.

Take care,
Don

Don Voigt, P.E.
Systems Engineer

April 1, 2009

Valuing “where to look” for solutions

Recently, I was visiting a customer’s plant as a follow up to earlier work.  In the general conversation, the customer had asked me a basic question as to the principals of operation of one of his process equipment units at his water treatment plant.  The question required a basic understanding of how his water filter operated and a related question as to the operation of his backwash pumps during the backwashing/cleaning of his filters.

Having been involved in both design and operation of the specific type of filter installed at his plant, I asked if we could go the filter building and observe the operation during backwash.  It turned out that, in doing so, I was able to help him understand how he could backwash without the need to operate a 40 hp backwash pump (the pump had been turned on for backwash for the entire plant history of more than 30 years) – thus, saving this energy and relevant costs and “demand” charges.

Since I was visiting the plant on my own volition, it seemed inappropriate to “invoice” for the solution I had just provided.  And, yet, I think that this is part of the “problem” with engineering…..it seems that many of the answers are simply practical and not theoretical or equation defined.  In other words, the supposition might be that any person could see the solution – given the same knowledge which I had acquired.  Yet, isn’t this the base of the conundrum which all engineers face….at any given time, we arrive at solutions which – in some circumstances and with some individuals – the answer could be provided by a casual observer or simple lay person or mechanic.

Now, this, I realize, sounds elitist but isn’t it the preparation, the background, the many hours at the drawing board, and even the mathematics in differential equations solutions which are embodied in such a solution?  The pump had run for 30 years – and survived the scrutiny of many previous witnesses and tours by dozens (hundreds?) of engineers and bystanders and no one “knew” what to look for.  My background and my arduous history of working in the internals of design and operation of this type of filter led me directly to the solution/resolution.  Luck?  I suggest that it is the embodiment of engineering knowledge that led me to the solution.  And, why do we feel that this is “un-billable work”….while we are so ready to pay an attorney’s invoice where she/he renders an opinion with much less productive results?

I don’t have the answer for this rhetorical question…perhaps you do?

Regards,
Don

In considering the more serious energy audits, the practitioner should be armed with a set of tools.  I’ve not seen a good practical list for this task so I thought it might be of value to begin a list, here.  Many of these tools are suggested in the many energy articles which have become prevalent in the trade journals.

My background is heavily oriented toward the water and wastewater markets – where I have spent the better portion of 35 years since college.  So, if you have a better list – based on your background – please add to this list with a comment below.

Here is a start:

• Amp probe or clamp on amp coils which fit around motor lead wires or lead wires leading to consumers of power.
• Watt meters – this is the logical next step up from amp meters and can be considered less popular due to costs and logistics of getting to a portable form of such watt meters.
• Flow meter – air and water flow meters are available from multiple rental sources.  GE rentals (a division of GE Company) have a number of models available for nominal rental fees.
• Pressure gages with snubbers (and diaphragm protectors) with ranges appropriate.  Such gages are now available in digital form and allow extensive recording/time tracking opportunities.
• Heat sensing imaging equipment (Fluke and others) which offer infrared images which can be timed to interface with other instruments in this family of devices.
• Digital cameras and video recorders – which record and date the data input/shown from the above family of devices
• Access to power company data for meters which are providing and recording power consumption at the sites being investigated.  Power companies have very detailed history for power being used at major meter locations – such as for a major pumping station and – for sure – at water and wastewater sites.

Of course, the next step is to actually compile the required data in a method which allows complete evaluation of efficiencies at a later date in another location (typically at an office the day or two after the data is compiled).  There are wonderful software tools to enable compiling and presenting the meaningful data which can – then – be made meaningful for those in control of making the necessary changes/investments to implement energy savings.

There are a few, select, engineers out there who can be of invaluable assistance in determining “what to measure” and “what to do with the data”. One of these would be the “Pump Guy”, Larry Bachus, who writes a regular column in Flow Control Magazine.

I’ll take this opportunity to put in a plug for the first Pump Guy Seminar, which will be held May 27-29, 2009 at the Astor Crowne Plaza hotel in New Orleans. You can learn more about it and register for the event on the Flow Control Network website.

Cheers,
Don

Yes, it’s been a cold and snowy winter in the northern tier states in the USA.  And, this tends to ameliorate and satisfy those of us hoping that “global warming” is just a politicians tool for exaggeration.  The reality, of course, is that global warming is very much a real and insidious fact.  No “cold winter days” are going to change the march of reality.  One need only look at the matter from afar…we are a troubled planet.  Recession of glaciers (see photos above) is only one of many symptoms.

As the first line of environmentalists, water and wastewater professionals (operators, engineers, and bureaucrats alike) are responsible and accountable for these matters.  We need to lead – not simply react.

This brings me to the reality of where our profession “is” at this point in this evolution.  The reality is present in our technical journals. Pick up the latest issue of whatever journal happens to be on your desk and tell me if you don’t see what I’m seeing….there is a huge disparity in going from one article to the next. You can find and read a very convincing article on energy conservation and techniques to reduce power consumption and – in the adjoining articles – there will be huge treatment plant designs showing the latest design by some consulting firm with thousands of horsepower installed and not one whisper of the “e” word. Energy – if we are true to our profession – should be an integral part of every technical presentation.  It should be as much a part of a water and wastewater article as the flow rate is, now.

For those of you who are reading technical journals, take a moment and reply to the journal or the authors of articles and ask for the missing “energy” equations or energy consumption for the plants or processes described. That is the most powerful message…a comment from a reader.

Keep your mind focused on the goal; hopefully, energy benchmarking is part of this goal.
Don Voigt, P.E.

Today’s quote from Draper Kaufman:

Nothing Grows Forever

The exponential growth curves produced by positive feedback keep on growing only in mathematics. In the real world, growth always stops sooner or later. The faster the growth, the sooner it will stop. The question is, how soon and in what way?

Thomas Friedman’s latest book – Hot, Flat, and Crowded – is another best seller. Similar to his previous book – The World is Flat – he shares a worldwide perspective on changes which are occurring in a very dramatic shift in world demographics and related political evolutions.

From his perspective the world is warming at an alarming rate caused by overuse of fossil fuel. He points out that Europeans have been energy conscious for decades and properly treat fuel as a limited resource.

Whether it is his book or other sources that stimulate us to look at our energy usage, it is clear that there is a trend in communities to become energy conscious and sustainable.

Energy conservation, whether to save costs or to save the planet, is a concept every community embraces and encourages. It will not be long before the success of water and wastewater facilities are measured by the energy efficiencies. As the world becomes hotter, flat and crowded, what can water and wastewater designers and staff do to maximize the energy efficiency of their facilities?

For the new plant designer:

• Select motor starters for energy conservation and peak power demand reduction
• Select the very highest motor efficiencies
• Select Variable Speed Drives (VSD’s) based on total system efficiencies
• Place watt meters on “screen savers” on SCADA systems
• Design facilities which provide for “benchmarked” minimized carbon footprints – from beneficial utilization of biogas to use of energy mass balance equation

For existing plant staff:

• Assign a key staff person as “energy Czar” and provide her/him with a budget and decision making powers
• Monitor Power trends, plot it, and report on it…for every possible meter site you have. This may be only one meter (main facility meter) but monitor it and report it to all members of the staff – on a prominent bulletin board and – of course, if you have it – on SCADA screens
• Require your engineer to integrate energy conservation and efficiency in your next design or upgrade
• Request an evaluation of power consumption at your facility and compare it to world standards for equivalent treatment (often available at no charge by people such as “Focus on Energy” or your power provider)
• Implement one or two key energy reduction initiatives at your facility and bring these to the attention of your management or city mayor or village president – and, the local newspaper
• Ask your regulatory agencies (such as EPA or DNR or your power company) what they can do to help you make an incremental improvement in power reduction
• Engage your local schools/teachers in projects where they can help you monitor changes/improvements. Children are very “green” these days…we all can learn a lot from them and they want to help.

Together, all things are possible. And, we are on this small planet, together. So lead, follow, or get the “h” out of the way! But do something about it…water and wastewater utilities are consuming () 5 to 7% of your community’s power!

Don

(This post was originally published in November 2008)