T OF ENERGY

DEPARTMEN

U

E

NITED STAT S OFA ERICA

M

An Office of Industrial Technologies 

Bimonthly Publication Focusing on

Energy Efficiency Opportunities for Today

www.oit.doe.gov

www.motor.doe.gov

Formerly Turning Point • September/October 1999

Issue Focus: 

Contracted Services and 

Other Partnerships 

IN THIS ISSUE

Small Town Plastics Manufacturer Produces

Big Local Energy and Cost Savings. . . . . . . . 1

Technical Advances Improve Industrial 

Energy Efficiency . . . . . . . . . . . . . . . . . . . . . . 2

Energy Service Companies: Cost-Savings

Partners for Industry . . . . . . . . . . . . . . . . . . . . 3

Choosing the Right Energy Service 

Company to Prove the Value of Motor 

Upgrade Projects . . . . . . . . . . . . . . . . . . . . . . 4

Energy Assets: Tapping the 

Hidden Value . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Steam Workshops Promote Energy 

Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Performance Optimization Tips . . . . . . . . . . . 6

Letters to the Editor. . . . . . . . . . . . . . . . . . . . . 7

New Online: Something Extra . . . . . . . . . . . . 7

Coming Events. . . . . . . . . . . . . . . . . . . . . . . . . 8

When the Board of Public Utilities (BPU)

in the small community of Salamanca,

New York, wanted to impact its energy

conservation program, Energy Discoveries,

sponsored by the Municipal Electric Utility

Association, they turned to Highland Injection Molding, Inc., the town’s largest consumer of electricity, for help. In an effort to

reduce energy consumption and keep

power costs low in the area, Highland

installed variable frequency drives (VFDs)

on two of its injection molding machines. 

By retrofitting the machines,

Highland reduced energy consumption, initiating cost savings of $13,000 annually.

Because of Highlands’

upgrades, the local power

company has also experienced

an annual savings of $3,500

through avoided purchases of

expensive incremental power

that would otherwise be

needed to supply the community with adequate power during the winter months. And,

Salamanca BPU’s savings are

ultimately passed along to its

utility customers. “The avoided kW demand

and kWh consumption enable us to keep

rates stable,” says Jim Brundage, general

manager at the BPU.

Highland, the largest industrial employer

in Salamanca, manufactures plastic parts

for a variety of automotive, consumer, and

industrial products. To handle production,

the company operates 24 machines, ranging in size from 100- to 1,200-ton press

capacity, around the clock. Large amounts

of energy are required where high-power

hydraulic pressures are needed, but this

only occurs during two stages of production. However, Highland’s pump motors

were operating at full capacity regardless

of the stage of the press cycle, wasting

energy and money in the process.

Seeking ways to reduce energy consumption, the city asked Honeywell DMC,

a Motor Challenge Allied Partner, to assess

the energy savings opportunity at Highland. Honeywell DMC used the MotorMaster+ software tool to analyze Highland’s energy options and determined that

the greatest potential savings would come

through managing the energy used by the

molding machines. 

In December 1996, drive units were

installed on two of Highland’s biggest and

most frequently used presses—a 700-ton

capacity molder with two 75-hp motors

and an 800-ton molder with 100-hp and

60-hp motors. 

By early January 1997, independent

monitoring performed by Technical Assistance and Services verified a 66% reduction in peak kW demand and a kWh

reduction of 71%. In addition to the cost

and energy savings, Highland has also

noticed reductions in wear and tear on the

pump motors and in the noise inside the

factory now that the motors do not continually run at full tilt.

If the steps taken by Highland exemplify

what a company of 130 employees can do

to reduce energy consumption and impact

the bottom line, larger companies can create even greater savings. According to

Mike Lyons of Honeywell DMC, “The Salamanca BPU has some of the lowest rates in

the country. If this project were implemented with an injection molder in a territory with more typical electricity costs,

payback would be in months.” 

Small Town Plastics Manufacturer Produces 

Big Local Energy and Cost Savings

Highland's molding machines benefitted from a VFD retrofit.
2 Energy Matters, September/October 1999

ENERGY MATTERS

(formerly Turning Point) is 

published bimonthly by the U.S.

Department of Energy’s (DOE)

Office of Industrial Technologies. 

Information contained in the

newsletter can be reproduced

without permission provided due

acknowledgement is given (the

U.S. Department of Energy’s

Energy Matters newsletter) and a

copy of the publication is 

supplied to the editor.

■

EDITORIAL BOARD

Floyd Barwig, Iowa Energy 

Center, representing Compressed

Air Challenge

Rob Boteler, representing

National Electrical Manufacturers

Association

Lynda Butek, representing 

Electrical Apparatus Service 

Association

Don Casada, Oak Ridge National

Laboratory

Keith Davidson, Onsite Sycom

Energy

Glenn Hahn, Spirax Sarco

Fred Hart, U.S. DOE, Steam 

Challenge

Chris Hunter, Johnson & Johnson

Roy Jones, representing

Compressed Air and Gas Institute

John Machelor, Macro 

International

Rick Payton, Rockwell 

Automation/Reliance Electric

Bill Stafford, Technical 

Association of the Pulp and Paper

Industry

Howard Snyder, Weirton Steel

Chuck Whelan, DuPont

■

COMMENTS? 

Contact: 

Julia Oliver, DOE, at 

(510) 637-1952, or e-mail

julia.oliver@oak.doe.gov

Erika Ericksen, 

Energy Matters Editor, at 

(303) 275-3914, or e-mail 

erika_ericksen@nrel.gov

1617 Cole Blvd., MS 1713

Golden, CO 80401

By CarolAnn Giovando, Associate Editor,

POWER Magazine

Excerpted from the May 1999 issue of

POWER Magazine and reprinted with permission. 

Industrial, commercial, and institutional

facilities have long recognized that energy

efficiency can boost productivity, lower

costs, and minimize environmental

impacts. But smaller facilities, of say, less

than 500 employees, often pay more for

their energy, per unit of production, than

larger facilities. Reasons may be that: (1)

they don’t qualify for large volume discounts; (2) they use less efficient equipment and processes; and/or (3) they lack

the capital or technical expertise to invest

in efficiency improvements.

According to DOE surveys, the potential

energy savings for these facilities are substantial because small and medium-sized

companies use over 42% of the energy

consumed by manufacturers and represent

over 98% of manufacturing plants.

Now, thanks to the power of partnerships and alliances, both large and small

facilities can benefit from energy efficiency

investments, even capital-intensive ones.

The case studies profiled here showcase

the range of today’s partnerships and

demonstrate how energy efficiency projects best leverage strengths and resources.

Pinch Some Pennies

Engineers at Pennzoil’s Atlas Refinery in

Shreveport, Louisiana, considered energyefficiency alternatives when adding a residual catalytic cracking (RCC) unit, a gas plant,

and an alkylation unit. Because the facility

expansion would significantly increase the

refinery’s electric demand, Pennzoil looked

to Southwestern Electric Power Company

(Swepco), in Shreveport, for energy efficiency ideas and to provide a detailed optimization study for the new equipment.

The study used pinch technology, developed by the Electric Power Research Institute (EPRI), Palo Alto, California, for

analysis and design of plant energy systems. Pinch technology tracks heat flow for

all steam processes. Swepco’s study uncovered opportunities to save nearly 24% of

process heat through improved system integration. Financial savings were estimated at

$880,000/yr in fuel and $475,000/yr in

electricity, for total savings of $13.7 million

over 10 years. Pennzoil incorporated several steam system optimization recommendations into the final design, including

installing a 4,400-hp steam turbine to drive

key equipment in the RCC steam system.

Pulp Mill Steam Recovery

Bowater Inc., Greenville, South Carolina, the world’s second largest producer

of newsprint and third largest producer of

market pulp in North America, operates 10

pulp and paper mills and three sawmills in

the United States, Canada, and Korea. One

of its most successful energy savings projects recaptures steam normally lost during

green-wood-chip processing. Key to the

energy savings: the thermo-mechanical

pulping process (TMP).

Energy formerly lost when low-pressure

steam from pulp production was vented

from seven refiner lines now is recaptured

with two mechanical vapor recompression

(MVR) heat pumps. The MVR pumps convert 19-psig steam at 250°F to 57-psig steam

at 470°F, and the recaptured steam is used

in paper-drying stages. The MVR pumps

feature a 50% turndown, which enables

rapid response to changing steam demands.

Other benefits include daily recovery of

approximately 200 gallons of turpentine—

a TMP byproduct—which is later resold,

and controlling steam vapor upon release

to the atmosphere, reducing the plant

noise level. The $1.5-million investment

was repaid within 1.5 years.

Upgrading Air Compressors

These days, most electric utilities are

willing to help customers evaluate their

manufacturing processes and suggest new

technologies to cut energy consumption.

Bodine Electric, Chicago, Illinois, a manufacturer of fractional-horsepower gear motors,

currently saves over $100,000 a year, thanks

to projects initiated by its utility, Commonwealth Edison (ComEd), in Chicago.

A key project was an upgrade of Bodine’s compressed air system. The utility

conducted an energy analysis and provided

technical recommendations to Bodine.

Before the analysis, Bodine considered

rebuilding its 10-year-old compressed air

system, which powers air drivers, screwguns, and other equipment. The analysis

convinced Bodine to exchange its three

aging, oversized compressors for three new

75-hp units and a sequencer controller,

which acts as the main control to constantly

monitor and meet compressed air needs.

Contact CarolAnn Giovando at POWER

Magazine by phone (314) 436-4252, or 

e-mail: carolann_giovando@mcgraw-hill.

com.

Technical Advances Improve Industrial Energy Efficiency
Energy Matters, September/October 1999 3

Energy Service Companies: Cost-Savings Partners for Industry

As electric utilities transform themselves to

meet the changing marketplace, energy

users must learn a new lexicon of

acronyms and abbreviations. Enterprises

such as ESPs, LDCs, ISOs, PXs, UDCs,

RESCOs, DISCOs, Transcos, and ESCOs

operate alongside traditional electric utilities. Of these, the ESCO, or energy service

company, may be the least understood,

since it offers services historically outside

the domain of regulated electric utilities.

ESCOs also provide the broadest range of

services to energy users.

What is an ESCO?

An ESCO provides energy efficiency

and/or load reduction services to commercial or industrial facilities. There are, however, many types of firms providing these

kinds of services. The table below shows

some of the energy efficiency services

offered by the various types of providers.

To one degree or another, the primary goal

of these energy services providers is to help

their clients reduce energy expenditures

through energy efficiency improvements. 

The ESCO is the only type of energy services provider whose compensation depends

upon energy savings. This is the “shared

savings,” or “performance-based” contract

where the ESCO retains a portion of the

value of the saved energy as compensation. 

ESCOs that concentrate their efforts

within the industrial sector tend to differentiate themselves by focusing within specialized industries, such as textiles or

petroleum refining. 

ESCO Services

ESCO projects often employ a variety of

measures and technologies to achieve

energy savings, including:

■ High-efficiency lighting

■ High-efficiency heating and air conditioning

■ Efficient motors and variable speed drives

■ Centralized energy management systems

ESCOs generally act as project developers and assume much of a project’s risk.

Typically, they offer these services: 

■ Develop, design, and finance energy

efficiency projects.

■ Install and maintain energy-efficient

equipment.

■ Measure, monitor, and verify the project’s energy savings.

■ Assume the risk of guaranteed energy

savings.1

For manufacturing facilities with significant motor-related end uses, there are

potentially large energy saving opportunities

through motor system and pump system

upgrades. However, resources such as time,

expertise, and capital are often not available to facility management for energy efficiency projects. In addition, management

may be more concerned with increasing

productivity and reliability than reducing

energy costs. 

Energy consumers tend to

look for comprehensive solutions

to their operating

situation instead of

just energy savings.

While the effort

may concentrate

on energy efficiency improvements, there are

usually collateral

improvements in

reliability, process

control, environmental compliance, and

increased productivity associated with it. 

Project Funding

One of the greatest benefits of the performance-based contract is that the ESCO

supplies the project funding, which

relieves the company of paying up-front

capital costs. This makes the ESCO a valuable partner for facility management and

ownership. In return for providing the upfront capital, the ESCO receives some portion of the measured savings that result

from the project over a number of years. 

Who is at Risk?

Clearly, there is risk associated with performance-based contracting, and there are

many ways the ESCO and customer can

share that risk. Typically, the ESCO shoulders much of the risk, since the ESCO estimates energy savings a priori and determines whether the savings will repay their

investment. However, if the customer does

not operate the project as planned, then

energy savings will be less than forecasted

and payback will be delayed. The same is

true if the ESCO overestimates savings,

even if the customer operates the project

as planned. Thus, ESCOs have led the

effort to measure and verify, rather than

simply estimate energy savings. 

When the customer is responsible for

operating the equipment, the ESCO must

train operating personnel in the principles

of energy efficiency and proper operation.

Training is also valuable to the customer,

who could assume some risk if energy savings do not meet forecasts. 

ESCO Accreditation

The National Association of Energy Service Companies (NAESCO) promotes the

delivery of “comprehensive energy services

including energy efficiency, to maximize

customer benefits and environmental sustainability.” Members represent several

types of energy services providers. 

NAESCO sponsors a rigorous accreditation program that encourages high standards of quality and integrity in members.

The process is exacting enough that just

over half of its eligible members have

received accreditation. While accreditation

indicates the ESCO is technically and managerially competent and committed to ethical business practices, it is not a guaranty

of energy savings. 

Energy consumers who seek total

energy solutions are likely to find firms that

can supply both the energy and energyrelated services they need. According to

Goldman and Dayton, “ESCOs that have

survived (to this point) have recognized

that most customers are looking for ‘solutions’ rather than improved energy efficiency, per se.”2

1 NAESCO

2 Goldman and Dayton

References:

1) Goldman, C.A. and D.S. Dayton. 1996. “Future

Prospects for ESCOs in a Restructured Electricity Industry.” 1996 ACEEE Summer Study on Energy Efficiency in

Buildings. 10.59. American Council for an Energy Efficient Economy: Washington, D.C.

2) NAESCO (National Association of Energy Service

Companies) Web site, 1999.

Energy Services Offered by Various Types of Providers

A&E Design/ 

Energy Services ESCOs Vendors Contractors Build Firms Consultants 

Energy Audits ✔ ✔✔✔

Engineering Design ✔ ✔ ✔ ✔ 

Equipment Installation ✔ ✔ ✔ ✔ 

Construction and ✔ ✔ ✔ 

Project Management

Performance Monitoring ✔ ✔ 

and Verification 

Performance Guarantees ✔ 

Commissioning ✔ ✔ ✔ ✔

and O&M 

Financing ✔ ✔

Integrator ✔ ✔

Source: Goldman and Dayton.
4 Energy Matters, September/October 1999

Choosing the Right Energy Service Company to Prove the Value of Motor Upgrade Projects

By Jay Raggio, PE, CEM, Manager, Energy

Services, Electro-Test Inc., Danville, CA

Imagine you’re a facility engineer with

responsibility for the operation and maintenance of numerous electric motors serving a

variety of applications. Each time you

review the monthly electric utility bill, you

have an intuitive feeling that a well-planned

program to upgrade your motors could save

real money for your facility. You consider:

■ Replacing existing motors with premium efficiency motors

■ “Rightsizing” motors 

■ Applying variable frequency drives

(VFDs) 

■ Installing control systems to vary motor

operations. 

The problem is—HOW? How do you

develop an accurate and compelling economic model to present to financial decision-makers? The answer could be in

finding the right qualified energy service

company (ESCO). 

What Can a Qualified ESCO Do?

In today’s rapidly changing electric

power industry, there may be more to consider than in the past. A qualified ESCO can

pull all of the pieces of the puzzle together

to accurately quantify the costs and benefits

of potential motor upgrade projects and

then provide results in a manner meaningful

to your facility’s financial decision-makers.

Utility Cost Savings

Often the single largest component of

future benefits, utility cost savings, is difficult to project. You must begin with a solid

understanding of the operational patterns

of the existing equipment. 

■ How many hours per year does each

motor operate?

■ Does each motor’s operation vary daily,

weekly, or seasonally?

■ Are there redundant motors for the

same application? 

A qualified ESCO can develop an accurate annual operating profile for each

motor that is a candidate for upgrading.

They employ “motor run-time metering,”

using loggers to assess motor run times

during different utility costing periods.

Motor loads must also be

assessed. The qualified ESCO conducts spot measurements of kilowatt

demand for each motor. Because

conditions such as ambient temperatures and filter cleanliness can

skew measurement results (e.g. kilowatt demand), it is important to

choose an ESCO that is experienced

and knowledgeable in the electrical

testing industry. 

Your Utility’s Rate Structure

Qualified ESCO’s take the time

to learn if your utility uses an

“energy charge rate” and a

“demand charge,” both of which

can vary daily and seasonally. They should

know the current rate structures and know

when rate changes may come about as a

result of pending competition. 

Overlaying motor operating profiles and

energy demands creates an “energy consumption profile” that, when applied to the

“utility pricing profile,” estimates energy

costs attributable to motor operation. From

this “baseline,” the ESCO can evaluate the

cost-effectiveness of various scenarios for

motor, VFD, and controls retrofits.

Traditional Utility Rebates

Your local utility may offer financial

rebates for new efficient motors, VFDs, and

controls. A qualified ESCO will carefully

evaluate potential rebates as these programs can change dramatically from year

to year. The ESCO should be knowledgeable about these rebate program nuances.

Performance-Based Energy Savings 

Incentives

“Performance-based incentives” offer

financial incentives tied directly to the

actual amount of energy savings produced

by the new equipment. Traditionally, two

identical premium-efficiency motors would

qualify for the same rebate even if one

operated 24 hours per day and the other

only one hour per day. In the performancebased incentive program, the motor running

continuously would qualify for a substantially larger incentive because it delivers

more energy savings to the utility. Although

they offer larger incentives, performancebased incentive programs have a cost.

They require facility managers to prove

their actual energy savings by measurement

and verification (M&V) in accordance with

the International Performance Measurement

and Verification Protocol (IPMVP). 

M&V starts with quantifying baseline

energy consumption by means of demand

measurements and operating hours monitoring. After the retrofit, additional demand

and operating hour measurements are

again conducted. The difference in energy

consumption (pre- to post-retrofit) is the

basis for incentive payments. Where loads

are dynamic and controlled operations

vary over time, continuous monitoring of

power consumption (kWh) is required. A

qualified ESCO can conduct the required

M&V and provide the energy savings documentation required to obtain the performance-based incentives.

All the Pieces of the Puzzle

 As you can see, a qualified ESCO can help

you bring together all of the pieces of the

energy puzzle. They should be partners

with you in improving the reliability of

your facility as well as evaluating costs and

benefits of upgrades. Qualified ESCOs offer

financing, installation, commissioning,

measurement, and verification of the entire

project to ensure that you achieve a more

energy-efficient facility with state-of-the-art

equipment for reliability, safety, and long

operating life.

Contact Jay Raggio by phone 

(925) 824-0330 x305, or e-mail: 

jay_raggio@electro-test.com.

Motor load measurements quantify energy savings.
Energy Assets: Tapping the Hidden Value

By Kurt Thielemann and Tim Fess,

DukeSolutions, North America

Some of the most creative engineering with

energy projects today has little to do with

rotating equipment or technical formulas.

The opportunity lies with interest rates, off

balance sheet financing, and economic

value added. Financial engineering is crucial to making an attractive energy project

come to fruition. Various financing options

including turnkey contracts, performance

contracts, or outsourcing supply agreements

provide distinct advantages to end users. 

For example, steam, compressed air,

and chilled water can now be purchased

like electricity or natural gas. By using a

comprehensive energy service company

(ESCO), an end user gains positive economics on its financial position, mitigates

risks of ownership, accesses world-class

technical capabilities, and can focus on

core businesses. 

Financial Benefits 

Working with an ESCO on an energy

project can offer financial benefits including:

■ Zero up-front capital

■ Off balance sheet financing for utilities

(steam, chilled water, or compressed

air) under a service agreement structure 

■ An infusion of capital from the sale of

existing assets.

Based on site-specific requirements and

initial capital investment, a financial structure can be developed to meet the end

user’s needs. In a “greenfield” environment

where no facility exists, the ESCO designs

an energy plant to meet the future production needs. In a “brownfield” application

where chillers, boilers, and compressors

already exist, an ESCO can monetize assets

for the customer. The ESCO implements

any modifications to the existing energy

infrastructure to reduce operating costs and 

deliver higher useful output. In either case,

the ESCO expends its own capital and

labor for engineering, construction management, operations, and maintenance

throughout the term of the contract.

Risk Mitigation

ESCOs can minimize the customer’s risk

associated with the implementation of

energy assets. They perform studies everyday in which energy projects, on paper,

show an acceptable return on investment

(ROI). Frequently, the end user takes the

risk of implementing the ESCO’s recommendations and experiences cost overruns

and/or underachieves energy savings targets, thereby missing the ROI. When this

occurs, executive management looks for

accountability and may think twice about

funding energy projects in the future. The

moral is an ESCO should not only author

the study but also accept the financial risk

associated with implementation.

The reason outsourcing is becoming

more intriguing is CEOs are motivated to

improve return on assets (ROA), reduce

operating costs, and shed operating risk.

An ESCO having assets under management

structures a contract with guarantees for

utility quality and availability while securing fiscal cost control for the end user.

Technical Expertise

Typically, customers looking to solve

energy problems search for suppliers with

expertise. One advantage of working with

an ESCO is access to the industry’s best 

(continued on page 7)

Energy Matters, September/October 1999 5

Steam Workshops Promote Energy Efficiency 

While, many industrial manufacturing

plants have the

technical capabilities on site to

achieve greater

energy efficiency,

plant and energy managers often believe

they lack the time and resources to implement changes. To address this issue, DOE,

the Alliance to Save Energy (ASE), Spirax

Sarco, and NALCO Chemical are sponsoring a workshop on steam system energy

efficiency on October 15, 1999, in

Naperville, Illinois. 

The workshop will present case studies

and success stories from energy managers

in the field. Attendees can interact with

peers to discuss energy management issues

and to learn more about the resources

available to help them improve plant 

performance. 

DOE and ASE, along with Allied Partner

companies, will present these workshops

approximately once every 2 months in

cities across the United States. The workshops are open to personnel of industrial

manufacturing plants. If you’re interested

in steam system efficiency projects and

would like more information on upcoming

workshops, contact David Jaber at 

(202) 530-2240 or djaber@ase.org. 

The steam used to heat large hydraulic

presses at a manufacturer of residential and

commercial goods is critical to the company’s production process. Natural gas and

coal were being used to fire pre-1960s boilers that were becoming obsolete. The manufacturer faced the prospect of curtailing

production because of a steam shortage.

DukeSolutions, a business unit of Duke

Energy, is an ESCO focusing on the industrial, commercial, institutional, and federal

markets, and worked with the manufacturer

to provide steam supply services. 

The new boiler plant will consist of three

natural gas/oil boilers and one waste wood

boiler. DukeSolutions provided the customer:

■ An evaluation of the existing and future

steam system requirements and the engineering required to design and implement

a steam program. 

■ The commitment of resources needed to

construct, own, operate, and maintain a

boiler plant with a peak capacity of

200,000 lbs/hr.

■ A cost-efficient means of burning more

than 30 tons per day of nonhazardous

process waste.

■ An implementation program that included

all permits and licenses for construction

and operation of the steam facility. 

Convinced that all requirements could be

met, the manufacturer decided to outsource

its steam instead of purchasing a new boiler

plant. This shift in thinking resulted in these

economic advantages:

■ No increase in net operating cost.

■ Off balance sheet financing. 

■ Zero initial capital.

■ Elimination of ownership risks.

■ Reliable operations and maintenance.

■ Flexible contract terms.

Even though the benefits of outsourcing utilities appeal to many companies today, the

main advantage for this customer was the

“one-stop shopping” with an acknowledged

leader in the energy business.

CASE STUDY
6 Energy Matters, September/October 1999

Performance 

Optimization Tips

Field Measurements in

Pumping Systems—

Practicalities and Pitfalls

By Don Casada,

Motor Challenge

Program, Oak Ridge

National Laboratory 

This article is the 3rd

in a series dealing

with practical considerations and pitfalls of field measurements needed to

understand pumping systems.

Pump Head

In the May and July issues, we discussed

pressure and elevation components of

pump head. We’ll finish here with the last

head element of that trio—velocity.

Velocity

 Velocity head equals the velocity squared

divided by two times the gravitational constant (V2/2g). For many centrifugal pumps,

the suction flange is one pipe size larger

than the discharge flange.1 When suction

and discharge pressure measurements are

made in different line sizes, an accounting

for the different velocity heads must be

made. But, in some applications, use of

expanders results in identical size suction

and discharge measurement points, meaning that the velocity heads in the suction

and discharge are equal. Be sure to note

the pipe dimensions where the suction and

discharge pressure measurements are

made, and adjust the head as necessary.2

Of course, the velocity is normally calculated from the pipe size and volumetric

flow rate. Using common U.S. units,

V (ft/sec) = gpm

2.45d2

(d is the inside pipe diameter in inches).

Which leads us to the next important

energy element in pumping systems—flow

rate.

Pump Flow Rate

Flow rate is usually the single most

important parameter to grasp in assessing

pumping system operation. Frequently, it is

also the most difficult to accurately acquire. 

In many systems, no permanently

installed flow instrumentation exists. In

such cases, either temporary flow instrumentation or alternative methods of estimating flow rate must be deployed. This

column focuses on considerations where

flow instrumentation exists.

Just because permanently installed flow

instrumentation exists does not mean it is

dependable. Many factors can affect the

accuracy of indicated flow rate. We’ll

touch on just three: installation layout;

degraded or uncalibrated instruments; and

unrecognized flow paths.

Installation layout

The most commonly used flow-measuring instruments depend on a fully developed, undisturbed flow profile. This means

several pipe diameters of straight pipe,

without fittings, upstream of the measuring

device. For example, an ASME standard for

flow measurement requires from 6 to 35

pipe diameters of straight length upstream

of the measuring device to keep associated

errors below 0.5%, depending on the type

of flow disturbance and meter design.3

Figure 1 shows an extreme example of

nonconformance. Based on other indications (primarily pump head), the indicated

flow rate from this meter is in error by

around 25%. Furthermore, the extent of

error is influenced by the distribution of

main and bypass flow. 

A quick review of the physical geometry

of a flow meter whose output is used in

system analysis is time well spent, whether

it provides some “warm fuzzies” or raises

the flag of uncertainty, as in this case.

Degraded or uncalibrated instruments

 Many common types of flow meters

involve a reduced flow area (e.g., orifices)

or an inserted, movable part (e.g., turbine

meters). The flow-measuring device is thus

a likely point for foreign materials, which

find their way into even “clean” fluid systems. If the meter totally fails, a problem

will be quickly obvious. But not all degradation results in total failure. Simple service wear from erosion and scale buildup

can, over time, degrade performance.

One of the most challenging, practical

aspects of any flow instrumentation is true,

comprehensive field calibration. While pressure instruments can be readily removed

and/or tested in service with calibrated

pressure sources, flow meters normally

cannot. As a result, plugging and wear or

other primary device problems would not

be discovered during calibration.4

However, the fact that an instrument is

periodically calibrated suggests that someone really does depend on it, and problems in actual service are more likely to be

noticed. Determining whether a flow meter

is periodically calibrated, finding out who

uses the indication, and then asking questions of the user can give at least a qualitative sense of data dependability.

Unrecognized flow paths

When getting flow data from an instrument, always ask: “Exactly what is this

thing measuring?”

Consider the simple flow diagram in

Figure 2, with four parallel pumps drawing

suction from a common tank and delivering the flow to the “Target.” The flow meter

installed in a common header may be

accurately reporting the flow rate going

through it, assuming it is the same flow

rate as Pump 2, the only running pump,

we may be in error. For example, the recirculation valve at the top, shown as closed

might actually be open, or one or more of

the discharge check valves on pumps 1, 3,

and 4 may be leaking. Pump 2 may be

pumping considerably greater flow than

the meter indicates. One could conclude 

continued on page 7

Figure 1. An undesirable flow meter (inside

oval) installation.

F

Target

Tank

1

2

3

4

Figure 2. Simple system flow diagram.
Energy Matters, September/October 1999 7

Letters to the Editor

Energy Matters welcomes

your typewritten letters and

e-mails. Please include your

full name, address, association, and phone

number, and limit comments to 200 words.

Address correspondence to:

Michelle Mallory, Letters to the Editor

NREL, MS 1713

1617 Cole Blvd.

Golden, CO 80401 

e-mail: michelle_sosa-mallory@nrel.gov

We publish letters of interest to our

readers on related technical topics, comments, or criticisms/corrections of a technical nature. Preference is given to letters

relating to articles that appeared in the previous two issues. Letters may be edited for

clarity, length, and style.

Editor:

Please describe performance measurements (including efficiency determination)

for pumping systems. We have clamp-on

meters for electrical input power to motor

measurement, pressure gauges, measuring

tapes, and tachometers for RPM measurement. Please suggest a testing method.

Also, we find that flow meters are

mostly absent in India, and as portable flow

meters are extremely costly, we are seeking

alternative solutions. Do any alternatives

(such as using characteristic curves) exist?

Indradip Mitra, 

Enhanced WAPP Systems (p) Ltd.

New Delhi, India

Don Casada writes Performance 

Optimization Tips for Energy Matters and

provided this response to our reader:

You have a good complement of tools,

except of course, flow rate measuring

equipment.

In the May 1999 Performance Optimization Tips* I referenced two pump performance measurement standards: 

■ ASME/ANSI Performance Test code 8.2-

1990, Centrifugal Pumps

■ ANSI/HI 1.6-1994, Centrifugal Pump

Tests

I strongly encourage you to obtain these

standards, which include good discussion

on practical field measurement issues.

The absence of flow meters you observe

in India also exists in the U.S. Many portable

flow meters are expensive and difficult to

operate. On Page 6 of this issue, we discuss

some important considerations, even when

an installed flow measuring device exists.

In upcoming issues, we’ll address the situation you mention, where flow rate is not

measured. We’ll discuss characteristic

curves, but also other practical, non-precision ways to estimate flow rate.

*Find the series of Performance Optimization Tips on the new Energy Matters Extra

Web page at www.motor.doe.gov/emextra.

How have you applied information from

this newsletter on the job? Send us an 

e-mail at motorline@energy.wsu.edu.

Energy Assets

continued from page 5

energy experts. An ESCO that has thousands of compressor horsepower under

management will have a group focused on

compressor system efficiency and controls.

This pool of experience can be used to

support a supply agreement for compressed air, steam, chilled water, etc. Additionally, most controls groups can integrate

the energy assets’ supply with the customer’s production equipment, providing

significant cost improvements. 

Focus on Core Business

By outsourcing energy systems services,

end users make a cultural decision to rely

on proven capabilities available in the

marketplace and can refocus efforts to

achieve financial goals. In leveraging an

ESCO’s financial and technical strengths,

end users can improve their economic

position by utilizing capital for revenue

producing actions. 

Send comments/questions to kbthiele@duke-energy.

com or tdfess@duke-energy.com; (704) 382-2646

(phone); (704) 382-1255 (fax).

New Online: Something Extra

Introducing Energy Matters Extra

There is now an online supplement to

Energy Matters! In addition to the information you find here in print, check out this

new Web page for more coverage of

energy efficiency opportunities related to

motor, steam, compressed air, and combined heat and power systems. The first

edition of EM Extra gives you more on this

issue’s editorial theme, contracted services.

You’ll find news you can use, such as

details about a premium efficiency motor

incentive program in the state of New York.

Link to other resources, such as a new

combined heat and power association and

just-available fact sheets that offer hot tips

on steam system efficiency. Look for the

series of technical articles by contributing

authors Don Casada and John Machelor.

You can also complete the Energy Matters

Reader Survey online. Find Energy Matters

Extra at www.motor.doe.gov/emextra.

continued from page 6

that Pump 2 is performing below expectation, when it is really a valve(s) problem.

This could lead to unnecessary corrective

maintenance actions.

But I Don’t Have a Flow Meter!

Some industrial systems have no flow

instrumentation. What are we to do in that

case? Tune in next time, same channel.

Comments/questions welcome by e-mail:

a85@ornl.gov.

1 In many applications there is no suction pressure measurement connection. An obvious example is in vertical

turbine pump applications where the pump draws suction from a tank, river, or other body of water.

2 In actual applications, components between the pump

and the measurement points will result in indicated

pump head that is less than in a pump test facility

because of losses across these components. Head losses

across the intervening components can be estimated

and added to the measured head to provide a more

accurate comparison with manufacturer test results.

3 The latest edition of the ASME standard notes the data

used to establish the lengths were acquired in 1927

and analyzed in the 1930s. More recent measurements

indicate even those lengths may not be enough.

4 Usually, it is also impractical to even visually verify

the condition of the primary sensing element.

References:

1) Measurement of Fluid Flow in Pipes Using Orifice,

Nozzle, and Venturi, ASME MFC-3M-1989.

Correction: In July’s Performance Optimization Tips, the

term specific weight (weight/unit volume) should have

been used in the expressions involving head instead of

density (mass/unit volume). Normally the symbols γ

and ρ are used for specific weight and density, respectively. The author apologizes for his mistake.

MORE COVERAGE OF ENERGY EFFICIENCY OPPORTUNITIES FOR YOUR INDUSTRY

N

E

EXTRA ERGY MATTERS T OF ENERGY

DEPARTMEN

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Coming Events 

INFORMATION

CLEARINGHOUSE

Do you have questions about 

using energy-efficient electric

motor systems? Call the OIT Challenge

Programs Information Clearinghouse 

for answers, Monday through Friday

9:00 a.m. to 8:00 p.m. (EST).

Fax: (360) 586-8303, or access our

homepage at www.motor.doe.gov

HOTLINE: (800) 862-2086

DOE Regional Support Office 

Representatives

■ Tim Eastling, Atlanta, GA, 

(404) 347-7141

■ Lili Griffin, Boston, MA, 

(617) 565-9714

■ Julie Nochumsom, Chicago, IL, 

(312) 886-8579

■ Gibson Asuquo, Denver, CO, 

(303) 275-4841

■ Julia Oliver, Seattle, WA, 

(510) 637-1952

■ Maryanne Daniel, Philadelphia, PA, 

(215) 656-6964

This document was produced for the Office 

of Energy Efficiency and Renewable Energy at

the U.S. Department of Energy (DOE) by the

National Renewable Energy Laboratory, a DOE

national laboratory.

DOE/GO-10099-908 • September/October 1999

T OF ENERGY

DEPARTMEN

U

E

NITED STAT S OFA ERICA

M

Printed with a renewable-source ink on paper

containing at least 50% wastepaper, including

20% postconsumer waste

UNDERSTANDING PUMP SYSTEMS/PSAT WORKSHOPS

These sessions present the fundamentals of optimizing industrial and municipal pump systems.

The workshops present case studies and focus on the Pump System Assessment Tool (PSAT).

■ September 28 in Sacramento, CA

■ September and October (date/cities TBD)

in Northern and Southern CA

■ October 5 in Millwood, NY

■ October 6 in Brooklyn, NY

■ October 6 in Portsmouth, NH

Call Anna Maksimova at (360) 754-1097, ext.100 for more information.

ADJUSTABLE SPEED DRIVE APPLICATION WORKSHOPS

These workshops address the fundamentals of ASDs and demonstrate the ASDMaster software.

■ October (date TBD) in Philadelphia, PA

■ October (date TBD) in Hartford, CT

■ October 27 in Newcastle, DE 

Call Anna Maksimova at (360) 754-1097, ext.100 for more information.

FUNDAMENTALS OF COMPRESSED AIR SYSTEMS

These 1-day Compressed Air Systems training seminars are for plant engineers and maintenance personnel responsible for optimum performance of compressed air systems. 

■ October 6 in Salt Lake City, UT 

For information or a registration form, call (800) 862-2086.

MOTOR SYSTEM MANAGEMENT

Six 1-day workshops on motor systems management are designed to reduce the expense

and complexities of managing and operating electric motor systems. 

■ September to mid-November (dates/cities

TBD) in the Midwest 

■ October 5 in Richmond, VA

Call Anna Maksimova at (360) 754-1097, ext.100 for more information.

WORKSHOP FOR STEAM USERS

■ October 15 in Naperville, IL

Call David Jaber at (202) 530-2240 for more information.

IMPROVED FACILITY PERFORMANCE THROUGH ENHANCED STEAM SYSTEMS

■ November 1999 through June 2000 (cities/dates TBD) in WI

Call Steve Nelson or Doug Presny at (608) 238-4601 for more information. 

EFFICIENCY AND SUSTAINABILITY: 2000 ACEEE SUMMER STUDY ON

ENERGY EFFICIENCY IN BUILDINGS

ACEEE announces a call for papers for this August 20-25, 2000, conference in Pacific

Grove, CA. Abstracts are due to the Summer Study Office by October 15, 1999. Contact

Rebecca Lunetta at (302) 292-3966 for more information.

U.S. Department of Energy

EE-20, 5G-067

1000 Independence Avenue, SW

Washington, DC 20585

Bulk Rate

U.S. Postage

PAID

Permit No. 258

Golden, Colorado

■ October and November (dates TBD) in

Houston, TX

■ November 15 in Latham, NY

■ November 16 in Wheatfield, NY

■ November 17 in Albany, NY

■ January 27 in Vancouver, WA

■ January 27 (city TBD) in MI

■ November 2 in Reading, PA

■ November 9 in Upper Darby 

Township, PA

■ October 27 in Everett, WA

■ November 3 in West Lebanon, NH 

■ November 17 in Birmingham, AL