Winter 2004

ISSUE FOCUS:

 The Value of Training

When the University of Miami’s Industrial Assessment Center evaluated one 

Florida manufacturer’s energy consumption 

recently, it reached a startling conclusion. 

More than 40% of the 107,000-square-foot 

facility’s electrical power usage was taking 

place during the 12 hours between 6:00 

pm and 5:59 am. But these were overnight 

hours when the plant was idle. The University of Miami team calculated the plant was 

spending nearly $90,000 a year for roughly 

1,850,000 kilowatt-hours of electricity (the 

equivalent of producing 4.2 million pounds 

of greenhouse gas emissions each year), all 

of it consumed when no manufacturing was 

taking place.

The University of Miami research team 

made its finding after studying energy use 

data gathered by data loggers, which the 

team installed during a detailed plant-wide 

energy assessment. Assessments are done 

as part of the Industrial Technologies Program’s Industrial Assessment Center (IAC) 

effort, available to small manufacturers in 

Florida and in many places nationwide.

As part of its program, the University of 

Miami’s energy monitors are attached to 

electrical devices throughout a participating 

Florida-based manufacturer’s facility. Once 

in place, the devices log how much energy 

each major piece of electrical equipment 

uses. Data are collected every 24 seconds for 

a full seven days.

At the start of its assessment, the 

research team typically installs at least 18 

and as many as 120 data loggers in a plant. 

At a minimum, each electrical main disconnect is monitored with one logger per 

phase. Additional monitors may be installed 

on equipment such as chillers, air conditioning units, compressors, and motors.

With 18 data loggers in place, as many 

as 450,000 pieces of data can be collected 

over the course of a week. With 120 loggers 

installed, the data points can exceed 3 million. Armed with this raw energy consumption data, the University of Miami IAC team 

uses a custom-designed software program 

known as LIBERTAD (Spanish for “freedom”) to estimate a plant’s annual energy 

use and related expenses.

Ghost Power

And because the data loggers record 

energy consumption every 24 seconds for 

seven days, the IAC team is also able to 

build a detailed energy usage profile for 

each day. (See the accompanying table.) The 

evaluation software divides each 24-hour 

period into four 6-hour segments. These are 

known as “Gate Power,” which lasts from 

6:00 am to 11:59 am; “Stretch Power,” from 

12:00 pm to 5:59 pm; “Red-Eye Power,” 

from 6:00 pm to 11:59 pm; and “Ghost 

Power,” which lasts from 12:00 am to 

5:59 am.

The software is also designed to account 

for any on-peak and off-peak energy pricing during each of the four daily segments. 

When all the data are analyzed, the resulting summary table looks like the one 

reproduced here, completed for an actual 

manufacturing facility. Using the table, 

plant managers can see how much energy 

their plant consumes every day of the week, 

and how much that consumption costs. The 

data are also used to estimate annual energy 

consumption and expenses.

T OF ENERGY

DEPARTMEN

U

E

NITED STAT S OFA

ERICA

M

(continued on page 2) 

“TURNING INFORMATION INTO ENERGY SOLUTIONS FOR INDUSTRY”

Energy Matters INDUSTRIAL TECHNOLOGIES PROGRAM

IN THIS ISSUE

Miami Device: Data Loggers Help 

IAC Team Identify Wasted Power 1

Fostering Good Habits Through 

Planned and Proactive Training . 2

Lunching on Leftovers . . . . . . . . 3

Achieving Immediate Savings by 

Taking a Systems Approach to 

Compressed Air . . . . . . . . . . . . . 5

North Star Steel Completes PlantWide Energy Assessment at 

Mini-Mill . . . . . . . . . . . . . . . . . . .5

Infrared Oven Saves Energy, Lifts 

Production at a Metal Finishing 

Plant . . . . . . . . . . . . . . . . . . . . . 7

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

Energy efficiency, increased 

productivity, and reduced waste at North 

Star Steel page 5.

U.S. Department of Energy 

Energy Efficiency 

and Renewable Energy

Bringing you a prosperous future where energy

is clean abundant, reliable, and affordable

Is Your Plant IAC Eligible?

To be eligible for an IAC assessment, a 

manufacturing plant must meet the following 

criteria: 

• Within Standard Industrial Codes (SIC) 20-39

• Within 150 miles of a host campus

• Gross annual sales below $100 million

• Fewer than 500 employees at the plant site

• Annual energy bills more than $100,000 and 

 less than $2 million

• No professional in-house staff to perform the 

 assessment

Miami Device: Data Loggers Help IAC Team Identify Wasted Power
2 Energy Matters, Winter 2004

For example, data loggers installed at the 

Florida manufacturer showed the plant had 

an annual energy consumption profile that 

looked like this:

• Ghost Power: 19% of total 

 consumption at a cost of $41,000

• Gate Power: 29% of total 

 consumption at a cost of $63,500

• Stretch Power: 30% of total 

 consumption at a cost of $66,000

• Red-Eye Power: 22% of total 

 consumption at a cost of $47,000.

This particular manufacturing facility 

was approximately 107,000 square feet in 

size (30,000 of offices and 77,000 square 

feet of manufacturing space). The entire 

facility was air-conditioned.

The University of Miami’s IAC is 

one of 26 university-based IACs located 

around the country. Dr. Shihab Asfour, 

chairman of the Department of Industrial Engineering, directs Miami’s IAC. 

He says the Miami IAC has been in 

existence for four years and has been 

using data loggers as part of its energy 

assessment strategy for 18 months.

No-Cost Assessments

Nationally, the IAC program 

provides small- and medium-sized 

manufacturers with no-cost individual 

assessments of their plant’s energy, 

waste, and productivity efficiency, followed by recommendations for specific 

cost savings.

These assessments are conducted 

by engineering faculty and students 

from IACs hosted by 26 universities 

across the United States. The Industrial 

Technologies Program sponsors the 

program as part of its efforts to transfer 

energy-efficiency and environmentally 

sound practices and technologies to 

U.S. industry.

Assessments are provided at no direct 

cost to participating manufacturers, who are 

under no obligation to act on any recommendations. On average, recommended 

actions from an assessment result in annual 

cost savings of about $55,000. The university-based IAC team typically conducts the 

assessment during a 1- or 2-day site visit. 

Within 60 days the team will send a report 

to the client detailing its analyses, findings, 

and recommendations. 

To find out if your company is eligible 

to benefit from the IAC program, check 

the IAC Web site at www.oit.doe.gov/

iac. Dr. Asfour may be reached at 

sasfour@miami.edu.●

Miami Device: Data Loggers Help IAC Team Identify Waste Power continued from page 1

ENERGY MATTERS

is published quarterly by the 

U.S. Department of Energy’s (DOE) 

Industrial Technologies Program. 

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

Tom Bishop

Electrical Apparatus Service 

Association

Rob Boteler, representing National 

Electrical Manufacturers 

Association

Eric T. Fletty, Business 

Development Manager, TAPPI

Gary L. Goehring, Alcoa 

North American Extrusions

Glenn Hahn, Spirax Sarco

J. Bruce Medaris, Facilities 

Consulting Services and 

Executive Director, Compressed 

Air Challenge®

Michael R. Muller, Center for 

Advanced Energy Systems, 

Rutgers University

Arvind Thekdi, E3M, Inc.

Chuck Whelan, DuPont 

■

DOE Staff

Chris Cockrill, BestPractices, 

Motors

Bob Gemmer, Process Heating and 

Steam

Grace Ordaz,

Technology Manager

Peter Salmon-Cox, Lead 

Technology Manager, Technology 

Delivery and BestPractices 

■

Comments? 

Contact: 

David Wagman, Energy Matters 

Editor, at 303-275-3602, 

e-mail david_wagman@nrel.gov

or Karen Atkison, Associate 

Editor at 303-275-3730, e-mail 

karen_atkison@nrel.gov

1617 Cole Blvd., MS 1609

Golden, CO 80401

For new subscriptions, go to 

www.oit.doe.gov/

bestpractices/explore_library/

energy_matters.shtml

For address/subscription changes, 

please contact the editor.

Fostering Good Habits Through Planned and Proactive Training

Adam Hudson and Christopher Russell

Alliance to Save Energy

Not long a go, we participated in an 

industrial steam training program. The class 

instructors discussed industrial boiler operations and safety. Each attendee came to learn 

something different. Most came to find ways 

to improve the operations of their respective 

plants to save money. 

Our instructor, a self-proclaimed “boiler 

Q-tip”, had a great deal of knowledge, and, 

perhaps more importantly, practical experience to share with us. The topics we covered 

included the function of boilers and their 

various components, characterizing and 

Gate Power

6:00 am to 11:59 am

Stretch Power

12:00 pm to 5:59 pm

Red-Eye Power

6:00 pm to 11:59 pm

Ghost Power

12:00 am to 5:59 am

On-Peak Off-Peak On-Peak Off-Peak On-Peak Off-Peak On-Peak Off-Peak

Days % Cost ($) % Cost($) % Cost ($) % Cost($) % Cost ($) % Cost ($) % Cost 

($) % Cost ($)

Sat. 0.00 0.00 2.19 4,765.00 0.00 0.00 2.29 4,987.10 0.00 0.00 2.06 4,478.70 0.00 0.00 1.96 4,270.80

Sun. 0.00 0.00 1.54 3,348.00 0.00 0.00 1.59 3,458.90 0.00 0.00 1.44 3,127.60 0.00 0.00 1.96 4,260.20

Mon. 1.28 2,793.50 3.98 8,657.00 3.43 7,456.60 2.10 4,572.70 2.37 5,167.00 1.56 3,386.40 0.00 0.00 2.03 4,418.20

Tues 1.29 2,811.60 3.96 8,620.00 3.53 7,690.80 2.17 4,716.30 2.49 5,412.10 1.51 3,285.30 0.00 0.00 3.15 6,847.70

Wed. 1.26 2,732.00 3.86 8,406.00 3.34 7,279.30 2.05 4,463.90 2.46 5,362.70 1.58 3,446.30 0.00 0.00 3.14 6,838.00

Thrs. 1.29 2,798.40 4.01 8,718.00 3.49 7,602.00 2.14 4,661.80 2.48 5,392.50 1.62 3,523.50 0.00 0.00 3.36 7,320.40

Fri. 1.10 2,394.80 3.32 7,218.00 2.62 5,697.90 1.61 3,494.20 1.37 2,989.80 0.87 1,883.00 0.00 0.00 3.16 6,874.40

Total 6.22 13,530.30 22.85 49,732.00 16.42 35,726.60 13.95 30,354.90 11.18 24,324.20 10.63 23,130.80 0.00 0.00 18.76 40,829.70

Annual Consumption of Electrical Energy in U.S. Dollars
Energy Matters, Winter 2004 3

Lunching on Leftovers

 generally shrinks as size increases. 

Such is the case for motors and pumps. 

Figure 1 shows typical top-of-line pump and 

motor efficiencies as a function of size. Figure 2 illustrates representative gaps between 

high- and medium-pump [3] and motor efficiencies as a function of size. 

While the efficiency gap between average and top-of-line performance equipment 

is larger for the smaller sizes, the gap is very 

small relative to the types of overall system 

efficiency improvements that would be pursued by the prescreening process. I usually 

expect to find 20% or greater systems-level 

savings opportunities in systems that have 

been flagged by the prescreening process. 

This is roughly an order of magnitude greater 

than the gap in component efficiencies 

shown in Figure 2.

But the fact that a gap exists points to 

the merits of implementing good standard 

policies and practices, such as purchasing 

policies that take energy considerations into 

account (including those for smaller components). 

Figure 1. Approximate top-of-line pump 

and motor efficiencies

Figure 2. Approximate gaps between 

top-of-line and average pump and motor 

efficiencies

accounting for system losses, and boiler 

safety and code compliance.

Along with technical instruction on boilers, our instructor shared many stories of 

hard-won lessons in boiler function and malfunction. Since most of the attendees were 

operators, the class taught primarily handson, usable theory supplemented with some 

technical information. Attendees were also 

given methods for quantifying system losses 

in dollar amounts

Students were exposed to projects and 

solutions in areas they had not previously 

considered. Instead of looking for savings 

through infrastructure changes, many 

operators will save money through simple 

changes in procedure and maintenance. An 

understanding of the steam system through 

training will allow these operators to anticipate problems instead of waiting for them to 

occur.

Workplace Culture

One of the most important lessons we 

learned was the value of training. The workplace isn’t only an environment but also a 

culture. Without proper guidance, the workplace can become a culture of bad habits. 

When employees lack an understanding of 

all aspects of the steam system, they can’t see 

the impact their actions have on the system. 

Under pressure to meet production goals, 

employees may use a quick fix to address 

a serious problem, not understanding the 

implications of such an action.

Whether they realize it or not, operators 

at industrial plants will receive some sort of 

“training” during their career. This training 

can be through a formal program, through 

mentoring by more experienced operators, or 

through the “school of hard knocks.” For an 

operator to know how to maintain a steam 

system and how to address failures and malfunctions effectively, a plant must be sure of 

the quality and method of training. An ad 

hoc, improvised training program will result 

in ad hoc results. The value of planned and 

proactive training is found in the creation 

of competent, effective, and proactive plant 

operators.

Interested in improving the efficiency of 

your plant’s compressed air, motor, pump, 

steam, and process heating systems? The 

Industrial Technologies Program offers system-wide and component-specific best practices training programs to help you run your 

plant more efficiently. Training is offered 

throughout the year and around the country. 

For a current calendar of training, as well as 

training locations, visit www.oit.doe.gov/

bestpractices/training/.●

Don Casada

Diagnostic Solutions, LLC

The DOE provides a system-level prescreening methodology whose goal is to 

highlight the most likely targets for energycost reduction in motor-driven pumping 

systems. Much of this process has been 

previously covered in Energy Matters [1, 2]. 

Although the methodology is specific to 

pumping systems, the same basic concepts 

apply in many other types of systems. 

The first two steps in the process narrow 

the focus to larger loads that run most of the 

time. Specific symptoms are then explored. 

The overall goal is to set the table with 

energy-reduction dishes that are likely to 

provide a feast of energy savings.

Does this mean that no energy-cost 

reduction opportunities exist in the “leftover” systems; namely, those that use smaller 

components, or those that run infrequently? 

The answer, of course, is no. This article 

explores a couple of areas that are explicitly 

excluded from more detailed system-level 

review.

Component-Level Opportunities

Two important efficiency-size relationships are common in most energy-related 

components:

• Efficiency increases as the component 

size increases

• The gap between top-of-the-line and 

 average-grade component efficiencies 

THE VALUE OF TRAINING

The value of a planned, proactive training 

program is the creation of competent, effective, and proactive plant operators, who can 

anticipate problems to ensure plant efficiency, 

reliability, cost-savings, and safety

For example, one steel company offered 

hands-on safety awareness training and 

supervisor safety training. In three years, 

recordable accidents decreased by 25% a 

year (63% overall). There also was a 75% 

increase in worker’s perception that they had 

some influence over co-worker safety

The lesson? Planned, high-quality training 

leads to proactive and effective operators.

0 100 200 300 400 500

0 10 20 30 40 50

100

95

90

85

Efficiency, %

Motor rated hp

Pump flow rate, 1000 gpm

pump

motor

0 100 200 300 400 500

0 10 20 30 40 50

4

2

1

0

Efficiency gap, %

Motor rated hp

Pump flow rate, 1000 gpm

pump

3 motor

(continued on page 4) 
The annual costs of operating the selected 

pump under the two rate structures and the 

two different motor sets are shown in Table 3 

for several assumed operating times. Several 

items are noteworthy. First, the premiumefficiency motor costs more to run than 

the energy-efficient motor. This is true even 

though it is 1% more efficient. There are two 

reasons for this:

• The 200-hp motor operates at a higher 

speed than the 150-hp motor when connected to the same equipment. Since 

this is a centrifugal pump, the shaft load 

is proportional to the cube of the speed. 

This speed difference essentially negates 

the greater efficiency, as indicated by the 

electrical power for the alternative motors 

in Table 2. 

• The slightly lower power factor with the 

200-hp motor results in the apparent 

power (kVA) being greater than for the 

150-hp motor. The demand charge for 

Schedule A, which is kVA-based, implicitly penalizes the lower power factor.

Another notable feature is that while 

Schedule A is clearly less costly for equipment that runs a lot, it is more expensive 

than under Schedule B for equipment that 

runs a relatively small amount of the time.

Perhaps the most interesting feature is the 

significant cost that can be incurred when 

operating times are low. The demand componet accounts for 60-80% of the pump’s total 

electrical cost if the pump is only operated 4 

hours a day.

An inherent assumption in calculating 

these costs is that the demand associated 

with this particular load is coincident with 

the 30-minute monthly peak demand. Of 

course, that may or may not be true. But 

unless some sort of active control is exercised 

to specifically avoid running this pump during periods when the combined sum of the 

other plant loads are at or near the maximum, chances are excellent that the pump 

will, in fact, add to the load. 

But that points toward the potential 

savings associated with an active control 

scheme that monitors the overall plant 

demand and regulates those seldom-used 

loads that can be operated in a flexible manner, time-wise. If it is feasible to move the 

operation of seldom-used equipment to periods when they will not add to the monthly 

peak, significant annual savings can result 

(the “Demand Component” on the last line 

of Table 3). This is certainly not a trivial 

amount. Furthermore, it could prove more 

important, cost-savings-wise, than anything 

we’d be likely to find in terms of the overall 

system optimization of this size that runs all 

of the time.

Moving the times when seldom-used 

equipment is operated may not save a single 

watt-hour of energy, but it can be an excellent option to consider in terms of reducing 

energy costs. Seldom-run loads that can be 

operated flexibly may not yield the feast that 

a systems-based approach does, but leftovers 

can be pretty tasty, too.

4 Energy Matters, Winter 2004

Lunching on Leftovers continued from page 3

The basis for not including systems that 

seldom run is obvious: they use less energy 

than comparably sized systems that run most 

of the time.

But energy and energy cost aren’t 

necessarily related on a straight-line 

basis. Many industrial, municipal, and 

large commercial rates include demand 

and power factor charges. These nonenergy-charge components can be 

significant parts of the overall bill. (For 

a brief discussion of these elements 

see the current issue of Energy Matters 

Extra at www.oit.doe.gov/bestpractices/

energymatters/emextra/). 

There are almost as many ways of assessing demand and power factor charges as 

there are utilities. But to illustrate what 

the charges can mean, we’ll use a pair of 

example rate structures, shown in Table 1. 

The energy charge rate for customers in the 

Schedule A territory is half the rate for those 

in Schedule B. Note that the demand charge 

for Schedule B is applied to the peak true 

power (kilowatts—kW) instead of the peak 

apparent power (kilovolt-amperes—kVA) 

used in Schedule A.

TABLE 1. RATE STRUCTURES FOR INDUSTRIAL 

CUSTOMERS IN TWO DIFFERENT PARTS OF THE 

COUNTRY

Schedule A B

Energy rate $0.019/kWh $0.038/kW

Demand rate 

(30-minute peak)

$7.00/kVA $7.00/kW

In addition to comparing the cost of 

operating under two rate schedules, let’s use 

a pump that is optionally driven by either 

a 150 horsepower (hp) energy-efficient 

motor, or a 200hp premium-efficiency open 

drip-proof motor. The fluid and electrical 

conditions specified in Table 2 are based on 

manufacturer-reported performance characteristics. Note that the larger premium-efficiency motor will operate at a higher speed; 

the pump fluid and power requirements are 

adjusted according to the centrifugal affinity 

laws.

*Hours 

per day

% of 

time 

running

Schedule A

150-hp EE motor 200-hp PE motor

Schedule B

150-hp EE motor 200-hp PE motor

24 100 $31,010 $31,272 $48,946 $48,929

20 83 $27,753 $28.016 $42,432 $42,418

16 67 $24,496 $24,760 $35,918 $35,906

12 50 $21,239 $21,505 $29,404 $29,394

8 33 $17,982 $18,249 $22,890 $22,882

4 17 $14,725 $14,993 $16,376 $16,371

1 4 $12,282 $12,551 $11,491 $11,487

Demand Component $11,469 $11,737 $9,862 $9,859

TABLE 2. ELECTRICAL AND FLUID DATA FOR THE SAME PUMP WHEN OPERATED BY TWO DIFFERENT MOTORS

Motor rated 

hp

Motor effi ciency 

class Speed, rpm Flow rate, gpm Head, ft Pump effi ciency

Shaft 

power, hp

Motor 

effi ciency

Power 

factor

True electric 

power, kW

Apparent power, 

kVA

150 Energy effi cient 1,783 3,000 150 76.0% 149.5 95.0% 86% 117.41 136.53

200 Premium effi ciency 1,789 3,010 151 76.0% 151.0 96.0% 84% 117.37 139.72

TABLE 3. ANNUAL OPERATING COSTS FOR TABLE 1 RATE SCHEDULES AND TABLE 2 CONDITIONS
References

1.The Vital Few, Energy Matters September 

2000, www.oit.doe.gov/bestpractices/

energymatters/emextra/casada_

sep00.shtml

2.A Symptoms Approach to Identifying Efficiency Improvement Opportunities, Energy Matters Spring 2003, 

www.oit.doe.gov/bestpractices/

energymatters/emextra/casada_

spr2003.shtml

3.ANSI/HI 1.3-2000, Centrifugal Pumps – for 

Design and Application, Hydraulic Institute, 

www.pumps.org●

Ram K. Kondapi, CPE, Chief Project Engineer, 

Crucible Specialty Metals

Compressed air is a utility that is generated in-house and is often referred to as the 

“fourth utility.” Because it is generated onsite, you have more control over it than any 

other utility. 

Paying attention to your compressed 

air system can lead to a number of 

benefits, including improved efficiency, 

reduced costs, and increased productivity and reliability. In turn, these 

benefits can lead to improved competitiveness, less downtime, and greater 

return on investment.

As an example of what can be 

accomplished through the application 

of a systems-based approach, recommended by the Compressed Air Challenge (CAC), Crucible Specialty Metals 

recently completed a comprehensive 

plant-wide study of compressed air 

generation, distribution, and usage at 

its main plant in Syracuse, New York. 

The study was funded by the New York 

State Energy Research and Development Agency (NYSERDA) and DOE, and 

included in-kind participation from 

Crucible’s staff. Also participating was 

Tom Taranto of ConservAir Technologies LLP, a Senior AIRMaster+ Instructor, Qualified AIRMaster+ Specialist, 

certified CAC Instructor, and co-developer of the DOE curriculum to qualify 

AIRMaster+ Specialists. 

Collecting Data

Before the study began, instrumentation was installed at key locations within 

the plant’s compressed air piping. This was 

done to monitor pressure and flow through 

major subsectors of the system. Along with 

pressure and flow instrumentation, kilowatt metering equipment was installed on 

four major compressors servicing the plant. 

Data were collected over a 2-week period, 

representative of typical plant operations. 

Data were also collected during a facility 

walk-through. Both sets of data were used to 

analyze and plot pressure and flow patterns 

for each of the major sectors, compressor 

cycling, and kilowatt power usage by each of 

the compressors servicing these sectors. 

The study team was able to: 

• Develop compressed air generation costs 

for each generation point as well as a 

plant-wide overall average generation 

cost.

• Outline a strategy to shut down the oldest 

and least efficient plant compressor and 

improve the utilization of other existing 

compressors. As part of implementing 

this strategy, a new plant compressed 

air primary distribution network was 

planned. All compressors would connect 

with this new system. Buying a smaller 

capacity compressor was also proposed. 

This alternative was expected to provide 

improved flexibility in generation capacity to match air demand, and needed 

backup capacity to make it easier to 

schedule maintenance. 

• Utilize ultrasonic leak detection methods to 

identify and repair major and minor air 

leaks resulting in overall annual net cost 

savings of approximately $200,000. 

• Identify point-of-use applications requiring 

further study to determine the feasibility 

of replacing compressed air applications 

with more energy efficient alternatives. 

These alternatives included blowers or 

other means to achieve the same objective. Intermediate controls and surge 

tanks were also proposed to achieve sector control and prevent overall system 

drawdown from short-cycle high-demand 

operations. These measures, along with 

integrating plant compressed air generation into the primary backbone piping 

when implemented, could yield additional significant energy cost savings. 

• Develop a plant-wide compressed air 

 strategy to implement monitoring, control, and data acquisition to facilitate 

ongoing management of compressed air 

as a utility.

Crucible’s pipe fitters and maintenance 

personnel have accomplished immediate follow-through on several cost-saving measures. 

In addition to the leak repairs mentioned 

earlier, rerouting distribution piping, equipment repair, and minor process changes 

have been implemented. These changes have 

resulted in 30% less running time on a 450 

horsepower (hp) compressor, and complete 

shutdown of another 100hp compressor. Savings to date have been achieved with a less 

than $40,000 investment, leading to a less 

than 3-month simple payback.●

North Star Steel Co.’s Wilton, Iowa, plant 

recently completed a plant-wide energy 

assessment designed to examine potential 

process changes and technologies that could 

improve energy efficiency. If all projects were 

implemented, the assessment team estimated 

that total annual energy savings would 

be about 139 billion British thermal units 

(MMBtu) in natural gas and nearly 39 million kilowatt-hours (kWh) in electricity. Total 

annual cost savings would be more than $2.6 

million. The estimated implementation cost 

for all projects would be about $8.2 million.

North Star Steel believes that the opportunities identified in the assessment and in 

the corresponding technical and management solution options will not only have a 

considerable impact on the plant’s energy 

efficiency, but will increase productivity and 

reduce waste as well. Furthermore, assessment methods, data, and technical solution 

options will be shared with North Star Steel’s 

other mini-mills where similar evaluations 

and energy or waste reduction improvement 

methods can be employed. 

Cargill, Inc., North Star Steel’s parent 

company, has embarked on a corporate-wide 

goal to reduce waste by 30% and reduce 

energy use by 10% by 2005. The North Star 

Steel plants have also adopted this goal. Total 

energy costs at the Wilton plant were $8.73 

million for fiscal year 2000-2001. Reducing 

energy consumption to match Cargill’s strategic goals would result in average annual 

savings of $873,000.

North Star Steel was founded in 1965 in 

St. Paul, Minnesota, and began steel scrap 

Energy Matters, Winter 2004 5

Achieving Immediate Savings by 

Taking a Systems Approach to 

Compressed Air

North Star Steel Completes 

Plant-Wide Energy Assessment 

at Mini-Mill

(continued on page 6) 
6 Energy Matters, Wnter 2004

North Star Steel Completes Plant-Wide Energy Assessment at Mini-Mill continued from page 5

recycling operations at the St. Paul minimill in 1967. Cargill acquired the company 

in 1974. North Star’s operations currently 

include electric-arc furnace mini-mills in 

Beaumont, Texas; Monroe, Michigan; St. 

Paul, Minnesota; and Wilton, Iowa. North 

Star also has a steel rolling mill in Calvert 

City, Kentucky, a grinding-ball plant in 

Duluth, Minnesota, and a joint venture with 

BHP Steel of Australia, which operates a 1.5-

million-ton-per-year flat-rolled steel minimill near Delta, Ohio. Since 1974, North 

Star’s annual steel-production capacity has 

risen from 300,000 tons to 3.5 million tons, 

and employment has increased from 600 to 

over 3,000.

Making Steel at Wilton

The Wilton plant is a steel mini-mill that 

uses electric arc furnace (EAF) steelmaking 

and 100% recycled steel scrap to manufacture steel products. The recycled steel scrap 

is melted in the EAF and refined by adding 

alloys, carbon, and other materials. The molten steel is tapped into a preheated ladle and 

transferred to the tundish at the billet caster. 

From the tundish, the molten steel flows into 

molds that make square billets that are then 

cooled, solidified, and cut to length. The billets are stored until needed, then fed into the 

reheat furnace and brought to a temperature 

of about 2,200°F. When the correct rolling 

temperature is reached, the billet is passed 

through water-cooled roll stands where the 

steel is formed and shaped. The final step 

involves shearing the steel products into custom lengths, which are bundled together for 

storage. The Wilton plant produces structural 

steel products including flats, angles, rebar, 

and round-cornered squares. 

A Total Assessment Audit (TAA) was used 

to evaluate the Wilton plant for energy 

savings, waste reduction, and improved 

productivity. TAA methodology is an integrated energy, waste, and productivity audit 

implemented by a team of experts chosen 

specifically for a particular manufacturing 

system facility. TAA was developed by the 

Iowa Energy Center (IEC) and deployed by 

the Iowa Manufacturing Extension Partnership (IMEP) under an IEC grant. Both IEC 

and IMEP, along with MidAmerican Energy 

Co., were partners in the Wilton assessment. 

TAA team members were asked to assess 

the plant’s chances of achieving its efficiency 

goal of 10% energy reduction and 30% waste 

reduction by 2005. The consensus was that 

a high probability of achieving the goals 

existed. North Star Steel and the TAA team 

members identified five areas for improvement based on pre-assessment findings:

• EAF dust reduction 

• Motor program 

• Melting and reheat process upgrades

• Heat recovery measures

• Overall energy planning.

These five areas were then scrutinized 

for ways to cut energy, reduce waste, and 

improve productivity. In addition to identifying projects to meet these goals, the benefits 

and costs of possible technological solutions 

or improvements were also studied. 

A number of projects were identified 

by the plant-wide assessment (PWA) with 

the potential savings in energy, waste, or 

increased productivity. Together, these could 

help North Star Steel more than achieve 

energy-savings goals identified by Cargill 

Corp.

The assessment identified several 

potential ways to improve the energy 

efficiency of the electric arc melting 

furnace. These included the following 

suggestions for further investigation:

• Use more powerful transformers and long 

arcs, which are efficient when a foamy 

slag practice is used to envelop the arc 

(thus minimizing heat losses and arc flare 

damage)

• Increase productivity by minimizing 

power-on time

• Identify bottlenecks in scrap charging 

efficiency and caster productivity. Install 

larger magnets and/or increase the power 

to reduce the number of lifts per bucket; 

increase tundish size

• Install a More’ lance system to permit carbon injection that promotes slag foaming 

which in turn increases the electrical efficiency of the furnace

• Increase casting speed by using longer 

molds and/or molds of different designs.

The potential annual energy savings 

were 19.8 million kWh (natural gas use 

will increase by 48,000 MMBtu); the 

potential annual cost savings were 

$675,000; and the implementation cost 

was $1,800,00.

Upgrades to the rolling mill billet 

reheat furnace include:

• Adding a bottom preheat zone, a top preheat zone, and replacing heat zone burners with lower capacity ultra low NOx 

burners

 • Replacing a natural draft stack with an 

ejector stack

• Relocating furnace controls to the charge 

end of the furnace to a new control area 

(pulpit)

• Relocating the controls for the initial rolling operation (rougher controls) to the 

main pulpit

The potential annual energy savings 

were 26,000 MMBtu; the potential 

annual cost savings were $341,000 

(including productivity increase and 

other non-energy related benefits); 

and the implementation cost was 

$3,000,000

Increasing the combustion air preheat 

temperature from 600°F to 900°F in 

the reheat furnace will increase efficiency and reduce energy consumption by about 10%. Potential annual 

energy savings were 62,000 MMBtu; 

the potential annual cost savings were 

$278,000; and the implementation cost 

was $150,000.

To learn more about the plant-wide 

assessments, visit http://www.oit.doe.gov/

bestpractices/plant_wide_assessments.shtml. 

Or, contact Grace Ordaz of the Department 

of Energy’s Industrial Technologies Program 

by phone at 202-586-8350 or by e-mail 

at grace.ordaz@ee.doe.gov. For technical 

details about the assessments, contact Bob 

Leach of the Oak Ridge National Laboratory 

by phone at 865-576-0361, or by e-mail at 

leachre@ornl.gov.●

Roll mill at North Star Steel
Energy Matters, Winter 2004 7

About the Office of Energy Efficiency 

and Renewable Energy

A Strong Energy Portfolio for a Strong 

America

Energy efficiency and clean, renewable energy 

will mean a stronger economy, a cleaner environment, and greater energy independence 

for America. By investing in technology breakthroughs today, our nation can look forward 

to a more resilient economy and secure future.

Far-reaching technology changes will be essential to America’s energy future. Working with 

a wide array of state, community, industry, 

and university partners, the U.S. Department 

of Energy’s Office of Energy Efficiency and 

Renewable Energy invests in a portfolio of 

energy technologies that will:

• Conserve energy in the residential, commer- 

 cial, industrial, government, and transporta- 

 tion sectors 

• Increase and diversify energy supply, with a 

 focus on renewable domestic sources 

• Upgrade our national energy infrastructure 

• Facilitate the emergence of hydrogen 

 technologies as a vital new “energy carrier.” 

The Opportunities

Biomass Program

Using domestic, plant-derived resources to meet 

our fuel, power, and chemical needs

Building Technologies Program

Homes, schools, and businesses that use less 

energy, cost less to operate, and ultimately, generate as much power as they use

Distributed Energy & Electric Reliability Program

A more reliable energy infrastructure and reduced 

need for new power plants

Federal Energy Management Program

Leading by example, saving energy and taxpayer 

dollars in federal facilities 

FreedomCAR & Vehicle Technologies Program

Less dependence on foreign oil, and eventual 

transition to an emissions-free, petroleum-free 

vehicle

Geothermal Technologies Program

Tapping the earth’s energy to meet our heat and 

power needs

Hydrogen, Fuel Cells & Infrastructure Technologies 

Program

Paving the way toward a hydrogen economy and 

net-zero carbon energy future

Industrial Technologies Program

Boosting the productivity and competitiveness of 

U.S. industry through improvements in energy 

and environmental performance

Solar Energy Technology Program

Utilizing the sun’s natural energy to generate electricity and provide water and space heating 

Weatherization & Intergovernmental Program

Accelerating the use of today’s best energyefficient and renewable technologies in homes, 

communities, and businesses 

Wind & Hydropower Technologies Program

Harnessing America’s abundant natural resources 

for clean power generation

To learn more, visit www.eere.energy.gov

Energy Matters Extra Highlights

Go online to see the Winter issue of 

Energy Matters Extra, which features 

extra information on topics covered 

in this newsletter and more. Link 

to supplemental material from Don 

Casada’s column on energy-cost reduction opportunities, and access the full 

plant-wide assessment report for North 

Star Steel. Learn about new reference 

materials that ITP is now offering, such 

as the Compressed Air Sourcebook, and 

ITP Annual Reports on energy-intensive 

industries. Make sure to check the training schedule to find DOE-sponsored 

training opportunities nearest you. 

And, access the newest version of AIRMaster+. You can download it directly 

to your computer or order it on CD. 

Find it all on Energy Matters Extra at 

http://www.oit.doe.gov/bestpractices/

energymatters/emextra/.●

EXTRA ENERGY MATTERS

to further increase production levels by 

using the IR oven for thinner products 

and exploring additional ways to fully 

utilize it. By optimizing the proportion 

of IR oven heating versus convection 

oven heating to deliver the highest 

efficiency, Progressive Powder Coatings 

improved the effectiveness of its production process.

 To learn more about this and other 

kinds of energy saving techniques 

that can improve your plant’s bottom 

line and overall productivity, visit the 

Industrial Technologies Program’s home 

page at www.eere.energy.gov/industry. 

Or call the Energy Efficiency and 

Renewable Energy Information Center 

at 877-EERE-INF or 877-337-3463●

Infrared Oven Saves Energy, 

Lifts Production at a Metal 

Finishing Plant

Progressive Powder Coating implemented a project at its metal finishing plant in Mentor, Ohio, that saved 

energy and increased production. The 

company uses a convection oven to 

cure its products but was experiencing 

bottlenecks in its production process. 

This was because curing thicker pieces 

of metal caused the conveyor line speed 

to slow, reducing productivity. In an 

effort to eliminate the production bottlenecks, Progressive Powder installed 

an infrared (IR) booster oven on its production line. 

 Because the IR oven can reach 

temperatures of up to 475° F, plant personnel used it to partially cure thicker 

pieces of metal after they left the powder booth and before they entered the 

convection oven. The IR oven also 

could fully cure many thinner pieces of 

metal.

 Installing the oven allowed the 

plant to increase its conveyor line speed 

from 4 feet per minute to 6 feet per 

minute, lifting production by 50%. The 

IR oven also improved product quality 

because less powder was shaken off by 

the conveyor line, or blown off by the 

convection oven’s turbulence prior to 

reaching gel temperature.

 Through this project, the plant 

reduced its annual natural gas consumption by 25%, yielding annual 

energy savings of approximately 

$54,000. With a total project cost of 

$136,000, the simple payback was 2.5 

years.

 Manufacturing plants having process heating applications may benefit 

from installing IR heating ovens, particularly if their product mix requires 

varying degrees of heat treatment for 

different lengths of time. In the case 

of Progressive Powder, an IR oven was 

able to pre-gel and cure many types of 

metal pieces before they entered the 

convection oven. This eliminated costly 

production bottlenecks, which led to 

increased production, better product 

quality, and reduced energy consumption.

 Since the IR oven’s installation, 

personnel at the plant have been able 

Attention: Decision Tools CD Users

If you have received a copy of 

Decision Tools for Industry: A Portfolio of Powerful Assessment Tools, 

dated March 2003 or December 

2003, please visit the BestPractices Software Tools Web page at 

www.oit.doe.gov/bestpractices/

software_tools.shtml to download the most current version of 

AirMaster+ 1.0.9.
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-102004-1852 • March 2004

T OF ENERGY

DEPARTMEN

U

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NITED STAT S OFA ERICA

M

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at least 50% wastepaper, including 20% postconsumer 

waste

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BestPractices

The Industrial Technologies Program’s 

BestPractices initiative and its Energy 

Matters newsletter introduce industrial end 

users to emerging technologies and wellproven, cost-saving opportunities in motor, 

steam, compressed air, and other plant-wide 

systems. 

FUNDAMENTALS OF COMPRESSED AIR SYSTEMS (LEVEL 1), RENO, NV 

■ Apr 14, 2004 

For more information, contact Dirk Van Zyl at dvanzyl@mines.unr.edu or call 775-784-

7039

FUNDAMENTALS OF COMPRESSED AIR SYSTEMS, ELKHART, IN 

■ Apr 20, 2004

For more information, contact Beth Holliday at bholliday@bmtadvantage.org or call 317-

635-3058

PUMPING SYSTEM ASSESSMENT (END USER), JOLIET, IL 

■ Apr 22, 2004

For more information, contact Tim Owens at towens@jjc.edu or call 815-280-1513 

PROCESS HEATING ASSESSMENT (END USER), HOUSTON, TX

■ Apr 23, 2004

For more information, contact Kathey Ferland at kferland@mail.utexas.edu or call 512-232-

4823

STEAM SYSTEM (END USER), NAPERVILLE, IL 

■ Jun 10, 2004

For more information, contact Debbie Bloom at dbloom@nalco.com or call 630-305-2445 

Coming Events

DOE Regional Office Representatives

■ David Godfrey, Atlanta, GA, 

 404-562-0568

■ Scott Hutchins, Boston, MA, 

 617-565-9765

■ Brian Olsen, Chicago, IL, 

 312-886-8479

■ Jamey Evans, Denver, CO, 

 303-275-4813

■ Chris Cockrill, Seattle, WA, 

 816-873-3299

■ Joseph Barrett, Philadelphia, PA, 

 215-656-6957

 EERE INFORMATION 

 CENTER

 Do you have questions 

about using energy-efficient process and 

utility systems in your industrial facility? 

Call the Energy Efficiency and Renewable 

Energy (EERE) Information Center for 

answers, Monday through Friday 9:00 

a.m. to 7:00 p.m. (EST).

HOTLINE: 877-EERE-INF

or 877-337-3463

Energy Matters