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More than 300 million motors are used in industry, large buildings and in infrastructure globally, and 30 million new electric motors are sold each year for industrial purposes alone. Electric motor driven systems (EMDSs) in industry are estimated to be responsible for approximately 29% of overall global, and 69% of industrial electricity consumption. Their energy costs are estimated to be USD 362 billion per year. By using existing technologies and practices the efficiency of industrial EMDSs can be cost-effectively improved on average between 20 – 30%.1 Such improvement holds the potential to reduce global electricity consumption by 3.2 to 4.8 EJ, cut the CO2 emissions by 770 – 1100 Mt, and save the industry between USD 72 – 108 billion, annually.2,3 This potential remains to be exploited. 

Electric motors convert electrical power into mechanical power and are often a part of a motor driven system. In industrial applications, electric motor driven systems are used for pumping, compressed air, fans, conveyance, and other forms of mechanical handling and processing. Although electrical motors and their controls, are typically the main electricity using parts in a motor driven system, their impact on the overall efficiency of the system is often limited. This is due to the fact that the other system components – such as pumps, fans, valves, pipes, ducts, and end-users – affect both the amount of mechanical power required by the entire system and the losses taking place during the delivery of this power, which collectively have a much larger influence on the overall energy consumption. Consequently, adopting a system approach is of great importance for optimizing energy efficiency of motor driven systems. The level of efficiency in a given system will depend on both the extent to which advanced solutions are used and the design of the overall system. In most cases, improving the effciency of a motor system includes the following:

  • Use of energy efficient motors;
  • Selecting the core components – like pumps, fans, compressors, transmissions, variable speed drives – with the right type and size and high efficiency;
  • Optimization of the design and operation of the complete system.

Motor Systems Schematic

Motor Systems Publications

Best Practices in Energy Efficient Industrial Technologies – Motor Systems

The report provides a summary of key energy efficiency options for electrical motor motor driven systems, and provides a comprehensive list of organizations and programs working with improving motor system efficiency at global and national levels.

Energy-Efficiency Policy Opportunities for Electric Motor-Driven Systems

This paper presents the findings of the first global analysis of energy consumption in electric motor‐driven systems (EMDS) and the options to reduce it. It assesses the energy currently used by EMDS and the potential for energy savings, examines market barriers to the adoption of energy‐efficient solutions, and reviews current policy settings and outcomes. The report then proposes a comprehensive package of policy recommendations to help governments tap the huge potential for energy savings in EDMS.

Motor Systems Tools

MotorMaster+ International

The MotorMaster+International free online software tool includes many of the capabilities and features of MotorMaster+. However, users can evaluate repair/replacement options on a broader range of motors, including 60 hertz (Hz) motors tested under the Institute of Electrical and Electronic Engineers(IEEE) standard, and 50 Hz motors manufactured and tested in accordance with International Electrotechnical Commission (IEC) standards. This tool allows users to:

The Motor Systems Tool

The Motor Systems Tool is developed under Electric Motor Systems Annex (EMSA) program of Efficient Electrical End-use Equipment (4E) forum. The tool is intended to assist engineers, machine builders, machine component suppliers, energy consultants and others working on optimizing machine systems to benefit from reduced electricity consumption.

Motor Systems Websites

Assessing the performance and improvement potential for an electric motor is relatively straight forward with the help of well established efficiency classes (see the graph below). Typically, energy efficiency can be improved by 4 to 5% by using the best available motor. Benchmarking of the entire motor driven systems, on the other hand, is more complex due to the fact efficiency is greatly influenced by the a wide range of system components and operational practices. Some generic benchmarks for different efficiency classes are provided below.

Motor Systems Benchmarks

Efficiency levels offered by different motor categories can be seen in the figure below1:

Efficiencies of different motor classes

Motor systems can show significant variations depending on the end-use, the type of core components used, and the level of optimization in the overall system. In table below, typical efficiency levels for low, medium, and high efficiency categories are summarized. (For a description of the characteristics assumed for different efflciency levels, please follow the links in the table)

Typical System Efficiencies for Electric Motor Driven Systems2
Motor System Type System Efficiency
Low End (%) High End (%) Average (%)
Pump Systems      
Low level of efficiency 20 40 30
Medium level of efficiency 40 60 50
High level of efficiency 60 75 67.5
Compressed Air Systems      
Low level of efficiency 2 5 3.5
Medium level of efficiency 4.8 8 6.4
High level of efficiency 8 13 10.5
Fan Systems      
Low level of efficiency 15 30 22.5
Medium level of efficiency 30 50 40
High level of efficiency 50 65 57.5

Total Annual Electricity Saving and CO2 Emission Reduction Potential in Industrial Pump, Compressed Air, and Fan Systems (UNIDO, 2010)
 

Total Annual Electricity Saving Potential in Industrial Pump, Compressed Air, and Fan System (GWh/yr)

Share of Saving fromElectricity use in Pump, Compressed Air, and Fan Systems in Studied   Industries in 2008

Total Annual CO2 Emission Reduction Potential in Industrial Pump, Compressed Air, and Fan System (kton CO2/yr)

Country Cost Effective Technical Cost Effective Technical Cost Effective Technical
US

71,914

100,877

25%

35%

43,342

60,798

Canada

16,461

27,002

25% 40%

8,185

13,426

EU

58,030

76,644

29% 39%

25,301

33,417

Thailand

8,343

9,659

43% 49%

4,330

5,013

Vietnam

4,026

4,787

46% 54%

1,973

2,346

Brazil

13,836

14,675

42% 44%

2,017

2,140

Total (Sum of 6 countries)

172,609

233,644

28% 38%

85,147

117,139

 

Footnotes

Benchmark Footnotes: 

[1]

International Energy Agency (2011) Energy-Efficiency Policy Opportunities for Electric Motor-Driven Systems. pp. 23)

[2]

UNIDO (2010) Motor Systems Efficiency Supply Curves. p. 19

Industrial electric driven motor systems (EMDSs) are very significant energy users. EMDSs in China, EU-27, and the US collectively account for around 56% of the global industrial EMDS consumption. If Japan, Russia and Canada are also added to this list, the collective share reaches close to 70%. Although this figure varies greatly between systems and between plants, on average 50% of the energy input into a motor system is lost leaving only 50% turned into useful mechanical application (IEA, 2011). More than 90% of the motors in the EU operate at or below standard efficiency, whereas more than 70% of all the motors in the US and Canada are high- or premium-efficiency motors (IEA, 2007). In China, the actual operational efficiency of electric motor systems is thought to be 10 – 30% below international best practice, depending on the industry (SWITCH-Asia, 2012). Approximately 97% of an electric motor's life cycle cost is associated with the cost of energy it uses (IEA, 2011). 

In the industrial sector, motors are used primarily for four main areas of applications.  These applications and their respective shares are summarized in table below. 

Estimated Demand by Application in Industrial Motor System Energy Use (IEA, 2011)

Application Demand (TWh/y) Share in Total
Pumps 942 21
Fans 718 16
Compressors 1122 25
Mechanical movement 1705 38
Total: 4488 100

Motors are grouped into three main categories as small, medium, and large. Of these, medium class motors (with an output between 0.75 and 375 kW) are responsible for 67.6% of electricity used in all motor systems.  The share of small (0.001 to 0.75 kW) and large (375 to 100 000 kW) motors are 23.3% and 9.1% respectively. Although their numbers are low, large electric motors are significant energy consumers due to their high power demand. The Table below provides an overview of types and characteristics of different motor categories. 

Motor
Size 

Motor output (kWm) Total
GWm
Operation

Running
Stock,
millions

Life
Time,
years
Sales,
millions
per year
Motor
Efficiency

Total
Electrical
Power, GWe

Electricity
Demand,
TWh/y
Min.

Max.

Median hrs/y Load
factor
Nominal Mean
Small 0.001 0.75 0.16 316 1500 40% 2000 6.7 300 40% 30% 422 632
Medium 0.75 375 9.5 2182 3000 60% 230 7.7 30 86% 84% 1559 4676
Large 375 100000 750 450 4500 70% 0.6 15.0 0.04 90% 88% 358 1611
Total       2948     2231 6.8 330   79% 2338 6919

Source: IEA, 2011. 

General Industry Characteristics

Life Cycle Cost Breakdown for an 11kW Motor Operated 4000 hr/y

See Source Data

2011 [1]

Name %
Initial capital cost 2.3
Repair and maintenance cost 1
Electric energy cost 96.7
TOTAL 100
Back to Chart

2011 [1]

Estimated Global Electricity Demand by Sector and End-Use (2006)

See Source Data

2011 [2]

Name TWh
Lighting 2900
Electronics 1600
Electrolysis 500
Heat 2900
Stand-by 500
Motors 7200
TOTAL 15600
Back to Chart

2011 [2]

Estimated Electricity Demand for all Electric Motors by Sector

See Source Data

2006 [3]

Name TWh/y
Industry 4488
Commercial 1412
Agricultural 101
Transport 159
Residential 948
TOTAL 7108
Back to Chart

2006 [3]

Footnotes

There are numerous organizations working at global, regional, national levels with improving the resource productivity and reducing the environmental impact of cement manufactuing. Some of the major ones are listed below:

Motor Systems Organizations Global

Motor Systems Organizations Australia

Motor Systems Organizations Canada

Motor Systems Organizations China

Motor Systems Organizations Europe

Motor Systems Organizations Hong Kong

Motor Systems Organizations India

Motor Systems Organizations United States

Motor Systems Organizations Japan

Motor Systems Organizations Mexico

Motor Systems Organizations United Kingdom

Motor Systems Programs Europe

Motor Systems Programs Global

Motor Systems Programs Australia

Motor Systems Programs Brazil

Motor Systems Programs United States

Motor Systems Programs Canada

Motor Systems Programs China

Motor Systems Programs United Kingdom

An industrial facility may contain thousands of electrical motors. In an operational plant that lacks a systemic motor management plan, motor decisions are usually made at the time of failures, where clock is ticking and restoring plant operation is of utmost importance. Such ad-hoc decision making often leads to sub-optimal solutions and comes at the expense of higher long-term operational costs. A systemic motor management plan, on the other hand, helps facilities to proactively manage its motor inventory which helps with maintaining an optimal system in place, while also reducing the risk of unplanned operational disruptions. These help reduce facilities' energy consumption and costs.  Typical elements of a motor management system may include: 

  • Creation of a motor survey and monitoring program;
  • Development of guidelines for repair/replace decisions;
  • Preparation for motor failure; 
  • Development of purchasing and repair specifications; 
  • Development and implementation of preventive and predictive maintenance programs (further information on these elements can be found, among others, in Motor Planning Kit developed by the Motor Decisions Matter Campaign).

Given the fact that motors are only a part of the motor driven systems, a higher level of energy savings can be realized by adopting a management system for the entire motor driven system. Guidance on developing an energy management system for the entire motor driven system can be found in US DOE's Energy Management for Motor Systems Guidebook

[1]

International Energy Agency (2011) Energy-Efficiency Policy Opportunities for Electric Motor-Driven Systems. pp. 33-34

[2]

Calculated from values given in International Energy Agency (2011) Energy-Efficiency Policy Opportunities for Electric Motor-Driven Systems. pp. 11-13, 36-37.

[3]

Studies by other organizations, such as UNIDO (2010) estimate the average cost-effective improvement potential for industry at around 28%, thereby supporting the hypothesis that actual saving potentials may be closer to the upper limits mentioned here.