The Motor Systems Market Assessment (MSMA) is a study that delves into significant detail on the number, disposition, and operating characteristics of electric motor-driven systems in US industrial and commercial facilities. The study’s in-depth details will inform numerous activities and industries, assisting in planning and decision-making. This NEMA analysis focuses on the regulatory impacts of the MSMA and how NEMA (and other entities) may use it to inform and influence US Department of Energy rulemakings for minimum energy conservation Standards for electric motors. 

Study Examines Operating Characteristics of Electric Motors

The Lawrence Berkeley National Lab (LBNL) MSMA is the first [1] of three research papers that examine the installed base of electric motors in the US and their operating characteristics. This study is an update to a similar investigation published in 2002. This paper aims to examine the study results and findings with respect to their potential use in and influence on US Department of Energy (DOE) rulemakings for minimum energy conservation Standards. Electric motors themselves are a regulated product class [2], and electric motors appear as components in dozens of other regulated product classes as well. [3] 

LBNL authors describe the scope of the study as follows:

The MSMA covered all three-phase AC and DC motors greater than and including one horsepower (hp). Advanced motor technologies, such as synchronous reluctance and permanent magnet, were also included (as AC motors). Fractional horsepower motors (motors < one hp) were excluded because they are often embedded within components, and it would be difficult to assess their installed base comprehensively. Further, excluding these motors aligns with the scope of the previous assessment. The assessments encompassed the drive, motor, transmission, end-use equipment, and distribution system (e.g., compressed air lines, water pipes). The types of end-use equipment evaluated included: pumps, fans/blowers, air compressors, refrigeration compressors, materials handling, and materials conveying. Motor systems that utilize non-electric energy sources (e.g., fossil fuels) were not part of the assessment scope.

Electric Motors in the Industrial and Commercial Sector

In terms of overall national electricity consumption, the study notes industrial and commercial three-phase motor systems greater than or equal to one hp consume ~1,079 terawatt-hours (TWh)/year, about 29 percent of the total electric grid load.  

• In the industrial space, in 1994, electric motor systems were responsible for 679 billion kilowatt-hours (kWh) of yearly electricity consumption, but by 2020 this decreased to 547 billion kilowatt-hours. The study notes various potential reasons for this, the most prominent being offshoring of industrial production and gains in energy efficiency. This 547 B kWh represents 69 percent of all electricity consumption in this space.
• In the commercial space, in 1995, electric motor systems were responsible for 343 billion kWh of yearly electricity consumption, but by 2020 this figure grew to 532 billion kWh.This 532 b kWh represents about 43 percent of all electricity consumption in this space.

Reading the study’s executive summary, proponents of increased Federal regulation of electric motors might start typing excited demands for more DOE rulemakings, but their enthusiasm would be premature and misplaced. The study notes 48 percent of all commercial sector motor system electricity consumption is for refrigeration compressors (e.g., chillers, air conditioners), and refrigeration compressor use accounts for 94 percent of the commercial sector’s motor system electricity consumption. The aforementioned products are all regulated by the DOE. The situation is less imbalanced in the industrial sector where 29 percent of all motor system electricity consumption is for materials processing, followed by 21 percent for pumps and fans/blowers each. Pumps and fans/blowers are also regulated systems.

The study notes that there are 52.5 million motor systems greater than or equal to one hp in the industrial and commercial sectors, with 10.8 million in industrial and 41.7 million in commercial facilities.  The average connected motor system horsepower at an industrial facility is 1,595 hp  and 89 hp for the commercial sector.  The average motor size is 27 hp for industrial and eight hp for commercial. So, while commercial facilities use more motors and industrial facilities use more horsepower, they both consume similar amounts of electricity (547 B kWh industrial and 532 B kWh commercial).

A quick note about DC motors: “It is estimated that there are 806,000 DC motor systems greater than or equal to 1 hp consuming 31,000 GWh annually in the industrial and commercial sectors. This represents 2 percent of all motors and 3 percent of total annual motor system electricity consumption in the industrial and commercial sectors.”  This sounds small, but three percent of over one trillion kWh (the preceding two electricity consumption figures) cannot be dismissed.

Regarding the horsepower ratings of motors in studied facilities: Ninety-nine percent of the motor system units in the industrial sector are in the one to 500 hp range, with 49 percent in the one to five hp range. Ninety-nine percent of the motor system units in the commercial sector are in the one to 50 hp size range. This begs the question of whether there is any worthwhile benefit to raising the upper bound of regulations, as some have proposed in the past.

Concerning expansion or increased stringency of existing DOE electric motor regulations, NEMA has commented more than once to DOE that there is no guarantee that improving the efficiency of any given component—in this case the electric motor—of a regulated product will make that product more efficient. A more efficient motor spins faster for a given input (design horsepower does not change since the work the motor is needed to perform does not bow to efficiency demands). Also, many efficiency improvement options add mass or increase the physical size of motors. Changes to the disposition and performance of any component factor into overall system/appliance design, and during design development, tradeoffs often occur. In the end, these regulated products and systems are not guaranteed to become more efficient if their electric motors become so.  Rather, designers will naturally perform technical and cost engineering trade-offs with only the final overall efficiency requirements and regulations in mind. 

NEMA has also commented in past DOE rulemakings that how motor systems are loaded in end-use applications factors heavily into whether a more efficient motor will yield any practical reductions in electricity consumption. Since electricity consumption is application-dependent, NEMA has encouraged DOE to pursue systems efficiency regulations and support programs to encourage better application of these systems. With regard to loading: In the industrial space, 27 percent of industrial sector motor system electricity consumption operates at variable[4] load, with load factors between 40 percent and 75 percent, while 42 percent of industrial sector motor system units operate at constant loads greater than 75 percent of full load. In the commercial space, 35 percent of commercial sector motor system electricity consumption operates at variable load, with load factors between 40 percent and 75 percent. At the same time, 30 percent of commercial sector motor system units operate at variable loads, with load factors between 40 percent and 75 percent.

Very little motor system electricity consumption takes place at load factors under 40 percent load. The study notes only six percent of industrial sector motor system electricity consumption, and eight percent of the industrial motor systems operate under 40 percent load factor.  Additionally, across all driven equipment types in the industrial sector, the most common operating condition is estimated to be constant motor load systems operating at 0.75 load factor. For the commercial sector, the most common operating conditions are very different, with 60 percent of commercial motor system electricity consumption attributable to variably loaded motors, and 35 percent is attributable to constantly loaded motors. It is worth recalling the above observation that many of these variable load conditions involve HVAC, compressors, pumps, fans/blowers, and other DOE-regulated systems.

Concerning load control: on average, 16 percent of motor system capacity at an industrial facility use variable frequency drives (VFDs), and 74 percent have no load control technology/equipment. Further, the rate of installation of VFDs and other load control technologies in the industrial and commercial sectors increases with motor system size. On average, four percent of motor system capacity at a commercial facility use VFDs, and 91 percent have no load control technology/equipment.

The study notes the uptake of VFDs by driven equipment type in the industrial sector is nearly uniform, at about 23 percent of electricity consumption for each equipment type, with most operating using temperature or pressure setpoints as the control mechanism. While the uptake of VFDs by driven equipment type in the commercial sector varies but is highest for fan/blower systems with the most common metric for VFD control being pressure setpoint.

The above numbers raise suspicion that increased application of VFDs could benefit the commercial sector and even more the industrial sector.  Likewise, there are some entities who believe energy efficiency requirements for the drives themselves are appropriate, for instance, the IEC.  However, one must bear in mind that the addition of a VFD does not guarantee overall efficiency gains depending on the system and how it is used (i.e., near or at full-load would not benefit from a VFD). Efficiency gains from incorporation of VFDs do sound possible, but they will be application- and load-dependent. 

Considering justification or opportunity for further DOE component regulations, it is important to revisit the preceding reference to pressure and temperature setpoints being the most common control metrics. These types of metrics are most commonly associated with air, water, and HVAC systems—systems that are already regulated for overall efficiency by the DOE. It is not clear from the initial study results in the US Industrial and Commercial Motor System Market Assessment Report Volume 1 (the subject of this paper) whether notable gains are feasible in the remaining portions of these system loads. Follow-up papers (two more are in progress) will more fully investigate this question.

Rather than interpret the above data points as justification for mandatory incorporation of drives on motors, or that VFD Standards should be written, one must respect the variety of applications. Instead, efforts should be made to accelerate and incent programs to educate and equip industrial and commercial facilities with VFDs where they are appropriate. A point-of-sale regulation from the DOE cannot accomplish this, but the DOE has other programs, and it can and should add VFD options to them. One example of a better approach for in-the-field energy efficiency improvements is the joint program founded by NEMA and the American Council for an Energy-Efficienct Economy (ACEEE) known as the Extended Motor Products (XMP) program.[5] The DOE Building Technologies Office (BTO) could help promote XMP nationwide. NEMA and its Motor and Generator Section Members invested several years’ effort with other interested parties to launch the XMP and more can and should be done to expand participation nationwide.

The study makes these observations about its own results: “Further, since these [initial 1990s] results were published, the US manufacturing sector has undergone a massive transformation. Due to global competition, some sectors have relocated operations overseas. Others have brought operations onshore to avail low cost and abundant natural gas. Additionally, automation and robotics have pervaded the entire sector.”

The study continues:

“Consequently, these two reports likely do not represent the current state of motor-driven systems in US industrial and commercial facilities. […]  Specifically, the lack of information affects a range of stakeholders:

• Governments must rely on outdated information when setting research agendas, developing policies, and designing energy efficiency programs and offerings.
• Utilities and energy efficiency programs cannot identify the current market needs or potential impact when designing rebate and energy efficiency programs.
• Electric grid planners cannot identify motor system usage characteristics when developing plans to support the resilience of the electric grid.
• Manufacturers of motors, motor-driven equipment, and drives are hampered when developing technologies to meet the needs of their market.
• Motor system end users are limited in their ability to identify energy-saving opportunities within their own facilities because they do not have reliable benchmark information.”

The lack of information or freedom of choice implied in any regulatory outcomes from the preceding five impact statements begs the question of whether further DOE regulations can improve outcomes. DOE regulatory reach can only impact reported efficiency of a product or appliance at its entry point into the market, whether manufactured domestically or imported.  DOE regulatory effect ends well before the end-use application of motor-driven systems. Since efficiency gains are more likely, and more beneficial, at the end-use, programs like the XMP program would seem more appropriate than other regulatory actions [6]. This approach would further build on the excellent energy savings already made by electric motor product class energy efficiency Standards. DOE has other programs that encourage better buildings, retrofits, and other improvements, but these are independent of its regulatory offices, and regulators often feel obliged to produce regulations even if they are not completely justified or may not be very effective. 

As to what is already being practiced with respect to reducing electricity consumption, the study notes the following findings from a survey of facility contacts: 59 percent of industrial facilities use an external energy assessor. Peer-to-peer knowledge sharing is used by 27 percent of all industrial facilities, and it is the most common method for large facilities (66 percent). Similarly, utility resources are used by 33 percent of all industrial facilities, but more often by large facilities than small facilities. Across all commercial facilities, peer-to-peer knowledge sharing is the most common method for identifying energy-efficiency measures  

The study provides excellent detailed reviews of motors and their disposition in the field by sector, by facility type, facility size, loading, disposition, and so on. This substantial amount of information (the report is 252 pages) cannot all be captured here. But NEMA staff has reviewed the report in detail and made extensive notes for future reference during DOE rulemaking proceedings.

Concerning DOE rulemakings, the MSMA will be very useful to all interested participants in the currently open rulemaking for electric motor energy conservation Standards. [7] This rulemaking is a mandatory six-year review of Standards, and the three MSMA reports and findings about the status of the market and how the market has changed will help inform the DOE and other rulemaking participants whether and where additional opportunities may exist for further investigation by DOE and others. 

Study Helps NEMA Members

The MSMA provides a detailed look into the population, electricity consumption and applications of electric motors in the US as well as insight into the facilities that employ these motors. Besides the regulatory applications this paper focuses on, the data and insights provided can aid NEMA Members in making business and planning decisions. The apparent low VFD deployment identifies opportunities for sales and upgrades outreach. The low rates of investment in facility energy efficiency programs and practices identifies opportunities for energy savings contracts and other improvement programs, whether private or government-sponsored. For NEMA Staff the MSMA provides useful insight into where Standards and other technical activities may be needed. Lastly, the study will provide rich context and useful data to contribute to better-informed and more effective consensus comments to DOE rulemakings on behalf of Members.