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Evaluating Sustainability Claims of Electric Motors

Evaluating Sustainability Claims of Electric Motors

There’s no disputing it. Every company should prioritize mindful stewardship of natural resources, including those of us in the industrial sector. To help us do that, we need standards and methodologies that can help us assess the life cycle of the products we deploy. With more knowledge, we can look for ways to lower emissions.

One industry that’s championed standards development and implementation is building and construction. Leadership in Energy and Environmental Design (LEED), the WELL Building Standard, the Living Building Challenge, and Energy Star are comprehensive certifications that account for a building’s lifecycle including, but not limited to, energy, lighting, acoustics, materials and site management. Some existing certifications, like the Living Building Challenge, go beyond reducing footprint. They demand that a building has a net positive impact.

Each of these certifications feature methodologies to assess carbon footprint. For example, LEED includes whole-building life cycle assessment (LCA)—a quantitative approach to comparing the environmental impacts of the products, processes and systems that go into constructing and maintaining a building. While these certifications aren’t perfect solutions, they establish a framework for the building and construction industry to better understand the impact of their work and act on behalf of the environment.

Industrial products and processes are starting to leverage LCA methodologies too. Rochester Institute of Technology defines an industrial LCA as “a systematic analysis of environmental impact over the course of the entire life cycle of a product, material, process, or other measurable activity.” They identify a linear production model that includes:

  • Material extraction
  • Production
  • Packaging and distribution
  • Use
  • End of use and waste treatment / recovery, which we’ll refer to as end of life (EOL)

Infinitum is starting down the path to identify baselines for motor production and operation because we believe that once we understand where we are, we can make better decisions on how to improve. Here’s how we’re starting to create a methodology and establish benchmarks.

Making the Infinitum Motor

To start, we’re using information about the procurement and refinement of the materials used in our electric motors as a proxy for the carbon footprint that results from making them. Over time, we aim to be able to assess the production, packaging and delivery processes as well.

The most common materials used in motor manufacturing are copper, iron/steel, aluminum and, sometimes, magnets. Unlike other motors, Infinitum also leverages printed circuit boards (PCBs). Each of these materials is assigned an emissions factor that indicates how much energy it takes to transform from a raw material to its fabrication-ready form.

From a materials standpoint, Infinitum motor emissions are estimated by multiplying the embodied energy (MJ/kg) of each individual material in the motor by its emissions factor. The same process is repeated for a baseline 10HP AC induction motor[1] for a point of comparison. Emissions are calculated based on type and quantity of materials used, and all emissions are measured in quantity of CO2. Our current methodology shows an overall CO2 reduction of 18 percent for a 10HP Infinitum motor[2] compared to a traditional 10HP AC induction motor (Figure 1). 75 percent of the aluminum Infinitum uses for motor housings is recycled material, and in this methodology, we assume the reference motor uses the same ratio.

Figure 1: Infinitum’s methodology shows an overall CO2 reduction of 18 percent for a 10HP Infinitum motor2 compared to a traditional 10HP AC induction motor. Key assumptions listed at the end of the page.

Running the Infinitum Motor

With our current methodology, energy consumption during operation is based on standards and published numbers. Energy consumption is based on power, operating time and the efficiency of the motor + VFD. For the sake of comparison, the same calculation is performed for a 10HP AC induction motor + VFD with IE1 efficiency.

For this calculation, emissions avoided from energy consumption are considered for both motor systems[1] over a 20-year period, and the cost of energy is estimated using U.S. Bureau of Labor statistics. The Infinitum motor system was found to produce 10 percent fewer CO2 emissions in operation.

In a practical example, over a period of 20 years, a 10HP AC induction motor + VFD uses 1,615 Gigawatt-hours (GWh) of energy while a 10HP Infinitum motor system uses 1,440 Gigawatt-hours (GWh). In this scenario energy cost savings amount to $30,000 (Figure 2). Over 20 years, every 100,000 Infinitum motors in service reduces CO2 emissions by 8 million metric tons. That’s the equivalent of pulling 1.5 million homes off the grid for a year.

Figure 2: In a practical example, over 20 years, a 10HP Infinitum motor system uses 1,440 Gigawatt-hours (GWh). This amounts to an energy cost savings of $30,000 compared to a 10HP AC induction motor + VFD.

It’s worth noting that there are a couple of well-known efficiency standards in the industrial space today. Standard IEC/EN 60034-30-1 and the National Electrical Manufacturers Association (NEMA) are typically used to compare one motor to another in terms of operational energy use. IEC, spanning from IE1 to IE5, focuses on application-specific performance. NEMA, spanning from “standard efficiency” to “super premium,” rewards motor designs with broader applicability across applications.

Managing End of Life (EOL) for the Infinitum Motor

At the end of a motor’s operational life, there are three main options: landfill, recycling of materials or remanufacturing (i.e., reuse of components). Infinitum motor components can be reused, so in each generation of manufacturing, CO2 reduction compounds, resulting in a 59 percent CO2 reduction for the second-generation Infinitum motor compared to the second generation 10HP AC induction motor (Figure 3). Assuming a useful lifetime of 10 years for a conventional 10HP AC induction motor, in 20 years, the conventional motor will have been manufactured twice. In the same amount of time, an Infinitum motor can be manufactured once and remanufactured from reused components. Our current methodology accounts for landfill and remanufacturing. Recycling materials like steel can save energy; however, we can’t confirm that recycled material is used to make the next motor, so that scenario has been omitted.

Figure 3: Infinitum’s methodology shows that CO2 reduction compounds, resulting in a 59 percent CO2 reduction for the second-generation Infinitum motor compared to the 10HP AC induction motor, which has to be manufactured from scratch both times. Key assumptions listed at the end of the page.

Matters of Methodology

The capacity to compare motors objectively is important. We need to explore the materials used in the motor, the manufacturing processes that turn those materials into components, the assembly process, transportation and distribution, operation and end of life (EOL). As we gain a better understanding of lifecycle emissions, we’ll be able to make informed decisions at each phase in a motor’s life and compare motors more holistically. At Infinitum we’ve begun this journey by measuring and benchmarking several of those methodology process steps.

In 2023, Sustainalytics, a Morningstar Company evaluated our methodology and deemed it “good practice” for impact reporting. We’re committed to making meaningful assessments and finding ways to improve.

Electric motors serve a variety of industries and functions, including HVAC operations where our LCA overlaps with the building and construction industry. Understanding how a well-designed motor can contribute positively to existing and emerging environmental certifications is important to us. By working with Infinitum, customers have access to state-of-the-art motors, but they also gain a sustainability partner for life. We’re always looking for ways to hold ourselves to a higher standard.

For further information on how to reduce the energy requirements of a motor, see How to Exceed Customer Expectations by Rightsizing the Motor for Your Fan System. For more information about how Infinitum can deliver sustainable motors for your application, reach out to our engineering team.

Key assumptions for Carbon Footprint Comparison

  • Motor compares are for 10 HP – 1800 configurations
  • AC induction motor weighs 85kg. Infinitum motor weighs 45kg. No VFD
  • Aluminum for both motors is assumed to be 75% recycled
  • Useful lifetime for motors assumed = 10 years

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How to Exceed Customer Expectations by Rightsizing the Motor for Your Fan System

How to Exceed Customer Expectations by Rightsizing the Motor for Your Fan System

Companies that develop fan systems for the HVAC market have a variety of requirements to consider; chief among them are performance and size. Achieving performance targets is the first order of business, but rightsizing the motor for the task at hand can lead to additional benefits. 

Finding the right motor is critical for delivering on these requirements at the systems-level. 
Here, we’ll:

  • Walk through the motor selection process
  • Dive into a few central ways motor design and selection can support overall fan system performance
  • Provide insights surrounding motor rightsizing and how it can be beneficial in applications with a large number of fans or fan arrays (e.g., data centers)

Unlocking the Potential in the Motor Selection Process
The motor selection process starts early in the fan system design cycle. Performance requirements are dictated by customers in the form of flow targets (cfm) and pressure targets (in-wg). With that knowledge, the fan design team makes two important selections:

  • A fan model that can deliver on flow rate expectations
  • A motor with the requisite torque and speed to drive the fan at the customer’s desired operating parameters

Take the example of a data center. These facilities require well-designed fan systems to cool servers, maintain airflow between aisles and sustain appropriate humidity levels. 

Our example data center application requires an operating point of 10,000 cfm at 2.5 in-wg of static pressure. The fan OEM uses that operating information as input for an in-house selection software that specifies an appropriate fan model and a motor that provides the brake horsepower (bhp) and motor speed (rpm) required  to drive that fan. Rather than using a software tool, for illustrative purposes, we’ll use a fan curve.

Based on our example application parameters, fan model ABC was selected. Once fan model selection is complete, the fan curve, shown in Figure 1, is used to determine the combination of motor power and speed that can deliver the requisite operating conditions.

Figure 1: Example fan curve; a tool used to visualize a fan’s flow rate and static pressure performance, which can be used to determine motor horsepower and speed requirements.

In this example, assume the motor that meets customer requirements is a 5.4 hp motor at 1208 rpm with a torque requirement of 23.5 lb-ft (31.8 Nm). Knowing the fan’s power and speed requirements are accounted for, the fan OEM looks for a motor with the best efficiency throughout the fan’s operating range.

Prioritizing Fan Performance and Efficiency in Motor Selection
Motor efficiency benefits the entire fan system, so motor selection is central to energy savings—a focus area for customers and regulators alike. Matching a motor’s peak efficiency with a fan system’s peak efficiency provides the optimal efficiency for the system overall. Motor efficiency curves are helpful for visualizing motor performance across a variety of loads and speeds.

Assess Motors at Partial, Optimal and Full Loads
While it’s important to know the system’s optimal duty point, there will be times when the motor runs at full or partial loads, so it’s equally important to consider how it’ll perform under those circumstances. For instance, when cooling demand decreases in an office building over the weekend, the system may run at a partial load. Alternatively, in a redundancy situation where one fan in an array fails, the others will work harder to maintain airflow and static pressure.

Understanding the reality of fan system operation, Infinitum motors are designed to deliver some of the highest levels of efficiency on the market across a wide range of load conditions and speeds. A flat efficiency curve across loads means the motor delivers higher levels of efficiency during the actual operating conditions of the fan system. Figure 2 shows that the Infinitum Aircore EC motor delivers better efficiency than two leading choices: Super Premium AC Induction Motor & VFD and a Leading EC Fan Motor.

Figure 2: Fan efficiency curve comparing Super Premium AC Induction Motor & VFD , a Leading EC Fan Motor and Infinitum’s Aircore EC motor.

Infinitum’s Aircore EC is built with an innovative PCB stator architecture which eliminates core losses and delivers high efficiency levels. The Aircore EC is a motor system that includes the motor and an integrated variable frequency drive (VFD). Each Infinitum motor system comes with a “Final Motor Verification and Test Report” which includes a motor efficiency curve like the one shown in Figure 3.

Figure 3: Example of Infinitum’s “Final Motor Verification and Test Report”.

How Infinitum Supports Motor Selection for Fan System Applications
To support the selection process, Infinitum offers the Aircore EC Motor Selection Tool to help fan OEMs select a properly optimized motor to fit their fan system. Returning to our fan system example, Figure 4 shows which motors best fit the 5.4 hp at 1208 rpm combination established using the fan curve. In this case, the motor selection tool provided two options. Fan OEMs can compare these motor recommendations, including rated power, rated speed, motor system efficiency, rated amps and rated torque.

Figure 4: Example results from Infinitum’s motor selection tool.

Then, fan OEMs select either:

  • A customized motor system configuration that is provided with a certified nameplate complete with the custom selection’s FLA, rated power, and rated speed
  • A motor with standard settings and nameplate that can be operated at the specified operating point

Custom Nameplating Services
With custom nameplating, motors like Infinitum’s can be rated with a lower amp rating. The motor selection tool includes the rated amps for each motor option. For the 5.4 hp motor, rated amps is 6.4 A. For the 10 hp motor, rated amps is 12.0 A. A lower input current allows the customer—in our case, a data center designer—to save on upstream electrical infrastructure costs by reducing the amount and size of wiring, circuit breakers and transformers.

In our example, input current savings would amount to 5.6 amps per motor. In a fan array composed of six fans, this amounts to 33.6 amps. The savings become significant when you consider that data centers usually require many fan arrays to prevent servers from overheating, allowing them to stay online for long periods of time. If, for example, the data center required 100 fan arrays (comprised of six fans each), the electrical infrastructure for the 5.4 hp motors would need to handle 3,840 amps (100 arrays x 6 fans x 6.4 amps) where the 10 hp motor would drive a requirement of 7,200 amps (100 arrays x 6 fans x 12 amps).

Size Optimizations at All Levels of Motor Design
Another important factor in motor selection is size. For many fan applications, the length of the motor is a crucial dimension in determining the width of the cabinet that houses the fan system. The Aircore EC motor series is shorter in length than an AC induction motor with comparable horsepower, due to its axial-flux motor design. For example, with the integrated VFD, a 10 hp Aircore EC motor at 1800 rpm is 8.9” in length, including the motor and drive. At 19.8”, a comparable AC induction motor from TECO-Westinghouse (10 hp / 1800 rpm) is more than twice the length. Optimizing the cabinet width to be as small as possible saves precious space in the data center mechanical room and simplifies transport and installation.

Because of the axial-flux motor design, the Aircore EC has a larger diameter than the typical AC induction motor. The larger diameter can be advantageous for centrifugal fan applications if it is close to the diameter of the wheel; in that case, there is less air turbulence through the fan array, so there is smoother airflow through the fan.

In summary, as we saw with our data center example, the ability to pinpoint the motor that best fits the actual power and speed needs of a given fan application will provide downstream benefits. Focusing on performance as early as the motor selection process results in reduced input power per motor, meaning fewer electrical infrastructure needs, reduced energy consumption and significant financial savings up front and over time.

To talk performance requirements with our team or try our motor selection tool for yourself, visit our website.

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How the Smallest of Components in your Motor May Have the Largest Impact on its Life Expectancy: Understanding Bearing Basics

How the Smallest of Components in your Motor May Have the Largest Impact on its Life Expectancy: Understanding Bearing Basics

When we talk about motor systems, it’s not if the motor will fail, it’s when.

Bearings are one of the main failure modes on an electric motor. High-frequency harmonics induce unbalanced phase voltages and currents in the stator and rotor cores. Add in thermal considerations, and over time, bearing lubricant can’t stand up to those conditions, and the bearing fails. Understanding bearing specifications during the process of motor selection can be a critical element in the effort to optimize the lifetime expectancy of your motor.

Bearing Basics

Before diving into the nuances of bearing selection, it’s important to understand the basic components that make up the structure of bearings and how each element plays a role in performance.

  • Rolling Elements: Balls and cylinders are the rolling elements in the bearing structure. While they can be made of plastic or ceramic, they’re typically made from high purity chrome alloy steel.
  • Race: The inner and outer race are mostly made from high purity chrome alloy. The raceway transfers force radially and/or axially depending on orientation. For motor applications, the inner race is rotating with the shaft and the outer race is stationary; rotors are connected to the shaft and rotate at the same speed.
  • Cage: Made from steel, brass, or polymer, the cage keeps rolling elements separate, so they don’t collide, while allowing them to rotate freely.
  • Shield / Seal: This combination offers protection against outside debris and keeps grease in. The shield is typically a metal plate while the seal is Nitrile/BUNA-N (NBR) or Fluoro (FKM) rubber.

Overall, bearing configuration depends on the application area. For example, the purpose of the shield / seal configuration is to retain grease and keep out debris, but the consequence is higher bearing loss. In electric motors, that increases the likelihood of seal failure. However, in water-tight environments (e.g., IP55 against water jet), a sealed bearing is mandatory (if there are no external seals), so the engineering team has no choice but to cope with lower motor efficiency due to the bearing loss in that case.

L10 and L10g

At Infinitum, we get a lot of questions about bearings—usually in the form of L10 life. By definition, L10 life refers to the number of hours in service at which 10 percent of bearings will fail due to metal fatigue (i.e., 90 percent reliability). It’s a measure of physical component life, and, by extension, provides insights on maintenance; downtime contributes to loss of revenue and additional service costs.

Grease life, L10g life, acknowledges the complexity of grease lubrication mechanisms by using empirical models as a basis for calculation. High temperature dramatically impacts L10g life. In motor applications, hybrid bearings, with ceramic balls and steel races, run much cooler, so they approximately double L10g life values compared to a steel bearing.

In large motors (i.e., 100 to 500 horsepower and up), L10 life is the more important calculation to consider because there are no pre-packed grease bearings. Regular re-greasing is part of maintenance. For smaller motors, like those produced by Infinitum, L10 grease life is the most important determining factor from a maintenance standpoint because of those pre-packaged grease bearings. Typically, grease will deteriorate faster than the actual component.

That said, these values hold a lot less meaning without context. L10 and L10g life are predominantly based on the speed and orientation of the motor that was used for assessment. When comparing L10 and L10g life values between vendors, make sure you’re comparing them within the same environmental context, or you won’t have an accurate snapshot of performance.

Material Selection

Materials matter when it comes to the physical life of components. Unless otherwise specified, Infinitum motors use steel bearings (balls and race).  

However, hybrid bearings (steel race, ceramic balls) balance performance and cost across a variety of motor applications. For instance, customers working in mission-critical applications where there are high temperatures, high speed, or strong electric current (e.g., data centers) tend to prefer hybrid bearings.

Infinitum uses hybrid 6200 series bearings or equivalent. Depending on the vendor, codes may provide more or less information about the bearing, but 6200 series specifications are consistent across the board.

There are certain situations where ceramic balls (i.e., silicon nitride) are better suited because they have stronger insulating protection than a steel balls. However, the price tag on hybrid bearings is 3 to 5 times higher than steel. Choosing to go that route adds additional safety margins to minimize risk, but it comes at a cost. On the other hand, applications with shock or sudden impact, like a monster truck motor, wouldn’t be ideal for ceramic balls because they’re too brittle to stand up to the shock.

Bearings play a critical role in motor design and operation. Understanding their characteristics provides helpful insights that set expectations for overall motor performance. At Infinitum, we look to understand your application and budget to ensure you have the best possible combination of components to keep your motor running. Contact us to discuss your upcoming project.

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Why Remanufacturing Electric Motors is a Big Idea

Why Remanufacturing Electric Motors is a Big Idea

To replace or repair? That’s the question.

In 2021, Deloitte reported that over two billion tons of waste ends up in landfills worldwide, and that number continues to rise. Add consideration for electronic waste, pollution, and the increasing strain on limited natural resources, and the case for sustainable manufacturing processes gets stronger and stronger.

800 million electric motors were sold in 2022, which represents a 10 percent increase from 2021. Today, electric motors consume roughly 50 percent of the world’s energy, a number that’s likely to grow as more industrial applications shift to electric power. With increased demand for electric motors, industrial companies, like Infinitum, are looking for ways to participate in the circular economy and assume greater ownership over end-of-life management through strategies like design for serviceability and remanufacturing.

The Ellen MacArthur Foundation defines a circular economy as one that decouples economic activity from the consumption of finite resources. Recycling and remanufacturing are two of several strategies under the circular economy umbrella that could positively impact lifetime emissions for electric motors:

Correctly Disposing of Equipment

Conceptually, recycling is simply disposing of equipment correctly at the end of its life. It involves waste management, like shredding and melting, to process materials for potential reuse. To maintain as much purity as possible, recyclers separate steel from other materials like copper, aluminum, or magnetic alloys. While it’s better than tossing equipment into a landfill, recycling is still labor intensive, so careful consideration should be applied when selecting it as a circular economy strategy.

Remanufacturing as a Circular Economy Pathway

Recycling levels up end-of-life for motors, but refurbishment and remanufacturing take it a step further by extending the life of the motor. In the remanufacturing process, a product or system is disassembled, and each component goes through an assessment process. Any worn components are replaced with updated equivalents to restore the product’s reliability, while keeping some original components and materials in use longer. This arrangement saves energy and avoids unnecessary waste.

Remanufacturing is commonplace in consumer electronics, and it has been for years. Companies like Apple and Best Buy have robust refurbishment programs, and consumers are buying in. One estimate projects the refurbished computer and laptop market will reach $8 billion USD by 2031, and that doesn’t account for smartphones or other consumer electronics that are eligible for refurbishment.

Remanufacturing is set to skyrocket as industrial companies look to apply this technique to cut waste and save energy in complex, high-tech manufacturing applications. Efforts in this space provide great value to customers because remanufacturing costs are typically lower than out-right replacement, and the process happens with zero effort on their part. At Infinitum, we’re excited to see more and more of our peers taking ownership of their product lifecycles.

Designing for Remanufacture

Designing out waste and limiting emissions creates a strong base for the circular economy. Incorporating elements that support remanufacturing sets our customers up for the greatest possible success. At Infinitum, we’re committed to design and manufacturing techniques that support the circular economy from the start:

  • Modular Design: Our approach allows us to meet application and output requirements by incrementally adding or removing stator panels and/or motor modules. By design, Infinitum motors are more easily customized, serviced, and disassembled for refurbishment or remanufacturing.
  • Materials Selection: By intentionally designing all aspects of our motors for lighter weight and lower operating noise (e.g., eliminating steel core and copper windings), we use fewer raw materials and precious resources, lessening demand on the environment and the supply chain. 
     
  • Shipping Practices: We reduce our transportation footprint through localized sourcing and production, but it’s not always about how you ship. What you ship matters too. Infinitum motors produce all the power in half the weight and size of a conventional motor. Smaller footprint and weight also contribute to reducing emissions in the shipping process.

By committing to emerging standards and implementing designs that support the circular economy, we can encourage the industry to be better stewards of our finite natural resources. By working with Infinitum, customers have access to state-of-the-art motors, but they also gain a sustainability partner for a lifetime, literally.

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Two Distinct Realms for Electric Motor Reliability Optimization

Two Distinct Realms for Electric Motor Reliability Optimization

Regardless of application, technical system performance and support costs depend on a motor’s ability to stand up to its environment. In a well-designed motor, reliability is essential. True, intrinsic reliability results from efforts in two distinct realms: motor architecture and predictive analytics.

From the motor architecture perspective, opportunities for reliability optimization appear in each major component of an electric motor. Condition of stator windings, sliding components, and bearings—the primary failure mechanism of an electric motor—all impact a motor’s lifespan:

  • Stator Windings: The iron core and copper windings in a traditional motor have different thermal expansion coefficients from one another. By nature, they expand at different rates as motor temperature changes, causing cracks in the winding insulation. Infinitum’s approach to this problem involves a PCB stator with layers of copper and glass-epoxy laminate. With less a smaller discrepancy in thermal expansion coefficient, temperature changes cause uniform contraction and expansion that prevents thermal cracks.
  • Bearings: Heat is a primary issue to contend with because it degrades bearing grease. System design should focus on keeping bearings cool and properly loaded. Exceeding a motor’s operational specifications shortens its life by adding unnecessary stress on the bearings. Early in development, Infinitum employs heat sink optimization and other thermal management techniques to achieve cooler operating temperatures for the whole motor.

    Infinitum motors come standard with steel bearings (balls and race), but hybrid ceramic bearings (steel race, ceramic balls) are available upon request. All Infinitum motors have an L10 bearing life of 50,000 hours for all orientations.

For more information on motor architecture and predictive analytics in electric motor design and manufacturing, check out our white paper “Designing Electric Motors for Intrinsic Reliability” where we’ll cover:

  • Areas of an electric motor that offer the greatest opportunities for design optimization
  • How analytics can help mechanical engineers apply precision improvements for greater reliability

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