PRACTICAL PERSPECTIVES ON MOTOR SYSTEMS EFFICIENCY

Transcription

1 PRACTICAL PERSPECTIVES ON MOTOR SYSTEMS EFFICIENCY By Ted Clayton Marketing Manager, Energy & Power, Kaman Industrial Technologies Michael Polo Marketing Manager, Electrical, Kaman Industrial Technologies TABLE OF CONTENTS Executive Summary 2 EISA Overview & Impact 2 The Premium-Efficiency Equation 2 Electric Motor Evolution 3 Proactive Motor Management 4 Taking A Systems Approach 4 Rebates & Financial Incentives 5 Energy Asset Management 5 Case Studies 6 Although premium-efficient motors offer significant energy savings potential, for maximum ROI, users should focus on optimizing system-wide efficiency. By focusing on the entire powertrain system, users can increase their savings potential by up to 10 times the savings achieved through a motor upgrade alone, generating exponentially greater operating efficiencies. Information Resources 8

2 2 EXECUTIVE SUMMARY The Energy Independence and Security Act (EISA) has reshaped the motor landscape, prompting industrial users to reconsider the repair/replace decision, along with many other historical practices related to electric motors. Despite purchase costs of up to 35% higher than standard-efficiency motors, premium-efficiency options offer dramatic energy savings that can offset the initial investment in as little as 16 to 18 months and continue to pay dividends as long as the motor is in service. These motors also lower operating costs when applied correctly and offer an extended warranty. Users can further optimize efficiency gains and reduce their payoff period by: > Implementing a practical motor management policy > Adopting a systems approach toward improving efficiency > Taking advantage of utility rebates and other financial incentives > Managing energy as a core asset This whitepaper outlines suggestions for industrial users to adopt these strategies to improve energy efficiency and their bottom line. EISA OVERVIEW & IMPACT Steadily rising electricity costs, projected power demands that outstrip available supply, and growing awareness of the dangers of greenhouse gas emissions have made increasing energy efficiency a national priority. While green building codes, Corporate Average Fuel Economy (CAFE) standards for automobiles, and consumer appliance standards are an important part of a comprehensive efficiency strategy, the industrial sector represents the greatest potential to reduce North American electrical energy use. The Energy Independence and Security Act of 2007 (EISA) builds on standards established by the Energy Policy Act of 1992 (EPAct), which authorized the U.S. Department of Energy (DOE) to set minimum efficiency standards for certain classes of motors. Effective Dec. 19, 2010, EISA specifies that motors previously regulated by EPAct must now meet premium-efficiency standards established by the National Electric Manufacturers Association (NEMA). In addition, EISA establishes lower but significant energy efficiency requirements for motors previously not regulated. T H E P R E M I U M-E F F I C I E N C Y E Q U A T I O N motors offer efficiency gains of up to 3 percentage points compared to EPAct options and up to 8 percentage points over unregulated, standard-efficiency EISA at a Glance Motors manufactured or imported for sale in the United States (alone or as a component of another piece of equipment) must now meet the following requirements: > General-purpose motors (Subtype I) with a power rating of 1 to 200 horsepower (HP) that were previously regulated by EPAct now must meet minimum efficiency levels specified in NEMA Table These NEMA Premium standards affect < volt, three-phase motors for both NEMA and IEC frame sizes. > General-purpose motors (Subtype II) with a power rating of 1 to 200 HP that were previously exempted due to mounting now must meet EPAct standards (NEMA Table 12-11). Products in this category include U-frame, Design C, footless and close-coupled pump motors. > NEMA Design B or IEC Design N general purpose motors with a power rating between 201 and 500 HP must now meet EPAct standards. > Motors not currently covered by the new energyefficiency requirements include single-phase, DC, two-digit (48-56) frame and fractional HP motors. Note: Natural Resources Canada (NRCan) regulations took effect on Jan. 1, 2011, and differ slightly from U.S. laws. Source: Electronic Code of Federal Regulations, Energy Independence and Security Act of 2007 Refer to:

3 3 motors. To deliver these results, these motors incorporate more copper and higher grades of steel, resulting in initial costs of 15% to 30% higher than EPAct motors, and 25% to 35% higher than standard-efficiency options. Despite the impact on initial motor spend, motors improved efficiency results in reductions in operating costs that quickly outweigh the increase in purchase cost. With power to run the motor representing 95% of its lifetime operating cost, improving energy efficiency can reduce total cost of ownership significantly. Upgrading from EPAct to typically pays back the increased cost to upgrade in less than two years. For some models and in areas with higher electricity rates, the payback period can be as low as 16 to 18 months. ELECTRIC MOTOR EVOLUTION Improvements in electric motor design have impacted efficiency, content and cost. Standard Efficient Motor 84% Sample Lifetime Motor Operating Costs Standard efficient motors were the original industrial workhorse. 95% Electricity Costs 5% Purchase Price plus Installation, Maintenance, and Other Costs EPAct Efficient Motor 87.5% Source: Motor Decisions Matter, Motor Planning Kit: Introduction to Motor Management In addition to increased efficiency and rapid return on investment (ROI), motors offer users a number of other benefits: > Longer life, due to premium-grade insulation systems and cooler operation > Quieter operation and reduced vibration EPAct added more copper to the windings and a longer stator to achieve incremental efficiency gains. Efficient Motor 89.5% > Increased warranty periods, typically 36 to 60 months versus 12 to 24 months for EPAct motors and unregulated, standard-efficiency motors > Greater application versatility, resulting in enhanced inventory flexibility > Inverter/variable speed drive capable Some motors may be slightly longer and heavier than the motors they replace due to additional materials needed to achieve the higher efficiency but, in motors further refined the design and materials and lengthened the stator core even further in some cases elongating the motor footprint.

4 4 general, most will fit into the original envelope, allowing direct substitution. Still, replacement motors that need to be mounted within a confined envelope should be checked for fit and conduit box location prior to selection. PROACTIVE MOTOR MANAGEMENT Relatively few industrial firms have reacted to welldocumented returns on premium-efficient motor upgrades by implementing widely-accepted best practices as part of an updated motor management plan. Comprehensive plans are most likely to be implemented by large corporations with established sustainability goals, but any plant can benefit from adopting a pragmatic approach to motor management. At the heart of this practical approach is a focus on motors that offer the greatest savings opportunities. This lowhanging fruit typically includes: > Motors that run the most hours or represent critical operation points > Larger motors, which consume the most energy > The largest motor populations, for maximum economies of scale > Motors that have been repaired multiple times To avoid reactive, crisis decisions in response to downtime situations, it is critical to develop a proactive motor management plan before equipment fails. Implementing a plan for your company should include: > Establishing a logical purchase specification for new motors > Determining a cost-effective repair/replace breakpoint > Defining and documenting appropriate repair standards > Implementing an effective motor maintenance program For a detailed overview on developing an effective motor management strategy, read Kaman s whitepaper, Practical Perspectives on Motor Management. Download a copy at TAKING A SYSTEMS APPROACH Although premium-efficient motors offer significant energy savings potential, for maximum ROI, users should focus on optimizing system-wide efficiency. By focusing on the entire powertrain system, users can increase their savings potential by up to 10 times the savings achieved through motor upgrade alone, generating exponentially greater operating efficiencies. Variable-load applications, including pumps, fans, blowers, dust collectors and cooling towers, typically offer the greatest returns, generating realistic energy savings of 30% to 50%. Too often, maintenance crews are pressed to solve the problem at hand and miss out on opportunities to achieve greater operational gains. For example, an industrial user may upgrade a belt or gearbox to a higher-efficiency model, but fail to evaluate the impact on other system components, such as the motor. In many cases, installing more efficient belts, gearing and variable-speed drives allows users to substitute a smaller horsepower motor in the application, further reducing operating costs. Similar to proactive motor management, this approach delivers the best return when systems are evaluated and tagged with the new replacement specifications before a component fails. Users typically see a 5% to 10% increase in energy savings from replacing a motor, belt or gearbox with a high-efficiency counterpart; replacing two components can cause savings to jump to 10% to 20%. Additionally, variable-frequency drives allow industrial users to switch from always on to on demand operation, and can result in a 30% to 50% increase in energy savings. While it may seem obvious, as a general rule of thumb, if more than one technology meets your requirements, installing the most energy-efficient solution available will maximize long-term ROI despite the added upfront cost. Other guidelines for implementing a systems approach include: > Install AC variable-frequency drives for centrifugal loads > Replace V-belts with synchronous belts > Convert worm gear reducers to more efficient inline helical gears or bevel reducers > Replace dampers and valves used to control flow and pressure with adjustable-speed drives on motors > Transition compressed air applications to more efficient electromechanical or hydraulic options where possible > Retrofit equipment with sensors, timers and other controllers to automatically turn off conveyors, exhaust systems and other processes when not in use

5 5 > For systems where rough start ups make shutting down equipment impractical, use variable-frequency drives to run the system at slower-than-production speed when idle There are a number of no cost tools available to help users implement a systems approach to improve energy efficiency. In addition to MotorMaster+, free software from DOE includes Quick Plant Energy Profiler; AIRMaster+; and assessment tools for fan, pumping, steam and chilled water systems. R E B A T E S & F I N A N C I A L I N C E N T I V E S Even with the clear payoff from upgrading to NEMA Premium motors and other energy-efficient components, some users hesitate to make the investment until absolutely necessary. For those on the fence, rebates, tax credits and other financial incentives can help compensate for the cost of conversion and significantly shrink payback times. Many utilities offer rebates and incentives to offset the cost premium to upgrade to higher efficiency motors, along with programs for variable-speed drives, pump optimization and other energy-efficient industrial products. Currently, there are over 1,000 utility, state and local incentive programs across the country, as tracked by both DOE and the Database of State Incentives for Renewable and Energy Efficiency. Pre-approved or prescriptive rebates for upgrading specific components are typically tied to nameplate efficiency. Pre-approved measures for industrial products frequently max out in the $25,000 to $50,000 range per facility, with payouts for upgrading to motors ranging from $1 to $50 per horsepower. While rebates are expected to phase out within six to 12 months of EISA s implementation, in the near term, they help stack the deck towards the replace side of the repair/replace decision. For a current listing of NEMA Premium rebates see: Motor upgrades that are part of larger projects are often eligible for incentives calculated on exact energy savings, based on usage before and after implementation. These performance-based incentives can add up quickly, often paying out in the $100,000 to $500,000 range, however the effort required to measure and document specific improvements can present a challenge. Users intimidated by the rebate landscape can shortcut this process and maximize potential return by working with their local utility s account executive or their industrial distributor to identify potential incentives and streamline the application process. Additional incentives available from utilities and government agencies include: > Technical assistance programs, including plant engineering studies, and motor and energy audits > Rebates on energy-efficient industrial lighting > Discounted loans or grants to fund initial investment on large, new or retrofit projects > Federal tax credits ENERGY ASSET MANAGEMENT Just as end users can maximize the ROI on premiumefficient motors by adopting a systems approach, treating energy as an asset can also deliver real return to the bottom line. DOE estimates that even plants with existing energy management programs can often increase savings by an additional 10% to 15% by using best practices to increase efficiency. ENERGY STAR, a joint initiative of DOE and the U.S. Environmental Protection Agency, demonstrates that industrial users can improve energy and financial performance, while distinguishing themselves as environmental leaders. To do so, the program advocates a 7-step process: 1. Make a commitment by forming an energy team that includes a full-time energy champion, and instituting an energy policy 2. Assess performance by periodically evaluating energy use, establishing baselines and benchmarking results 3. Set clear, measurable performance goals to drive energy management and promote continuous improvement 4. Create a detailed action plan that lays out a systematic process to implement energy performance measures, including defining technical steps and targets, and determining roles and resources 5. Implement an action plan that includes internal and external communication to raise awareness across the organization 6. Evaluate progress by comparing energy-use data and activities compared to performance goals 7. Recognize achievements to sustain momentum and support for the program

6 6 1 CASE STUDIES Small motors offer exponential returns Case Study: Annual Savings from Upgrading 100 Horsepower of Motors from EPAct to Upgrading larger horsepower motors to may offer particularly rapid payback, but even small motors merit close consideration. Although motors smaller than one horsepower are not regulated by EISA or EPAct, they offer significant energy savings. Upgrading a one-horsepower motor from EPAct to NEMA premium results in three full percentage points of efficiency gain, compared to less than one point for a 100-horsepower motor. Since small motors typically make up the majority of any plant s motor population, the potential aggregate savings can add up quickly. Quantity HP Annual Electricity Costs EPAct Motor Efficiency Motor Efficiency Annual Electricity Savings $56, % 95.4% $ $57, % 94.5% $ $60, % 91.7% $1, $65, % 85.5% $2, (1-phase) $78, % 78.5% $10, (3-phase) $77, % 84.0% $13,901 Source: Kaman Industrial Technologies. Based on purchase of one or more motors representing 100 total horsepower, with 6,000 operating hours per year and electricity rate of $0.10/kWh. 2 Investing in premium efficiency pays off Case Study: Upgrading Motor and Gearbox Efficiency Increases System Efficiency by >31% A commercial bakery planned to upgrade 2,000 feet of conveyor that included 50, one-horsepower motor and gearbox units. Replacing existing standard efficiency motors and worm gearboxes with motors and helical gearboxes resulted in a 32% increase in overall net efficiency and over $8,770 in annual savings. Standard-Efficiency Scenario Standard efficiency motor = 80% efficient Worm gearbox = 77% efficient Net Efficiency (%) = Motor Efficiency (%) x Gearbox Efficiency (%) High-Efficiency Scenario motor = 85.5% efficient Helical gearbox = 95% efficient Net efficiency = 80% x 77% = 61.6% Net efficiency = 85.5% x 95% = 81.2% Annual operating costs = $36,331 Annual operating costs = $27,561 Net Efficiency Improvement = 81.2% % 61.6% = 31.8% Annual Operating Cost Savings = $36,331-$27,561 = $8,770 Source: Kaman Industrial Technologies. Based on purchase of 50 units, 1 HP each, with 7,200 operating hours per year and electricity rate of $0.10/kWh.

7 7 3 Systems approach maximizes ROI Case Study: Systems Focus Delivers 27% Savings Over Component Approach A hospital planned to upgrade its air handling system, which runs 24/7 and relied on outlet damper control. Upgrading eight, 40-horsepower motors from EPAct to would have delivered annual savings of over $7,300 and paid back the investment in a little over three years. Regulating air flow with a variable-speed control instead of dampers and upgrading from V-belts to synchronous belts increased the annual savings by more than tenfold and paid for itself in only seven months. Motors Component Approach Upgrade from EPAct to Systems Approach Upgrade from EPAct to Belts V-belts Upgrade from V-belts to synchronous belts Purchase cost $24,693 $48,235 Annual operating cost $280,071 $203,731 Annual energy savings $7,330 $83,670 Lifetime energy savings $75,516 $861,986 Annual CO 2 emission reductions 57 tonnes tonnes Simple pay back 40.4 months 6.9 months Savings 2.6% 29.9% Source: Kaman Industrial Technologies customer application. Based on purchase of eight units, 40 HP each, with 8,736 operating hours per year, system life of 10.3 years and electricity rate of $0.10/kWh. 4 On-demand operation slashes energy costs Case Study: Converting to On-Demand Operation Saves 164,000 kwh Each Year A firearms manufacturer planned to upgrade a dust collection system that services 24 work stations. Incorporating automatic blast gates to close off inactive stations and variable-speed blower control converted the system from always on to on-demand operation, reducing the fan output to match production. Combined with upgrading to a high-efficiency motor and belt drive, the plant saved 164,364 kwh each year with a payback period of 14 months. Motor Component Approach Upgrade from EPAct to Systems Approach Upgrade from EPAct to Belt V-belts Upgrade to synchronous belts Flow control Mechanical Upgrade to variable-frequency drive Purchase cost $1,014 $22,564 Annual operating cost $36,073 $16,855 Annual energy savings $532 $19,218 Lifetime energy savings $7,973 $288,270 Simple pay back 22.9 months 14.1 months Savings 1.5% 53.3% Source: Kaman Industrial Technologies customer application. Based on purchase of one, 60-HP unit, with 6,000 operating hours per year, system life of 15 years and electricity rate of $0.10/kWh. For component approach, purchase cost represents motor upgrade at time of failure; payback reflects additional cost of purchasing a premium efficiency motor.

8 8 INFORMATION RESOURCES Applied Proactive Technologies, Inc. (Springfield, Mass.) Baldor Electric Company (Fort Smith, Ark.) Consortium for Energy Efficiency ( Copper Development Association ( DSIRE: Database of State Incentives for Renewables & Efficiency ( ENERGY STAR for Industry ( Kaman Industrial Technologies, Practical Perspectives on Motor Management ( LEESON Electric Corporation (Grafton, Wis.) Motor Decisions Matter ( National Electrical Manufacturers Association ( U.S. Department of Energy, Office of Energy Efficiency & Renewal Energy, Industrial Technologies Program ( To contact Ted Clayton: To contact Michael Polo: 1 Waterside Crossing Windsor, CT