Changing boilers and fuel sources puts a German tannery in line with its desires to balance economy and ecology.
A Q & A with Danita Knox, GE Energy Connections.
When’s the best time to upgrade a power system? According to Danita Knox of GE Energy Connections, Atlanta, it can vary. Consider the following situations as ideal opportunities:
- if a facility had or is planning a significant expansion that might affect overall power-system loading
- if a recent arc-flash study revealed significant incident levels or danger of exposure for electrical workers or operators
- if personnel are having difficulty locating replacement and spare parts for the site’s electrical system
- if plant personnel desire better monitoring of the overall power system.
Once the decision has been made to move forward on an upgrade, what’s next? We asked Knox for some insight into what facilities can do to make these projects go smoothly.
MT: What trends in power-system upgrades are you seeing among older installations?
Knox: One trend involves customers replacing older electromechanical relays, meters, and trip units with newer digital “smart” equivalents. This provides a single, multi-function device that incorporates communications (local and network), event logging, and monitoring (graphical screens and remotely using web tools). Critical applications include upgrading to smart switchgear offerings that feature built-in monitoring, diagnostics, redundancy, and remote-control capabilities.
Facilities are also adding devices to their power systems that help locate workers further away from the equipment they operate. This is done, in some cases, by adding remote racking devices to existing breakers or using robot-type devices to operate equipment from a safe distance. We’re seeing more sites updating old fused devices, such as a load interrupter switch, with faster-operating vacuum breakers and relay equivalents that reduce arc-flash incident levels.
Finally, with limited budgets for large capital projects in many plants, it’s essential for them to find ways to extend the life of their existing equipment. To that end, facilities are often looking at retrofit options.
MT: What tips do you have for sites that are embarking on a power system upgrade?
Knox: Ideally, it helps to start with a comprehensive arc-flash study. This can provide remediation suggestions on how to reduce arc-flash exposure levels and improve personnel and equipment safety. To begin an arc flash study, an operation needs an accurate schematic or diagram of the facility. Plant personnel familiar with the electrical system can usually collect the information needed to build this diagram. An accurate schematic also provides critical information that can be a great tool to develop safe and proper LOTO (lock-out/tag-out) practices.
With a thorough arc-flash study, plant operators can then evaluate multiple options that help define steps to start upgrading a power system. Upgrade projects can be prioritized into smaller projects, depending on employee exposure, process needs, available outage periods and budget constraints.
MT: To get management buy-in, what’s the best way to estimate the return on investment (ROI) and benefits of an upgrade?
Knox: Often the need to upgrade is based on some failure or electrical incident that has caused downtime, equipment damage, or, worst-case scenario, employee injury.
When you look at the cost associated with downtime and/or injury, it’s fairly easy to calculate ROI if the project is done in a phased approach. Some trip unit, relay, and breaker upgrades can be done under the threshold of a maintenance budget.
MT: Are there any budget-friendly ways to upgrade a legacy system?
Knox: Yes, there are. It’s important to look at upgrade options that solve the most problems with minimal disruption to plant operations and equipment.
Consider, for example, if a single upstream breaker/relay combination in the facility can reduce arc-flash exposure for downstream feeder breakers without upgrading each breaker. Does the site have unused spare breakers that can be rotated out with a local service shop for upgrades that can later be installed during a short outage?
If a plant is updating old relays and meters, it should get new doors with new components prewired. This allows a shorter outage while equipment is being replaced. Also, “replacing the guts” in the existing compartment in a field outage can help reduce upgrade costs, assuming the new equipment has been pre-determined to fit the compartment and it can be easily wired. MT
Danita Knox is senior product manager for Power Delivery Services within GE Energy Connections, headquartered in Atlanta.
Steps to a Successful Power-System Upgrade
According to GE’s Danita Knox, as a site prepares for a power-system upgrade, it’s important to identify and select a reputable vendor that’s experienced, trained, and knowledgeable in designing this type of complex project. A power-system upgrade includes these steps:
- Budgeting for hardware, software, and labor.
- Development of a project schedule and careful outage planning for the upgrade.
- Design of the system and procurement of all components prior to the outage.
- Labor and logistics planning for the outage to ensure that work is completed on time.
- Testing of all critical components prior to the outage.
- Failure mode and effects analysis to plan for challenges during the outage and prepare solutions or workarounds.
- Site safety and work policy that includes LOTO (lock-out/tag-out) training and documentation.
“During the upgrade,” Knox said, “an experienced project manager with a background in power systems is indispensable. Many facilities operate continuously with infrequent planned outages. Careful planning and execution is required to maximize work and re-energize systems in a timely manner.”
Knox advises creating a detailed schedule and work procedures early on, including planning types of labor and required skill-sets and procuring all materials well in advance. “Regarding procurement,” she cautioned, “be careful to consider smaller items, such as personal protective equipment and installation components. If these small details are missed in outage planning, they can create schedule slippage, safety risks, or technical errors while limiting the amount of work accomplished.”
While Bulk Electric System power-generation facilities have until 2019 to conform to the PRC-025-1 standard, early adopters can begin capturing a range of benefits now.
By Jane Alexander, Managing Editor
In August 2003, an electric power blackout across the northeast United States and Ontario, Canada, affected an estimated 50 million people. Analysis of this and other major disturbances over the past 25 years has revealed generators tripped for conditions that did not pose a direct risk to those units and associated equipment.
As a result, the North American Electric Reliability Corp. (NERC), Atlanta, created the PRC-025-1 Generator Relay Loadability Standard. According to Steve Nollette, supervising engineer for Emerson Network Power’s Electrical Reliability Services, Columbus, OH, the intent of the standard is to increase grid stability during system disturbances by reducing unnecessary tripping of generators or the number of “misoperations” caused by incorrect settings, logic, or design errors.
The Federal Energy Regulatory Commission (FERC), Washington, has launched a campaign designed to reduce misoperations by 25%, including implementation of standardized setting methodologies such as PRC-025-1, which is currently enforceable.
Bulk Electric System (BES) generation facilities, according to the NERC definition, are required to conform to PRC-025-1 by October 2019. Nollette explained that, while this seems like ample time, facilities should begin planning a loadability study now to reap the following benefits associated with early adoption and, thus, avoid the costly consequences of delay or noncompliance.
Better access to engineering resources. As regulatory requirements governing operations continue to change, single generation sites that operate with limited engineering resources may need assistance from external or outsourced resources such as contractors, who can perform the highly technical tasks needed to meet the new regulatory requirements. While multi-site generation entities often already utilize an engineering team specializing in matters pertaining to NERC compliance, they may also need assistance due to the volume of work related to analyzing, implementing, and testing all of their protective relays.
“The economic laws of supply and demand dictate that, as a deadline approaches and more generation plants rush to seek out contract assistance, the available supply of contractors and engineering firms will dwindle,” Nollette said. “This translates into higher costs and potentially lower quality. Early adopters will have access to greater engineering resources at lower costs.”
Less business interruption. For generation sites that have completed a system assessment and require changes to the load-sensitive protective relay settings, implementation and testing will need to be scheduled, requiring a maintenance outage. When a loadability study is performed earlier, there is a greater ability to schedule the implementation and testing during a planned outage rather than having to schedule a separate maintenance outage. Nollette explained that planned outages are typically part of a forecast and budget while unplanned maintenance outages typically incur additional unexpected costs and are disruptive to normal operations.
More time for special cases. In some instances, an existing relay system may not be capable of using the settings required by NERC PRC-025-1. In these special cases, the deadline for compliance is extended by two years to allow retrofit of the existing protective-relay system. As Nollette pointed out, this is a significant engineering effort that is best performed carefully, with sufficient time and resources. Early adopters will have the benefit of adequate time to plan, budget, engineer, remove, install, and test the new protective relays.
Planning, executing loadability studies
The complexity and amount of effort required to perform a generator loadability study, according to PRC-025-1, can vary widely depending upon system design, configuration, age, and documentation. Generation facilities should already be developing plans of action to meet the compliance deadline.
Start by determining if outside engineering help is needed. It’s likely that most generator owners (GOs) and generator operators (GOPs) already understand the make-up of their technical resources. Determining if external resources are needed to supplement compliance efforts could be as simple as not having enough staff for the number of facilities requiring assessment.
Determine the scope of your study. “Most engineers, facing PRC-025-1 compliance considerations for the first time, will need to exert significant time and effort to learn the new standard and how it applies to their site,” Nollette said. “To determine the scope of their efforts, GOs and GOPs need to evaluate which of their protective relays require analysis and how close they are to compliance.”
The first step in determining the scope is to gather generation-unit data, which will be used throughout the assessment process. Collecting this basic generation-unit information will provide a preview for the amount of work that will be needed.
Nollette stated that required information can be found in the following documents: one-line drawings, three-line drawings, protective relay settings, relay test reports, and component nameplates.
To help with determining how the standard applies to a given plant, the PRC-025-1 application guidelines illustrate a comprehensive protective-relay scheme for a generation unit. However, not all relays illustrated will necessarily exist in every system (see Fig. 1).
Once the generation system protective relays have been sorted into the appropriate options, as seen in Fig. 1, the remaining necessary information is gathered to assess each protective relay’s compliance. This information is also found within the documentation initially gathered for the generation unit data.
Understand the options available for compliance. NERC PRC-025-1 provides multiple options for setting load-responsive protective relays, as outlined in Attachment 1, Table I of the application guidelines. Each relay may have as many as three options available. Option A is the simplest to apply, but generally results in a less-accurate assessment. Software simulation, referred to as either Option B or Option C in the application guidelines, is more accurate because it models the machine’s reactive-power capability using field forcing simulations.
Compare nameplate data and relay settings with the PRC-025-1 standard to determine compliance. GOs must determine whether or not protective relays within the generation unit meet compliance requirements. The process of comparing as-found settings with the standard will require relay-specific information such as instrument transformer ratios and protective-relay pickup and/or tap values.
Start assessment process early and allot enough time for corrective actions. Whether determining the reactive power rating through conservative calculation (Option A) or through software simulation, corrective actions will likely need to be taken. Actions will include scheduling an outage for the implementation, testing, and documentation of the relay setting changes—all of which can take significant time to complete.
“No matter which compliance option is chosen, any changes to the existing settings should be carefully reviewed by the original-equipment manufacturer (OEM) and the protection engineers who are responsible for upstream coordination, prior to implementation,” Nollette said.
Compile all information to complete the demonstration report. A thorough report for generator loadability will contain all information that was gathered during the assessment phase, supportive calculations from PRC-025-1 application guidelines, results from the software simulations (if performed), and documentation of any corrective actions and testing.
According to Nollette, assimilating reporting characteristics that make the auditing process efficient will contribute to a successful audit with the Electrical Reliability Organization (ERO). Reporting methods that support a searchable document, a linked table of contents, bookmarking, and embedded links to supporting documentation should be an integral part of the demonstration report, Nollette explained.
Achieving NERC PRC-025-1 compliance requires a concerted effort. GOs or GOPs will need to rely heavily on either internal or external engineering
resources, especially when moving beyond the conservative calculations used in Option A to more-accurate software simulations. While these simulations take more time to execute, they ultimately require fewer setting changes for better protection. Nollette concluded that a well-executed compliance plan rewards generating entities with a protected and more stable system and grid. MT
Steve Nollette is a supervising engineer for Emerson Network Power, Electrical Reliability Services, Columbus, OH. He has more than 20 years of experience performing and managing electrical testing, maintenance, and engineering services.
EDITOR’S NOTE: To help facilities streamline the loadability study process, Emerson’s Electrical Reliability Services team has created a tool that automates the process of comparing settings with standard requirements. Download it at http://bit.ly/1Xqo4I6. For additional assistance, email NERCcompliance@Emerson.com or visit emersonnetwork.com.
Just how much revenue can your process operations afford to lose?
Shakopee, MN-based Emerson Process Management (emersonprocess.com) has released an Engineer Insight Report to help industrial end-users better understand where and how energy can be saved in their operations. Entitled Top 5 Measurements for Energy Efficiency, it identifies priorities with equipment systems that “should be a concern for any plant-management team looking to gain better insight into process energy use.” The report also details some real-world successes and energy savings realized by other end-users and highlights the measurement technologies they leveraged.
Utility Fluids (metering flow and managing use)
Utility fluids, i.e., water, air, gas, and steam, are the lifeblood of a plant. A shortage of any one of them could lead to a shutdown. Emerson acknowledges that, while every plant is different, for most, it’s reasonable to say, that 5% to 15% of a site’s energy is wasted in the form of lost or misused utility fluids. Metering the flow and managing the use of utility fluids could be an opportunity to save between $1 million and $15 million annually.
Compressed Air (measuring flow to identify leaks and manage use)
Compressed-air systems in plants are major energy users and generally have many leaks and other issues leading to waste. Measuring flow in a compressed-air system helps identify areas of excessive use and ways to better manage overall air use. Measuring air use is best done with several points of flow measurement throughout the system, i.e., at each compressor, at headers, and at major branch lines. More measurement points allow tighter leak control and better management of system health.
Boilers (improving drum-level measurement)
In boilers, the water level in the steam drum must be precisely controlled to optimize steam production, maximize boiler efficiency, and maintain safety. If water levels are too low, there’s a risk of damage to the boiler—and a significant risk of costly boiler trips. If levels are too high, water could be carried with the steam, reducing heat-transfer effectiveness and possibly damaging downstream turbines. Steam-system performance is most efficient when boiler operation is stable and costly shutdown, purge, and re-start cycles are avoided. According to Emerson experts, reliable drum-level measurements are important in achieving that desired condition.
Heat Exchangers (predicting and detecting fouling)
Process facilities may have hundreds of heat exchangers that can foul over time, directly affecting production capacity, maintenance costs, and energy use. Heat-exchanger fouling is accelerated by many factors, including sediment, corrosion, decomposition, and crystallization. Unfortunately, due to the difficulty and perceived high cost of real-time monitoring, many of these units may only be checked periodically, during field rounds. Operators using visual and manual measurement methods are often challenged to spot signs of contamination and, over time, build-up occurs—impeding heat transfer, reducing throughput, and driving up energy consumption. Energy costs rise when fouling requires additional heat for a needed temperature change.
Steam Systems (monitoring steam traps)
Most industrial plants use steam heat to provide the energy that drives processes. Boilers and steam-distribution lines are the obvious components of these systems. However, critical steam traps, i.e., mechanical valves that let condensed water out of the system while keeping the steam in, are frequently overlooked. A large plant can have thousands. They fail in one of two ways: open or closed. An open trap leaks steam, wasting energy. A closed trap lets condensed water build up in the steam pipe, creating reliability issues and causing “water-hammer” events that can damage the steam system and connected equipment. Steam traps have an average life expectancy of about five years. Regular replacement of failed traps is essential for proper steam-system operation.
Download the complete report, along with a free White Paper entitled Process Energy Efficiency: Measure, Monitor—Then Improve, at emr.sn/Mwn. MT
A large construction project at Endress+Hauser’s U.S. headquarters operation significantly advances the site’s sustainability factors.
By Rick Carter, Executive Editor
Because European companies have traveled the sustainability road longer than most of their U.S. counterparts, key green practices like energy efficiency, recycling and others are often the rule for these entities, not the exception. Thus, it’s no surprise that Endress+Hauser, a Switzerland-based instrumentation and process-automation company with operations around the world, has infused its Greenwood, IN-based U.S. headquarters with impeccable sustainability credentials. But it has only been within the past half-decade or so that the 70-acre campus, 10 miles south of Indianapolis, has come to resemble the parent company’s high level of sustainability in nearly every way. Thanks to a recent construction boom, the site features two new LEED-certified* manufacturing buildings and a new high-tech Customer Center that awaits LEED certification, which added nearly 300,000 sq. ft. of space to the campus. The project also added a long list of impressive sustainable features, not the least of which is a $1.2 million geothermal heating and cooling system that serves the new manufacturing facilities.
The large, concurrent building project was OK’d not just for its environmental returns, but as part of the company’s long-term strategy to gain U.S. market share. It also reflects the company’s worldwide (and sustainable) policy to manufacture as close as possible to its customers rather than sourcing product from overseas operations. The U.S. team is extremely proud of its recent site improvements, most of which came together over a short period of time.
“For over five years, this campus has been a construction zone,” says Todd Hubbell, Vice President of Operations. First, he says, Endress+Hauser Flowtec AG (USA), the company’s U.S. flow-meter-manufacturing operation, built a new facility in 2008 and expanded it in 2012. That same year, Endress+Hauser Automation Instrumentation, Inc. (USA), where the company manufactures level and pressure instrumentation devices, built a new building, which finished 30 days apart from the other one. “And immediately after those two buildings were done,” says Hubbell, “we tore down Automation’s old building, and built an energy-efficient and sustainable Customer Center in its place.”
Despite the enormous inconvenience caused by simultaneous, large-scale construction projects taking place next to each other, Endress+Hauser’s North American customers had no idea things weren’t humming along normally in Indiana. “No production was ever down here in Greenwood,” says Mike Moore, Industrial Engineering Manager, and 36-year Endress+Hauser veteran. “We promise that customers will get their products on time, and none of our delivery dates were compromised or missed,” he says. “We didn’t want any customer to notice anything that was happening here.”
Considering the unusual business hierarchy used at Greenwood—the site actually encompasses five independent Endress+Hauser companies—and that all company products are made-to-order, the feat is exceptional. It’s also indicative of this operation’s ability to work together toward common goals. “Our organization is different, but unbelievably successful because it forces us at a campus level for the general managers and the management structure to work together,” says Hubbell.
Greenwood’s team strength developed in response to the company’s plan for the site to not just be a distribution/sales outpost, but a functioning manufacturing arm, each part of which (within the five companies) has its own challenges to resolve. In the 40 years Endress+Hauser has been in Greenwood, the staff has proven its resourcefulness in this regard, and positioned itself as a good steward of the company’s sustainability policies.
“The whole culture of producing close to the customer is part of sustainability,” explains Steve Demaree, Technical Services Manager and 37-year Endress+Hauser veteran. “Compared to a lot of our competitors who produce offshore, no matter what they do, they are less flexible. When you try to produce far from your customer, your options are long-distance deliveries or some type of regional stocking program of completed instruments. To have the broad flexibility to reach your customer throughout the world is using sustainability as a competitive advantage. And it has been an effective business model for us.”
Demaree adds that the privately held Endress+Hauser has always been more focused on long-term improvement projects. “They have to be good investments,” he adds, “but if it has good long-term return, it’s likely to be accepted, which is also part of sustainability, to not be so tightly controlled.”
When it came time to expand Greenwood, it was assumed any new design under discussion would reflect advanced green elements. “The Endress family has always been a big proponent of the environment,” says Hubbell, adding that the campus has been developed with that in mind. “With our recent LEED initiatives, our environmental efforts just came naturally; there was no ‘program’ in place. It has always been assumed that we will approach all projects from an environmental perspective.”
Making it work
The company’s partner in its recent projects was Genesis Property Development, based in nearby Shelbyville, IN. Bill Poland, VP of Construction for Genesis, says the Endress+Hauser projects were different from others he’s worked on because of the company’s “passion for their facilities. We were here every day,” he says, “and we interacted with them regularly, which I’ve never dealt with before. Usually, once the design is done, the owner goes about their business and doesn’t want to know what goes into the project on a daily basis. These folks did, and it was fantastic.”
The result, says Poland, is that the new facilities “do exactly what they need them to and, from a sustainability standpoint, nothing was wasted.” He adds that with the elevated level of on-site building activity and with regular company operations continuing unabated, their interest and involvement was especially appreciated. The pursuit of LEED certification for manufacturing operations is difficult enough, he says, but the large geothermal project at Endress+Hauser proved a particular challenge.
The main external feature of the geothermal project—a narrow channel more than a quarter mile long (1370 ft.), 90 ft. wide and 14 ft. deep—is situated along the property’s western boundary, at a distance from on-site vehicle and foot traffic, and largely out of view. Had they gone with a more traditional oval-shaped pond, a much wider swath of land would have been needed, which would have disrupted the flow of on-site traffic. And while outdoor ponds are not part of every geothermal project, it was chosen for this one as a two-part solution to also address an existing water runoff problem. Hubbell says that with more paved surfaces being added to the site, they knew the flooding issue would have to be resolved, so they chose a solution that would do that and become a resource for reducing energy costs. “It was a case of making lemonade out of lemons,” says Poland.
Following a construction-plan analysis of the site’s water issue, the company purchased enough adjoining land to accommodate both the new manufacturing operations and the planned retention pond. Poland explains that the pond design allows for a desired “normal” level of water to be maintained year-round. “But it can accept a tremendous amount of water,” he says, which is allowed by the pond’s length, depth and vertical walls. The current design allows the pond level to rise by as much as 12 ft. in heavy rain, “which can happen quickly,” says Poland. “The water is then released slowly through a weir system, which controls flooding downstream.”
An additional four feet of depth over and above what was needed to improve drainage helps maintain water at the desired level longer. This feature also allows for possible later expansion of the geothermal system for building HVAC purposes or for use in industrial processes.
The completed geothermal system is now the only heating and cooling system in place for the two new manufacturing buildings. “It never shuts off,” says Demaree. “When the pond is frozen, we extract heat from it. When it’s in its warmest condition, we put heat into it.” He adds that it has already passed the heating-and-cooling comfort test many times over, starting on the day the Flowtec building was inaugurated. “It was 90 degrees outside, and we had what will probably be the most number of people we’ll ever have in it, and it was totally comfortable.” The system is also saving money, beating the heating and cooling costs in the buildings that were replaced by more than 40%.
Other LEED issues
Substantial as the geothermal project was, it added only six points to the company’s LEED tally for its two new manufacturing buildings. And while many fundamental LEED requirements were included in the buildings’ designs (see sidebar), it was important that the design team also include one or two larger ones. The new Customer Center, for example, which awaits its LEED certification, features a high-tech boiler/chiller system for its heating and cooling. Though located too far from the pond to be on the geothermal system, this building’s HVAC system “does the same things mechanically the pond does,” says Poland, and it built LEED points. The company also opted for white roofs on all new buildings—an unusual feature for structures in central Indiana, but necessary for LEED.
Other significant LEED add-ons included energy-efficient lighting and building automation systems and construction procedures that called for controlled debris removal. “We were required to divert at least 75% of the site’s construction material away from landfills,” says Poland. His crews were able to top that, diverting about 87% from the three-building project. Detailed docuamentation was also required, both for disposed/recycled material and material used in construction, which had to include certain levels of recycled content, and be sourced locally. “This meant that everything we used—steel, drywall, concrete—had to be produced within 500 miles of this area,” says Poland. “We could not bring in material from outside that radius.”
While there was never an argument against pursuing LEED certifications for the new Greenwood buildings, it was decided early on to seek only the LEED level that proved most practical from a business perspective, which was “Certified.” The Greenwood team reasoned that the added cost needed to obtain the higher point requirements of Silver, Gold and Platinum levels would not produce significantly greater environmental paybacks. “We were not going to ‘buy into’ levels,” says Demaree. “It didn’t make sense to us. But where there was good ROI in terms of energy savings, we would go for that. We wanted to take a very practical approach.”
Their decision means that a high-point/high-cost upgrade like a solar photovoltaic system was not considered for the Greenwood project. But the sun was not left out of their plans. “All the new buildings have light-harvesting components,” says Poland. “These include skylight systems and a tremendous amount of sidewall lighting. These features add to their energy-efficiency as well, because on sunny days, the buildings are all well-lighted.” The company’s LEED investment added an estimated 10% to the total construction cost, along with a little extra time. “But the benefits were so substantial,” says Poland, “they were worth it. With this company, getting it right was more important than the cost. There was a premium placed on having things done the way they needed to be done.”
“When we did these projects, it was based on a five-year plan, taking us up to 2017 or 2018, at least on the Automation side,” says Moore. With the new buildings in place, he says, “We’re now aggressive in projects to build more products on site. We also built the Automation building in such a way that we could build a mirror image of it and expand on the south side of the property.”
Hubbell believes expansion is likely. “We’ve had fast growth in the marketplace over the past few years and believe we must continue investing in our infrastructure,” he says, noting that the company has spent more than $150 million on such projects at its U.S. operations in the past five years.
Endress+Hauser is also working to improve production efficiencies at Greenwood. Efforts include increased parts-sharing across the company’s supply chain, making better use of remote-monitoring to implement higher levels of predictive maintenance, and building up recently enacted 5S and TPM programs. They also plan to more closely monitor energy consumption using their new building automation systems. “We are just now starting to work with this,” says Demaree, “but it should play a much bigger role in our future ability to conserve energy. We’ll use this data to support other projects and further reduce energy throughout our facilities.”
They’re also looking beyond elements over which they have direct control in order to push Greenwood’s sustainability boundaries. “We’ve been working with the city to get an interchange off of the local interstate,” says Hubbell. “This would save eight traffic lights for the trucks that come here, not to mention help our employees on their commutes.” Hubbell adds, though, that since business for Endress+Hauser through Greenwood has lately been “so fluid and our growth so dynamic,” it’s hard to say exactly what paths they might choose over the next several months or years. “But I do know,” he says, “that we’ll meet whatever challenge comes at us.” MT
* LEED stands for Leadership in Energy & Environmental design. It is a world-recognized green-building certification program created by the U.S. Green Building Council (usgbc.org).
Just like turning out the lights when you leave a room, a good energy-efficiency strategy for compressed air is to turn the equipment off when not required. Leaving the equipment running will waste energy, increase maintenance costs and shorten its life cycle.
Industrial compressed air systems rarely have flat, constant loads. Compressed air demand typically follows varying production activity, with higher peak flows during daytime shifts and lower flows during evenings, lunch breaks, weekends and holidays. The equipment that makes the compressed air must match this air demand during peaks and turn itself down during the lulls in production.
It’s often necessary for multiple air compressors, and associated equipment such as air dryers, to run during peak production, while slower periods only require the capacity of one air compressor. If air compressor controls are not properly coordinated, and energy-saving features on compressor controls not activated, excess system capacity can remain running when not required.
When air compressors run partly loaded, or unloaded, compressor efficiency can drop. Consider a 100 hp air compressor consuming about 88 kW at full load while producing 440 cfm of compressed air. This unit would be producing air at a specific power of 20 kW per 100 cfm produced. If this compressor was running lightly loaded at 25% duty (110 cfm), while running in modulation control mode, it would consume power at a rate of 62 kW per 100 cfm or about three times higher than rated.
Even if this compressor was unloaded, but kept running, it would consume about 25 to 35% of its full load, or 22 to 30 kW while producing zero air flow. At a level of 30 kW, an air compressor running 4000 hours per year unloaded would waste $12,400 per year in electricity costs. Additionally, because the compressor motor is still driving the compression element, and the lubricating oil continues to flow, these elements are slowly wearing out, which shortens equipment life and causes extra maintenance costs.
Low load levels can represent significant operating hours in a shift-oriented plant. Consider a typical plant with two eight-hour weekday production shifts. Of the 16 hours on shift, about two hours may be taken up by breaks and lunch periods. Considering weekends, holidays and plant shutdowns, the low-load periods can represent more than 5000 hours per year of the total 8760 annual hours.
Consider the following strategies to help reduce your compressor run time:
- Enable compressor blow-down timers that automatically turn off compressors when not required.
- Run smaller compressors during light loading, either manually or with automated control.
- Turn the compressed air supply to plant equipment off when not producing product.
- Turn the complete compressed air system off at night and over weekends.
- Reduce compressed air leaks using a repair program.
Learn more about compressed air efficiency and strategies you can use at our Compressed Air Challenge seminars. For a list of seminars and more information on the subject, visit compressedairchallenge.org. MT
The Compressed Air Challenge® is a partner of the U.S. Department of Energy’s Industrial Technology programs. To learn more about its many offerings, log on to compressedairchallenge.org, or email: firstname.lastname@example.org.
“Strategic Energy Management” seems to be the new buzz term for industrial and commercial businesses that want to boost their bottom lines and reduce their environmental footprint through continuous energy improvements. Unfortunately, implementing a corporate energy-management program, as described in ISO 50001, can be costly and time-consuming. While applying strategic energy management concepts to an entire facility may seem daunting, you can begin your journey to success on a smaller scale: by managing down the energy costs of your site’s common motor-driven equipment.
Released in 2011, ISO 50001 standardizes the requirements for every element involved in the implementation of an energy-management system. Due to the comprehensive nature of these standards, managers tasked with administering them have been known to feel as if they were assigned to read a thousand-page book in one night. ENERGY STAR’s 43-page Guidelines for Energy Management, however, provides a step-by-step roadmap for continuous improvement based on energy-management best practices. These guidelines (available at energystar.gov) help make energy-management programs more approachable.
Scalability and applicability
Strategic energy management is scalable and applicable to a broad range of facilities, as well as to particular processes or systems like pumps, fans and air compressors. Depending on your industry, such systems may account for a substantial portion of your electric load. For example, Bonneville Power Administration reports that in industrial machinery, compressed air represents 16% of total load. Improved management of this seemingly small element of motor operation can clearly lead to significant energy savings.
Management of entire motor systems has become a primary focus for businesses to achieve energy savings, and motor-system management has much in common with strategic energy management. It is a continuous process that involves: 1) measuring and assessing motor-system energy performance; 2) developing key performance indicators (KPIs); 3) identifying and committing to goals; 4) establishing an action plan; 5) implementing improvements; 6) conducting planned and preventive maintenance; 7) tracking and reporting performance over time; and 8) sharing success stories from your strategic-management experience.
The biggest challenges to implementing strategic energy management at any scale aren’t technical: They are managerial and operational. Overcoming these challenges calls for commitment and support of all industrial personnel—from corporate executives and plant managers to engineers and maintenance staff—to continually track their performance and implement improvements as necessary. Whether looking at an entire facility or a single machine, strategic energy management requires setting performance goals and monitoring achievement of those goals over time.
Large savings opportunities open up when you look at motors as an entire system incorporating a number of various components, as opposed to one stand-alone piece of rotating equipment. Motor Decisions Matter (MDM) is a campaign with many resources to help you boost your bottom line by applying concepts of energy management to your motors. Visit the MDM Website (motorsmatter.org) to browse case studies, tools, news articles and other helpful items to help you conserve electricity and improve your budget by strategically managing your motor systems, one component at a time. MT
The Motor Decisions Matter campaign (MDM) is managed by the Consortium for Energy Efficiency (CEE1.org), a North American nonprofit organization that promotes energy-saving products, equipment and technologies. Contact: email@example.com or 617-589-3949.