SME Speaks: When is Green Manufacturing Green?
The term "green manufacturing" has different meanings to different people, usually based on their discipline and training. You can get needlessly sidetracked by definitional disputes. Becoming green should be considered to be a journey, not a destination or static state. Green manufacturing is a key component of operating a sustainable business that helps you uncover hidden value for your business, while creating value for the environment, the stakeholders, and the greater community both now and in the future. There is very serious interest in green manufacturing within the manufacturing community. We are currently seeing a major shift in philosophy, acceptance, and emphasis.
Becoming green can be viewed as a process where you start using more eco-friendly feed stocks that have low embedded energy and come from renewable resources. You will use these materials to produce products that meet sustainable product standards promulgated by standards-setting bodies like ANSI and ISO. We refer to this as the green-transformation process. Methods for measuring embedded energy and other green properties of the goods provided by your suppliers are available or being formulated at this time. Product standards, such as the ANSI NSF 410 sustainable carpet standard, are also either available or in process.
Next, you need to operate an ecoefficient manufacturing process. You need to pay attention to the direct and indirect use of all resources (i.e., energy, water, and materials), and the loss of these resources from each activity in your product and service processes. The indirect use and loss of resources comes from all of your supporting processes (e.g., air compressors, air and water-pollution control equipment, boilers, chillers, etc.). It's important for you to measure and monitor your resource productivity. Many manufacturing firms use a variety of management system standards and business excellence frameworks to effectively manage their processes for eco-efficiency.
You cannot ignore the manufacturing environment as a source of green opportunities. This includes the building, lighting, HVAC, logistics, visual factory, cleaning, information technology, and nonproduction facilities (e.g., offices, cafeteria, lavatories, grounds keeping, etc.). There are a lot of quick wins available in this category.
An interest in green manufacturing does not automatically translate into a commitment to make the necessary changes at your facility. The process of becoming green is really a matter of money. The only reason why a manufacturing plant would resist the move to a green or a more sustainable business is because of the costs that are associated with the "leaning" of the transformation process, the manufacturing processes, and the associated supporting and manufacturing environment processes.
So what are the real costs of going green? Many manufacturing plants view this as a choice between being more environmentally responsible and allowing employees to keep their jobs. This view of green is slowly being converted to realizing business opportunities that gain positive feedback from environmentally conscious customers, and the increase in sales because of it. Reducing energy and water use are the most common and simplest places to start when it comes to turning your plant green. Eliminating all wastes from all business practices is an important mid-term goal. In the longer term, you can develop green technology and products that take your manufacturing business to a higher level of green. Remember that this is a journey. Environmental responsibility in the manufacturing sector not only includes contributing to the creation of your own company, but also in being able to manufacture those supplies that will facilitate the ability of other sectors in becoming green. Everything is connected to everything else.
Having a successful journey to business sustainability requires you to align the green manufacturing program with your company's vision, mission statement, and guiding principles. Only by fully integrating the effort with the core business will it have the management support necessary for enabling your company to complete that journey. You need to have the employees involved in the planning as well as the implementation of your programs. Employees are a key source of knowledge for your green transformation. It is important to have mutually beneficial relationships with your suppliers, your customers, and your key stakeholders. As mentioned above, you must maintain a process focus and a systems approach to management. Finally, you must use lean, six sigma, and other process-improvement approaches to maintain continual improvement throughout your journey.
Green manufacturing becomes green when you integrate a number of proven methods competently to meet customer and market needs with eco-efficient processes and their corresponding benefits to the environment, key stakeholders, and the community at large. The real green comes from the value to your top line (branding) and your bottom line as you contribute positively to the local economy. This may be the best argument to use with your executives as you seek their support for your green manufacturing initiatives.
Innovations That Could Change the Way You Manufacture
Ultracapacitors: Have Batteries Met Their Match?
Adam W. Stienecker, PhD
Ohio Northern University
For years the manufacturing sector has relied on portable energy in the form of the battery and the internal combustion engine to supply energy to the vast array of different vehicles within a plant. These vehicles range from AGVs to worker-operated forklifts, with capabilities ranging from simple transport of parts to complex network-operated systems. This equipment has served industry well, but has some major power-system drawbacks. Today's vehicles are likely to be powered by a lead-acid battery. These battery packs suffer from an array of disabling problems that require complex charging systems and large amounts of precious plantfloor real estate, not to mention an overwhelming supply of spare batteries. A more recent development in the technology of power storage has created a buzz among researchers. While the advances throughout the years in battery science have been numerous, this advance is causing many engineers to think twice about specifying a battery in their system.
This new phenomenon is not really new at all. More than 260 years ago the invention of the capacitor opened up the opportunity for scientists to store a small charge of electricity. Almost 40 years later, the battery was invented and was able to store much more energy per unit weight and volume than the capacitor. At this time the capacitor was thrown aside as a form of meaningful energy storage. However, in the mid-1960s, the capacitor was reexamined for its energy-storage capabilities, and the ultracapacitor (UC) was born. A capacitor is made up of two plates that serve as electrodes and are a specific distance apart. The capacitance, or the amount of energy storage capacity, is then dependant on the surface area of the electrodes and the distance between them. The UC takes these to the absolute maximum to exploit the dependency. This exploitation results in very high capacitance and much more reasonable energy-storage capacities. The energy storage capability of the UC is still below that of the lead-acid battery, however, the power density (or ability to deliver power per unit volume) is much larger than a battery can provide. In other words, for similar weight and volume, the battery can store more energy, but the UC can deliver it faster with lower losses. Since the 1960s, the UC industry has made many advances in both the capacities of the UC and its manufacturability. Recent advances have reduced the price to the end user to the point where we can consider using them for more than a public relations stunt.
The Problem with the Battery
The traditional lead-acid battery has many disadvantages for use in industrial vehicles. To many, the problems are obvious: charging time, complex charging systems, spare batteries, real estate, power delivery, and life expectancy. To operate the lead-acid battery successfully, you must charge it for a rather long time. To charge the battery, you must have a large and complicated charger for each vehicle, and possibly store and maintain a spare battery for each battery in operation. These chargers and spare batteries are not small, and are regularly housed in an entire section of the plant that could be better used for other systems. And then there's the costs associated with the extra staff required to maintain the spare batteries and the chargers.
Another nonvisible problem with the lead-acid battery is that it is not really suited for the task. Many manufacturers of the lead-acid battery claim to have deep-cycle batteries specially suited for this type of application that are much better at deep discharges, but not optimal for regular use. The major problem in a lead-acid battery is the issue of sulfation. Sulfation, a degradation of the electrode, occurs when a lead-acid battery is left slightly or fully discharged for long periods of time. Sulfation also occurs when deepcycling the battery, which is the state of operation encountered in a forklift truck. The deep-cycle, lead-acid battery attempts to solve the sulfation problem by increasing the size of the electrode at the sacrifice of power density. Unfortunately, in manufacturing both energy and power density are often needed.
Furthermore, something that many people do not consider is the life of the battery after we have used it. In the past few years, lead-acid recycling programs have increased in number, but there are still many environmental concerns associated with both improperly disposed batteries and the recycling process.
Battery technology has also advanced beyond the lead-acid battery and into the nickel-metal hydride (NiMH) battery and the lithium-ion (Li-Ion) battery. These technologies are leaps and bounds above the lead-acid technology, but are much more expensive, and have some unique drawbacks.
What does all this mean for manufacturing? There are a series of advantages and disadvantages to using the UC instead of the lead-acid battery.
- Energy and Power Density. The specific energy (ratio of energy storage to weight) of the leadacid battery will be around 20–30 W-hr/kg, whereas the specific energy of the UC will be around 4–6 W-hr/kg. The specific power, however, will be around 150–400 W/kg for the lead-acid battery and as much as 5000 W/kg for the UC. This is advantageous if the battery is not completely depleted under normal operation before charging. If the battery is routinely taken down to a 30% state of charge before charging, however, then the UC would only benefit if the charging routines currently used can be altered. Otherwise, the UC would be so large that it would encumber the vehicle.
- Charging Equipment and Time. To charge a lead-acid battery requires a somewhat complicated system, because the voltage at the terminals is not linearly related to the state of charge. In other words, many batteries require a charging algorithm such as 50 amps for 2 hr, then 10 amps for 1 hr, then 2 amps for 5 hr to optimize the charge on the battery. The UC, however, has an opencircuit voltage that is linearly dependant on the state of charge, and requires a very simple charging algorithm to reliably charge. The charger is simply current-limited, and peaks at the rated voltage of the UC. Due to rather low internal impedance, this current limit can be much higher than in a battery, on the order of 1000 amps. This yields charge times on the order of a minute. To achieve these charging times, however, may require specialized and more expensive equipment. A more reasonable charging time might be 5–10 min. This, of course, all depends on the size of the UC, and the abilities of the charging equipment and the available electrical supply. Due to the fast charging times achieved by the UC, it would no longer be necessary to possess a multitude of chargers. Rather, a charging schedule would be set up to periodically charge the UCs on the floor with a minimum number of chargers.
- Charge Frequency. Because the charge time is greatly reduced, it may be feasible to reduce the overall size and cost of the required UC by charging more frequently. If one or two charging stations are set up along a common loop, then the vehicles could be charged every hour or so rather than overnight. Or they could be charged during a 15-min break and during shift changes.
- Spare Batteries. Because the UC can charge so rapidly, and because of the reliability of the units, the number of spare UCs required to be kept on hand would be minimal.
- Lifetime. The UC is currently rated to last 1,000,000 charge/discharge cycles. This rating is given at a knee in the performance graph. The units will continue to perform well beyond these numbers, but the charging times may increase as the age advances beyond the specified lifetime. This equates to more than 100 years of life at extreme use.
- Extra Equipment. Because the open-circuit voltage of the UC varies linearly with the state of charge, a DC/DC converter would be needed inside the vehicle. The size and cost of this component will vary with the size and power requirements of the vehicle. The converter may already be used within the vehicle, depending on the motor drive system.
- Cost. As the saying goes, you get what you pay for. The UC is no exception. Because the UC is not yet mainstream, the costs associated with it will be higher than you will face when using lead-acid battery packs. However, because the number of required packs and charging stations are cut, and because less maintenance is needed, the savings may outweigh the extra costs.
Given the above advantages and disadvantages, it should be clear that there is an opportunity to increase the overall productivity and availability of equipment, as well as to decrease real estate consumed by the vehicle overhead required to keep the fleet running. But the above has never been attempted, to this author's knowledge, and development would have to take place to make these opportunities real. The following would likely have to occur to produce a reliable and functioning system:
- Research the overall plant operation to alter the charging methods from overnight or long-time interval charging to more frequent, shorter-time charging, ideally reducing overall charge time and increasing equipment availability.
- Research and develop highpower UC chargers. This technology already exists, but the bells and whistles normally associated with it are not needed, and removing them would be very cost effective.
- Reengineering the vehicles involved in the upgrade to house the UC, possibly working hand-in-hand with the vehicle manufacturer to develop new vehicles.
- Research the cost-balancing and tradeoffs between the reduced amount of equipment and the added costs associated with the UC.
Three years ago, the Society strategically identified four industry focus areas: Aerospace and Defense, Transportation (Motorsports), Oil and Gas, and Medical Device Manufacturing. SME's ultimate goal was to serve as a technical resource to these industries through our members.
SME Members Support Top Race Teams
The member-led Motorsports advisory committee started introducing themselves to major racing organizations. This effort involved SME with the National Hot Rod Association (NHRA), NASCAR, and the Indy Racing League, LLC (IRL). SME then started to leverage its resources to attract attention from the top teams, including Kalitta Motorsports, Ypsilanti, MI, which participates in the NHRA.
In 2006, SME collaborated with Kalitta Motorsports to host an open house at SME Headquarters, where Top Fuel personality and team member Hillary Will signed autographs alongside her LLC Top Fuel dragster. After examining the dragster, it was apparent how the diverse technologies represented within the Society's own membership were used in the construction of the 8000-hp (5976-kW) vehicle. From the carbon-fiber seat, rear wing, and driver controls to the precision welds holding the chromolly tube frame together, this vehicle represented the many facets of manufacturing and the technologies touched by our members every day.
In 2007, two tragic accidents occurred at NHRA racing events—Eric Medlen died in a crash in March, and 14-time NHRA champion John Force was nearly killed in October. After these two accidents, SME was asked to connect its technology experts (SME members) to the racing experts. This collaboration ultimately led to industry design changes by top chassis builder and SME member Murf McKinney of McKinney Corp., Lafayette, IN. Eleven SME members, all of whom possess impressive credentials in the field of engineering, participated in numerous conference calls and provided valuable technical assistance to the SFI Funny Car Chassis Spec project. According to Arnie Kuhns, president and chief executive officer of the SFI Foundation, which oversaw the project, development of the Funny Car spec was aided by the resources available for the project and the open lines of communication that were maintained between all parties.
Unfortunately, another recent tragedy would bring about another call to action, and SME would again offer our members' knowledge to the racing community. On June 21, 2008, Scott Kalitta, 46, died after a crash during qualifying at the NHRA SuperNationals in Englishtown, NJ. Kalitta earned most of his racing wins in Top Fuel, where he claimed back-to-back world championship titles in 1994 and 1995. He started his pro career in Top Fuel in 1982, running limited events for four seasons before moving to Funny Car in 1986. Kalitta returned full-time in 2006. He posted a runner-up finish on June 8 in Chicago, his 36th career NHRA final-round appearance.
A new chassis, designed for safety, became mandatory for all Funny Car teams in July with the Mopar Mile-High NHRA Nationals in Denver (Chicago Tribune 2008). Drivers are hoping that Kalitta's death will lead to even safer dragsters.
In light of the Scott Kalitta tragedy, we want to ensure that we are doing everything possible to advance motorsports technology and manufacturing. If you are an SME member wanting to participate, or a nonmember who has a technology or talent in forming and fabricating, machining and material removal, or rapid prototyping, we want and need your support. Please send any inquires to firstname.lastname@example.org.
Cost-Effective Ways to Attend IMTS
SME Chapter 1's Trade Show Bus Trip
Members of SME Chapter 1 will leave SME Headquarters in Dearborn, MI, on Thursday, September 11, 2008, at 7 am to attend IMTS 2008 in Chicago. The cost of the trip is $95 for senior members and $50 for student members (IMTS 2008 show admission is included in the cost). The reservation deadline is Friday, August 15, 2008. Who should consider going?
Decision-makers for smaller companies on a limited budget, an engineer considering a job change, or even a student who might never have an opportunity to view a trade show of this magnitude. If you are interested in joining SME Chapter 1 on this trip, please contact Paul Hampton, SME Chapter 1 chair, by telephone at (586) 754-8220.
Milwaukee Chapter 4's IMTS Bus Tour
Join SME Chapter 4 on Thursday, September 11, 2008, for a full day at IMTS 2008. The cost of the trip for SME members is FREE; nonmembers are required to pay $20. Bus tour does not include admission fee to IMTS. The bus will leave the Brown Deer P&R lot at 7 am and the College Ave Southwest P&R lot at 7:30 am. The bus will return to Milwaukee at 4:30 pm. As part of the tour, donuts and coffee will be available in the morning; beverages and snacks will be provided on the return ride. The reservation deadline is Monday, September 8, 2008. No phone reservations will be accepted. Visit http://chapters.sme.org/c004/ to save your spot.
Do you have a SME Chapter event or news item that you would like publicized? All SME Chapter events and news items are posted on the Chapter landing page, www.sme.org/chapters. This is a great way to let everyone know what your chapter is up to, as well as to get more attendance at local events. To have your news item or upcoming event posted, please email email@example.com.
Exemplary Students are Engineering's Future
The SME Education Foundation recently announced the winners of its annual Directors and Family Student Scholarships. The top award, the SME Education Foundation Family Scholarship, will provide a scholarship for four years to Kyle Riegel of Newton, IA, to help fund his undergraduate degree in engineering. Christopher Bird, a senior at Robert Morris University in Pennsylvania, and Benjamin Ferron, a sophomore at the University of Wisconsin-Stout, each received the SME Directors Scholarship, a one-year award that will help fund the completion of their degrees. The winners were honored at the SME Annual Meeting and International Awards Gala, held at the Detroit Marriott Renaissance on June 2.
"The SME Education Foundation is pleased to be able to support these outstanding students," said Glen Pearson, president of the Foundation. "Our donors recognize the importance to inspire, support and prepare a new generation of engineers and technologists who will keep our manufacturing capabilities strong and vital. We believe that the contributions they will make to engineering will ensure a vibrant, healthy future for our industry and create the workforce development needed for it to thrive."
This article was first published in the August 2008 edition of Manufacturing Engineering magazine.