Designing for Energy Efficiency (DfEE) crosses the supply chain, from generating energy more efficiently to decreasing energy usage on a large scale to reducing the impact of energy usage on the environment. The techniques required to achieve these efficiencies are becoming more available and easier to use with tools like graphical system design that put the power of DfEE into the hands of engineers.
Everywhere one looks, green has become a primary focus of attention. From prime-time television ads to presidential debates to main selling points for consumer products, reducing environmental impact and energy consumption is rapidly becoming a top priority for consumers, companies, and governments from all regions of the world.
While this focus may seem sudden, numerous reasons explain its rapid acceleration, including global concerns about climate change, the seemingly never-ending escalation of oil and energy prices, and increased government legislation and mandates.
To create differentiated products, adhere to new regulations, decrease environmental impact and energy consumption, not to mention save money, small companies and multinational corporations are scrambling to not only create products and technologies that address these new priorities but also change the processes through which they are developed and manufactured.
Engineers and scientists are leading the charge to address this challenge, and they have the unique opportunity to make a bigger impact on the environment than any government policy. Green engineering provides the tools, techniques, and technologies to foster this needed innovation.
What is green engineering?
Engineers who want to create products requiring less energy to operate, develop new technologies that generate clean power, reduce emissions of fossil fuel-based engines, and better understand the global ecosystem need green engineering. Green engineering uses measurement and control techniques to design, develop, and improve products, technologies, and processes that result in environmental and economic benefits.
While green is the focus today, green engineering is fundamentally no different than any other type of engineering innovation in that designers must first measure and understand real-world data and then correct or fix the problem by designing the next generation of products and technologies that achieve the desired goal.
Today, many of these goals are centered on improved efficiency and reduced environmental impact. Some of the common measurements include power quality and consumption; emissions from vehicles and factories, such as mercury and nitrogen oxides; and environmental data, including carbon, temperature, and water quality.
Tools and technology advancements
In a recent article in The Economist, Linda Fisher, chief sustainability officer at DuPont, emphasized the importance of the first step in the engineering innovation process. "We find with energy and greenhouse gases, if you start to measure, people reduce the usage," Fisher said. "Measuring is not a simple task, but once a company has a proper baseline, it can see what can be changed."
While this latter statement highlights a considerable challenge, there is good news. Significant innovations in measurement, automation, and design tools, the technology components required for green engineering, are more accessible, easier to use, and available at lower prices than ever before.
Key technologies that enable green engineering include:
* High-speed and high-resolution measurements
* Domain-specific analysis libraries
* FPGAs for advanced control
* Graphical programming to measure and implement control
Some of these new technologies have resulted from growth in the semiconductor industry, which has led to major advancements in the capabilities of analog-to-digital converters while also decreasing costs associated with the mass adoption of consumer electronics. Other technologies have been around for some time, but new improvements to design and engineering tools such as graphical programming have made them more usable by domain experts rather than solely technology experts.
This innovation in engineering tools puts the necessary technology directly into the hands of those who are closest to the problems, empowering them to develop systems faster and with more success than in the past.
Application areas
Green engineering applications range from monitoring forest health so ecologists can understand the effects of climate change (see Figure 1) to developing renewable power-generation technologies. While green engineering often conjures up images of solar power and windmills, the application areas it could impact the most today are nontraditional green industries, such as oil and gas, power generation, and heavy manufacturing. These markets can benefit and better compete in the global economy by implementing more efficient, optimized systems and technologies.
The following examples demonstrate green engineering in these two aspects: renewable power generation with wind turbines and machine and process optimization for steel recycling.
Renewable power generation
One of the biggest areas of focus for green engineering is renewable power generation, which covers a diverse range of technologies including wind, solar (photovoltaic and thermal), biofuels, hydro, wave harvesting, geothermal, and even high-energy physics. Engineering innovation in these areas is exploding around the world, driven in large part by ever-increasing government legislation aimed at protecting the environment.
Today, more than 50 countries from all ranges of political, geographical, and economic situations have set aggressive targets for the amount of energy generated from renewable sources (see Table 1).
As society's environmental and energy challenges become more acute, innovative engineers and scientists must step up to measure and fix the world around them.
As aggressive government mandates require up to 60 percent of electricity to come from renewable sources with deadlines as early as 2010, these goals pose a significant engineering challenge. To put this into perspective, only 3 percent of the energy consumed worldwide in 2007 was from renewable sources.
While this task may seem daunting, efforts made during the last two years have shown significant progress toward achieving these goals.
During his keynote address at last yearճ Embedded Systems Conference, former Vice President Al Gore declared who he thought would be able to provide solutions to this global crisis. "The earth has a fever. We all need to take care of it now, and science and engineering must lead the way," he asserted. "Engineers have a vision and put it into a real working system to fix problems they are required to fix." Engineers and scientists have historically risen to meet seemingly far-fetched goals, such as putting man on the moon. What makes todayճ situation even more hopeful is the global scope.
Modern windmills, now called wind turbines, are significantly different from their ancient ancestors that were attached to barns and used to grind grain or pump water. Today, they are the largest source of renewable energy generation (excluding hydro) and are significantly more complex to develop, manufacture, and maintain.
A big challenge for engineers working on wind power technology is integrating wind turbines with the electrical grid. Faults on the grid can produce voltage dips that traditionally caused wind turbines to drop out or trip out of the system. However, it is now considered advantageous for wind turbines to stay online and connected during disturbances, which requires equipment to be tested for low-voltage ride-through capability. To do this, a mobile test system must generate short circuits on-site through circuit breakers at voltages up to 36 KV, requiring significant user safety precautions.
Energy To Quality S.L., based in Madrid, Spain, has been testing wind farms according to European and American grid codes for the past two years with a mobile voltage dip generator (Figure 2) controlled by a National Instruments (NI) PXI data acquisition system. The system measures secondary voltages at 110 VAC while controlling relays connected to tripping coils. This hardware communicates test results to a remote computer via TCP/IP for user safety. With a test time of under a minute, operators know immediately if the wind turbine complies with the requirements, enabling new wind farms to come online more quickly.
Machine and process optimization
Nucor Steel, one of the largest steel companies in the world and Americaճ largest recycler, provides another example of how green engineering is being used to enhance old processes and technologies.
When Nucor Steel acquired the Marion Steel Company in 2005, one of the first projects the company initiated was adding automation systems throughout the newly acquired Marion, Ohio mini mill plant to increase efficiency and safety (Figure 3). The process of melting and recasting steel requires a large amount of electricity, and even small increases in efficiency throughout this process result in huge energy and economic savings.
Dave Brandt, an electrical engineer at Nucor Marion, was charged with the task of implementing the automation systems. Brandt used NI tools, including programmable automation controllers and LabVIEW to develop a variety of automation systems, including a scale and weighing system, an online reactor in series with the furnace, and a remote switching station. These systems have greatly reduced electricity usage, eliminated potential safety issues, and contributed to Nucorճ pioneering commitment to environmental stewardship.
Brandt used LabVIEW and Compact FieldPoint hardware to create a scale and weighing system that determines the exact amount of steel and therefore the exact amount of energy needed to heat its electricity-powered furnace.
Before Nucor implemented this system, the company estimated the amount of steel in each burn, which resulted in hit-or-miss results and oftentimes overheated the steel, wasting electricity and producing unacceptable quality cast steel. As a result, the steel had to be reheated, which used a significant amount of energy and cost Nucor a great deal of money.
Since implementing this weighing system, Nucor has drastically decreased the amount of reheats it performs, reducing the 2007 total number to 10 out of more than 6,000 batches.
Improving the world
As societyճ environmental and energy challenges become more acute, innovative engineers and scientists must step up to measure and fix the world around them.
It is apparent that green applications will be the engineering and technology focus for the next 5-10 years. Advances in green engineering technology will continue to empower engineers and scientists to solve complex environmental issues while encouraging them to improve their products and processes.
About the Author:
Joel Shapiro is the industrial measurements and control group manager at National Instruments (NI), based in Austin, Texas. Joel is the strategic lead for NIճ green engineering initiative focusing on external and internal marketing efforts, fostering industry partnerships, and product strategy development. During his six years at NI, Joel also has served as an Applications Engineer (AE), AE team manager, and industrial communications product manager. Joel holds a bachelorճ degree in Computer Science from the University of Tennessee.
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