Everywhere you look, green has become a primary focus of attention.
What is green engineering?
Engineers, who want to create products that require less energy to operate, develop new technologies that generate clean power, reduce emissions of fossil fuel-based engines, or better understand the global ecosystem need green engineering. Green engineering is the use of measurement and control techniques to design, develop, and improve products, technologies, and processes, resulting in environmental and economic benefits. While green may be the focus today, green engineering is fundamentally no different than any other type of engineering innovation. First, you need to measure and understand real-world data and, second, correct or fix the problem by designing and developing the next generation of products and technologies that achieve your desired goal. Today, many of these goals are centred on improved efficiency and reduced environmental impact, and 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.
Green engineering tools and technology
In a recent article in the Economist, Linda Fisher, the chief sustainability officer at DuPont, pointed out 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 goes on to say that “Measuring is not a simple task, but once a company has a proper baseline it can see what can be changed.” While this latter quote points out a significant challenge, there is good news. There has been significant innovation in measurement, automation, and design tools; thus, the technology components required for green engineering are not only accessible but also easier to use and available at a lower price than ever before. Some of the key technologies that enable green engineering include the following:
* High-speed and high-resolution measurements.
* Domain-specific analysis libraries.
* Field-programmable gate arrays (FPGAs) for advanced control.
* Graphical programming to measure and fix.
Green engineering applications
Green engineering applications cross almost every industry and range from monitoring the health of forests, so ecologists can better understand the effects of climate change, to developing new renewable power-generation technologies. While green engineering often conjures up images of engineers working on solar power and windmills, and, indeed, it is heavily used in developing those technologies, perhaps some of the areas it can impact the most today are in non-traditional green industries, such as oil and gas, power generation, and heavy manufacturing. These areas can also benefit and better compete in a global economy by implementing more efficient, optimised systems and technologies. The following examples demonstrate green engineering in renewable power generation with wind turbines and in machine and process optimisation for steel recycling.
Renewable power generation
One of the biggest areas of focus for green engineering is in the field of renewable power generation, which covers diverse technologies including wind, solar (photovoltaic and thermal), bio-fuels, hydro, wave harvesting, geothermal, and even high-energy physics. The engineering focus on innovation in these areas is exploding around the world, driven in large part by environmental suitability goals and ever-increasing government legislation. 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).
With aggressive government mandates requiring up to 60% of electricity to come from renewable sources, and deadlines as close as 2010, there is no doubt that these goals pose a significant engineering challenge. To put this into perspective, only 3% of the energy consumed worldwide in 2007 was from renewable sources. While this may seem daunting with much work to be done, there are significant reasons to believe we can achieve it, and even the last two years have shown significant progress toward these goals.
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, as you can imagine, are significantly more complex to develop, manufacture, and maintain. One of the biggest challenges 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, but to do so, the equipment must be tested for low-voltage ride-through capability. To validate this functionality, a mobile test system generates short circuits on-site through circuit breakers at voltages up to 36 kV, requiring significant user safety precautions.
Machine and process optimisation
Nucor Steel, one of the largest steel companies in the world and America’s largest recycler, is an example of how green engineering is being used to greatly improve old processes and technologies. It has delivered significant improvements in environmental impact and energy conservation. When Nucor Steel acquired the Marion Steel Company in 2005, one of its first actions was to add automation systems throughout the newly acquired Marion, Ohio, mini-mill plant to increase efficiency and safety. 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 Steel, was charged with the task of implementing the automation systems. Brandt used National Instrument tools, including programmable automation controllers (PACs) and NI LabVIEW software, 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, which have greatly reduced electricity usage, eliminated potential safety issues, and contributed to Nucor’s pioneering commitment to environmental stewardship.
Brandt used LabVIEW and NI Compact FieldPoint hardware to create a scale and weighing system to determine the exact amount of steel and, therefore, the exact amount of energy needed to heat Nucor Steel Marion’s electricity-powered furnace. Before it 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 in the process and producing unacceptable-quality newly cast steel. As a result, the steel had to be reheated, which used a significant amount of energy and cost Nucor Steel a lot of money. Since implementing this weighing system, the company has drastically decreased the amount of reheats it performs, reducing the 2007 total number to 10 out of more than 6000 batches.
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