Maybe Ben Franklin realized it in June 1752, as he (legendarily) dangled from the spire of Christ Church in Philadelphia to launch a kite into a thunderstorm: the small piece of metal he’d attached to it was both literally and figuratively a key – one that held the power to unlock a modern, technological way of life.
Power is so essential to daily existence that, paradoxically, people often don’t think much about the commonplace wonder of flipping a switch that actuates an enormous, intertwined, and complex set of systems—production, transmission, distribution, and control—and brings to life all manner of technology.
Whatever its original energy source, electricity boots our devices, lights our screens, computes our data, moves our money, heats and cools our homes, illuminates our buildings and streets, refrigerates our food, cleans our dishes and clothes … it gets to be an exhaustive list, as does the inventory of expertise needed to support it.
“Electrical networks by their nature are interdisciplinary,” says Larry Snyder, associate professor of industrial and systems engineering. “They involve electrical engineering, industrial engineering, computer modeling, optimization and control, communications and networking security, and economics, to name a few.”
According to Snyder, who plays a key role in Lehigh’s Integrated Networks for Electricity (INE) research cluster, the key is to integrate and capitalize on innovation from across these interconnected disciplines in order to ultimately solve the complex challenges of modernizing global power infrastructures.
The INE is a collaborative, multi-faceted team of Lehigh researchers focused upon the interdependent flow of electricity, information, and money needed to operate what’s popularly known as the ‘smart grid’—a term that represents broad efforts across industry, academia, and government to incorporate and leverage modern technologies across power infrastructures. It’s an evolving, complex approach to modernizing electricity provision, and would entail overlaying the existing power grid itself with an Internet-like information network that ultimately allows the system to be more responsive, efficient, reliable, and conducive to alternative energy sources.
Lehigh researchers are also expanding horizons of what’s possible in energy generation by developing or refining technologies and understanding fundamental scientific phenomena that promise to help unleash new energy resources. These include power from ocean waves, nuclear fusion, geothermal reserves, and techniques to enhance the sustainability of traditional energy sources.
The overarching goal: to meet global energy demand while protecting the environment for future generations. “In a research area where teams tend to be dominated by traditional fields and perspectives, few academic research centers can do what Lehigh does,” says Rick Blum, the Robert W. Wieseman Professor of electrical and computer engineering and director of the INE. “We excel at developing interdisciplinary teams that incorporate and leverage expertise in areas like systems engineering, electrical and computing fields, data analytics, and economics—and solving real problems.”
With support and collaboration from stakeholders in industry and government, Lehigh investigation into the future of power generation and distribution are making progress in a number of key initiatives.
Making the Smart Grid Greener
A key to future energy networks will be integrating renewable energy resources. The challenges of doing so are rooted in limits on storing electricity. Energy generally must be produced in amounts that balance with demand, and forecasting how much energy will be available at any given time becomes important for keeping the system stable. But that’s difficult in a system that incorporates significant amounts of solar or wind energy, which can vary unpredictably when clouds roll in or the breeze dies.
Other complexities arise from a growing profusion of relatively small, decentralized energy sources. Readily controlled power generation from, say, coal-fired power plants must now integrate with everything from spinning turbines on wind farms to individual homeowners with excess power to offer from rooftop solar arrays.
“You’ve got power flowing in multiple directions, more parties, smaller players, different kinds of users, third parties buying and selling power, complexities in demand response—there are just many more pieces to the system,” Snyder says. “They’re all good, but they introduce new risks and opportunities for things to go wrong.”
INE research projects address many of these challenges through analyzing, quantifying, and modeling data associated with the flow of power and information, along with their economic effects.
“When renewables under-produce, the system needs to turn on relatively dirty fossil-fuel generators,” Blum says. “There are costs associated with that. In other words, what’s often thought of as ‘free’ renewable energy actually isn’t, especially in the face of uncertainty."
Researchers including INE faculty member Alberto Lamadrid, assistant professor of economics with Lehigh’s College of Business and Economics, work to quantify costs associated with energy variation and consistency, along with a wide range of other factors. These include problems associated with economic dispatch—determining how electricity-generating facilities can produce optimal output to meet system loads at the lowest possible cost, given operational and transmission constraints.
Wenxin Liu, P.C. Rossin assistant professor of electrical and computer engineering, studies control and optimization of microgrids and power electronic systems. His advanced experimental platform, developed with meaningful contributions from his post-docs and students, facilitates hardware experimentation to test a wide range of algorithms for microgrids, smart grid, and the so-called “energy Internet.”
“We’re helping to prove the viability algorithms and models for energy management systems and demand response,” says Wenxin. “Our high-fidelity testing will help new techniques be ‘ready for prime time’ as the smart grid ecosystem develops.”
Running a grid with many levels of complexity requires vast amounts of information, and related Lehigh investigations are studying data science methods such as how data from sensors and measurement units can optimally be collected and processed.
“We’re not only advancing knowledge,” Blum says, “we’re making contributions that can be used in real systems.”
Harvesting Waves
The problematic, unpredictable nature of renewables begs a question: What if you could find an abundant natural energy source that was more consistent than wind and sunshine? If you live in a coastal area—as the majority of the U.S. population does—you don’t have far to look for a prospect: the ocean.
Studies find that statistical wave parameters can be predicted as far as two days into the future, according to Shalinee Kishore, professor of electrical and computer engineering. That means wave energy could factor into daily supply-and-demand planning, which would open electricity markets to renewable producers because they’d be better able to guarantee delivery of power.
Kishore is principal investigator for a nearly $1 million grant from the National Science Foundation (NSF) that was provided to Lehigh’s PORT (Power from Oceans, Rivers, and Tides) Lab. It’s part of a Department of Energy (DOE) initiative to expand the nation’s renewable portfolio to include marine hydrokinetic (MHK) energy.
“We have the capacity to generate one-third of the country’s electricity just based on MHK resources,” says project co-investigator Arindam Banerjee, associate professor of mechanical engineering and mechanics, who specializes in fluid dynamics.
Harvesting that energy depends on developing wave energy converters (WECs) that would be arrayed just below the surface in clusters or farms near shore. Such farms promise to have higher capacity factor than wind farms in which windmill blades often aren’t turning. “If you ask what percentage of its useful life a device generates at rated capacity, with wind it might be as high as 40 percent,” Banerjee says. “Waves are flowing all the time, so MHK is significantly higher—in the 70 or even 90 percent range.”
But while tidal energy technology is relatively mature, WEC technology is in its infancy, and Lehigh researchers are creating ripples of innovation on problems such as optimal buoy placement in wave farms. “By better understanding WEC hydrodynamics, we can see how wave states affect the devices, how WECs interact with each other, and how to lay them out to increase the amount of power they can generate,” Banerjee says.
The more that’s known about how WECs perform and behave, the easier it will be for wave-energy technologies to attract investors. “Right now, wave energy resources provide zero watts of power to the grid,” Banerjee says. “We’re trying to speed the process of bringing technology from bench to site by understanding the fundamental physics.”
Focusing on Fusion
Obtaining controlled energy production from nuclear fusion has intrigued and eluded scientists for more than 60 years. Fusion could produce vast amounts of energy using readily available fuels such as water-derived hydrogen isotopes and lithium.
“Compared to fission, which is currently used to generate nuclear power, fusion offers a number of advantages,” says Eugenio Schuster, director of Lehigh’s Plasma Control Laboratory and professor of mechanical engineering and mechanics. “Fuel is abundant, there’s little risk for nuclear accidents, and power generation doesn’t produce long-term radioactive waste or materials that can be dangerous on any number of levels.”
Yet fusing these atoms requires temperatures of around 100 million degrees Kelvin. At much lower temperatures than this, the fuel gas ionizes and becomes a plasma. This incredibly hot plasma must be contained and controlled for a reactor to work. Because plasma is ionized, it’s readily affected by electromagnetic forces, which are used to confine the ionized gas in sophisticated experimental devices called tokamaks.
“It’s like creating an invisible bottle that prevents the plasma from touching the inner wall of a reactor,” Schuster says. “But under the intense heat and pressure required to fuse normally repellent ions together, plasma becomes unstable, making a sustained reaction difficult. It’s a very complicated problem, and controlling plasma variables in a tokamak is the main focus of our work.”
A small number of tokamaks exist around the world, and thus research into plasma control often takes on international dimensions involving collaborations between nations. A major new facility called ITER—the world’s largest tokamak—is now being constructed in France in a cooperative effort involving 35 countries. It’s designed to be the first fusion device to sustain reactions, produce more power than it consumes, test integrated technologies, and prove fusion’s feasibility as a large-scale, carbon-free energy source.
Schuster led a Lehigh team directly involved in the design of ITER’s plasma control system, and continues to work toward solving many related issues. The work has included the control of plasma variables such as temperature, pressure, and current in time and in space, using complex, partial differential equations and models while avoiding and mitigating magnetohydrodynamic instabilities.
“ITER represents a critical moment in fusion worldwide,” Schuster says. “If it succeeds, nuclear fusion will proceed. If not, we’ll need to find new, creative ways to get there. Either way, I’m very proud of what we’re achieving at Lehigh.”
Legacy sources, new perspectives
While some researchers investigate future technologies, others work to advance innovation and efficiency in mature ones. Consider the usual way that traditional thermal power plants, fired by fuels like natural gas or coal, condense steam that propels turbines—by using water-based condensers and cooling towers. The process requires huge amounts of water, accounting for some 40 percent of U.S. freshwater use. In dry areas such as the West where freshwater supplies are dwindling, air-cooled condensers (ACCs) are an appealing alternative. Yet they account for only 1 percent of condensers in U.S. thermal plants. One reason: “As midday air temperatures rise, you lose a lot of cooling efficiency,” says Carlos Romero, director and principal research scientist at Lehigh’s Energy Research Center (ERC).
With funding from the DOE, a team composed of Advanced Cooling Technologies, the University of Missouri, Evapco and Lehigh University is working to improve ACC efficiency by using phase-change materials that absorb thermal energy and later release it as the material shifts from solid to liquid form.
“We’ve tried a variety of inorganic salts, including calcium chloride hexahydrate, magnesium chloride, and potassium nitrate, and are narrowing them down as we design and build cycling machines that will take us to a prototype,” Romero says. “We expect to scale up a design and test it in a power plant in the future.”
Using innovative ideas for a familiar process is also at the heart of an ERC collaboration with academic and government bodies in Mexico. The three-year project is studying and testing ways to use carbon dioxide emitted from fossil fuel power plants, in a supercritical state (sCO2), to extract geothermal energy from underground dry hot rock and hydrothermal geothermal reservoirs. Geothermal extraction generally relies on water or brine to capture heat.
“But sCO2 is a better fluid that can double the ability of water or brine to pick up heat, especially at lower temperatures,” he says. “Recycling CO2 in geothermal reservoirs also provides the added benefit of sequestering greenhouse gas emissions under the ground.”
Further efficiencies can be found in handling fuels themselves. Coal-burning plants, for example, burn coal of varying quality from various mines. Analyzing quality so that coal can be burned more efficiently relies on nuclear instrumentation that make use of potentially dangerous radioactive materials.
“We’re working on a commercial instrument that uses a laser beam, instead of radioactive materials, to excite a sample on a coal conveyer and analyze it,” Romero says. “This laser-induced breakdown spectroscopy (LIBS) system is being tested at a power plant near Pittsburgh—it is easy to install, has a smaller footprint and is lighter than nuclear instruments, and doesn’t require cumbersome radioactivity safety measures. It provides an accurate entire analysis of the coal—elemental composition, heating value, sulfur, ash content, fusion temperature of the ash—it’s all valuable knowledge for managing the coal supply.”
“The energy field is at an inflection point driven by the economies of fuels, environmental constraints and rapid scientific advancement,” he continues. “Through efficiency improvement, innovation, and new technology development, we’re helping the power industry meet the challenges of this century.”
Guarding the grid from cyberthreat
When you put all the elements together, however, the grid faces still more challenges beyond those of generating, transmitting, controlling, and analyzing power. In an era marred by terrorism and between-nation cyberattacks, there’s also a need for security and attack resilience.
That’s why the DOE has invested in a $12.2 million grant to support a five-university Center for Cybersecurity for Energy Delivery grant. The center, a partnership among Lehigh, University of Arkansas, Carnegie Mellon University, and Florida International University, along with industry partner Arkansas Electric Cooperative Corp, will develop and test new technologies to help modernize the U.S. electrical power grid.
$3.5 million of that funding will support Lehigh researchers as they develop technologies that will protect the grid from cybercriminals and similar threats. Lehigh’s work focuses on five distinct areas that nine faculty members—the largest concentration of investigators in the project—approach from a variety of perspectives. These include detecting attacks, mitigating attacks that can’t be identified, managing security systems, and testing and validation—including the discovery of false data.
Suppose, says Snyder, that a demand-response system with time-dependent rates was susceptible to injections of false information about usage or pricing.
“Bad guys could misuse demand-response signals and controls to steal energy or money, or simply to cause damage to the system or its users,” he says. “Malicious data indicating swings in demand could imbalance the relationship between energy supply and consumption. It could cause significant problems like big oscillations or even blackouts.”
Lehigh researchers are developing algorithms and optimization tools that, for example, could detect, measure, and compare redundant signals at multiple locations in the grid. If two signals that should be the same are different, one could be a lie. Such problems will be critical to the energy future whether the grid uses legacy resources, renewables, or fusion—all of which significantly overlap in Lehigh’s multidisciplinary research model.
“The INE research cluster has done really well in the five years it’s been in existence,” Blum says. “But research into the energy infrastructure is broad work, here on our campus and elsewhere, and progress will require a lot of interconnection. With a strong interdisciplinary work ethic already in place, Lehigh is well positioned to help lead the way.”
Story by Richard Laliberte
