Greening the Grid
The power grids that light and power our homes and business are evolving to become more reliable and equitable. Stevens researchers are helping engineer that future.
The nation's aging power infrastructure needs upgrading. Events like the February 2021 power grid failure that blacked out Texas for 3 long days, killed hundreds and nearly took the state down for months demonstrate the need to modernize in order to ensure life-threatening outages don't happen.
At the same time, the ways we light and power our homes and businesses are also changing. Powered by the urgency of climate change, emerging renewable energy technologies and infrastructure designed to take advantage of wind, solar, hydroelectric and other sustainable power sources are rapidly coming online — including at Stevens.
What will the power grid of the future look like? How will cities, towns, neighborhoods, homes, apartment complexes and businesses connect to the greener grid of the near-future?
Stevens is helping figure it out.
"We're interested in reimagining what the energy grid will look like," says graduate student Danielle Preziuso, who chose Stevens' Department of Systems and Enterprises for its expertise in intelligent energy technologies. "To ensure that it works flexibly, fairly and equitably."
"This," agrees systems professor Philip Odonkor, who advises Preziuso and also conducts his own power-grid research, "is the future."
Plugging into the neighborhood
In the United States, electricity is typically created at a few points, by large facilities, at bulk scale. Series of step-down transmission systems and substations then move the energy to cities, towns and homes for local distribution and consumption.
But this aging and incredibly complex electrical network can develop problems.
"As you go from generation to delivery, there are congestion points both at the transmission and distribution level," notes Odonkor, an energy systems expert. "These points of failure can cause problems when there is a disruption, such as an extreme weather event that causes a sudden shock in supply or demand."
The resiliency of these vulnerable grid nodes and linkages will become critical to consider as the U.S. begins reimagining both the national and regional grids to accommodate new types of renewable resources, he adds.
"Some of the most promising renewable-energy resources — such as wind power facilities — won't necessarily be located close to where most of the people are," he says. "Storage capabilities will need to be built, loads will need to be re-forecasted, consumption patterns will need to be simulated and modeled, and infrastructure will need to be retrofitted or built from scratch."
One way in which the nation's power grid will soon begin evolving to accommodate renewables and adapt to the new normal, Odonkor predicts, is through the development of "microgrids" deployed in communities or regions to supply local power generation. These could also more efficiently manage the continual changes in local and regional energy demand that cause blackouts and brownouts.
"You are seeing power generation become more distributed and located closer to where people are consuming," he points out. "Local communities are beginning to seriously discuss issues like renewable sourcing and localized grids, rather than simply hooking up to a distant transmission line which they basically have no control of or input to."
A key question local planners, communities and agencies will need to solve: where exactly will cities, towns and energy utilities place all the newly created generators, transmission lines and power storage facilities — and what sorts of technology will need to be designed, developed, tested and installed in order to connect, monitor and network them intelligently?
Odonkor is working on it.
With energy technology entrepreneur Matthew Cristaldi, he recently created a new algorithmic startup known as Grid Discovery. The team's AI-powered system inputs local data on population, climate, building stock, energy demand and other variables, then does the number-crunching to narrow down the optimal city, suburban and rural locations for creating and situating energy nodes and smaller local grids.
The proposed technology recently placed third in Princeton University's EmPower pitch competition, earning the partners a $10,000 prize.
"Intelligently locating significant numbers of regional, community-sized or neighborhood-sized sustainable energy resources," says Odonkor. "That's the goal, and Stevens can be part of it."
Diving into 'energy equity'
As a mathematics undergraduate student at Bryn Mawr College in Pennsylvania, Preziuso had studied the potential of wind and solar power in the Pennsylvania-Delaware-New Jersey region.
Her growing interest in renewable energy led her to Iceland — a nation that runs almost entirely on renewables — for a master's degree in Reykjavik University's' Iceland School of Energy.
"The university has a lot of industry partners," she explains, "so I actually had the opportunity to work for the National Power Company of Iceland as I completed my master's thesis. They had over 3 terabytes of historical wind resource data that I was able to leverage for a nationwide wind resource assessment. It was a great experience."
Master's degree in hand, she then took a position at the prestigious Pacific Northwest National Laboratory in Washington state, working on distributed wind energy, marine renewable energy and energy policy.
That's when she decided to pursue a Ph.D. at Stevens.
"I was looking for Ph.D. programs that were interdisciplinary in nature, specifically seeking out those that looked at the interface of society, policy and technology," Preziuso notes.
"I came across Stevens' Socio-Technical Systems degree. I knew I wanted to work with distributed energy resources in my own research, and appreciated Dr. Odonkor’s expertise in this space — as well as his approach to advising doctoral students."
As the U.S. moves from its original electric grid to a cleaner, more decentralized grid deriving energy from a mix of renewable-energy sources, individual buildings will be key to the transition, she says.
"The existing building stock has the potential to be more efficient and flexible in its energy consumption," Preziuso explains. "Buildings can become valuable assets to the electric grid when they optimize consumption to not just meet the needs of their occupants, but also to improve grid conditions — for example shifting consumption outside periods of peak demand."
New technologies are emerging to enable this to happen, such as the emergence of so-called "grid-interactive efficient buildings".
But what if certain buildings, neighborhoods or communities are more historically and technically advantaged to leverage new systems than others?
"Technology adoption is unlikely to be uniform," concedes Preziuso, "so understanding what sort of policy levers we can we pull to more equitably distribute the benefits of a low-carbon electric grid is critical. A low-carbon electric grid is not guaranteed to be equitable, so we need to make sure we’re asking this question as we come up with the technical solutions for developing the grid of the future.
"The task of defining what an equitable grid looks like, though, will be challenging."
To do it, she suggests, we may need to begin redefining energy beyond the kilowatt-hour.
"We need to go beyond simply measuring amounts of electricity and start acknowledging other types of value streams. For example, what is the human value of energy within a given community or individual home?" asks Preziuso. "What are their unique needs? Might a building require around-the-clock energy generation for life-saving medical care, or additional heat to remain comfortable for its occupants for some reason?"
She has begun her doctoral research by examining building stock tracked by New York state's energy and research development authority, NYSERDA, in order to explore how buildings can play a role in both a more equitable and lower-carbon energy future.
"It's about elevating the voices of communities, and bringing people with different expertise to the table," she sums. "You have experts in environmental and energy justice, power systems engineering, and policy, and you have communities with varied experiences with their energy sources.
"Bringing them all together, and ensuring communities are central in defining their energy futures, will be very important.
Consistent demand, intelligent storage: hidden keys
As it evolves from several very large "chunks" into a mix of smaller, more numerous and localized grids, the nation's energy distribution will require more careful management during peak and off-peak periods and during the transitions between those periods.
"Consistency is the key," explains Stevens Electrical and Computer Engineering Professor Lei Wu, a national expert on power grid system management. "You can't demand too much at the wrong time, and you also need to have your storage facility shedding, or sharing, some energy during slow-demand times of day, week or year."
Improved energy storage technology, he stresses, is an unseen but critical element of any sustainable power system.
"Energy storage is one of the key technologies that can mitigate the variabilities and uncertainties involved in renewables such as wind and solar, as well as in demand response," he notes.
One technology to do so, "pumped hydro," releases water through hydroelectric dams and turbines, generating energy when needed. During off-peak periods, or when there is excess energy (particularly from renewables), the system stores energy by recirculating water back to an upper reservoir. Wu develops algorithmic methods that balance and optimize the energy stored, delivered and shed by each pumped-hydro facility locally and to surrounding regions.
Working with the Missouri University of Science & Technology and industry partners, he was recently awarded $1.25 million by the U.S. Department of Energy (DOE) to support the work.
Wu also collaborates with Portland General Electric and the University of Arizona on a project to model, forecast and optimize water flow in the Oregon utility's system by factoring in rainfall, snowmelt, evaporative temperatures and other inputs. That project has secured an additional $1.25 million in support from DOE.
Stevens researcher Junjian Qi investigates power systems, as well, receiving two recent National Science Foundation (NSF) awards to develop power grid innovations. Qi received a five-year NSF CAREER award to study cascading failure and power system resilience and funding for a separate project with the University of Central Florida that will design and deploy novel systems to coordinate photovoltaic, local energy storage and intelligent microinverters.
"We can’t rebuild the grid," Wu concludes. "But we can redesign and optimize the tools that control and operate it to develop a greener, more efficient system that can withstand and rebound from weather extremes."