Department of Energy

Researchers Receive ARPA-E Funding to Develop Eco-Friendly High-Voltage Circuit Breaker

admin — Tue, 07 Feb 2023 16:52:11 +0000

Researchers Receive ARPA-E Funding to Develop Eco-Friendly High-Voltage Circuit Breaker admin Tue, 02/07/2023 - 11:52

Replacing the potent greenhouse gas SF₆in high-voltage circuit breakers with a clean alternative is critical as the U.S. looks to upgrade its aging electrical infrastructure.

Although well-known greenhouse gases like carbon dioxide (CO₂) and methane contribute the most emissions, it is a lesser-known greenhouse gas, sulfur hexafluoride (SF₆), that owns the title as the “most potent.” The man-made gas has a global warming potential 23,900 times than that of CO₂ and an atmospheric lifetime persistence of up to 3,200 years.

Like other greenhouse gases, SF₆, plays a significant, albeit indirect, role in everyday life, as it is a key component in high-voltage circuit breakers and switchgear for electric power systems. For the U.S. to effectively decrease carbon emissions to goals set at the 2021 United Nations Climate Change Conference (COP26), the country’s electrical power grid will need substantial updating, which includes finding an alternative to SF₆ electrical equipment

“High-voltage alternating current (AC) SF₆-insulated circuit breakers can be found in most electrical substations in the U.S. and around the world. They are vital mechanisms for a reliable and resilient power grid,” said Lukas Graber, associate professor in the Georgia Tech School for Electrical and Computer Engineering. “But any leaks of SF₆ are extremely bad for the environment due to its greenhouse gas effect.”

A team of researchers from Georgia Tech, led by Graber and in collaboration with Mississippi State University, has recently been awarded nearly $4 million from the Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E) to develop a three-phase SF₆-free AC high-voltage circuit breaker. Fittingly, the proposed design is called TESLA (Tough and Ecological Supercritical Line Breaker for AC), acknowledging AC electricity pioneer Nikola Tesla.

The Impact of SF₆

From 2008 to 2018, the annual emissions rate of SF₆ rose from about 7,300 tons to approximately 9,040 tons, an increase of 24%, according to a 2020 study published by the European Geosciences Union. That amount of SF₆ equates to greenhouse gas emissions of approximately 44 million passenger vehicles driven for one year, or 226 billion pounds of coal being burned.

According to ARPA-E, equipment leaks are a major source of SF₆ emissions from the electrical transport and distribution sector. This is particularly true for aging equipment which, due to natural deterioration, is more prone to gas leaks. Ironically, as the U.S. strives to supplant fossil fuel-derived electricity generation with cleaner wind and solar power, the power grid will become increasingly decentralized, which will require more SF₆ gas-insulated equipment.

“The electrical infrastructure in the US is in desperate need of upgrades to accommodate an increasing share of renewable energy, the electrification of the transportation sector, and improved resiliency against cyberattacks,” said Graber. “Existing electrical substations will require new equipment, and as part of these upgrades, a new eco-friendly generation of circuit breakers should be implemented.”

Looking to Supercritical Fluids

Replacing SF₆ is no easy task. While SF₆has exceedingly high global warming potential, the synthetic gas is an excellent electrical insulator — a material in which electric current does not flow freely. The gas is known for its effectiveness, stability, and intrinsic non-toxic, non-corrosive, and non-flammable nature, and while non-SF₆ equipment has long been available for low to medium-voltage applications, there are no alternatives for high-voltage equipment ready for market.

The team’s research has shown that the key to success may be utilizing recent breakthroughs in the dielectric (or electrical insulating) properties of supercritical fluid. A supercritical fluid is a highly compressed fluid that combines the properties of gases and liquids, and is most frequently used for power generation. The team is currently experimenting with supercritical CO₂, which has ecologically friendly attributes that could be utilized in high-voltage equipment.

“Our preliminary results show that the supercritical fluid is a better dielectric than SF₆,” said Zhiyang Jin, research engineer in Graber’s Plasma and Dielectrics Lab at Georgia Tech. “The breakdown voltage of supercritical CO₂ is at least three times that of SF₆, and since CO₂ is everywhere, so a man-made gas will no longer be needed.”

Unlike SF₆ circuit breakers, the design pressure needed for supercritical fluid in TESLA is significant — about ten times higher than SF₆ counterparts. Achieving this design means developing a different circuit breaker chamber to maintain structural integrity during and after the fault current interrupting event. Computational fluid dynamics models have already been developed to study the pressure and temperature changes, and the velocity distribution of supercritical fluids for designs of the chamber, nozzle, and contact system.

In addition to the engineering challenge of connection compatibility with existing high-voltage electrical equipment/infrastructure, and the subsequent workforce training that will entail, market adoption is critical hurdle to clear.

“To replace existing circuit breakers, we cannot just show that TESLA passed all required tests,” said Jonathan Goldman, principal at Georgia Tech’s Venturelab. “Gaining trust from large utility companies is also one of our crucial tasks. We will seek opinions from experts from various backgrounds.”

Goldman and electrical engineering professor Santiago Grijalva will work with several industry partners to guide the design process, explore additional application segments, and advise on the commercialization of TESLA.

Getting to Work

The interdisciplinary team will design and build the proposed circuit breaker at a high voltage rating (245 kV, 4 kA) and validate the design and functionality using a synthetic test circuit. The testbed will be modular in design and enable both high-current and high-voltage testing without needing access to a high-power source or generator. According to Graber, the development of such experimental capability is not only important for the TESLA project, but also for the power and energy industry of the U.S.

The three-year ARPA-E-funded project will culminate in the development of a TESLA prototype tested at the Paul B. Jacob High Voltage Laboratory at Mississippi State University — the largest university-operated high voltage facility in North America. The lab is directed by Chanyeop Park, who received his Ph.D. at Georgia Tech.

The team also includes Juergen Rauleder, assistant professor in the Daniel Guggenheim School of Aerospace Engineering, and Lauren Garten, assistant professor in the School of Materials Science and Engineering.

Raulder will investigate the fluid dynamics inside the circuit breaker and provide guidance for mechanical designs of a high-pressure tank, contact system, and arc quenching mechanism, while Garten will research metal oxide varistor characteristics for direct current circuit breaker applications. Garten’s research would have an impact on another ARPA-E-funded project at Georgia Tech called EDISON led by Graber.

“Edison and Tesla as people never got along with each other, but through advancements in high-voltage circuit breakers, we’re trying to make them good friends,” said Graber. “There is no win or lose for choosing AC or DC nowadays, together they can both make our world a better place to live.”

Summary sentence

Replacing the potent greenhouse gas SF6 in high-voltage circuit breakers with a clean alternative is critical as the U.S. looks to upgrade its aging electrical infrastructure.

Dateline

Tue, 06/14/2022 - 12:00

Contact

Dan Watson
dwatson@ece.gatech.edu

Location

Atlanta, GA

Associated importer

Keywords

Advanced Research Projects Agency-Energy

ARPA-E

High-Voltage Circuit Breaker

Lukas Graber

Supercritical Fluids

Department of Energy

Juergen Rauleder

Lauren Garten

Santiago Grijalva

Jonathan Goldman

venturelab

Zhiyang Jin

Chanyeop Park

go-researchnews

Core research areas

Energy and Sustainable Infrastructure

Mercury ID

658887

Source updated

Mon, 06/27/2022 - 10:08

Department of Energy Awards Georgia Tech Grant for Energyshed Project

admin — Wed, 07 Dec 2022 16:23:12 +0000

Department of Energy Awards Georgia Tech Grant for Energyshed Project admin Wed, 12/07/2022 - 11:23

For decades, the U.S. energy generation, transmission, and distribution model has been developed and planned around large-scale power plants that combust fossil fuels to create power that is then transferred to population centers via a network of powerlines.

With the recent and rapid growth of distributed renewable technologies — wind, solar, and hydropower, and storage assets like batteries — a team of researchers at the Georgia Institute of Technology is reimagining the planning paradigm for electric power infrastructure. The hope is to help shape new models that are better suited to community needs and include input and decision-making at the local level.

As envisioned, the Georgia Energyshed (G-SHED) will analyze the benefits, costs, and effects of various electricity generation, distribution, and usage-and-demand scenarios via use-case tests and modeling. That data will then be used to inform policy decisions at the local level and the implementation of new ideas for the 11-county metro Atlanta area as defined by the Atlanta Regional Commission (ARC).

“What’s unique about this proposal is we’re using this funding to explore a new planning mechanism that would really listen to the voices of these communities around their energy matrix,” said Richard Simmons, director of research and studies at Georgia Tech’s Strategic Energy Institute. Simmons is the project's principal investigator.

Announced on November 2, the energyshed award is part of the federal agency’s push to encourage a regional approach to understanding local energy demands and needs — and the best solutions to solve them tailored to those communities. Through its Office of Energy Efficiency & Renewable Energy, the DOE funding is part of a wider strategy to help communities understand the impacts and benefits of consuming energy that they generate locally.

“The idea is not only to better include these communities in the conversation, but demonstrate that they can realize more local benefits from their and input and decisions.”

Leading the initiative is the Energy, Policy, and Innovation Center (EPICenter). An arm of the Strategic Energy Institute, EPICenter is tasked with marrying innovation with energy technology and policy; contributing to sound recommendations for the Southeast through unbiased research and analysis.

“This grant is ideally suited for the mission of the EPICenter, which really tries to take leading energy technology and apply it in a local context that is mindful of the economic and social implications,” Simmons said.

The Georgia Tech team also includes researchers from the School of Public Policy, the School of City and Regional Planning, and the College of Engineering.

To conduct the work, Georgia Tech is collaborating with key partners: the Atlanta Regional Commission (ARC), which has engaged in similar planning and modeling processes for regional water and transportation usage and trends; and the Southface Institute, a sustainability non-profit with extensive experience in outreach, and community engagement research. Another nonprofit, the Partnership for Southern Equity, has also provided a letter endorsing the initiative.

A New Approach to Resource Management
The G-SHED idea is modeled after the watershed concept, which takes a regional, solutions-based approach to address water demand and usage at the community level. Much like watersheds, where water collection, processing, distribution, use, and discharge is determined at the community level, Simmons said the idea is to explore how a similar approach can be valid for planning and infrastructure related to energy systems, such as electricity.

“There do appear to be some critical advantages by looking at local generation, consumption and even storage of renewable energy,” said Simmons. “That might help not only meet the needs of the local populace, but it could have conversion efficiency benefits and have more direct impact on both the economic and environmental wellness of the area.”

While individual people and organizations already make energy-related decisions — consumers buying electric vehicles or developers erecting green or sustainable office buildings, for example — there’s greater impact when broadened to the community or regional level, said Joe Hagerman, EPICenter director.

“So, when decisions are made, they are being made at a community level and capture a more representative local understanding. That information can be shared both upstream and downstream to the utilities, planners, and policymakers,” Hagerman said. “We’re hoping to create a tool that will help people make those decisions in a more holistic way, rather than making it all individually.”

Ensuring All Voices Are Heard
A key component of the G-SHED effort is to ensure all communities are included in the regional energy planning and decision-making processes.

Marilyn Brown, Regents’ Professor and Brook Byers Professor of Sustainable Systems in the School of Public Policy, has conducted pioneering work on energy burdens in the Southeast.

“The goal is balanced growth and shared prosperity in the Atlanta metropolitan area by helping local communities and neighborhoods,” Brown said.

The Southface Institute and ARC will leverage novel socio-technical tools developed by Georgia Tech to assess ways metro Atlanta can ensure all residents benefit from the transition to a cleaner and more sustainable energy economy. The team will survey community groups about energy use and service options, access to rate plans, ease of understanding electric bills, and familiarity with community energy options. Then, they will build an online toolkit to address these needs and help them learn how to use it.

“Focusing on that aspect is critical to the overall project’s success because rising energy and utility costs fall disproportionately on those who can least afford them and yet have limited influence in the decision making,” said Chandra Farley, the city of Atlanta’s chief sustainability officer.

Nationally, Atlanta is 4th highest in median energy burden levels (behind Memphis, New Orleans, and Birmingham, respectively) and 3rd highest among low-income household populations.

“Evaluating energy needs at the local and metro area level with direct input from the communities who have typically had no voice in energy decision making is an important tool in energy planning,” Farley said. “The work that Georgia Tech is leading on energysheds will support community-informed energy planning and reinforce our efforts in the city of Atlanta to address energy affordability and advance access to the benefits of renewable energy projects leading to healthier communities and economic empowerment.”

Summary sentence

Energy, Policy, and Innovation Center leads effort to develop new energy planning models for metro Atlanta

Summary

The U.S. Department of Energy award, announced on November 2, is part of the federal agency’s push to encourage a regional approach to understanding local energy demands and needs.

Dateline

Wed, 12/07/2022 - 12:00

peralte.paul@comm.gatech.edu

Contact

Peralte C. Paul
peralte.paul@comm.gatech.edu
404.316.1210

Associated importer

Keywords

energyshed

go-researchnews

Marilyn Brown

Green Buzz

Joe Hagerman

Richard Simmons

Department of Energy

News room topics

Business and Economic Development

Science and Technology

Department of Energy

Researchers Receive ARPA-E Funding to Develop Eco-Friendly High-Voltage Circuit Breaker

Keywords

Categories

Core research areas

Department of Energy Awards Georgia Tech Grant for Energyshed Project

Keywords

News room topics

Categories