Using EPB's fiber-optic network and smart grid in Chattanooga, ORNL scientists here are able to remotely and virtually test ways to better deploy the power grid to maintain reliable electricity supplies in a cleaner, more efficient manner.
"President Biden has a goal of getting to 100% clean electricity generation by 2035 and net-zero carbo emissions by 2050," U.S. Energy Secretary Jennifer Granholm said during a recent visit here. "The solutions that are being worked on here at this lab are the solutions that we need to deploy to meet these goals. The great thing about being near a facility like this is that the lab is thinking into the future even as it is helping industries in the present."
EPB signed a memorandum of understanding to work with the Oak Ridge National Laboratory in 2014, allowing Department of Energy researchers to connect with EPB's fiber network that runs both its smart electric grid and the nation's first citywide high-speed broadband Internet network.
ORNL is developing grid technologies, cybersecurity equipment and battery storage capabilities to help utilities like EPB adapt to the emerging distributed energy market where more power is generated at scattered sites from solar panels, windmills and other renewable sources.
"We're trying to improve the efficiency, reliability and sustainability of energy systems going from small appliances all the way to entire electric systems," said Dr. Richard "Rick" Raines, the director of the Electrification and Energy Infrastructures Division (EEID) at Oak Ridge National Laboratory (ORNL).
Over the past seven years since ORNL began working with EPB, the Chattanooga utility has helped in over $98 million of Department of Energy research projects.
"The Oak Ridge lab is a real jewel for our region and our industry and it's been a great partnership working with them," said former EPB Chairman Joe Ferguson, who worked with U.S. Rep. Chuck Fleischmann to help expand ORNL's presence in Chattanooga.
A TESTBED FOR MICROGRID CONTROLS
Within the Grid Research Integration and Deployment Center at the Hardin Valley campus of the ORNL, researchers have developed the Commander test bed to perform research on secure controls and hardware for local networked power grids called microgrids.
With their power generation and storage capabilities, distributed energy assets like microgrids can supply electricity to homes, businesses and factories. Commander receives real-time data from three research microgrids in EPB's service territory in and around Chattanooga using secured communications architecture.
The 2-megawatt solar array and a 500-kilowatt battery storage facility at Chattanooga's airport is one of the microgrids being studied and evaluated for ways it can help to not only power the airport terminal but offer backup electricity when needed elsewhere. DOE is also helping provide battery storage for another solar-powered microgrid being developed at the Chattanooga police and fire headquarters on Amnicola Highway.
ORNL researchers use artificial intelligence to analyze the data and create precise simulations of the grid. Commander uses simulations to evaluate the performance of the grid technology under various scenarios, including disruptive weather events.
"We are establishing a living emulation of various types of microgrids to see how they can be coordinated to build on a region's electricity reliability and resilience and even be used as backstop resources for the grid," said Madhu Sudhan Chinthavali, a group leader for Power Electronics Systems Integration at ORNL. "EPB is helping us test these controls in some of the microgrids established and planned in their service area."
The testbed evaluates new hardware and controls before they are deployed on the live grid system. Controls and hardware solutions demonstrated on Commander give EPB and other utilities the ability to harness the load-balancing potential from regional network microgrids for a more resilient power grid.
"The electric grid today is the biggest and most complicated machine on the planet and it is highly centralized," said Jim Ingraham, vice president of strategic research at EPB. "But these microgrids give us a capacity to dispatch power across peaks to allow us to lower the cost of service to our customers and to generate power with more renewable sources like the sun or wind."
As research projects, not every new technology works as well as initially hoped. Four years ago, DOE helped fund and install a 100-kilowatt vanadium redox battery at EPB's community solar facility near EPB's distribution center off of Holtzclaw Avenue. The battery didn't meet expectations and has since been removed.
DOE is now funding and will soon install new lithium-ion batteries for EPB to help the local power company better store and deploy energy from its own community solar project on Holtzclaw Avenue and to aid in creating a more robust network of microgrids for the solar array at the Chattanooga airport.
BUILDING A SMARTER GRID
When EPB initially issued $170 million in municipal bonds to finance a fiber-optic network for a smarter electric grid in 2009, the city-owned utility estimated it would take 10 years to install the estimated 9,000 miles of fiber optic lines needed to cover EPB's service territory.
Under the American Recovery and Reinvestment Act adopted more than a decade ago, EPB secured the largest federal grant of any Tennessee utility from the stimulus bill to expedite the fiber optic buildout. EPB was granted more than $111 million to get its smart grid up and running within about four years, or six years ahead of schedule, to serve every household and business in EPB's delivery area.
EPB helped establish Chattanooga as "Gig City," where everyone has access to gigabyte-per-second Internet speeds and where high-speed Internet links open the door for an array of new electric grid improvements. EPB has a smart grid with more than 1,200 IntelliRupter switches installed on its 12-kilovolt distribution network and more than 200 smart switches on its 46-kilovolt transmission system. Using the fiber optic network to communicate, the switches work together to isolate faults and re-route power when an outage occurs.
Nearly 175,000 smart meters give customers the option to monitor and manage their electricity usage, while giving EPB key information about outages, voltage fluctuations, and anomalies.
Ingraham said ORNL also used EPB's smart grid to test optical sensors at its power substations to help act as cybersecurity barriers for the utility's automated switching systems to protect the network from an outside hacking attempt and to provide more real-time information for better maintenance and power reliability. By detecting temperature changes and vibrations in EPB's power transformers and other equipment, the sensors can provide early detection of faulty equipment and allow for preventative maintenance measures to avoid power interruptions.
EPB estimates since it installed its fiber-based smart grid, it has reduced the average length and number of power outages by nearly 55%, according to EPB spokesman J.Ed. Marston.
AUTOBEM SEES ENERGY USE AT EVERY SITE
Across its 600-square-mile service territory, EPB's fiber-optic network allows the utility to detect and model energy use for every building in the Chattanooga area.
Buildings use 40 percent of America's primary energy and 75 percent of its electricity. DOE's Building Technologies Office has set a goal of reducing the energy consumption per square foot of American buildings by 30 percent from 2010 to 2030 across America's 124 million building structures.
A team led by research and development senior staff member Joshua New at ORNL developed a model for every building in Chattanooga based upon its age, type and size and he has used data from the smart grid to assess the model's predictions. The ORNL approach uses publicly available data and satellite images and crunches the data into ORNL's supercomputers to model energy use and suggest improvements for any building in Chattanooga through its AutoBEM process.
Through more than 2 million simulations, ORNL researchers estimate that EPB could potentially save as much as $35 million per year by adjusting electricity usage during peak critical times.
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