Duke Energy Adds Microgrid Controls to an 11 MW Florida Battery, Backing Up 1,500 Customers
- Emergency & Local Government Microgrids News
Marin Holt
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- 8 minutes read
- Battery capacity: 11 MW
- Customers backed up: About 1,500
- Backup duration: Up to four hours
- Facility in service since: 2022
- Duke Energy Florida battery sites: 6 statewide
- Energy rating disclosed: None
Duke Energy Florida added microgrid controls this summer to its 11 MW lithium battery facility in Trenton, about 30 miles west of Gainesville in Gilchrist County. The utility announced the change on August 31, 2026. The controls let the site island during an outage. It then runs apart from the grid and feeds power to roughly 1,500 residential, commercial and industrial customers for up to four hours. When the grid comes back, the facility reconnects on its own and returns to its earlier job of balancing demand. Duke built the Trenton battery in 2022 to store energy and to defer conventional grid upgrades. Nothing about the hardware changed. The utility bolted a control layer onto an asset that already existed and turned it into a community backup resource. Trenton is the second Duke Energy Florida battery configured this way. The first sits in Micanopy, in Alachua County, and reached service in 2025. Duke now runs six battery facilities across Florida.
What Changed at Trenton
A grid-tied battery follows the grid. It charges and discharges against a price signal or a peak, and it shuts down when the line it sits on goes dead. Islanding is the difference. The site has to form its own voltage and frequency, pick up load in the right order, and hold the island stable with no rotating machine behind it.
That is a controls and protection problem, not a cell problem. Duke did not announce new capacity at Trenton, new chemistry, or a new site. It announced that an existing 11 MW asset now carries the equipment to serve a defined set of customers on its own. Melissa Seixas, state president of Duke Energy Florida, framed it in cost terms. “We are continually making smart grid investments to improve reliability for our customers, while keeping costs as low as possible,” she said.
Why It Matters
Utilities across the Southeast own a growing fleet of distribution-connected batteries bought for deferral and peak service. Those assets sit idle through most outages because nobody paid for the controls that would let them island. Trenton shows that the retrofit, and the retrofit alone, buys a resilience product for a town.
The reach is narrow. About 1,500 customers out of the 2 million Duke Energy Florida serves across a 13,000-square-mile territory works out to under a tenth of a percent. Two sites out of six batteries is the more useful ratio for anyone tracking how fast this spreads. Rural feeders are the natural target, because a single battery at the end of a long radial line backs up a whole town, and because the alternative is a diesel generator that somebody has to start.
What Duke Did Not Publish
The announcement gives a power rating and a duration but no energy rating. Duke did not disclose the megawatt-hour capacity of the Trenton battery, which is the number that decides how long the island actually lasts. Four hours is the utility’s stated capability, not a promise about any particular outage. Real duration depends on how much load the islanded customers draw and on the battery’s state of charge when the line opens. A battery part way through a discharge cycle when a storm hits delivers a different result than a full one.
Duke points to other reliability work in the same state. About 50 percent of its Florida distribution system runs underground, 82 percent of customers sit behind self-healing automation, and the utility replaced 60 percent of its wooden transmission poles over the past five years. Those programs reach far more people than two microgrids do. The microgrid is the part that keeps the lights on when all of that fails.
Critical Perspective
Duke moved about 1,500 customers onto backup by adding controls to an 11 MW battery that was already there, with no new cells. Micanopy took the same path a year earlier and is still the only other Duke Energy Florida site that islands. Four of the six batteries in that fleet were bought for deferral and peak service and stay grid-following through every outage. If a control layer is the only thing separating the two groups, what is stopping the other four?
Sources
- Duke Energy: Duke Energy Florida launches its second battery facility capable of providing backup power for customers (August 31, 2026)
- Microgrid Knowledge: Duke Energy Florida’s Trenton Lithium Battery Facility Gets a Microgrid Upgrade
- Microgrid Media: Duke Energy Trenton Community Microgrid Backs Up 1,500 Customers
