11,000-Plus Lose Power Across Sumner, Robertson Counties as Storms Loom

More than 11,000 Cumberland Electric Membership Corporation customers lost power Sunday afternoon across a swath of Sumner and Robertson counties, with crews pointing to a problem originating outside the co-op's own local grid as severe weather threatened the region. The outage hit White House, Millersville, Hendersonville, Greenbrier, and Ridgetop, leaving thousands sweating out the last weekend of August without air conditioning.

According to WSMV, the CEMC outage map showed 11,180 customers without power as of 3:32 p.m. Sunday. Local outlet Smokey Barn News put the total even higher, reporting more than 13,000 CEMC customers affected across the same five communities. CEMC said crews were already working to restore power at the outage site and were investigating the cause.

Trouble Traced Upstream of CEMC's Own Lines

CEMC said early indications pointed to an issue upstream of its system, according to the WSMV report. That distinction matters: CEMC is a distribution cooperative that buys all of its wholesale electricity from the Tennessee Valley Authority, which owns and operates the high-voltage transmission lines and substations that feed power into CEMC's local network, per the Tennessee Utility Providers and Grid Infrastructure. When CEMC describes a fault as upstream, it typically points to a disruption on a TVA transmission line or wholesale substation rather than a problem within CEMC's own distribution equipment.

TVA serves as the exclusive wholesale power provider for 153 local power companies across the region, per the same source. CEMC itself directs between 71% and 75% of its total annual operating expenses toward wholesale power purchases from TVA, leaving roughly a quarter of its budget for local distribution maintenance and storm response. That structure leaves co-ops like CEMC dependent on TVA's transmission network functioning properly, even as CEMC's own crews handle the on-the-ground repair work.

Severe Weather in the Forecast

The outage unfolded as the National Weather Service in Nashville issued a weather outlook warning of potential late-afternoon and evening severe thunderstorms across Middle Tennessee, with the potential for strong, damaging winds. Severe weather had already affected multiple parts of Tennessee over the weekend. The dossier does not confirm whether storm activity caused the upstream fault that knocked out power to CEMC customers, and that link remains unconfirmed.

CEMC said crews were working to restore power to thousands of customers, though the company did not provide a specific restoration timetable in its statement to WSMV. The exact TVA facility or line responsible for the disruption has not been identified.

A Pattern of Grid Strain in CEMC's Territory

Sunday's outage is the second significant power disruption in CEMC's five-county service area in less than a week. On August 17, a downed utility pole near Main Street in Ashland City, which doubles as Tennessee State Route 12, cut power to roughly 1,600 CEMC customers in Cheatham County before crews isolated the circuit and made repairs, as Hoodline reported.

The same week, Greenbrier Middle School in Robertson County battled repeated central air conditioning failures during a heat advisory that pushed heat index values to 105 degrees, forcing the district to rely on portable cooling units in classrooms. Greenbrier was among the five towns affected by Sunday's outage, underscoring how infrastructure strain in the county has piled up heading into the storm season.

CEMC is headquartered in Clarksville and ranks as the third-largest electric distribution cooperative in Tennessee, maintaining more than 8,000 miles of distribution lines and serving over 116,000 homes and businesses across Cheatham, Montgomery, Robertson, Stewart, and Sumner counties. The co-op also operates Cumberland Connect, a fiber-to-the-home broadband subsidiary serving more than 42,800 members, meaning major outages can ripple into internet and phone service alongside electricity.

TVA, for its part, approved its 2026 Integrated Resource Plan and updated wholesale rate structures on August 20, allocating more than $13 billion through fiscal year 2029 toward generation capacity and transmission reliability upgrades, according to T&D World. Whether that investment plan bears any relation to Sunday's upstream fault is not established in available reporting.

How to Report an Outage

CEMC members can report power loss through the SmartHub mobile app, online at trouble.cemc.org, or by texting or calling 800-987-2362. The company's outage map updates in real time as crews isolate affected circuits and restore service.