It's not a surprise that a recently completed external audit finds that Michigan's two largest utilities have a worse-than-average track record for restoring power after storms.
For years, DTE Energy and Consumers Energy have languished in the lowest quarter of a utility industry measure for average duration of customer power loss, both for outages during normal weather, and after storms.
But the audit by Liberty Consulting Group shows the two utilities face unique problems that contribute to both companies' poor track records for outages.
The audit was ordered by the Michigan Public Service Commission after a string of storm-related outages in 2022 left customers of both companies without power for long periods.
In Consumers Energy's case, the audit found the utility is taking 10 years to cycle through its tree trimming schedule, when other utilities take four or five. That makes its power lines vulnerable to falling trees and limbs.
And Consumers' response time after storms is impaired due to having so many different low voltage connections throughout its system, the audit found.
The audit notes that response times by DTE Energy are slowed by the high number of hard-to-access circuits that its workers must access in brush-filled alleys behind homes and buildings, as well as the system's many hard-to-repair, ungrounded, low kilovolt circuits. Nearly half of DTE's customers are served by these low voltage ungrounded circuits.
The audit also noted that DTE suffers from periodic excessive loadings, which contribute to high substation transformer failure rates.
The utilities declined to respond to specific issues raised in the audit.
“We remain laser-focused on delivering on our commitment to our customers, reducing power outages by 30% and cutting outage time in half by 2029," DTE Energy said in a statement. “To meet that commitment, as well as the customer service standards set by the Michigan Public Service Commission, we’ve been making significant investments as part of our accelerated plan to quickly transition to a smarter grid, aggressively trimming trees, updating our existing infrastructure and rebuilding significant portions of the grid."
In its statement, Consumers Energy said the MPSC audit has been "constructive" and it "appreciates the deep experience and expertise Liberty brought to the process."
"Michiganders are facing more severe and frequent storms, which is why we announced our Reliability Roadmap in 2023, a blueprint for fewer and shorter outages, including no customer going more than 24 hours without power," the utility said. "Our investments are focused on the customers we serve by adding technology, burying power lines and clearing trees."
The MPSC will hear from the audit's authors in a public meeting on Thursday, September 26.
Consumers Energy and DTE Energy are among Michigan Public's corporate sponsors.
