Ann Arbor hopes to create solar-powered utility

The city of Ann Arbor looks to create its own utility, run on solar and battery storage. It wouldn’t be a replacement for DTE so much as a supplement to it. 

Ann Arbor calls it a “sustainable energy utility.” It would distribute electricity “from local solar and battery storage systems installed on homes and businesses throughout the city,” according to the city’s website. 

In Nov. 2019, Ann Arbor City Council passed a resolution naming carbon neutrality as a citywide goal.

If the utility comes to pass, participants would get a bill from DTE Energy and the Ann Arbor utility.

The service will draw on solar power and battery-stored solar power. Only when those resources aren’t available would the DTE energy kick in.

In that sense, the sustainable energy utility is a “supplemental” source of energy to DTE, not a replacement, explained Missy Stults, Ann Arbor’s sustainability and innovations director, in a 12-minute video explaining the plan.

Ann Arbor believes its utility will be less vulnerable to bad weather with a solar-powered grid.

As homes and blocks are connected on “microgrids,” the video explained, the potential for widespread outages is lessened.

The plan presents four scenarios. In scenario D in the diagram above, there are DTE outages while the sustainable utility keeps the power on.

“Residents reliant on DTE lose power when DTE’s infrastructure fails,” the diagram explains, while “most residents retain power through the SEU’s renewable energy, dispersed through microgrids and stored in batteries.”

DTE, meanwhile, says it is five years from implementing automation technology allowing mass power outages to be restored with keystrokes, rather than large and expensive crews of linemen.

But solar energy is sun-powered; Michigan is a state with long winters. Even if a solar-and-battery-powered utility existed in Ann Arbor during the ice storm and thundersnow of February and March, would it have helped?

Jason Hayes, director of energy and environmental policy at the Mackinac Center, has his doubts.

“Cities like Ann Arbor often publicize the notion that they can provide ‘100% clean, reliable, locally built, and affordable electricity’ with solar. However, Ann Arbor plans to remain connected to DTE’s distribution system, demonstrating that they know solar isn’t actually reliable,” Hayes told CapCon.

“During Michigan’s overcast winter months, solar systems effectively sit idle over 90% of the time,” Hayes said, citing data from the U.S. Energy Information Administration.

“Even with battery backup,” Hayes added, “these systems would have to carpet far more than the entire city to produce sufficient electric supply to keep those batteries charged.”

Jay Flannelly is an Ann Arbor-based freelance reporter. James David Dickson is managing editor of Michigan Capitol Confidential. Email him at dickson@mackinac.org.