DTE Energy is working to improve reliability for our customers through a four-point plan: trimming trees, rebuilding older sections of the grid, accelerating our transition to a smart grid and upgrading our existing infrastructure. For nearly a year, we’ve been repairing, strengthening and modernizing the electrical grid on Grosse Ile to increase reliability, safety and the grid’s capacity to support our customers’ growing energy needs. 

The $14 million project includes repairing a vital trunkline — a cable that delivers power from a nearby substation to Grosse Ile — under the Detroit River. Although the system is designed to continue operating without this trunkline, fixing this line will provide additional capacity. Additionally, we are replacing another cable under the river that is aging. This cable will act as a backup path for power should there be any disruption to other lines. The added redundancy will help increase electric reliability for those in the area.  

To install the trunklines, we bored under the Detroit River and installed a new pipe, otherwise known as conduit, which will house and protect the cables. 

Since then, our crews have been working to pull the new cables through the pipe — this work is about 90% complete and will wrap up in October. We are also currently working at the local substation that powers Grosse Ile, making upgrades to the underground infrastructure. This work is necessary so we can energize the new cables. 

Reels of new cable being pulled into the pipe under the Detroit River.

Once the substation work is complete later this fall, we will energize the new lines and remove the generators on Grosse Ile. We are expecting this project to be complete by the end of 2023.  

Learn more about work happening in your neighborhood or our four-point plan at empoweringmichigan.com/reliability-improvements.