Key takeaways
- The Powerwall 3 is the same battery whoever installs it. The installer decides the design, the placement, the DTE paperwork and the support after it’s switched on.
- Tesla says installation should only be performed by a Tesla Certified Installer. Check any company on Tesla’s installer locator yourself.
- In a Michigan home, a Powerwall goes in a non-living space, out of the car’s path, and away from flooding and snow buildup. It’s rated to operate down to -4°F.
- DTE says interconnection typically takes five to six weeks for residential systems when the paperwork is complete, and your city has its own permits and inspections.
- Before you sign, ask who will be on your roof, who handles DTE and the city, and who supports the system after it’s on.
Frequently asked questions
How do I find a Tesla Certified Installer near Detroit?
Use Tesla’s installer locator to look up certified companies near you, and confirm any company’s certification there yourself. Tesla’s installation documentation says Powerwall installation should only be performed by a Tesla Certified Installer.
Does it matter who installs my Powerwall for the warranty?
Yes. Tesla’s Powerwall warranty runs 10 years, and it excludes damage caused by installations that don’t follow Tesla’s specifications, as well as modifications or repairs by anyone other than Tesla or a Tesla Certified Installer.
Where should a Powerwall go in a Michigan home?
In a garage, on an exterior wall or in another suitable non-living area. In a garage it has to stay out of the driving path. Tesla’s manual also says to keep it out of flood-prone spots and not to let snow build up around it, which rules out some low basement corners and exterior walls that catch drifts.
How long does DTE approval take for solar and a Powerwall?
DTE says the process typically takes five to six weeks for residential systems up to 150 kW when the paperwork is complete and on time. Both DTE and your local municipality have to approve the system before it’s turned on, and DTE asks homeowners to notify it before adding a battery.
Does the Powerwall 3 work in Michigan winters?
Yes. Tesla rates the Powerwall 3 to operate from -4°F to 122°F, indoors or outdoors. Placement still matters, so an installer should plan around snow and water, not just wall space.
Search “Tesla Powerwall” plus almost any Oakland County town, from Milford and Wixom to Troy, Royal Oak and Southfield, and you’ll find plenty of companies willing to install one. Every one of them is selling the same hardware. The part you’re really choosing is the installer: the people who design the system around your house, file the DTE application, pull the city permit and commission the battery so it does what you bought it to do.
Here is what to look for.
What a Powerwall 3 is
The Tesla Powerwall 3 is a home battery with a solar inverter built in. According to Tesla’s datasheet:
- Energy: 13.5 kWh (nominal) per unit
- Power: up to 11.5 kW continuous, with a 185 A locked-rotor rating for the startup surge of motor loads like a sump pump
- Solar: a built-in inverter that accepts up to 20 kW of panels
- Expansion: up to four Powerwall 3 units in one system, plus up to three Powerwall 3 Expansion units (13.5 kWh each, no inverter)
- Temperature: rated to operate from -4°F to 122°F, indoors or outdoors
That last point matters in Michigan. An installer who knows the hardware will plan placement around winter, not just around wall space.
What “Tesla Certified Installer” means
Tesla installs Powerwalls directly in some areas and relies on trained Certified Installers in others. Tesla’s installation documentation says installation should only be performed by a Tesla Certified Installer, and you can look up certified companies near you with Tesla’s installer locator.
Certification also matters after installation. Tesla’s Powerwall warranty runs 10 years, and it excludes damage caused by installations that don’t follow Tesla’s specifications, as well as modifications or repairs by anyone other than Tesla or a Tesla Certified Installer. In plain terms: you want the company that installs your battery to be one Tesla recognizes.
Where it goes in a Michigan home
Tesla’s installation manual sets the ground rules, and a good installer will explain how they apply to your house:
- Not in living spaces. The Powerwall goes in a garage, on an exterior wall, or in another suitable non-living area.
- Out of the car’s path. In a garage, it must stay out of the driving path, ideally on a side wall or above bumper height.
- Away from water and snow. Tesla’s manual says to keep it out of flood-prone spots and not to let snow build up around it. That rules out some low basement corners and some exterior walls that catch drifts.
How DTE interconnection works
Every solar system in DTE territory has to be approved by DTE before it runs. Under DTE’s Distributed Generation program:
- Residential systems up to 150 kW apply through DTE, with a $50 application fee.
- DTE says the process typically takes five to six weeks for systems that size, if the paperwork is complete and on time.
- You sign a Parallel Operating Agreement, and both DTE and your local municipality have to approve the system before it’s turned on.
- DTE reprograms your meter to measure electricity flowing in and out of your home separately, under Michigan’s inflow/outflow billing.
DTE also asks homeowners to notify it before adding a battery, and its rules say batteries aren’t permitted to discharge back onto the grid. The Michigan Public Service Commission oversees the program statewide.
An installer who handles DTE applications every week will know what gets a file approved the first time. One who doesn’t will learn on your project.
City permits are separate
DTE approval is only half of it. Each city has its own building and electrical permits and inspections, and the rules in Royal Oak aren’t always the same as the rules in Troy or Waterford. Ask who pulls the permit, who schedules the inspection, and who’s there when the inspector arrives.
Questions to ask before you sign
- Are you a Tesla Certified Installer? Check it on Tesla’s locator yourself.
- Who will be on my roof and in my garage? The U.S. Department of Energy suggests asking whether an installer uses subcontractors and verifying their credentials.
- Are your installers NABCEP certified? The North American Board of Certified Energy Practitioners offers credentials for both PV installation and energy storage installation.
- Whole-home or partial backup? Ask to see which circuits will run during an outage, and why.
- Who handles DTE and the city? Get the timeline in writing.
- Who supports the system after it’s on? Monitoring, warranty claims and questions in year three shouldn’t send you to a call center three states away.
Choose the installer, not just the battery
The Powerwall is the easy part. The design, the DTE paperwork and the commissioning are what decide whether it carries your home through the next ice storm. Stellar Solar’s Michigan headquarters is in Royal Oak, our team installs Tesla Powerwall systems across metro Detroit, and the company has installed more than 5,000 batteries since 1998.
Ready to take control of your energy costs and protect your home from Michigan’s frequent outages? Request a free, no-obligation quote from Stellar Solar Michigan, serving Michigan homeowners with solar and battery storage since 1998 and A+ rated with the BBB, or call 858-395-6905.