Annual production, and the survey that replaces the estimate
Plan on roughly 1,218 kWh a year for every kW of panels in Sterling Heights. That estimate comes from satellite irradiance data with a standard performance ratio applied, not from measured local systems, so its job is to tell you whether solar is worth investigating rather than to predict your own array.
The site survey is where the number becomes real. Orientation decides the daily shape of production, pitch affects both yield and how quickly snow clears, and usable roof area shrinks once vents, plumbing stacks, chimneys and required setbacks are removed. Shade is the item most often waved away at the kitchen table and most often decisive on the roof.
Ask to see modelled output per roof plane, with the shading assumptions attached. Two quotes with the same annual total can hide quite different designs, one where every panel sits on a good plane and one where a third of them are filling space on a face that will never pay for itself.
Where the credit actually lands on your bill
Under Rider 18, the power you export is valued at the power supply component of the retail rate on your schedule, including Power Supply Cost Recovery. The credit that produces is then applied against all electric charges at the premise except securitization charges.
That last clause is worth reading twice, because it is better than people expect. The credit is not locked to the energy line of the bill. It reaches the delivery charges and the other components too, with securitization charges the single carve-out, so a month of strong generation reduces more of the bill than a narrow energy-only credit would.
Anything the month does not absorb goes into an Excess Generation Bank and carries forward. In a climate where June output is several times December output, that carry-forward is what makes an annual view of the system meaningful rather than a monthly one. It also sets a limit on the value of oversizing, since credit that accumulates and never gets used is not money.
Applying under Rider 18
Rider 18 is open to systems up to 550 kW, a ceiling set by Michigan's 2023 Public Act 235, and the same act limits a customer to 110 percent of their prior 12 months of usage. For a household, the usage limit is the operative one and it is worth knowing before design starts rather than after.
The interconnection application is a separate approval from anything the city requires, and the two run on their own timetables. When you ask where a project stands, ask which of the two is outstanding rather than accepting one switch-on date, because a system can be fully installed and waiting on the utility.
It is also worth seeing the application before it is submitted. It defines the system that gets approved, so a change to array size afterwards means going back to the utility, and that is avoidable rework rather than a fee anyone will absorb quietly.
Attached roofs, small apartment buildings and mobile homes
Single-detached houses are 66.9 percent of the 53,607 units here, and that group has the simple version of this: one roof, one service, one decision.
Single-attached row houses and townhouse-style units are 9.0 percent. Sharing a roofline with the neighbouring unit does not prevent an installation, but it makes the survey matter more, because the roof plane, the property line and the fire separation all have to be established on site rather than from an aerial photograph. Ask the installer whether they have walked the property.
Buildings of 5 to 9 units hold 8.1 percent of the stock, and in those the roof is the building owner's, so a resident cannot commission an installation and the array normally offsets a building account. Mobile homes are 2.9 percent, and there the questions are structural and contractual before they are electrical: what the roof can carry, what the ground allows and what the park permits.
Costs and financing in 2026
Remove the federal credit from any arithmetic you have been shown. The 30 percent residential credit under Section 25D applied through December 31, 2025 and does not cover a purchased home system placed in service after that date, so a 2026 purchase here cannot claim it. Payback periods that still assume it are describing a different year.
Where a homeowner uses a lease or a power purchase agreement instead of buying, the provider may claim the business version of the credit under Section 48E and pass some of that value through in the rate. Ask the provider what they claim and what reaches you, and verify with a tax advisor rather than with the sales material.
Michigan Saves is the financing route most Michigan installers will mention. It is a nonprofit green bank connecting homeowners with participating credit unions for qualifying improvements including solar photovoltaic systems, battery storage and EV chargers, with rates starting at 5.99 percent APR and terms up to 180 months. It requires an authorized contractor and its own portal application, and its rates and contractor list are both updated, so confirm the current terms at quote time.