Winter and snow on solar panels: what to read in your papers and who to call

Start from the ground

Snow or ice on an array is no reason to climb up. For how to clear the array, go by your installer’s written care instructions and the warranty, and ask for both in writing. Everything else you can check from where you’re standing.

Read the inverter display or the monitoring app and write down what it shows, with the date. Look at your utility bill for the exports it records. Put the contract, the warranty papers and the utility’s approval in one folder. If the display or app shows less than it usually does and you can’t tell why, that’s a job for a company: the repair and cleaning pages for Michigan and California describe what a visit covers.

Never open an inverter or disconnect anything yourself. Smoke, a burning smell or fire at the inverter, the panels or the wiring is a 911 call.

Michigan: the roof rules and the warranty

The 2015 Michigan Residential Code is current as of LARA’s notice, and Michigan’s rule R 408.30521a adds a rooftop PV section to it. Rooftop PV must comply with the code, Section R324 and NFPA 70. The roof must support the loads. The system is installed per the manufacturer’s instructions, with roof penetrations flashed and sealed.

Section R324 is about access. As one city’s checklist reproduces the residential code, it calls for pathways at least 3 ft wide from eave to ridge, panels at least 3 ft below the ridge, and at least 18 in. from a hip or valley when panels sit on both sides. The permit drawing shows how your array is laid out against those lines, and how solar permits work in Michigan explains who files it.

The Michigan Public Service Commission’s consumer tips say to ask what warranties come with a system. For a winter question that’s the paper that counts. Ask, in writing, whether it covers damage from snow or ice, and what it says about who may clear the array. The Michigan cleaning page covers what a cleaning visit is.

Michigan: how your credits carry over

DTE’s Rider 18 charges the power you draw at the retail rate and credits the power you send out at the power supply rate, including the power supply cost recovery factor. Those credits can offset all electric charges except securitization charges, and excess goes to an Excess Generation Bank that’s carried forward. DTE says the credits “do not expire and cannot be withdrawn or transferred,” and that the first Rider 18 bill takes one to two billing cycles.

Consumers Energy credits excess energy at the power supply rate including transmission. Since February 27, 2024 it has applied those credits to all electric charges. Its page defines the inflow and outflow it measures as the power supply and distribution parts of the bill, not surcharges or per-meter charges. Consumers also says that even with a perfect system you’ll still have a bill for fixed charges, which is worth knowing before a month with little export on it arrives.

If the power goes out

The Michigan Public Service Commission says inverters shut off in an outage by national standards, so backup power needs a battery. Panels without one won’t keep the lights on when the grid is down. The battery storage guide covers what a battery adds and what the incentive lines say in each state.

California: how exports are credited month to month

The same checks from the ground apply in California, and so does the 911 rule. What the state puts in writing for the months between is how exports are credited.

Since April 15, 2023, new PG&E, SCE and SDG&E customers applying for interconnection have taken service on the net billing tariff, which the utilities call the Solar Billing Plan. The CPUC says export credits come from Avoided Cost Calculator values by the hour, are usually lower than the retail rate, and can rise above it on late summer evenings. The CPUC also notes that about 70 percent of NBT customers had paired a battery by the end of 2024.

NBT customers must use an electrification time-of-use rate, and their bills are due monthly. Residential PG&E and SCE customers who apply before the end of 2027 get slightly higher export credits, an adder, for nine years; SDG&E customers don’t. SCE’s Solar Billing Plan factsheet puts the extra first-year export credit at $0.04 per kWh ($0.09 for low-income residential customers). NEM 2.0 customers are different: they may stay on that tariff for 20 years from the date they interconnected, and the CPUC puts net surplus compensation at the annual true-up at about $0.02 to $0.03 per kWh.

California: the roof rules

The 2022 California Residential Code R324.6 calls for at least two pathways on separate roof planes, each not less than 36 inches wide. At a horizontal ridge it sets an 18-inch setback for arrays covering 33 percent or less of the plan-view roof area, and 36 inches above that. The 2025 code took effect January 1, 2026, and its values may differ, so ask your building department which edition it’s applying.

For snow or ice, your installer’s warranty and written care instructions are still the papers that answer the question, and the California cleaning page covers what a cleaning visit is.

A log for the cold months

A dated log gives whoever you call something to compare against. Each month, write the date, what the inverter display or app shows, and anything unusual you can see from the ground, such as an error message or a monitoring app that’s gone offline. Photograph the display, not the roof, and keep the photos with the warranty papers.

Before the first snow, ask your installer in writing three things: who services the system, what the warranty says about snow and ice, and who to call when the display shows a drop.