How to work out the right size, step by step
Start with your own consumption rather than your roof. Take twelve months of electricity bills and add up the kilowatt hours, not the dollars. That annual total is the target the system should be built around, and it is the single number an installer most often is not given.
Divide that total by the local yield figure of roughly 1,186 kilowatt hours a year per kilowatt installed. The result is the approximate panel capacity that would cover your consumption over a year on a well oriented, unshaded plane. If your best available plane faces east or west, or carries shade for part of the day, the capacity needed will be higher, so ask the installer to redo the calculation for the plane you can actually use.
Then ask Ohio Edison the question that decides whether to stop there. The Ohio statute requires credits be valued at the full retail rate, with excess credits rolling forward as kilowatt-hour credits to subsequent months rather than converting to cash. But annual true-up provisions vary by utility tariff: some Ohio utilities reset accumulated credits to zero at the end of a 12-month period, forfeiting any remaining balance, and others permit indefinite rollover.
If your tariff resets, stop at your annual consumption, because everything above it is surrendered once a year for nothing. If it rolls over indefinitely, you can reasonably build a little beyond current use where a known future load is coming, such as an electric vehicle or a heat pump. Those are the only two answers, and the difference between them is worth a phone call before you sign anything.
Who owns the roof, and what decides its output
Single-detached houses are 68.9 percent of Canton's 33,836 housing units per the Census Bureau's 2020-2024 American Community Survey estimates. For roughly seven in ten households the roof, the electrical service and the decision belong to one owner, so no third party needs to agree before quotes are worth collecting.
For the rest, the roof generally belongs to a building owner or is shared, and the route is a written proposal to that owner covering cost, ownership of the equipment, insurance and roof replacement, rather than a quote for your unit. It is worth establishing which category you are in before a site visit rather than after.
Once ownership is settled, output comes down to three things. Orientation: a south-facing unshaded plane produces the most, east and west planes give up output, and a north plane rarely repays the hardware. Shading: the costliest variable, because it removes production in the middle of the day, and it needs assessing across the year rather than at the hour of the site visit. And the roof covering: panels outlast most coverings, so one within a few years of replacement should be replaced first rather than paying later to remove and reinstall the array.
Rebuilding the arithmetic without the federal credit
The 30 percent federal residential tax credit under Section 25D applied through December 31, 2025 and is not available for a purchased home system placed in service after that date. A purchase in Canton now cannot claim it, and the loss is large enough to change the shape of the decision rather than just the timing.
Anything you read that still applies the credit is describing an earlier year. That includes online calculators, published guides and quotes prepared from templates, and it is often carelessness rather than dishonesty, but the payback figure is wrong either way. The test is simple: ask the installer to show you the same calculation with the credit removed.
What remains on the value side is straightforward and worth stating plainly. Retail-rate credits for exported power under the Ohio statute, the electricity you no longer buy from the grid, and whatever the true-up terms of your Ohio Edison tariff allow you to carry forward. There is no state solar rebate in Ohio to add to that.
If you take a lease or a power purchase agreement rather than buying, the provider may claim the business version of the credit under Section 48E and reflect part of that value in the rate they offer you. What they claim and what reaches you are separate questions, so put both to the provider and confirm with a tax advisor rather than with the sales material.