The state net metering requirement does not reach you
Ohio Revised Code Section 4928.67 is the provision requiring net metering, and it applies to the investor-owned electric utilities the Public Utilities Commission regulates. Municipal electric systems operating under their own charters are not subject to it.
Hamilton operates its own municipal electric utility, so what you are offered for exported generation is a decision made by the city rather than a requirement imposed by the state.
Many Ohio municipals do offer some version of net metering voluntarily, and some are generous. The point is not that municipal is worse, it is that municipal is not guaranteed, and the difference between retail-rate crediting and a low wholesale rate is the difference between a good project and a poor one.
This is also why so much Ohio solar content misleads here. Guidance describing the statutory arrangement is accurate for AEP Ohio, Duke, AES Ohio and the FirstEnergy companies, and a reader who does not notice the distinction applies it to the wrong account.
The questions to put to the city utility
Ask first whether net metering is offered at all, and if so what exported energy is credited at and on what basis that rate is set. A rate tied to a fuel or wholesale figure moves; a stated retail credit does not.
Ask whether credits roll over between billing periods and whether they expire. An expiry puts a hard ceiling on useful system size, because generation beyond what you can absorb before the reset is lost rather than banked.
Ask about the interconnection process: what application is required, whether approval must come before installation, what it costs and how long it takes. Programmes requiring approval first are the ones where installing early costs people the entire benefit.
Get the answers in writing and check them against whatever your installer assumed. An installer working mostly in Duke or AES territory nearby may carry the statutory arrangement across without realising it does not apply in Hamilton.
Locally set terms can also be locally changed
Because the arrangement is set by the city rather than by the Public Utilities Commission, it can be revised by the city. There is no regulatory proceeding behind it and no commission decision to appeal to.
That is not automatically a disadvantage. A municipal utility answerable to its own residents can be more generous than a regulated one, and several are. It does mean the terms are policy rather than entitlement.
So ask two further questions: how long is any rate you are quoted guaranteed for, and what process would be followed to change it. Knowing the mechanism is more useful than assuming stability.
Customers elsewhere have learned this the hard way. Municipal utilities in other states have halved solar buyback rates by council vote with little notice, so it is a reasonable thing to ask about before committing to a twenty-five year asset.
What is true whatever the answer
Self-consumption is worth your retail rate under any arrangement, because electricity used in the moment it is generated avoids a purchase. That is the stable part of the return while you establish the rest.
So it is safe to design around your daytime consumption before the export terms are settled. Sizing against your own daylight draw is the conservative approach and does not depend on the unknown.
Ask for the system modelled two ways, once assuming generous export crediting and once assuming very little. If it only works under the generous assumption, you have learned something important before signing.
The 30 percent Residential Clean Energy Credit under Section 25D expired for property placed in service after 31 December 2025, so a cash or loan purchase receives no federal credit. Section 48E survives at 30 percent for third-party owners under a lease or power purchase agreement.