Retail inside your usage, avoided cost beyond it
The Oklahoma Corporation Commission requires investor-owned utilities to offer net metering for systems up to 300 kW. Within a billing period, generation offsets consumption at the retail rate.
That is better than it sounds, and better than several neighbouring arrangements. Under monthly netting your midday production offsets your evening usage within the same month, so timing through the day matters far less than it does in Georgia or Indiana.
Where the arrangement turns is at genuine surplus. The Commission rules do not require utilities to compensate excess beyond your usage at the full retail rate, and both major utilities credit it at avoided cost, roughly 3 to 5 cents per kWh.
Against a retail average around 13.4 cents, that is roughly a third of the value. So the first kilowatt hours a system produces are worth about three times the last ones, if the last ones are surplus.
The sizing rule that follows
Build to your consumption and no further. That is an unusually clean rule and it falls directly out of the tariff rather than being a general caution.
A system matched to your annual usage captures the retail-rate offsetting almost entirely. Every kilowatt hour beyond that is surplus, credited at roughly a third the value while having cost full price to generate.
Ask what percentage of your annual usage the proposed system covers, and ask to see the twelve months of bills the design was built from.
A design meaningfully above 100 percent needs a specific reason. A concrete planned increase in load, such as an electric vehicle or a heat pump, is one. A general expectation of using more electricity is not.
Oklahoma summers work in your favour
Air conditioning is a very large load through an Oklahoma summer, and it runs hardest in the afternoon, which is when a solar array produces most.
Under monthly netting that overlap matters less than it would under instantaneous netting, because production and consumption are netted across the period anyway.
But it still helps at the margin, because a household with heavy summer cooling consumes more of its own generation and therefore reaches the surplus threshold later.
Ask for the analysis month by month rather than as an annual total. In a state where surplus is worth a third of retail, seeing which months tip into surplus is exactly the view that tells you whether the design is right.
Building the number without the federal credit
The 30 percent federal Residential Clean Energy Credit under Section 25D expired for property placed in service after December 31, 2025, so a cash or loan purchase in Oklahoma City receives no federal tax credit, and Oklahoma has no state solar tax credit.
Section 48E survives at 30 percent for third-party owners under leases and power purchase agreements, so ask what a provider claims and what reaches you in the rate.
What exists is retail-rate offsetting within the billing period, avoided cost for surplus beyond your usage, and the electricity you stop buying at around 13.4 cents per kWh.
Ask for the savings split into those two lines with the monthly profile shown, so you can see which months tip into surplus and how much of the system output lands there.