Missouri gives you full retail one-to-one netting, which is the treatment most states have spent the last five years dismantling. Then it attaches a clock. Any credit you bank expires uncompensated twelve months after it is issued, under the Net Metering and Easy Connection Act. Nobody sends you a warning, nothing appears on the bill, and the credit simply stops existing. That single sentence in the statute decides what size system belongs on a Missouri roof, and it is the reason the biggest system a salesperson can sell you is rarely the right one.
The Twelve-Month Clock on Every Credit
The mechanism is worth understanding exactly, because the generosity has a hard limit. Within each monthly billing period you net one-to-one at the full retail rate: a kilowatt-hour you export cancels one you import, at the rate your own supplier bills, modeled here at the 12.36¢ statewide average. If you finish the month with more exports than imports, that surplus is not carried at retail. It is credited to your next bill at the utility’s avoided fuel cost, a far lower figure, and it then sits there with an expiry date.
To see how Missouri pricing stacks up against every other state, browse our national solar cost guide.
Stage | What your kilowatt-hour is worth | What can go wrong |
|---|---|---|
Used in the house as generated | Full 12.36¢ retail | Nothing. This is the best outcome available. |
Netted within the same month | Full 12.36¢ retail | Nothing, provided imports and exports fall in the same billing period. |
Monthly surplus carried forward | Avoided fuel cost only | A steep markdown the moment you generate more than you use in a month. |
Carried credit at twelve months | Nothing at all | Expires uncompensated. Spring surplus can die before winter uses it. |
The last two rows show the tradeoff: monthly surplus is marked down, and the leftover credit expires. Missouri rewards matching your generation to your consumption month by month, and quietly penalizes the classic strategy of overbuilding in spring to coast through winter. A system sized 20% larger than your usage does not bank 20% more value here. It banks a markdown with an expiry date on it.
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Cheap Power Is the Real Obstacle Here
Missouri electricity costs 12.36¢ per kilowatt-hour, which ranks 48th in the country. That is excellent news for your bill and awkward news for solar, because every kilowatt-hour you displace is worth less than it would be almost anywhere else. The typical household spends about $123.72 a month on 1,001 kWh, and a system has to work against that modest number rather than against a punishing one.
Install pricing helps. At $2.66 per watt (as of March 1, 2026) Missouri ranks 10th cheapest, and the typical system is 8.59 kW at about $22,849 gross, producing roughly 12,017 kWh a year around Kansas City. Consumed as generated, that output is worth about $1,485 a year at the statewide average, a 15.4-year payback. Rates have risen 2.99% a year over the last five, which shortens that gradually, and the federal residential credit is $0 for systems you own whose installation is completed after December 31, 2025 under Public Law 119-21, so there is no subsidy waiting to rescue a weak quote.
Sizes at the benchmark, gross before incentives; the expiry rule makes the middle rows the safe ones for most households:
| System size | Gross cost at $2.66/W |
|---|---|
| 5 kW | $13,300 |
| 6 kW | $15,960 |
| 8 kW | $21,280 |
| 8.59 kW, the typical Missouri system | $22,849 |
| 10 kW | $26,600 |
| 12 kW | $31,920 |
The monthly bill, the yearly value and the payback all run on the statewide average, which is ranking context rather than a billed rate. Ameren Missouri, Evergy Metro and Evergy Missouri West each file their own residential rates, so rerun the chain with the rate on your own bill.
Sizing Against the Expiry, Not the Roof
Practically, this is what the twelve-month clock means when you are reading a proposal. A quote that offsets 100% of your annual usage sounds ideal, but annual is the wrong unit in a state that nets monthly and expires yearly. Ask instead for a month-by-month production and consumption table, and look at what happens in April, May and June, when output peaks and air conditioning has not started.
- Aim for high self-consumption rather than high offset. The two are not the same, and only the first is worth full retail.
- Shift what you can into daylight. Water heating, laundry, EV charging and pool pumps move real money at a 12.36¢ spread against avoided-cost surplus.
- Treat a battery as a credit-expiry hedge, not just a backup. Storing an evening’s worth keeps kilowatt-hours at retail value instead of sending them into a markdown.
- Ask what your utility’s avoided fuel cost actually is. Ameren’s summer figure is quoted in the market near 5.39¢, but we could not confirm it against the tariff sheet, and the winter figure is not something we would guess at. Evergy Metro and Missouri West apply the same twelve-month expiry.
Who Should Wait in Missouri
- Anyone being sold maximum roof coverage. In a monthly-netting, annual-expiry state, oversizing converts retail kilowatt-hours into expiring ones. Get the monthly table before you sign.
- Daytime-empty households with no shiftable load and no battery. The full retail rate only applies to what you net within the month.
- Anyone quoted materially above $2.66 per watt. With 12.36¢ power and no federal credit, install price is doing most of the work in this equation.
- Short-stay owners. Even a strong self-consumption profile is looking at 15 years here.
Missouri Solar Cost FAQs
About $2.66 per watt installed, the 10th cheapest in the country, as of March 1, 2026. The typical Missouri system is 8.59 kW, roughly $22,849 before incentives, producing around 12,017 kWh a year in Kansas City sun.
Yes, full retail one-to-one within each monthly billing period, for systems up to 100 kW, under the Net Metering and Easy Connection Act. The catch is what happens to a surplus: monthly excess is credited at the utility avoided fuel cost rather than retail, and any credit expires uncompensated twelve months after it is issued.
Yes. Credits expire uncompensated twelve months after issuance, so a spring surplus can disappear before winter demand arrives to use it. This is why sizing to your monthly consumption matters more in Missouri than maximising annual offset, and why a battery here functions partly as protection against expiry.
About 15.4 years for a household that consumes what it generates. Missouri electricity is cheap at 12.36¢ per kWh, 48th in the country, so each displaced kilowatt-hour is worth less than in most states. Rates have risen 2.99% a year over five years, which shortens the figure gradually.
Not for systems you buy yourself. Section 25D is $0 for owner-purchased systems whose installation is completed after December 31, 2025 under Public Law 119-21. The commercial credit can still reach residential rooftops through third-party ownership where that is available, so ask any installer to state plainly which credit, if any, their pricing assumes.
Your monthly shape decides this, not your annual total. Enter your ZIP code and we will bring you installers who will show you the month-by-month table.
See the month-by-month table before you sign
Methodology: cost figures use the EcoGen Solar Cost Index for Missouri, $2.66 per watt as of March 1, 2026, with payback modeled with no federal residential credit for owner-purchased systems, full retail netting within the monthly period, rate escalation at the state 5-year average of 2.99%, 0.5% annual panel degradation, and a 25-year horizon. The Ameren summer avoided-cost figure circulating in the market is quoted as indicative only and flagged as unconfirmed against the tariff sheet.
References & Research Sources
EcoGen America reviewed Missouri’s net metering statute and rules, Public Service Commission case terms, federal electricity price and utility datasets, Census home-value data, and federal tax guidance for this Missouri solar cost guide. Sources were accessed between June 10 and August 17, 2026, unless another date is listed below.
- Missouri Legislature. RSMo 386.890: Net Metering and Easy Connection Act. Monthly retail netting, avoided-fuel-cost treatment of surplus, and the twelve-month credit expiry, with rules at 20 CSR 4240-20.065. Accessed June 11, 2026.
- Missouri Public Service Commission (PSC). Case EE-2019-0056: Evergy Net Metering Terms. Evergy Missouri Metro and Missouri West treatment of net excess generation. Accessed June 11, 2026.
- U.S. Energy Information Administration (EIA). Electric Power Monthly, Table 5.6.A. Average residential electricity prices by state, March 2026 edition. Accessed June 10, 2026.
- U.S. Energy Information Administration (EIA). Form EIA-861: Annual Electric Power Industry Report, 2024. Residential customer counts for Union Electric, Evergy Metro, Evergy Missouri West, and Empire District. Accessed June 10, 2026.
- U.S. Census Bureau. American Community Survey, 2024. Median home value data used for cost-to-value context. Accessed June 11, 2026.
- Internal Revenue Service (IRS). One, Big, Beautiful Bill Provisions. Guidance on Public Law 119-21, including termination of the Section 25D residential credit for systems whose installation is completed after December 31, 2025. Accessed August 15, 2026.
