Solar resource
Your solar production in St. Louis
4.67 avg peak sun hours/day
Monthly avg solar radiation (kWh/m²/day) — St. Louis, MO. Bars update to show estimated kWh production when you use the calculator above.
Utility rate
Ameren Missouri electricity rate
$0.11/kWh residential
- Utility
- Ameren Missouri
- Residential rate
- $0.11/kWh (blended)
Ameren Missouri is the primary investor-owned electric utility serving the City of St. Louis and St. Louis County. Missouri's net metering law (RSMo Section 393.320) requires 1:1 net metering for residential systems up to 100 kW — one of the most generous net metering caps in the country. Most states that have revised net metering in recent years have reduced the cap or moved to avoided-cost crediting; Missouri's 100 kW residential cap at full retail rate remains intact as of 2026 and is a meaningful differentiator for homeowners considering larger systems. St. Louis receives approximately 4.67 peak sun hours per day annually — moderate for the continental U.S. Winter cloud cover (December: 2.22 kWh/m²/day) is the primary production constraint, while summer months produce strongly (June: 6.48 kWh/m²/day).
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Incentives
Available solar incentives in St. Louis, MO
Federal + state + utility
| Incentive | Type | Value | Scope |
|---|---|---|---|
| Federal Solar Investment Tax Credit (ITC) | Tax Credit | 30% of system cost | Federal |
| Missouri Net Metering (1:1 at Retail Rate, up to 100 kW) | Net Metering | Full retail rate ($0.110/kWh) for exported solar energy, up to 100 kW system size | State |
| Missouri Solar Energy System Property Tax Exemption | Exemption | 100% of added home value from solar system | State |
Incentive amounts and eligibility rules change. Verify current terms with your installer and a tax professional before installation.
System cost
Cost breakdown (6 kW default)
- Gross system cost
- $17700
- Federal ITC (30%)
- −$5310
- Net system cost
- $12,390
- Installed cost per watt
- $2.95/W
Lawrence Berkeley National Laboratory Tracking the Sun 2024 — Midwest median installed cost for systems 3–10 kW. St. Louis's installer market is growing but less competitive than larger Sunbelt cities; $2.95/W is a reasonable installed cost estimate for a standard 6 kW system.
Payback & long-term value
25-year outlook
- Annual savings (yr 1)
- $914
- Simple payback period
- 13.6 years
- 25-year net savings
- $17990
- Assumed annual rate increase
- 2.5%/year
25-year estimate uses flat electricity rate for conservative baseline. Accounting for 2.5% annual rate increases, lifetime savings increase substantially.
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How it works
How solar savings work in St. Louis
- Your panels capture St. Louis sunlight across all four seasons St. Louis averages 4.67 peak sun hours per day annually, with strong summer production (June: 6.48 kWh/m²/day) and reduced winter output (December: 2.22 kWh/m²/day). The region experiences significant cloud cover from November through February, but spring and summer production strongly compensates. A 6 kW system in St. Louis produces roughly 8,310 kWh per year.
- You use solar power instead of buying from Ameren Missouri Every kWh your system produces during daylight reduces what you purchase from Ameren Missouri at approximately $0.110/kWh. A 6 kW system producing 8,310 kWh/year saves approximately $914 annually at current rates.
- Excess power earns full retail credit under Missouri's generous net metering law Missouri law (RSMo §393.320) requires Ameren Missouri to credit excess solar exported to the grid at the full retail rate — $0.110/kWh — for residential systems up to 100 kW. This 1:1 net metering at retail rate is significantly more favorable than states that have moved to avoided-cost crediting, and the 100 kW cap means even a large residential system qualifies.
- You claim the 30% federal tax credit In the tax year your system is installed, claim the federal Investment Tax Credit (30%) — $5,310 on a $17,700 system. This reduces your net system cost to $12,390. Missouri does not have a separate state solar income tax credit, but the property tax exemption on the system's added home value provides ongoing savings.
- Your savings grow as Ameren Missouri rates rise over time As Ameren Missouri rates increase over time (historically approximately 2.5%/year), your solar savings compound. Over 25 years, a 6 kW system in St. Louis nets approximately $17,990 after recovering the installation cost — reasonable economics anchored by Missouri's strong 1:1 retail net metering framework.
FAQ
Common solar savings questions for St. Louis, MO
How much can I save with solar in St. Louis?
A 6 kW system in St. Louis produces roughly 8,310 kWh/year and saves approximately $914/year at Ameren Missouri's current blended rate of ~$0.110/kWh. After the 30% federal tax credit ($5,310), the net system cost is about $12,390, with a payback period of approximately 13.6 years and estimated 25-year net savings of $17,990.
Why is Missouri's net metering law considered unusually generous?
Missouri Revised Statutes Section 393.320 requires investor-owned utilities including Ameren Missouri to offer 1:1 net metering at the full retail rate for residential systems up to 100 kW. Most states that have revised their net metering rules in recent years have reduced the system size cap (often to 10–25 kW) or moved to below-retail avoided-cost crediting for exports. Missouri's combination of full retail credit and 100 kW cap means homeowners with larger systems — including those considering commercial-scale rooftop arrays — still receive full retail value for every kWh exported. This is a meaningful long-term differentiator for St. Louis solar economics.
Is St. Louis a good city for solar panels?
St. Louis is a moderate solar market. With 4.67 peak sun hours per day, it produces meaningfully more solar energy annually than cities like Chicago (3.8) or Seattle (4.1), but significantly less than Southwest cities like Tucson (6.39) or Albuquerque (6.77). The payback period is longer (approximately 13–14 years) compared to high-sun cities, but Missouri's strong net metering law and property tax exemption improve the long-term economics. System sizing for near-zero grid import (rather than export optimization) maximizes savings under current Ameren rates.
Does Missouri have a state solar tax credit?
No. Missouri does not have a state income tax credit specifically for residential solar installation. The primary incentives for St. Louis homeowners are the 30% federal Investment Tax Credit (ITC), Missouri's 1:1 retail net metering (up to 100 kW), and the Missouri solar property tax exemption (RSMo §137.100), which exempts the added home value from solar from property tax assessment.
How does St. Louis solar compare to other Midwest cities?
St. Louis compares favorably against northern Midwest cities. St. Louis (4.67 peak sun hours) outperforms Chicago (3.8), Detroit (4.0), and Minneapolis (4.5) on annual solar resource. Ameren Missouri's rates are modest compared to utilities in some northern cities, but Missouri's 1:1 net metering at retail is a standout policy advantage. The payback period of 13–14 years is longer than the Sun Belt but competitive for the Midwest region.
What is the Missouri solar property tax exemption?
Missouri Revised Statutes Section 137.100 exempts the value added to a home by a solar energy system from property tax assessment statewide. A 6 kW system typically adds approximately $12,000–$16,000 to home value in the St. Louis market. At St. Louis City/County combined effective property tax rates (approximately 1.7–2.1%), the exemption saves roughly $204–$336 per year — a modest but ongoing benefit in addition to the federal ITC and net metering savings.
Sources
Data sources and freshness
- https://pvwatts.nrel.gov/
- https://www.ameren.com/missouri/residential/rates
- https://revisor.mo.gov/main/OneSection.aspx?section=393.320
- https://revisor.mo.gov/main/OneSection.aspx?section=137.100
- https://openei.org/apps/USURDB/
- https://dsireusa.org/state/missouri/
- https://emp.lbl.gov/tracking-the-sun
- https://www.energy.gov/eere/solar/homeowners-guide-federal-tax-credit-solar-photovoltaics
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Disclaimer: This calculator provides estimates for informational purposes only — not financial or investment advice. Solar savings depend on actual shading, roof orientation, energy usage patterns, rate changes, and equipment performance. Consult a licensed installer and a tax professional before making purchasing decisions. Verify incentive eligibility with official sources. Data last verified 2026-04-19.