Short answer: for most St. Louis homeowners who own their home and plan to stay 7+ years, solar is worth it. Here's the complete analysis — including who it doesn't make sense for.

Missouri's Solar Resource: Better Than You Think

Missouri averages 4.8 peak sun hours per day — ranking it in the top third of states for solar potential. St. Louis metro specifically receives excellent solar irradiance due to its latitude and relatively low cloud cover compared to the Pacific Northwest or New England. A properly sized system produces 4.5–5.5 kWh per watt of installed capacity annually.

Utility Rates: The Math That Drives ROI

Ameren Missouri residential rates run approximately $0.11–$0.14 per kWh in 2026 (including distribution charges). Rates have increased an average of 2–3% per year over the past decade. A solar system that offsets your entire usage saves $1,000–$1,600 per year on a typical St. Louis home. At 2.5% annual rate increases, that number grows substantially over 25 years.

Payback Period and Lifetime ROI

Average payback period for a properly sized St. Louis area system after the 30% ITC: 7–10 years. System expected productive life: 30–40 years. Lifetime