How many nuclear reactors would it take to power St. Louis?
Scenario estimates of how many reactors of various sizes would be required to cover the St. Louis, MO-IL metro's annual electricity demand — and what it would take with other power sources.
Reactors needed to power St. Louis
Switch between reactor sizes. Each tab shows the count, the icon grid scaled to that count, and rough capital cost bands. Default view is large reactors — the fewest, biggest units.
Conventional gigawatt-scale plants like the AP1000 deliver firm baseload power with the smallest land footprint per MWh of any source. Build times are 7–12 years for first-of-a-kind delivery; the largest tradeoff vs alternatives.
St. Louis's current energy usage
Where the metro's grid actually gets its power today, and how its electricity demand has trended over the last 25 years.
Replacing the fossil portion (68% of generation) with nuclear would avoid roughly 15,179,702–22,266,338 tons of CO₂ per year for this metro's share of demand. Range uses EPA eGRID 2023 Total Output rate (low) and Non-baseload rate (high) for SRMW. See methodology.
What it takes to power St. Louis with alternative energy sources
Same annual MWh as the reactor scenarios — just translated to other source archetypes. Variable sources (solar, wind) include a firm-equivalent figure for storage-backed 24/7 power. Switch tabs to compare.
Variable output. Raw count assumes same annual MWh; firm equivalent accounts for storage and oversizing needed for 24/7 power.
All sources, scaled to St. Louis
Every source overlaid on the metro outline at true scale. The visual gut-check on land use: nuclear's footprint nearly disappears against firm-equivalent renewables.
All sources, scaled to St. Louis
Each colored square shows the land area a single source would need to cover this metro's entire 36.0 TWh of annual electricity demand — drawn at the same scale as the metro outline below it. Solar and wind use firm-equivalent capacity (with storage) per NREL Standard Scenarios.
Data provenance
- Demand basis
- MO state per-capita × metro population (v2 methodology, 2025 basis year)
- Demand period
- historical state trend: 2001–2025
- Population source
- U.S. Census Vintage 2025 estimates
- Reactor cost basis
- NREL ATB 2024, with widened bands for FOAK uncertainty
- Grid mix source
- EPA eGRID 2023 (subregion SRMW)
- Source comparisons
- Hardcoded archetypes — see methodology page
These figures are screening-level scenario estimates. They are not forecasts, project proposals, or permitting determinations.