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408 MW Hydro operating in Reynolds, MO — Midcontinent Independent Transmission System Operator, Inc..
408 MW
Nameplate Capacity
2
Generators
units
Hydroelectric Pumped Storage
Technology
1963
Operating Since
Coordinates
37.5208, -90.8347
County
Reynolds, MO
| Field | EIA | GEM | Wikidata |
|---|---|---|---|
| Operator | Union Electric Co - (MO) | Union Electric | — |
| Owner(s) | Union Electric Co - (MO) | Ameren | — |
| Status | Operating | operating | — |
The Taum Sauk pumped storage plant is a power station in the St. Francois mountain region of Missouri, United States about 90 miles (140 km) south of St. Louis near Lesterville, Missouri, in Reynolds County. It is operated by Southeastern Ameren Missouri.
Read more on WikipediaThe Taum Sauk pumped storage plant is located in Reynolds County, Missouri. It has a total capacity of 408 MW across two hydroelectric pumped storage generators. The plant's primary fuel source is water (WAT). Taum Sauk is owned and operated by Ameren, specifically Union Electric Co - (MO), and began operating in 1963. It is the largest of four pumped storage plants in Missouri, and ranks 60th out of 194 such facilities nationally.
Taum Sauk operates within the Midcontinent Independent Transmission System Operator (MISO) balancing authority and the SERC NERC region. Financial data indicates an installed cost of $268.77 per kW, according to FERC filings. The plant has been the subject of nine news articles, with five focusing on industry-related topics and four concerning hazards.
Generated from EIA, GEM, and public data sources
ISO/RTO
MISO
Market
ISO/RTO Member
NERC Region
SERC — SERC Reliability Corporation
Balancing Authority
−10.5K MWh
Net Charging
-159.8K MWh
Annual Net Energy
-4.5%
Capacity Factor
Positive values indicate net discharge (generation exceeds station load). Negative values indicate net charging. Pure battery storage plants are typically net negative due to round-trip efficiency losses.
UNION ELECTRIC COMPANY · Data from 2015–2024
$386/kW
Installed Cost
$12.6/MWh
Operating Cost
Annual Capital & Operating Expenses
Cumulative Installed Cost
Per-Unit Cost Trends
Market Position
ISO/RTO Market
MISO
LMP Node
AMMO.TS1
Pricing Hub
ILLINOIS.HUB
Location Type
Generation Node
Node Source
EIA-860 direct report
Last updated 2026-03-26
View all 8 articlesNo ask pi reports yet for this entity.
ask pi about Taum SaukMidcontinent Independent Transmission System Operator, Inc.. (MISO)
Grid Voltage
138.0 kV
Regulatory Status
RE — Regulated
Entity Type
Investor-Owned Utility
Sector
Electric Utility