Marion County, Missouri: Power, Data Centers and the Local Economy
Home to Hannibal and Palmyra
The data center boom is not abstract in Marion County: it is on the ground here. The SAVRN Data Center Map lists 1 data center in Marion County. Marion County is home to Hannibal, Palmyra and part of Monroe City (509 of its 2,714 residents). The Moratorium Tracker holds 1 local measure here (0 in force); the latest is “Rescinded county moratorium on data centers”. 76 MW of new generation is planned here across 2 units, led by Missouri Jnt Muni.Pwr Elec. Ut. Comm. (natural gas). Construction employs 506, down 12.0% since 2019.
Cities and towns in Marion County
Marion County is home to Hannibal, Palmyra and part of Monroe City (509 of its 2,714 residents).
- Hannibal also extends into Ralls County.
- Monroe City also extends into Monroe County.
Unincorporated communities (governed by the county): Philadelphia.
Residents are 2025 Census estimates for the part of each city, town or township inside this county. Census publishes no annual estimate for unincorporated communities.
What changed in Marion County
1st = the most. Ranks cover counties with a value on record.
| Measure | Then | Now | Change | Rank in Missouri |
|---|---|---|---|---|
| Population (2020 → 2025) | 28,480 | 28,525 | ▲ 0.2% | 38th of 115 by size |
| Total jobs (2019 → 2025) | 13,325 | 12,987 | ▼ 2.5% | 89th of 115 by growth |
| Average annual pay (2019 → 2025) | $38,497 | $53,464 | ▲ 38.9% | — |
| Construction jobs (2019 → 2025) | 575 | 506 | ▼ 12.0% | 63rd of 71 by growth |
| Unemployment rate (2019 → August 2026) | 3.3% | 3.9% | ▲ 0.6pts | — |
| Generating capacity added since 2019 | — | 0 MW | — | |
| Generating capacity retired since 2019 | — | 20 MW | — | |
| Planned generation (Aug 2026) | — | 76 MW | no fleet today | 12th of 14 by size |
20 MW has retired here since 2019, including Hannibal - Oakwood Substation (petroleum, 16 MW, 2021). Unemployment was 3.9% in August 2026, against 3.3% in 2019. Employers here counted 12,987 jobs in 2025, down 2.5% from 2019. Union Electric Co - (MO) is the largest utility serving Marion County, one of 7 with territory here. Its residential customers paid an average 12.56¢/kWh in 2024. 28,525 people live here, up 0.2% since 2020.
Who powers Marion County
Utilities with service territory in Marion County
| Utility | Ownership | Service | Residential customers (systemwide) | Residential price, 2024 | Commercial share of sales |
|---|---|---|---|---|---|
| Union Electric Co - (MO) | Investor Owned | Bundled | 1,095,619 | 12.56¢ | 44% |
| City of Hannibal - (MO) | Municipal | Bundled | 7,639 | 12.91¢ | 12% |
| Missouri Rural Electric Coop | Cooperative | Bundled | 5,049 | 13.62¢ | 11% |
| Lewis County Rural E C A | — | — | — | — | — |
| City of Monroe City - (MO) | — | — | — | — | — |
| City of Palmyra - (MO) | — | — | — | — | — |
| Ralls County Electric Coop | — | — | — | — | — |
Customer counts, prices and sales shares cover each utility's whole system in the state, not only this county. Commercial sales include data centers.
No operating power plant is located in Marion County in the EIA-860M inventory. Its power comes over the grid from plants elsewhere.
Planned generation 2
| Plant | Technology | MW | Status | Year | Owner |
|---|---|---|---|---|---|
| Hannibal Energy Center | Natural Gas Fired Combustion Turbine | 38 MW | Planned, approvals not started | 2029 | Missouri Jnt Muni.Pwr Elec. Ut. Comm. |
| Hannibal Energy Center | Natural Gas Fired Combustion Turbine | 38 MW | Planned, approvals not started | 2029 | Missouri Jnt Muni.Pwr Elec. Ut. Comm. |
Retired since 2019
| Plant | Technology | MW | Year |
|---|---|---|---|
| Hannibal - Oakwood Substation | Petroleum | 16 MW | 2021 |
| Hannibal - Wastewater Treatment Plant | Petroleum | 2 MW | 2021 |
| Hannibal - Water Treatment Plant | Petroleum | 2 MW | 2021 |
The Marion County labor market
| Industry (2025) | Jobs | Average pay | Concentration vs U.S. |
|---|---|---|---|
| All industries | 12,987 | $53,464 | 1.00 |
| Construction | 506 | $69,644 | 0.74 |
Concentration is the BLS location quotient: 1.0 means the industry holds the same share of local jobs as it does nationally. Industry rows count private employers; cells BLS suppresses are left out.
Data centers and local rules in Marion County
1 data center in Marion County is on the SAVRN Data Center Map.
Local measures 1
| Measure | Status | Date | |
|---|---|---|---|
| Rescinded county moratorium on data centers | Failed / vetoed | 2026-01 |
Marion County and its neighbors
Of the 6 counties that border Marion County, Adams County carries the most build-out activity: data centers, planned generation and operating plants combined.
| County | Population | Jobs since 2019 | Operating MW | Planned MW | Data centers | Local measures |
|---|---|---|---|---|---|---|
| Marion County | 28,525 | ▼ 2.5% | — | 76 MW | 1 | 1 |
| Adams County IL | 64,267 | ▼ 1.2% | 12 MW | 140 MW | — | — |
| Lewis County | 9,879 | ▼ 6.8% | — | — | — | — |
| Monroe County | 8,959 | ▲ 2.6% | — | — | — | — |
| Pike County IL | 14,231 | ▼ 3.9% | 78 MW | 1 MW | — | — |
| Ralls County | 10,444 | ▲ 2.1% | 58 MW | 66 MW | — | 1 |
| Shelby County | 5,870 | ▲ 1.0% | 15 MW | — | — | — |
More of Missouri
Marion County, answered from the record
Who provides electricity in Marion County, Missouri?
7 utilities have service territory in Marion County in the EIA-861 2024 report: Union Electric Co - (MO), City of Hannibal - (MO), Missouri Rural Electric Coop, Lewis County Rural E C A. The largest, Union Electric Co - (MO), charged residential customers 12.56¢/kWh on average in 2024.
What county is Hannibal, MO in?
Hannibal is in Marion County, Missouri. About 16,521 people live there (2025 Census estimate).
How much new power is planned in Marion County?
76 MW across 2 units in the August 2026 EIA-860M inventory, 0 MW of it under construction or built. The largest owner is Missouri Jnt Muni.Pwr Elec. Ut. Comm..
Are there data centers in Marion County?
Yes. The SAVRN Data Center Map lists 1 data center in Marion County.
Is Marion County adding jobs?
Employers counted 12,987 jobs in 2025 against 13,325 in 2019 (-2.5%, BLS QCEW). Construction went from 575 to 506.
Does Marion County have a data center moratorium?
The SAVRN Moratorium Tracker holds 1 local measure for Marion County, 0 in force.