Data centers and new power in Mason County, IL
1.0 GW of new power is waiting to connect to the grid in Mason County, IL — 5 active requests. Typical wait: 4.1 years. 3 projects are built, 10 withdrawn. Data as of 14 October 2026.
Is one near your house?
We have not mapped a large AI data center inside Mason County itself — but we track the biggest ones nationally, and requests to connect new power here are on the public record.
What is happening with electricity in Mason County
Every new power plant, battery or big customer has to join a waiting list before it can plug into the grid. This is what that list looks like in Mason County right now.
Where every request ever filed here ended up
Most requests in the US are withdrawn — a developer tests a site and moves on. That is normal, not a warning sign for Mason County.
What kind of power is asking to connect
By capacity requested. Data as of 14 October 2026.
All the numbers
18 requests ever filed
Source: interconnection queues published by MISO. Parsed and normalised by Watt Street. Data as of 14 October 2026. A queued project is a request, not a commitment.
Outcome of every request filed here
| Outcome | Projects | Capacity | Share |
|---|---|---|---|
| Built | 3 | 391 MW | 16.7% |
| Still waiting | 5 | 1.0 GW | 27.8% |
| Withdrawn | 10 | 1.3 GW | 55.6% |
| Paused | 0 | — | 0.0% |
Waiting to connect, by type of power
| Type | Projects | Capacity requested |
|---|---|---|
| Solar | 3 | 642 MW |
| Wind | 2 | 400 MW |
Key dates for projects here
1 dated · next closes 2027-09-10 (MISO)
| Queue | What closes | Closes | Standing |
|---|---|---|---|
| MISO | MISO DPP-2026 Definitive Planning Phase application deadline Attachment X of the tariff and BPM-015. | 2027-09-10 | confirmed source |
| FERC | FERC large-load show cause — stakeholder comments on RTO responses Comments on the six RTO/ISO responses to the FPA section 206 show-cause orders of 18 June 2026 (PJM EL26-67, SPP EL26-68, NYISO EL26-69, MISO EL26-70… | No date published yet | unconfirmed source |
| FERC | FERC RM26-4 — generic large-load rulemaking Still at ANOPR stage. | No date published yet | confirmed source |
| FERC | Georgia PSC - Georgia Power must file large-load contracts 30 days before execution A standing obligation rather than a dated one: large-load contracts must be filed with the commission at least 30 days before they are executed. | No date published yet | confirmed source |
A date marked confirmed was checked by a person against the authority's own tariff, order or form page. Anything else is listed so you know it exists, with a link so you can check it yourself. Full calendar.
The biggest projects on file
top 15 by size
| Project | Type | Capacity | Status | Filed | Queue |
|---|---|---|---|---|---|
| 4PURO - 4HAVANA3 138.0kV | Solar | 320 MW | active | 2022-09 | MISO |
| Powerton 345kV | Wind | 208 MW | withdrawn | 2010-08 | PJM |
| Indian Creek | Solar | 200 MW | withdrawn | 2024-04 | MISO |
| Puro | Wind | 200 MW | active | 2022-09 | MISO |
| Mason 138kV | Solar | 200 MW | withdrawn | 2022-09 | MISO |
| Winnebago | Wind | 200 MW | withdrawn | 2024-04 | MISO |
| Quiver | Wind | 200 MW | active | 2024-04 | MISO |
| Havana - Shockey 138 kV Line Tap | Wind | 188 MW | completed | 2019-04 | MISO |
| 4HAVANA2 - 4CINCINATTI 138.0kV | Solar | 180 MW | active | 2022-09 | MISO |
| Havana-Shockey (138kV) | Solar | 150 MW | withdrawn | 2022-09 | MISO |
| Mason Substation 138 kV Bus | Wind | 144 MW | completed | 2018-03 | MISO |
| Cane | Solar | 142 MW | active | 2022-09 | MISO |
| Quiver | Solar | 136 MW | withdrawn | 2025-05 | MISO |
| Mason 138 kV Substation | Wind | 58 MW | completed | 2019-04 | MISO |
| Cane 138 kV | Solar | 52 MW | withdrawn | 2022-09 | MISO |
How Mason County compares
#361 in the US · #18 in IL
Mason County ranks #361 of 1,607 US counties by power waiting to connect, and #18 of 64 in Illinois.
| County | Waiting | Capacity queued |
|---|---|---|
| Lee County | 12 | 6.4 GW |
| Will County | 5 | 4.3 GW |
| McLean County | 11 | 2.9 GW |
| Ogle County | 5 | 2.9 GW |
| LaSalle County | 7 | 2.8 GW |
| Christian County | 8 | 2.3 GW |
| Peoria County | 7 | 2.1 GW |
| Tazewell County | 10 | 1.9 GW |
Common questions about power in Mason County
How long does it take to get power for a data center in Mason County, IL?
The median wait for a project still in the interconnection queue in Mason County is 4.1 years. Across the US, most large loads are quoted three to seven years depending on the market and whether network upgrades are needed. 3 projects in Mason County have reached energization and 10 were withdrawn, so the withdrawal rate here is a better guide to risk than any single quoted timeline.
How much capacity is available in Mason County, IL?
1.0 GW is currently requested across 5 active interconnection requests, and 391 MW has actually been built. A queued megawatt is a request, not deliverable capacity — most queued projects are never built. For deliverable offtake capacity at a specific substation you need a utility study, not a queue.
Is Mason County, IL a good site for a data center?
This page gives you the power half of that answer: what is queued, what has been energized, how long the wait runs, and which large load interconnection requests are already recorded nearby. The other half — the state policy position, moratoriums and large load tariffs — is on our Illinois policy page.
Where does the data on this page come from?
The interconnection queue published by the transmission providers serving Mason County — MISO — parsed and normalised by Watt Street. Every figure carries the date it was true. Data as of 14 October 2026.
Go deeper on Mason County
The interactive map plots every one of these applications, and a generated county report puts them in a sourced PDF with the date each figure was true on every page.