| State Rank | County | Net Generation (Past Year) | Power Plants |
| #80 | Adams County, IL | 2.1 GWh | 7 |
| #69 | Boone County, IL | 8.2 GWh | 3 |
| #85 | Brown County, IL | 3.0 MWh | 1 |
| #17 | Bureau County, IL | 2.3 TWh | 19 |
| #78 | Carroll County, IL | 2.8 GWh | 1 |
| #48 | Cass County, IL | 302.6 GWh | 5 |
| #45 | Champaign County, IL | 390.4 GWh | 16 |
| #19 | Christian County, IL | 1.9 TWh | 7 |
| #47 | Clark County, IL | 314.4 GWh | 4 |
| #36 | Clay County, IL | 515.0 GWh | 7 |
| #64 | Clinton County, IL | 23.6 GWh | 12 |
| #41 | Coles County, IL | 443.7 GWh | 4 |
| #37 | Cook County, IL | 512.8 GWh | 82 |
| #72 | Crawford County, IL | 5.4 GWh | 4 |
| #49 | Cumberland County, IL | 302.5 GWh | 1 |
| #7 | De Witt County, IL | 9.0 TWh | 5 |
| #29 | DeKalb County, IL | 682.3 GWh | 21 |
| #28 | Douglas County, IL | 719.5 GWh | 2 |
| #35 | DuPage County, IL | 533.3 GWh | 26 |
| #73 | Edgar County, IL | 4.9 GWh | 2 |
| #83 | Effingham County, IL | 75.0 MWh | 1 |
| #51 | Fayette County, IL | 228.5 GWh | 5 |
| #23 | Ford County, IL | 1.3 TWh | 5 |
| #77 | Franklin County, IL | 3.8 GWh | 1 |
| #52 | Fulton County, IL | 219.0 GWh | 4 |
| #2 | Grundy County, IL | 22.2 TWh | 12 |
| #84 | Hamilton County, IL | 42.0 MWh | 1 |
| #79 | Henderson County, IL | 2.5 GWh | 1 |
| #20 | Henry County, IL | 1.8 TWh | 11 |
| #27 | Iroquois County, IL | 794.3 GWh | 4 |
| #67 | Jackson County, IL | 8.9 GWh | 6 |
| #12 | Jasper County, IL | 3.3 TWh | 2 |
| #76 | Jefferson County, IL | 4.3 GWh | 3 |
| #50 | Jersey County, IL | 263.4 GWh | 1 |
| #70 | Jo Daviess County, IL | 7.7 GWh | 4 |
| #59 | Kane County, IL | 76.0 GWh | 20 |
| #30 | Kankakee County, IL | 667.6 GWh | 29 |
| #10 | Kendall County, IL | 5.4 TWh | 7 |
| #65 | Knox County, IL | 18.0 GWh | 9 |
| #38 | Lake County, IL | 505.5 GWh | 9 |
| #4 | LaSalle County, IL | 19.5 TWh | 27 |
| #74 | Lawrence County, IL | 4.7 GWh | 1 |
| #9 | Lee County, IL | 5.6 TWh | 15 |
| #16 | Livingston County, IL | 2.3 TWh | 23 |
| #21 | Logan County, IL | 1.6 TWh | 7 |
| #18 | Macon County, IL | 1.9 TWh | 9 |
| #54 | Macoupin County, IL | 194.2 GWh | 9 |
| #40 | Madison County, IL | 481.8 GWh | 12 |
| #60 | Marion County, IL | 74.6 GWh | 4 |
| #44 | Marshall County, IL | 395.5 GWh | 6 |
| #22 | Mason County, IL | 1.3 TWh | 6 |
| #33 | McDonough County, IL | 537.5 GWh | 6 |
| #62 | McHenry County, IL | 58.3 GWh | 24 |
| #13 | McLean County, IL | 3.3 TWh | 16 |
| #66 | Mercer County, IL | 16.0 GWh | 3 |
| #81 | Monroe County, IL | 751.0 MWh | 2 |
| #56 | Montgomery County, IL | 93.7 GWh | 6 |
| #46 | Morgan County, IL | 377.6 GWh | 8 |
| #82 | Moultrie County, IL | 569.0 MWh | 1 |
| #3 | Ogle County, IL | 19.7 TWh | 12 |
| #57 | Peoria County, IL | 87.2 GWh | 14 |
| #43 | Perry County, IL | 407.6 GWh | 6 |
| #25 | Piatt County, IL | 947.8 GWh | 5 |
| #55 | Pike County, IL | 152.7 GWh | 5 |
| #68 | Pulaski County, IL | 8.8 GWh | 2 |
| #71 | Putnam County, IL | 7.6 GWh | 3 |
| #8 | Randolph County, IL | 6.1 TWh | 6 |
| #75 | Richland County, IL | 4.4 GWh | 2 |
| #5 | Rock Island County, IL | 16.4 TWh | 7 |
| #39 | Saline County, IL | 491.7 GWh | 3 |
| #15 | Sangamon County, IL | 2.9 TWh | 11 |
| #63 | Scott County, IL | 34.7 GWh | 1 |
| #14 | Shelby County, IL | 3.1 TWh | 3 |
| #6 | St. Clair County, IL | 12.3 TWh | 11 |
| #42 | Stark County, IL | 411.5 GWh | 2 |
| #34 | Stephenson County, IL | 537.1 GWh | 27 |
| #11 | Tazewell County, IL | 3.4 TWh | 12 |
| #24 | Vermilion County, IL | 1.1 TWh | 13 |
| #58 | Warren County, IL | 76.4 GWh | 1 |
| #32 | White County, IL | 607.2 GWh | 5 |
| #61 | Whiteside County, IL | 61.5 GWh | 21 |
| #1 | Will County, IL | 26.9 TWh | 44 |
| #26 | Williamson County, IL | 810.7 GWh | 11 |
| #53 | Winnebago County, IL | 215.4 GWh | 25 |
| #31 | Woodford County, IL | 622.9 GWh | 3 |
Net Generation data is based on the last 12 months since Dec 2025