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Long-Term Debt - Debt Outstanding (Details) - USD ($) $ in Millions | Dec. 31, 2024 | May 31, 2024 | Feb. 07, 2024 | Dec. 31, 2023
--- | --- | --- | --- | ---
Long-term debt |  |  |  |
Total | $ 19,023.9 |  |  | $ 16,724.3
Long-term debt, including current portion | 18,907.1 |  |  | 16,631.1
Unamortized debt issuance costs | (103.2) |  |  | (80.2)
Unamortized discount, net and other | (21.1) |  |  | (20.5)
Current portion of long-term debt | (1,729.0) |  |  | (1,264.2)
Long-term debt | $ 17,178.1 |  |  | $ 15,366.9
WE |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 4.55% |  |  | 4.22%
Unsecured debt | $ 3,935.0 |  |  | $ 3,285.0
WEPCo Environmental Trust Finance I, LLC |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 1.58% |  |  | 1.58%
Secured debt | $ 88.0 |  |  | $ 97.0
WPS |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 4.17% |  |  | 4.11%
Senior notes | $ 2,275.0 |  |  | $ 1,975.0
WG |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 3.92% |  |  | 3.35%
Unsecured debt | $ 840.0 |  |  | $ 790.0
PGL |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 3.56% |  |  | 3.53%
Secured debt | $ 1,995.0 |  |  | $ 2,070.0
PGL | Collateralized First Mortgage Bonds |  |  |  |
Long-term debt |  |  |  |
Secured debt | $ 100.0 |  |  |
NSG |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 3.81% |  |  | 3.81%
Secured debt | $ 177.0 |  |  | $ 177.0
MERC |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 3.04% |  |  | 3.04%
Senior notes | $ 210.0 |  |  | $ 210.0
MGU |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 3.45% |  |  | 3.18%
Senior notes | $ 175.0 |  |  | $ 150.0
UMERC |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 3.26% |  |  | 3.26%
Senior notes | $ 160.0 |  |  | $ 160.0
Bluewater Gas Storage |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 4.07% |  |  | 3.76%
Senior notes | $ 131.9 |  |  | $ 109.8
ATC Holding LLC |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 4.05% |  |  | 4.05%
Senior notes | $ 475.0 |  |  | $ 475.0
We Power |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 5.67% |  |  | 5.65%
Secured debt | $ 814.3 |  |  | $ 856.4
WECC |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 6.94% |  |  | 6.94%
Unsecured debt | $ 50.0 |  |  | $ 50.0
WECI Wind Holding I |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 2.75% |  |  | 2.75%
Senior notes | $ 246.4 |  |  | $ 307.7
WECI Wind Holding II |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 6.38% |  |  | 6.38%
Senior notes | $ 167.6 |  |  | $ 191.4
WECI Energy Holding III |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 5.73% |  |  | 0.00%
Senior notes | $ 488.7 |  |  | $ 0.0
Jayhawk Wind LLC |  |  |  |
Long-term debt |  |  |  |
Long-term debt, including current portion | $ 7.5 |  |  | $ 7.5
WEC Energy Group |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 4.13% |  |  | 3.68%
Senior notes | $ 6,045.0 |  |  | $ 5,320.0
Current portion of long-term debt | (620.0) |  |  | (600.0)
Long-term debt | $ 6,135.4 |  |  | $ 5,192.8
WEC Energy Group | WEC Energy Group junior notes due 2067 |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate |  |  |  | 7.75%
Unsecured debt |  | $ 377.9 | $ 500.0 | $ 500.0
Interest rate |  |  |  | 7.75%
WEC Energy Group | 2024 Junior Notes |  |  |  |
Long-term debt |  |  |  |
Weighted average interest rate | 6.72% |  |  |
Unsecured debt | $ 750.0 |  |  |
WEC Energy Group | 2024A Junior Notes due June 15, 2055 |  |  |  |
Long-term debt |  |  |  |
Interest rate | 6.69% |  |  |
WEC Energy Group | 2024B Junior Notes due June 15, 2055 |  |  |  |
Long-term debt |  |  |  |
Interest rate | 6.74% |  |  |

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