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Asset Retirement Obligations (Tables)
 12 Months Ended
Dec. 31, 2023
Asset Retirement Obligations Disclosure [Line Items]  
Summary of Asset Retirement Obligations By Type
The following table presents the Company's ARO liabilities by asset type as of December 31 (in millions):
20232022
Wind-powered generating facilities$452 $353 
Quad Cities Station407 417 
Fossil-fueled generating facilities402 396 
Solar-powered generating facilities36 30 
Offshore pipeline facilities15 14 
Other116 118 
Total asset retirement obligations$1,428 $1,328 
Quad Cities Station nuclear decommissioning trust funds$767 $664 
Reconciliation of Asset Retirement Obligation
The following table reconciles the beginning and ending balances of the Company's ARO liabilities for the years ended December 31 (in millions):
20232022
Beginning balance$1,328 $1,340 
Change in estimated costs54 2 
Acquisitions— 29 
Additions56 32 
Retirements(64)(122)
Accretion54 47 
Ending balance$1,428 $1,328 
Reflected as:
Other current liabilities $34 $76 
Other long-term liabilities1,394 1,252 
Total ARO liability$1,428 $1,328 
PAC  
Asset Retirement Obligations Disclosure [Line Items]  
Reconciliation of Asset Retirement Obligation
The following table reconciles the beginning and ending balances of PacifiCorp's ARO liabilities for the years ended December 31 (in millions):
20232022
Beginning balance$331 $304 
Change in estimated costs(4)20 
Additions27 3 
Retirements(9)(6)
Accretion11 10 
Ending balance$356 $331 
Reflected as:
Other current liabilities$9 $11 
Other long-term liabilities347 320 
$356 $331 
MEC  
Asset Retirement Obligations Disclosure [Line Items]  
Summary of Asset Retirement Obligations By Type
The following table presents MidAmerican Energy's ARO liabilities by asset type as of December 31 (in millions):
20232022
Quad Cities Station$407 $417 
Fossil-fueled generating facilities62 76 
Wind-powered generating facilities305 210 
Solar-powered generating facilities and other4 4 
Total asset retirement obligations$778 $707 
Quad Cities Station nuclear decommissioning trust funds(1)
$767 $664 
(1)Refer to Note 6 for a discussion of the Quad Cities Station nuclear decommissioning trust funds.
Reconciliation of Asset Retirement Obligation
The following table reconciles the beginning and ending balances of MidAmerican Energy's ARO liabilities for the years ended December 31 (in millions):
20232022
Beginning balance$707 $787 
Change in estimated costs56 (27)
Additions3 2 
Retirements(21)(85)
Accretion33 30 
Ending balance$778 $707 
Reflected as:
Other current liabilities$10 $24 
Asset retirement obligations768 683 
$778 $707 
NPC  
Asset Retirement Obligations Disclosure [Line Items]  
Summary of Asset Retirement Obligations By Type
The following table presents Nevada Power's ARO liabilities by asset type as of December 31 (in millions):
20232022
Waste water remediation$33 $31 
Evaporative ponds and dry ash landfills12 14 
Solar-powered generating facilities6 3 
Other11 11 
Total asset retirement obligations$62 $59 
Reconciliation of Asset Retirement Obligation
The following table reconciles the beginning and ending balances of Nevada Power's ARO liabilities for the years ended December 31 (in millions):
20232022
Beginning balance$59 $68 
Change in estimated costs6 5 
Additions3 — 
Retirements(9)(16)
Accretion3 2 
Ending balance$62 $59 
Reflected as:
Other current liabilities$9 $16 
Other long-term liabilities53 43 
$62 $59 
SPPC  
Asset Retirement Obligations Disclosure [Line Items]  
Summary of Asset Retirement Obligations By Type
The following table presents Sierra Pacific's ARO liabilities by asset type as of December 31 (in millions):
20232022
Asbestos$5 $5 
Evaporative ponds and dry ash landfills3 3 
Solar-powered generating facilities
1 — 
Other3 3 
Total asset retirement obligations$12 $11 
Reconciliation of Asset Retirement Obligation
The following table reconciles the beginning and ending balances of Sierra Pacific's ARO liabilities for the years ended December 31 (in millions):
20232022
Beginning balance$11 $11 
Additions1 — 
Ending balance$12 $11 
Reflected as -
Other long-term liabilities$12 $11 
EEGH  
Asset Retirement Obligations Disclosure [Line Items]  
Reconciliation of Asset Retirement Obligation
The following table reconciles the beginning and ending balances of Eastern Energy Gas' ARO liabilities for the years ended December 31 (in millions):
20232022
Beginning balance$48 $55 
Additions— 4 
Retirements(19)(12)
Accretion1 1 
Ending balance$30 $48 
Reflected as:
Other current liabilities$5 $25 
Other long-term liabilities25 23 
Total ARO liability$30 $48 
EGTS  
Asset Retirement Obligations Disclosure [Line Items]  
Reconciliation of Asset Retirement Obligation
The following table reconciles the beginning and ending balances of EGTS' ARO liabilities for the years ended December 31 (in millions):

20232022
Beginning balance$48 $55 
Additions— 4 
Retirements(19)(12)
Accretion1 1 
Ending balance$30 $48 
Reflected as:
Current liabilities$5 $25 
Other long-term liabilities25 23 
Total ARO liability$30 $48