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Asset Retirement Obligations (AROs)
 12 Months Ended
Dec. 31, 2021
Asset Retirement Obligation Disclosure [Abstract]  
Asset Retirement Obligations (AROs) Asset Retirement Obligations (AROs)
We have recognized AROs related to our coal-fired generation plants, natural gas combustion turbines and wind turbines. The cost of AROs include items such as site restoration, closure of ash pits, and removal of certain structures, generators, asbestos and storage tanks. We have other legal obligations associated with the retirement of a variety of other long-lived tangible assets used in electric operations where the estimated settlement costs are individually and collectively immaterial. We have no assets legally restricted for the settlement of any AROs.
A reconciliation of the carrying amounts of AROs for the years ended December 31, 2021 and 2020 is as follows: 
(in thousands)20212020
Beginning Balance$23,821 $12,656 
New Obligations Recognized— 8,062 
Adjustments Due to Revisions in Cash Flow Estimates(568)3,110 
Accrued Accretion938 570 
Settlements— (577)
Ending Balance$24,191 $23,821 
The new AROs recognized during the year ended December 31, 2020 arose from obligations associated with our Merricourt wind farm and Astoria Station natural gas plant.