Asset Retirement Obligations

3 Months Ended

Mar. 31, 2019

Asset Retirement Obligations [Line Items]

Asset Retirement Obligations

ASSET RETIREMENT OBLIGATIONS

A reconciliation of the changes in asset retirement obligations associated with long-lived assets for the three months ended March 31, 2019 is as follows (in millions):

	Alliant Energy			IPL
Balance, January 1		$177.5			$118.3
Liabilities settled	(0.7		)	(0.6		)
Liabilities incurred (a)	25.9			25.9
Accretion expense	1.6			1.0
Balance, March 31		$204.3			$144.6

(a) During the three months ended March 31, 2019, Alliant Energy and IPL recognized additional asset retirement obligations related to IPL’s newly constructed Upland Prairie and English Farms wind sites. The increases in asset retirement obligations resulted in corresponding increases in property, plant and equipment, net on the respective balance sheets.

IPL [Member]

Asset Retirement Obligations [Line Items]

Asset Retirement Obligations

ASSET RETIREMENT OBLIGATIONS

A reconciliation of the changes in asset retirement obligations associated with long-lived assets for the three months ended March 31, 2019 is as follows (in millions):

	Alliant Energy			IPL
Balance, January 1		$177.5			$118.3
Liabilities settled	(0.7		)	(0.6		)
Liabilities incurred (a)	25.9			25.9
Accretion expense	1.6			1.0
Balance, March 31		$204.3			$144.6

(a) During the three months ended March 31, 2019, Alliant Energy and IPL recognized additional asset retirement obligations related to IPL’s newly constructed Upland Prairie and English Farms wind sites. The increases in asset retirement obligations resulted in corresponding increases in property, plant and equipment, net on the respective balance sheets.