Property, Plant and Equipment, Net (Notes)

12 Months Ended

Dec. 31, 2014

Property, Plant and Equipment, Net [Abstract]

Property, Plant and Equipment, Net [Text Block]

(4)Property, Plant and Equipment, Net

Property, plant and equipment, net consists of the following as of December 31 (in millions):

	Depreciable
	Life	2014			2013
Regulated assets:
Utility generation, distribution and transmission system	5-80 years	$	64,645		$	57,490
Interstate pipeline assets	3-80 years	6,660			6,448
		71,305			63,938
Accumulated depreciation and amortization		(21,447		)	(19,874		)
Regulated assets, net		49,858			44,064
Nonregulated assets:
Independent power plants	5-30 years	4,362			1,994
Other assets	3-30 years	673			522
		5,035			2,516
Accumulated depreciation and amortization		(839		)	(678		)
Nonregulated assets, net		4,196			1,838
Net operating assets		54,054			45,902
Construction work-in-progress		5,194			4,217
Property, plant and equipment, net		$	59,248		$	50,119

Construction work-in-progress includes $4.3 billion and $2.8 billion as of December 31, 2014 and 2013, respectively, related to the construction of regulated assets.

As a result of PacifiCorp's depreciation study approved by its state regulatory commissions, PacifiCorp revised its depreciation rates effective January 1, 2014. The approved depreciation rates resulted in an increase in depreciation expense of $35 million for the year ended December 31, 2014 as compared to the year ended December 31, 2013.

During the third quarter of 2012, MidAmerican Energy revised its depreciation rates for certain coal-fueled generation facilities reflecting shorter estimated useful lives. The effect of this change increased depreciation and amortization expense by $5 million in 2012 and $11 million annually based on depreciable plant balances at the time of the change. During the third quarter of 2013, MidAmerican Energy revised its depreciation rates for certain electric generating facilities based on the results of a new depreciation study. The new rates reflect longer estimated useful lives for wind-powered generating facilities placed in-service in 2011 and 2012 and a lower accrual rate for the cost of removal regulatory liability related to coal-fueled generating facilities. The effect of this change was to reduce depreciation and amortization expense by $20 million in 2013 and $49 million annually based on depreciable plant balances at the time of the change. Effective January 1, 2014, MidAmerican Energy revised depreciation rates for certain electric generating facilities based on the results of its 2013 Iowa electric retail rate case. The new depreciation rates reflect longer estimated useful lives for certain generating facilities. The effect of this change was to reduce depreciation and amortization expense by $50 million annually based on depreciable plant balances at the time of the change.