Income tax Income tax (Tables)

3 Months Ended

Mar. 31, 2018

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

The significant differences between the U.S. Federal statutory rate and PGE’s effective tax rate for financial reporting purposes are as follows:

	Three Months Ended March 31,
	2018		2017
Federal statutory tax rate	21.0	%	35.0	%
Federal tax credits*	(18.0	)	(16.1	)
State and local taxes, net of federal tax benefit	6.5		5.0
Flow through depreciation and cost basis differences	1.0		1.0
Other	0.6		(0.9	)
Effective tax rate	11.1	%	24.0	%

* Federal tax credits consists of production tax credits (PTCs) earned from Company-owned wind-powered generating facilities. The federal PTCs are earned based on a per-kilowatt hour rate, and as a result, the annual amount of PTCs earned will vary based on weather conditions and availability of the facilities. The PTCs are generated for 10 years from the corresponding facilities’ in service dates. PGE’s PTC generation endsat various dates between 2017 and 2024.