Related Party Transactions (Tables)

12 Months Ended

Dec. 31, 2018

Significant affiliate transactions among the companies and related parties including billings under the Interchange Agreement for the years ended Dec. 31:



(Millions of Dollars)	2018		2017		2016
Operating revenues:
Electric	$	157.9	$	177.2	$	170.4
Operating expenses:
Purchased power	410.9		421.6		413.6
Transmission expense	62.8		68.6		61.9
Other operating expenses — paid to Xcel Energy Services Inc.	86.9		92.7		106.5

Accounts receivable and payable with affiliates at Dec. 31 were:



	2018				2017
(Millions of Dollars)	Accounts Receivable		Accounts Payable		Accounts Receivable		Accounts Payable
NSP-Minnesota	$	—	$	11.0	$	—	$	17.8
PSCo	0.2		—		—		—
Other subsidiaries of Xcel Energy Inc.	14.9		9.0		3.4		11.8
	$	15.1	$	20.0	$	3.4	$	29.6