Related Party Transactions

12 Months Ended

Dec. 31, 2018

Xcel Energy Services Inc. provides management, administrative and other services for the subsidiaries of Xcel Energy Inc., including SPS. The services are provided and billed to each subsidiary in accordance with service agreements executed by each subsidiary. SPS uses the service provided by Xcel Energy Services Inc. whenever possible. Costs are charged directly to the subsidiary and are allocated if they cannot be directly assigned.

Xcel Energy Inc., NSP-Minnesota, PSCo and SPS have established a utility money pool arrangement with the utility subsidiaries.

See Note 5 for further information.

Significant affiliate transactions among the companies and related parties for the years ended Dec. 31:



(Millions of Dollars)	2018		2017		2016
Operating expenses:
Purchased power	$	—	$	1.4	$	8.8
Other operating expenses — paid to Xcel Energy Services Inc.	195.1		196.6		188.2
Interest expense	0.6		—		0.2

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	$	4.7	$	—	$	1.0	$	—
PSCo	—		0.7		—		0.3
Other subsidiaries of Xcel Energy Inc.	5.8		19.2		0.3		22.3
	$	10.5	$	19.9	$	1.3	$	22.6