Expenses by Nature

12 Months Ended

Dec. 31, 2018

Expenses classified by nature are as follows:



Year ended Dec. 31	2018		2017		2016
	Fuel and purchased power	Operations, maintenance and administration	Fuel and purchased power	Operations, maintenance and administration	Fuel and purchased power		Operations, maintenance and administration
Fuel⁽¹⁾	656	—	685	—	665		—
Coal inventory writedown (recovery)	—	—	—	—	(4	)	—
Purchased power	210	—	162	—	143		—
Mine depreciation	136	—	73	—	63		—
Salaries and benefits⁽¹⁾	98	245	96	248	96		249
Other operating expenses	—	270	—	269	—		240
Total	1,100	515	1,016	517	963		489

(1) $90 million in both 2017 and 2016 was reclassified from fuel to salaries and benefits to be consistent with the 2018 classification.