11. Commitments:

a. Operating leases

As of December 31, 2016, our estimated minimum rental commitments for our railcar leases for use at our coal-fired facilities over the next five years and thereafter are as follows:


		(dollars in thousands)

2017	$	5,277
2018		5,277
2019		2,923
2020		583
2021		–
Thereafter		–

These railcar leasing costs are added to the cost of the fossil inventories and are recognized in fuel expense. Rental expenses totaled $4,456,000, $4,849,000 and $5,139,000 in 2016, 2015 and 2014, respectively.

b. Fuel

To supply a portion of the fuel requirements to our generating units, Southern Nuclear on our behalf for nuclear fuel, and Georgia Power, on our behalf for coal, have entered into various long-term commitments for the procurement of coal and nuclear fuel. The contracts in most cases contain provision for price escalations, minimum and maximum purchase levels and other financial commitments. The value of the coal commitments is based on maximum coal prices and minimum volumes as provided in the contracts and does not include taxes, transportation, government impositions or railcar costs. For further discussion of total nuclear fuel expense, see Note 1h.

As of December 31, 2016, our estimated minimum long-term commitments are as follows:


		(dollars in thousands)
		Coal		Nuclear Fuel

2017	$	19,164	$	46,600
2018		10,837		35,600
2019		4,972		30,500
2020		–		25,700
2021		–		30,800
Thereafter		–		60,000