Commitments and contingencies (Tables)

12 Months Ended

Dec. 31, 2012

Schedule of future minimum lease commitments under operating leases

Future minimum lease commitments under operating leases for the years ending after December 31, 2012, are as follows (in thousands):


2013	$	1,048
2014		1,064
2015		677
2016		460
2017		451
Thereafter		4,805

	$	8,505

Schedule of estimated commitments under transmission, interconnection and long-term service agreements

As of December 31, 2012, our commitments under such outstanding agreements are estimated as follows (in thousands):


2013	$	3,178
2014		3,225
2015		4,744
2016		4,754
2017		4,615
Thereafter		22,777

	$	43,293

Schedule of estimated commitments under fuel supply and transportation agreements

We have entered into long-term contractual arrangements to procure fuel and transportation services for our projects. As of December 31, 2012, our commitments under such outstanding agreements are estimated as follows (in thousands):


2013	$	77,329
2014		80,862
2015		80,921
2016		82,722
2017		18,249
Thereafter		114,054

	$	454,137