Derivative instruments (Tables)

9 Months Ended

Sep. 30, 2014

Derivative Instruments

Schedule of volume activity of natural gas derivatives that is expected to settle or mature each year

The following table reflects the volume activity of our natural gas derivatives as of September 30, 2014 that is expected to settle or mature each year:

Year	Natural Gas Swaps (MMBTUs) (in millions)
2014	0.4
2015	7.9
2016	5.4
Total	14.3

Schedule of remaining notional amount of forecasted debt issuances hedged in each year with LIBOR swaptions

The following table reflects the remaining notional amount of forecasted debt issuances we have hedged in each year with LIBOR swaptions as of September 30, 2014.

Year		LIBOR Swaption Notional Dollar Amount (in thousands)
2014	$	143,629
2015		470,624
2016		310,533
2017		80,169
Total	$	1,004,955

Schedule of fair value of derivative instruments and their effect on condensed balance sheets

The table below reflects the fair value of derivative instruments and their effect on our condensed balance sheets at September 30, 2014 and December 31, 2013.

	Balance Sheet Location		Fair Value
			2014		2013
			(dollars in thousands)
Not designated as hedges:
Assets:
Interest rate options(1)	Other deferred charges	$	13,110	$	63,471
Natural gas swaps	Other current assets	$	258	$	1,011
Liabilities:
Natural gas swaps	Other current liabilities	$	2,022	$	—

(1)Excludes liability associated with cash collateral of $0 and $34,970,000 as of September 30, 2014 and December 31, 2013, respectively, which is recorded as an offset to the fair value of the swaptions on the unaudited condensed balance sheets.

Schedule of the gross realized gains and (losses) on derivative instruments recognized in margin

The following table presents the gross realized gains and (losses) on derivative instruments recognized in margin for the three and nine months ended September 30, 2014 and 2013.

	Statement of Revenues and Expenses		Three months ended September 30,						Nine months ended September 30,
	Location		2014			2013			2014			2013
			(dollars in thousands)
Not Designated as hedges:
Natural Gas Swaps	Fuel	$	638		$	122		$	1,874		$	688
Natural Gas Swaps	Fuel		(889	)		(3,089	)		(890	)		(4,002	)
		$	(251	)	$	(2,967	)	$	984		$	(3,314	)

Schedule of gross unrealized gains and (losses) on derivative instruments deferred on the balance sheet

The following table presents the unrealized gains and (losses) on derivative instruments deferred on the balance sheet at September 30, 2014 and December 31, 2013.

	Balance Sheet Location		2014			2013
			(dollars in thousands)
Not designated as hedges:
Natural gas swaps	Regulatory liability	$	—		$	1,011
Natural gas swaps	Regulatory asset	$	(1,764	)	$	—
Interest rate options	Regulatory asset		(47,598	)		(15,003	)
		$	(49,362	)	$	(13,992	)

Schedule of gross amounts of derivatives and their related offset amounts as permitted by their respective master netting agreements and obligation to return cash collateral

		Gross Amounts of Recognized Assets (Liabilities)		Gross Amounts offset on the Balance Sheet			Cash Collateral			Net Amounts of Assets Presented on the Balance Sheet
		(dollars in thousands)
September 30, 2014
Assets:
Natural gas swaps	$	261	$	(2,025	)	$	—		$	(1,764	)
Interest rate options	$	13,110	$	—		$	—		$	13,110
December 31, 2013
Assets:
Natural gas swaps	$	1,069	$	(58	)	$	—		$	1,011
Interest rate options	$	63,471	$	—		$	(34,970	)	$	28,501