Exhibit 99.1

FOR IMMEDIATE RELEASE
April 29, 2011		Analyst Contact: Britta Carlson, (702) 402-5624
		Media Contact: Karl Walquist, (775) 834-3891

NV Energy, Inc., Reports First Quarter 2011 Earnings

Las Vegas — NV Energy, Inc. (NYSE: NVE) today announced consolidated net income of $2.3 million, or one cent per share diluted, for the period ended March 31, 2011, compared with a consolidated net loss of $1.7 million, or one cent per share diluted, for the same period in 2010.

Earnings for the quarter were positively influenced by higher gross margin and an increase in Allowance for Funds Used During Construction for the construction at the Harry Allen Generating Station near Las Vegas.

“We are pleased with our first quarter 2011 earnings,” said Michael Yackira, President and Chief Executive Officer of NV Energy, Inc. “We are continuing to focus on controllable costs and operational efficiencies while implementing our long-term energy strategy.”

Webcast Scheduled for 7 a.m. PDT today, Friday, April 29, 2011

Senior management of NV Energy will review the company’s first quarter 2011 financial results and other matters during a conference call and live webcast today, Friday, April 29, at 7 a.m. Pacific Daylight Time.

The webcast will be accessible on the NV Energy website:

www.nvenergy.com.

An archived version of the webcast will remain on the NV Energy website for approximately one month following the live webcast. To listen to a recording of the call by telephone, call (800) 475-6701, and international callers should dial (320) 365-3844. Use the conference call access code, 198281, to listen to the recording.

Headquartered in Las Vegas, NV Energy, Inc. is a holding company whose principal subsidiaries, Nevada Power Company and Sierra Pacific Power Company, are doing business as NV Energy. Serving a 44,424 -square-mile service territory that stretches north to south from Elko to Laughlin, NV Energy provides a wide range of energy services and products to approximately 2.4 million citizens of Nevada as well as approximately 40 million tourists annually.

This press release may contain forward-looking statements regarding the future performance of NV Energy, Inc. and its subsidiaries, Nevada Power Company and Sierra Pacific Power Company both d/b/a NV Energy, within the meaning of the Private Securities Litigation Reform Act of 1995. These statements are subject to a variety of risks and uncertainties that could cause actual results to differ materially from current expectations. These risks and uncertainties

include, but are not limited to, NV Energy Inc.’s ability to maintain access to the capital markets, NV Energy Inc.’s ability to receive dividends from its subsidiaries, the financial performance of NV Energy Inc.’s subsidiaries, particularly Nevada Power Company and Sierra Pacific Power Company both d/b/a NV Energy, and the discretion of NV Energy Inc.’s Board of Directors with respect to the payment of future dividends based on its periodic review of factors that ordinarily affect dividend policy, such as current and prospective financial condition, earnings and liquidity, prospective business conditions, regulatory factors, and dividend restrictions in NV Energy Inc.’s and its subsidiaries’ financing agreements. For Nevada Power Company and Sierra Pacific Power Company both d/b/a NV Energy, these risks and uncertainties include, but are not limited to, future economic conditions both nationally and regionally, changes in the rate of industrial, commercial and residential growth in their service territories, their ability to procure sufficient renewable energy sources in each compliance year to satisfy the Nevada Renewable Energy Portfolio Standard, changes in environmental laws and regulations, construction risks, their ability to maintain access to the capital markets for general corporate purposes and to finance construction projects, employee workforce factors, including changes in and renewals of collective bargaining agreements, strikes or work stoppages, unseasonable weather, drought, threat of wildfire and other natural phenomena, explosions, fires, accidents, mechanical breakdowns that may occur while operating and maintaining an electric and natural gas system, their ability to purchase sufficient fuel, natural gas and power to meet their power demands and natural gas demands for Sierra Pacific Power Company d/b/a NV Energy, financial market conditions, and unfavorable rulings in their pending and future regulatory filings. Additional cautionary statements regarding other risk factors that could have an effect on the future performance of NV Energy, Inc., Nevada Power Company and Sierra Pacific Power Company both d/b/a NV Energy are contained in their Annual Reports on Form 10-K for the year ended December 31, 2010, each filed with the SEC. NV Energy Inc., Nevada Power Company and Sierra Pacific Power Company both d/b/a NV Energy undertake no obligation to release publicly the result of any revisions to these forward-looking statements that may be made to reflect events or circumstances after the date hereof or to reflect the occurrence of unanticipated events.

NV ENERGY, INC.
CONSOLIDATED STATEMENTS OF OPERATIONS
(Dollars in Thousands, Except Per Share Amounts)
(unaudited)

		Three Months Ended
		March 31,
		2011				2010
OPERATING REVENUES		$	640,983			$	714,489
OPERATING EXPENSES:
Fuel for power generation			146,338				221,619
Purchased power			135,016				107,363
Gas purchased for resale			52,632				65,559
Deferred energy			(1,952	)			17,566
Other operating expenses			105,974				106,626
Maintenance			29,762				25,729
Depreciation and amortization			83,102				80,948
Taxes other than income			16,245				16,173
Total Operating Expenses			567,117				641,583
OPERATING INCOME			73,866				72,906
OTHER INCOME (EXPENSE):
Interest expense (net of AFUDC-debt: 2011 - $6,210, 2010 - $4,939 )			(77,343	)			(80,064	)
Interest income (expense) on regulatory items			(3,762	)			(2,071	)
AFUDC-equity			7,642				5,953
Other income			5,858				5,877
Other expense			(4,656	)			(3,066	)
Total Other Income (Expense)			(72,261	)			(73,371	)
Income (Loss) Before Income Tax Expense			1,605				(465	)
Income tax expense (benefit)			(725	)			1,256
NET INCOME (LOSS)		$	2,330			$	(1,721	)
Amount per share basic and diluted
Net income (loss) per share — basic and diluted		$	0.01			$	(0.01	)
Weighted Average Shares of Common Stock Outstanding — basic			235,526,425				234,858,642
Weighted Average Shares of Common Stock Outstanding — diluted			236,784,658				234,858,642
Dividends Declared Per Share of Common Stock		$	0.12			$	0.11

NEVADA POWER COMPANY
CONSOLIDATED STATEMENTS OF OPERATIONS
(Dollars in Thousands)
(unaudited)

		Three Months Ended
		March 31,
		2011				2010
OPERATING REVENUES		$	390,068			$	425,799
OPERATING EXPENSES:
Fuel for power generation			101,070				156,115
Purchased power			95,566				71,227
Deferred energy			6,730				19,463
Other operating expenses			65,101				66,719
Maintenance			22,337				17,019
Depreciation and amortization			57,673				55,101
Taxes other than income			10,058				10,026
Total Operating Expenses			358,535				395,670
OPERATING INCOME			31,533				30,129
OTHER INCOME (EXPENSE):
Interest expense (net of AFUDC-debt: 2011 - $5,790, 2010 - $4,532)			(52,033	)			(53,356	)
Interest income (expense) on regulatory items			(1,451	)			(31	)
AFUDC-equity			7,098				5,362
Other income			3,632				2,583
Other expense			(2,732	)			(1,132	)
Total Other Income (Expense)			(45,486	)			(46,574	)
Income (Loss) Before Income Tax Expense			(13,953	)			(16,445	)
Income tax expense (benefit)			(4,933	)			(4,119	)
NET INCOME (LOSS)		$	(9,020	)		$	(12,326	)

SIERRA PACIFIC POWER COMPANY
CONSOLIDATED INCOME STATEMENTS
(Dollars in Thousands)
(unaudited)

		Three Months Ended
		March 31,
		2011				2010
OPERATING REVENUES:
Electric		$	178,617			$	208,662
Gas			72,294				80,020
Total Operating Revenues			250,911				288,682
OPERATING EXPENSES:
Fuel for power generation			45,268				65,504
Purchased power			39,450				36,136
Gas purchased for resale			52,632				65,559
Deferred energy — electric — net			(11,931	)			(1,500	)
Deferred energy — gas — net			3,249				(397	)
Other operating expenses			40,216				39,353
Maintenance			7,425				8,710
Depreciation and amortization			25,429				25,847
Taxes other than income			6,024				6,066
Total Operating Expenses			207,762				245,278
OPERATING INCOME			43,149				43,404
OTHER INCOME (EXPENSE):
Interest expense (net of AFUDC-debt: 2011 - $420, 2010 - $407)			(16,946	)			(17,045	)
Interest income (expense) on regulatory items			(2,311	)			(2,040	)
AFUDC-equity			544				591
Other income			2,052				1,755
Other expense			(1,594	)			(1,869	)
Total Other Income (Expense)			(18,255	)			(18,608	)
Income Before Income Tax Expense			24,894				24,796
Income tax expense			8,318				7,676
NET INCOME		$	16,576			$	17,120

Gross margin is presented by Nevada Power Company and Sierra Pacific Power Company both d/b/a NV Energy in order to provide information that management believes aids the reader in determining how profitable the electric and gas business is at the most fundamental level. Gross margin, which is a “non-GAAP financial measure” as defined in accordance with SEC rules,

provides a measure of income available to support the other operating expenses of the business and is utilized by management in its analysis of its business.

Nevada Power Company and Sierra Pacific Power Company both d/b/a NV Energy believe presenting gross margin allows the reader to assess the impact of regulatory treatment and their overall regulatory environment on a consistent basis. Gross margin, as a percentage of revenue, is primarily impacted by the fluctuations in electric and natural gas supply costs versus the fixed rates collected from customers. While these fluctuating costs impact gross margin as a percentage of revenue, they only impact gross margin amounts if the costs cannot be passed through to customers. Gross margin, which Nevada Power Company and Sierra Pacific Power Company both d/b/a NV Energy calculate as operating revenues less energy costs, provides a measure of income available to support the other operating expenses. Gross margin changes are based primarily on general base rate adjustments (which are required to be filed by statute every three years). Reconciliations between GAAP operating income and gross margin are provided in tables herein. These non-GAAP measures should not be considered as substitutes for the GAAP measures.

RECONCILIATION OF NON-GAAP FINANCIAL MEASURES
Gross Margin
(Dollars in Thousands)
(Unaudited)

		Three Months Ended								Change
		March 31,								from Prior
Nevada Power Company		2011				2010				Year %
Operating Revenues		$	390,068			$	425,799				-8.4	%
Energy Costs:
Fuel for power generation			101,070				156,115
Purchased Power			95,566				71,227
Deferred energy			6,730				19,463
			203,366				246,805				-17.6	%
Gross Margin		$	186,702			$	178,994				4.3	%
Other operating expenses			65,101				66,719
Maintenance			22,337				17,019
Depreciation and amortization			57,673				55,101
Taxes other than income			10,058				10,026
Operating Income		$	31,533			$	30,129				4.7	%

		Three Months Ended								Change
		March 31,								from Prior
Sierra Pacific Power Company		2011				2010				Year %
Operating Revenues:
Electric		$	178,617			$	208,662
Gas			72,294				80,020
		$	250,911			$	288,682				-13.1	%
Energy Costs:
Fuel for power generation			45,268				65,504
Purchased Power			39,450				36,136
Gas purchased for resale			52,632				65,559
Deferred energy — electric — net			(11,931	)			(1,500	)
Deferred energy — gas — net			3,249				(397	)
		$	128,668			$	165,302				-22.2	%
Energy Costs by Segment:
Electric		$	72,787			$	100,140
Gas			55,881				65,162
		$	128,668			$	165,302				-22.2	%
Gross Margin by Segment:
Electric		$	105,830			$	108,522
Gas			16,413				14,858
Gross Margin		$	122,243			$	123,380				-0.9	%
Other operating expenses			40,216				39,353
Maintenance			7,425				8,710
Depreciation and amortization			25,429				25,847
Taxes other than income			6,024				6,066
Operating Income		$	43,149			$	43,404				-0.6	%

Summary of Selected Operating Statistics

Nevada Power Company
Operating Revenues
(dollars in thousands)

		Three Months Ended								Change				Average
		March 31,								from Prior				Change in
		2011				2010				Year %				customers
Operating Revenues:
Residential		$	184,973			$	196,167				-5.7	%			1.1	%
Commercial			85,856				94,014				-8.7	%			0.3	%
Industrial			103,475				119,183				-13.2	%			-1.2	%
Retail revenues			374,304				409,364				-8.6	%
Other			15,764				16,435				-4.1	%
Total Operating Revenues		$	390,068			$	425,799				-8.4	%
Retail sales in thousands of MWhs			4,140				4,086				1.3	%

Sierra Pacific Power Company
Operating Revenues
(dollars in thousands)

		Three Months Ended								Change				Average
		March 31,								from Prior				Change in
		2011				2010				Year %				customers
Electric Operating Revenues:
Residential		$	64,047			$	82,675				-22.5	%			0.3	%
Commercial			62,087				76,421				-18.8	%			1.6	%
Industrial			34,491				42,352				-18.6	%			3.8	%
Retail revenues			160,625				201,448				-20.3	%
Other			17,992				7,214				149.4	%
Total Revenues		$	178,617			$	208,662				-14.4	%
Retail sales in thousands of MWhs			1,853				1,960				-5.5	%

		Three Months Ended								Change				Average
		March 31,								from Prior				Change in
		2011				2010				Year %				customers
Gas Operating Revenues:
Residential		$	39,177			$	42,363				-7.5	%
Commercial			17,277				20,482				-15.6	%
Industrial			4,786				5,939				-19.4	%
Retail revenues			61,240				68,784				-11.0	%			0.7	%
Wholesale revenue			10,178				10,561				-3.6	%
Miscellaneous			876				675				29.8	%
Total Revenues		$	72,294			$	80,020				-9.7	%
Retail sales in thousands of decatherms			6,534				5,985				9.2	%

Financial Highlights
(Dollars in Thousands)
(Unaudited)

NV Energy, Inc
Capital Structure		March 31, 2011								March 31, 2010
Current maturities of long-term debt		$	355,847				4.1	%		$	7,785				0.1	%
Long-term debt			4,905,822				57.1	%			5,546,626				63.4	%
Total Debt		$	5,261,669				61.2	%		$	5,554,411				63.5	%
Total Shareholders’ equity			3,331,367				38.8	%			3,197,525				36.5	%
Total Capitalization (including current maturities of long-term debt)		$	8,593,036				100.0	%		$	8,751,936				100.0	%

Nevada Power Company
Capital Structure		March 31, 2011								March 31, 2010
Current maturities of long-term debt		$	355,847				5.6	%		$	7,785				0.1	%
Long-term debt			3,218,908				50.4	%			3,779,120				59.1	%
Total Debt		$	3,574,755				56.0	%		$	3,786,905				59.2	%
Total Shareholder’s equity			2,807,365				44.0	%			2,610,729				40.8	%
Total Capitalization (including current maturities of long-term debt)		$	6,382,120				100.0	%		$	6,397,634				100.0	%

Sierra Pacific Power Company
Capital Structure		March 31, 2011								March 31, 2010
Current maturities of long-term debt		$	—				0.0	%		$	—				0.0	%
Long-term debt			1,180,413				55.3	%			1,281,863				55.8	%
Total Debt		$	1,180,413				55.3	%		$	1,281,863				55.8	%
Total Shareholder’s equity			953,869				44.7	%			1,013,388				44.2	%
Total Capitalization (including current maturities of long-term debt)		$	2,134,282				100.0	%		$	2,295,251				100.0	%

NVE Available Liquidity as of March 31, 2011 (dollars in millions)
		NVE				NPC				SPPC
Cash and Cash Equivalents		$	6.9			$	61.6			$	65.8
Balance available on Revolving Credit Facilities			N/A				585.6				237.5
Less reduction for hedging transactions							(13.6	)			(4.5	)
		$	6.9			$	633.6			$	298.8