Exhibit 99.1

FuelCell Energy Reports Second Quarter Results

and Business Highlights

DANBURY, Conn., June 5, 2012 (GLOBE NEWSWIRE) — FuelCell Energy, Inc. (Nasdaq: FCEL), a leading manufacturer of ultra-clean, efficient and reliable fuel cell power plants, today reported results for its second quarter ended April 30, 2012 along with an update on its key business highlights.

Financial Results

Second quarter 2012

FuelCell Energy (the Company) reported total revenues for the second quarter of 2012 of $24.2 million compared to $28.6 million in the same period last year. Product sales and revenues in the second quarter were $22.1 million compared to $26.7 million in the prior year quarter, as revenue in the current quarter consisted primarily of fuel cell kits whereas revenue from the second quarter of 2011 included a mix of both complete power plants and fuel cell kits. The Company made adjustments to reduce production levels in mid-April 2012 to align with contractual delivery dates and is currently in the process of raising production levels to meet increased second half demand. Second quarter product revenue included $14.3 million of fuel cell kits and power plants, $4.4 million of power plant component sales, installation services and commercial building application fuel cell joint development revenue, and $3.5 million of service and power purchase agreements.

Product sales and service backlog totaled $167.6 million as of April 30, 2012 compared to $135.5 million as of April 30, 2011. Product sales backlog was $89.3 million and $60.4 million as of April 30, 2012 and 2011, respectively. Service agreement backlog was $78.4 million and $75.1 million as of April 30, 2012 and 2011, respectively. Backlog excludes the 120 megawatt (MW) memorandum of agreement with POSCO Energy.

Research and development contract revenue was $2.0 million for the second quarter of 2012 compared to $1.9 million for the second quarter of 2011. The Company’s research and development contract backlog totaled $12.1 million as of April 30, 2012 compared to $15.2 million as of April 30, 2011.

Total gross profit was $0.2 million in the second quarter of 2012, compared to an adjusted gross loss of $2.1 million in the second quarter of 2011, excluding a non-recurring charge incurred in 2011 as explained in the reconciliation of GAAP to non-GAAP information at the end of this release. Gross profit for product sales and revenues improved $2.3 million compared to the adjusted second quarter of 2011. Year over year margin improvements reflect cost reduction efforts including manufacturing and supply chain efficiencies as well as improved services margins as some older early generation power plant service contracts are concluded.

Second quarter 2012 loss from operations decreased to $7.8 million compared to an adjusted loss from operations of $11.1 million for the comparable prior year period, excluding a non-recurring charge incurred in 2011. Operating expenses decreased year-over-year due to continued focus on cost reduction initiatives. Net loss to common shareholders for the second quarter of 2012 decreased to $9.1 million, or $0.06 per basic and diluted share, compared to $29.7 million or $0.24 per basic and diluted share in the second quarter of 2011, or an adjusted net loss to common shareholders of $12.0 million or $0.10 per basic and diluted share, excluding two non-recurring charges as explained in the reconciliation of GAAP to non-GAAP information at the end of this release.

Year-to-Date 2012

For the six months ended April 30, 2012, the Company reported revenue of $55.5 million compared to $56.7 million for the comparable prior year period. Product sales and revenues were $51.7 million compared to $52.4 million for the prior year period. Research and development contract revenue was $3.8 million compared to $4.3 million for the prior year period.

For the six months ended April 30, 2012, the Company generated a gross profit of $2.3 million compared to a gross loss of $13.2 million for the six months ended April 30, 2011, or an adjusted loss of $4.4 million that excludes a non-recurring charge as explained in the reconciliation of GAAP to non-GAAP information at the end of this release. The year-over-year improvement of $6.7 million, excluding the non-recurring charge, was achieved from the continued emphasis on reducing product costs through manufacturing and supply chain efficiencies and improvements in the Services business, as contracts for some older early generation installations are concluded.

Loss from operations for the six months ended April 30, 2012 was $13.2 million, compared to $30.4 million for the six months ended April 30, 2011. Excluding a non-recurring charge incurred in 2011, adjusted loss from operations for the six months ended April 30, 2011 was $21.7 million. The year-over-year improvement of 39 percent, excluding non-recurring charges, is the result of lower product costs and lower operating expenses.

Net loss to common shareholders for the six months ended April 30, 2012 was $15.8 million or $0.11 per basic and diluted share compared to $41.5 million or $0.35 per basic and diluted share for the six months ended April 30, 2011. Excluding the non-recurring charges incurred in 2011, net loss to common shareholders for the six months ended April 30, 2011 was $23.7 million or $0.20 per basic and diluted share.

Cash and cash equivalents

Total cash and cash equivalents were $60.3 million as of April 30, 2012, which does not include the previously announced investment of $30 million by POSCO Energy. The investment was closed on, and the shares of the Company’s common stock were issued to POSCO Energy on April 30, 2012. The cash proceeds were received on May 2, 2012 and was accounted for as a receivable as of April 30, 2012 on the Consolidated Balance Sheets. Net cash use for the second quarter was $13.4 million, excluding the net proceeds of $32.1 million from the public offering of common stock. The change in cash during the quarter included a net increase in working capital (inventory plus trade accounts receivable less accounts payable) of $4.6 million as increased inventory and lower accounts payable were only partially offset by collection of accounts receivable. Higher inventory levels are in preparation for expected near term order activity. Capital spending for the second quarter of 2012 was $0.8 million and depreciation expense was $1.4 million.

Business Highlights

Strategy Execution

“Cost reduction efforts and streamlining certain aspects of our business over the past year allowed us to break-even at the gross profit level this quarter despite lower revenue year-over-year, with a gross margin improvement of $2.3 million on an adjusted basis,” said Chip Bottone, President and CEO, FuelCell Energy, Inc. “Continued execution of our strategic initiatives will provide expanding order growth from the growing demand in Asia, market development actions in Europe, as well as resurgence of our US domestic market.”

Market Updates

The Company announced memorandum of agreements with POSCO Energy for a 120 MW multi-year order and for executing a cell licensing agreement, and announced the acceleration of deliveries under the existing 70 MW order. Execution of the 120 MW order and licensing agreements are expected by the end of the third quarter of 2012.

An expanded cell license agreement would have multiple benefits for both FuelCell Energy and POSCO Energy. Production in South Korea will improve responsiveness for meeting demand under the South Korean Renewable Portfolio Standard. The Company will avoid capital investment for Asian market development and benefits from market expansion by receiving a royalty payment from POSCO Energy for each power plant sold, with an expected multi-year royalty term. Establishing a second source of supply for fuel cell modules mitigates a risk factor for prospective customers evaluating long term fuel cell power plant projects that include scheduled replacement stacks. Increased production volume, whether in the USA or South Korea will reduce the cost of DFC plants, further spurring market adoption.

In the USA, specific projects in Connecticut and California continue to progress towards closure and the outlook for project finance continues to improve. A strong cash position and the pending second manufacturing facility in South Korea are favorable developments for project investors evaluating fuel cell projects.

The Company plans to develop and deploy fuel cell power plants in the European market utilizing FuelCell Energy Solutions, GmbH (FCES), a German company formed by FuelCell Energy, Inc. Subsequent to the end of the second quarter of 2012, a former partner of the Company contributed fuel cell production equipment and fuel cell parts to FCES and fuel cell intellectual property to Fraunhofer IKTS. No consideration was paid for any of the assets. Fraunhofer IKTS is expected to become a minority owner of FuelCell Energy Solutions, GmbH in June, 2012 and will contribute its fuel cell intellectual property to the joint venture, as well as its R&D and materials science expertise and relationships with government and industry.

Profitability Outlook

The Company has achieved gross margin breakeven at a production rate of approximately 50 MW annually. The expected 120 MW POSCO Energy order, combined with scheduled re-stacks of existing power plant installations that are currently under long term service agreements, provides a base level of production of approximately 50 MW per year through 2016 at the Company’s production facility in Torrington, Connecticut.

EBITDA (earnings before interest, taxes, depreciation and amortization) breakeven is expected with annual production volume of approximately 80 MW. Based on cost reduction trends and greater clarity around anticipated order volume, the Company expects to reach positive quarterly cash flow by late 2013 or early 2014 as measured by EBITDA. Order flow is expected to accelerate based on the expected closure of projects currently under discussion with prospective customers and project finance investors as well as opportunities arising from the execution of strategic initiatives discussed previously in this press release.

Cautionary Language

This news release contains forward-looking statements within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, including, without limitation, statements with respect to the Company’s anticipated financial results and statements regarding the Company’s plans and expectations regarding the continuing development, commercialization and financing of its fuel cell technology and business plans. All forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially from those projected. Factors that could cause such a difference include, without limitation, changes to whether the Company is able to reach definitive agreements on the terms contemplated in the recently announced memorandums of agreement with POSCO Energy, projected deliveries and order flow, changes to production rate and product costs, general risks associated with product development, manufacturing, changes in the regulatory environment, customer strategies, changes in critical accounting policies, potential volatility of energy prices, rapid technological change, competition, and the Company’s ability to achieve its sales plans and cost reduction targets, as well as other risks set forth in the Company’s filings with the Securities and Exchange Commission. The forward-looking statements contained herein speak only as of the date of this press release. The Company expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any such statement to reflect any change in the Company’s expectations or any change in events, conditions or circumstances on which any such statement is based.

About FuelCell Energy

Direct FuelCell^® power plants are generating ultra-clean, efficient and reliable power at more than 50 locations worldwide. With approximately 180 megawatts of power generation capacity installed or in backlog, FuelCell Energy is a global leader in providing ultra-clean baseload distributed generation to utilities, industrial operations, universities, municipal water treatment facilities, government installations and other customers around the world. The Company’s power plants have generated over one billion kWh of power using a variety of fuels including renewable biogas from wastewater treatment and food processing, as well as clean natural gas. For more information please visit our website at www.fuelcellenergy.com

The FuelCell Energy, Inc. logo is available at http://www.globenewswire.com/newsroom/prs/?pkgid=3284

Direct FuelCell, DFC, DFC/T, DFC-H2 and FuelCell Energy, Inc. are all registered trademarks of FuelCell Energy, Inc. DFC-ERG is a registered trademark jointly owned by Enbridge, Inc. and FuelCell Energy, Inc.

Conference Call Information

FuelCell Energy management will host a conference call with investors beginning at 10:00 a.m. Eastern Time on June 6, 2012 to discuss the second quarter results. An accompanying slide presentation for the earnings call will be available at http://fcel.client.shareholder.com/eventdetail.cfm?eventid=109986 immediately prior to the call.

Participants can access the live call via webcast on the Company website or by telephone as follows:

The webcast of the conference call will be available on the Company’s Investors’ page at www.fuelcellenergy.com. Alternatively, the replay of the conference call will be available approximately two hours after the conclusion of the call until midnight Eastern Time on June 12, 2012:

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FUELCELL ENERGY, INC.

Consolidated Balance Sheets

(Amounts in thousands, except share and per share amounts)

(Unaudited)

FUELCELL ENERGY, INC.

Consolidated Statements of Operations

(Amounts in thousands, except share and per share amounts)

(unaudited)

FUELCELL ENERGY, INC.

Consolidated Statements of Operations

(Amounts in thousands, except share and per share amounts)

(unaudited)

FUELCELL ENERGY, INC.

Reconciliation of GAAP to Non-GAAP Consolidated Statements of Operations

(Amounts in thousands, except share and per share amounts)

(Unaudited)

Notes to Reconciliation of GAAP to Non-GAAP Consolidated Statements of Operations

For the Three and Six Months Ended April 30, 2012 and 2011

Results of Operations are presented in accordance with accounting principles generally accepted in the United States (“GAAP”) and as adjusted for certain items referenced below which relate to fiscal year 2011 only. Management also uses non-GAAP measures which exclude non-recurring items in order to measure periodic operating performance. We have added this information because we believe it helps in understanding the results of our operations on a comparative basis. This adjusted information supplements and is not intended to replace performance measures required by U.S. GAAP disclosure. Notes to the reconciliation of GAAP to non-GAAP Consolidated Statements of Operations information are as follows:

(1) Note that there were no adjustments to GAAP results as reported for the three and six months ended April 30, 2012.

(2) FuelCell Energy, Inc. has committed to a repair and upgrade program to fix a performance shortfall for a select group of 1.2 MW fuel cell modules produced between 2007 and early 2009. Second quarter 2011 earnings was impacted by a charge of approximately $8.8 million, which was accounted for as an increase to cost of goods sold. Our product sales, cost of product sales and revenues, profit (loss) and cost to revenue ratio for the three and six months ended April 30, 2012 and 2011 were as follows:

(3) During the three months ended April 30, 2011 the Company entered into an agreement with Enbridge, Inc. to modify an agreement for the Series 1 preferred shares. While this modification did not result in a material change to future cash flows, it did result in a revaluation of the instrument and a reclassification of amounts due as short and long term liabilities. An adjustment to additional paid in capital and loss to common shareholders of $9.0 million was incurred in the second quarter of 2011 to adjust the carrying value of the Series I preferred shares on the modification date to the fair value of the modified instrument.