In addition during this call, statements may include financial measures as defined as non-GAAP financial measures by the Securities and Exchange Commission such as EBITDA and adjusted EBITDA. The presentation of financial information is not intended to be considered in isolation or as a substitute for financial information prepared and presented in accordance with GAAP.
Management of Ormat Technology believes that adjusted EBITDA may provide meaningful supplemental information regarding liquidity measurements for both management and investors' benefit from referring to these non-GAAP financial measures in assessing Ormat Technologies' liquidity and when planning and forecasting future periods. This non-GAAP financial measure may also facilitate management's internal comparisons to the company's historical liquidity.
Before I turn the call over to management, I would like to remind everyone that the slide presentation accompanying this call may be accessed on the company's website at ormat.com under the IR Event and Presentations link that's found in the Investor Relations tab.
With that said, I would now like to turn the call over to Dita. Dita, the call is yours.Yehudit Bronicki Thank you, Rob, and good morning to everyone. Thank you for joining us today for the presentation of our fourth quarter and full year 2011 results and outlook for the near future. 2011 was highlighted by increased revenue and increase in operating cash flow, steady growth in total generation and an exceptionally strong performance in the product segment. Our 2011 net income was negatively impacted by a noncash, tax-related valuation allowance of $61.5 million, which were recorded against the company's U.S. deferred tax assets. Realization of these deferred tax assets is dependent on generating sufficient taxable income in the U.S. prior to the expiration of the tax losses and credit. Although valuation allowances recorded against these deferred tax assets, no economic losses appeared in the underlying net operating loss carryforwards and other tax credits remain available to reduce future U.S. taxes to the extent income is generated.