This excerpt taken from the ORA 10-K filed Mar 2, 2009.
Use of estimates in preparation of financial statements
The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the dates of such financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could differ from those estimates. The most significant estimates with regard to the Companys consolidated financial statements relate to the useful lives of property, plant and equipment, impairment of
ORMAT TECHNOLOGIES, INC. AND SUBSIDIARIES
NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
long-lived assets and assets to be disposed of, revenue recognition of products sales using the percentage completion method, asset retirement obligations, valuation of auction rate securities, and the provision for income taxes.