results of operations for the respective period. Depreciation of renewable energy facilities is recognized using the straight-line method over the estimated useful lives of the renewable energy facilities, which range from 20 to 30 years for the Company's solar generation facilities. Effective October 1, 2016, the Company changed its estimates of the useful lives of the major components of its wind power plants to better reflect the estimated periods during which these major components will remain in service. These major components comprising our wind power plants have remaining useful lives ranging from 5 to 41 years and have an overall weighted average remaining useful life of 24 years as of October 1, 2016. This prospective change in estimate increased depreciation expense and net loss by $1.9 million for the quarter and year ended December 31, 2016 and increased basic and diluted loss per share by $0.02 for the quarter and year ended December 31, 2016.
The Company's intangible assets and liabilities represent revenue contracts, consisting of long-term power purchase agreements ("PPAs") and renewable energy certificates ("RECs"), lease agreements and O&M contracts that were obtained through third party acquisitions. The revenue contract intangibles are comprised of favorable and unfavorable rate PPAs and REC agreements and the in-place value of market rate PPAs. The lease agreement intangibles are comprised of favorable and unfavorable rate land leases, and the O&M contract intangibles consist of unfavorable rate O&M contracts. Intangible assets and liabilities that have determinable estimated lives are amortized over those estimated lives. Amortization of favorable and unfavorable rate revenue contracts is recorded within operating revenues, net in the consolidated statements of operations. Amortization expense related to the in-place value of market rate revenue contracts is recorded within depreciation, accretion and amortization expense in the consolidated statements of operations, and amortization of favorable and unfavorable rate land leases and unfavorable rate O&M contracts is recorded within cost of operations. The straight-line method of amortization is used because it best reflects the pattern in which the economic benefits of the intangibles are consumed or otherwise used up. The amounts and useful lives assigned to intangible assets and liabilities acquired impact the amount and timing of future amortization.
Impairment of Renewable Energy Facilities and Intangibles
Long-lived assets that are held and used are reviewed for impairment whenever events or changes in circumstances indicate carrying values may not be recoverable. An impairment loss is recognized if the total future estimated undiscounted cash flows expected from an asset are less than its carrying value. An impairment charge is measured as the difference between an asset's carrying amount and fair value. Fair values are determined by a variety of valuation methods, including appraisals, sales prices of similar assets and present value techniques. During the year ended December 31, 2016, the Company recognized a $19.0 million impairment charge related to its portfolio of residential rooftop solar assets as reflected within impairment of renewable energy facilities in the consolidated statement of operations (see Note 4. Assets Held for Sale for further discussion). There were no impairments of renewable energy facilities or intangibles recognized during the years ended December 31, 2015 and 2014.
Goodwill represents the excess of the purchase price of acquired businesses over the estimated fair value assigned to the individual assets acquired and liabilities assumed. The Company does not amortize goodwill, but instead evaluates goodwill for impairment at least annually on December 1st. The Company performs an impairment test between scheduled annual tests if facts and circumstances indicate that it is more-likely-than-not that the fair value of a reporting unit that has goodwill is less than its carrying value.
The Company may first make a qualitative assessment of whether it is more-likely-than-not that a reporting unit’s fair value is less than its carrying value to determine whether it is necessary to perform the two-step quantitative goodwill impairment test. The qualitative impairment test includes considering various factors including macroeconomic conditions, industry and market conditions, cost factors, a sustained share price or market capitalization decrease and any reporting unit specific events. If it is determined through the qualitative assessment that a reporting unit’s fair value is more-likely-than-not greater than its carrying value, the two-step impairment test is not required. If the qualitative assessment indicates it is more-likely-than-not that a reporting unit’s fair value is not greater than its carrying value, the Company must perform the two-step impairment test. The Company may also elect to proceed directly to the two-step impairment test without considering such qualitative factors.