Amendment #4 Page 649 of 868 !Air .4 Conon% Cash and cash equivalents Cash and cash equivalents include all cash balances are the bank deposits with orgnsi maturity pens of three months or less Restrlded cash Restricted cash casts of cash on Delanoe in barks and financial insteutions that are resincted from use in operations pursuant to requirement of certain debt agreemerts These funds ale used to pay for current operating expenses and current debt service requirements in accordance with the restnctons n the debt agreement Accounts receivable Accounts recewable are reporteden the conned balance sheets at the invoiced amounts adiusted for any write-or Is and an allowance tel doubtful accounts We establish an allowance for doubtful /toxins to aceust our recervebtes to amounts considered to be ulbmately colectele. Cur aloft:arca s based on a vanety of factors indulng the length of tine receivables are past due, signitcart one-tone events the financial heath, of or customers arid histacal experience There was no allowance for doubtful accounts as d December 31, 2014 and 2013 Unbilled receivables intruded vi acoaum receivables were RJR 36,8E0,640 and RIR 37,918,672 as d Detente, 31, 2014 and 2013 respectively Property and equipment Ropeny and equipment consists d wind energy systems arc construction in progress and is stated at cost Experdeures Ice major addlions and improvements are captained and minx replacements, mairterence and repairs are charged to expense as nouns Wren property and equernert s rested, or otherwise dspased of, the cod and accunalated depreciation is removed from the accounts and any resieirig gen or loss is included in the resole of operators for e'e respective period Depreciation of property and equipment is recognized tang the sUaght-kne method over the enameled use4LI Ives d the wind energy systems, which is the lesser of twenty five years or the term of the underlying nonrenewable real property ease to welch the assets are