Receivables

The components of accounts receivable consisted of the following:



Accounts Receivable	As of September 30, 2011			As of September 30, 2010
(in thousands)	As of September 30, 2011			As of September 30, 2010
Accounts receivable	$	33,938		$	37,574
Accounts receivable – unbilled	4,269			10,950
Accounts receivable, gross	38,207			48,524
Allowance for doubtful accounts	(3,332		)	(8,399		)
Accounts receivable, net	$	34,875		$	40,125

Unbilled accounts receivable represents revenue recognized but not yet billed as of the period ended. Billings on contracts using the percentage-of-completion method usually occur upon completion of predetermined contract milestones or other contract terms, such as customer approval. The allowance for doubtful accounts is based on the age of receivables and a specific identification of receivables considered at risk of collection.

As of September 30, 2011 and 2010, we had $3.3 million and $18.4 million, respectively, of accounts receivable recorded using the percentage of completion method. Of these amounts, $1.3 million was invoiced and $2.0 million was unbilled as of of September 30, 2011; and, $8.8 million was invoiced and $9.6 million was unbilled as of September 30, 2010. The allowance for doubtful accounts specifically related to receivables recorded using the percentage-of-completion method totaled $5.1 million as of September 30, 2010, and as noted below, this allowance was reclassified to a non-current receivable account in fiscal 2011.

During the three months ended March 2011, we entered into an accounts receivable settlement agreement related to a large fixed-priced international solar power system contract that was accounted for using the percentage-of-completion method. Based upon the terms of the settlement agreement, we reclassified a net accounts receivable balance of approximately $2.0 million from a current receivable account to a long-term receivable account within other non-current assets, leaving approximately $0.2 million as a current receivable which was paid in October 2011. The reclass consisted of a billed receivable balance of $5.8 million, unbilled receivable balance of $1.5 million, along with an allowance for doubtful accounts that totaled $5.3 million. During the three months ended June 30, 2011, we wrote off $2.9 million related to the long-term receivable that was fully reserved for.

The following table summarizes the changes in the allowance for doubtful accounts within accounts receivable:



Allowance for Doubtful Accounts (in thousands)	For the Fiscal Years Ended September 30,
	2011			2010			2009
Balance at beginning of period	$	8,399		$	7,125		$	2,377
Provision adjustment - expense, net of recoveries	30			2,238			5,065
Reclass of amount to a long-term receivables account	(5,253		)	—			—
Impact from foreign exchange translation adjustment	181			103			—
Write-offs - deductions against receivables	(25		)	(1,067		)	(317		)
Balance at end of period	$	3,332		$	8,399		$	7,125

During fiscal 2009, we recorded $5.1 million in bad debt expense, of which $0.7 million related to our Fiber Optics segment and $4.4 million related to our Photovoltaics segment, primarily related to receivables from the sale of terrestrial solar power products. During fiscal 2010, we recorded a $2.4 million reserve on accounts receivable related to a solar power system contract that management had uncertainty with respect to its total collectability.