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Pass-through Financing Obligations | 6 Months Ended
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Jun. 30, 2018
Property Subject to or Available for Operating Lease, Net [Abstract] |
Pass-Through Financing Obligations | Pass-through Financing Obligations The Company's pass-through financing obligations ("financing obligations") arise when the Company leases solar energy systems to Fund investors under a master lease agreement, and these investors in turn are assigned the Customer Agreements with customers. The Company receives all of the value attributable to the accelerated tax depreciation and some or all of the value attributable to the other incentives. The Company assigns to the Fund investors the value attributable to the ITC and, for the duration of the master lease term, the long-term recurring customer payments. Given the assignment of the operating cash flows, these arrangements are accounted for as financing obligations. Under these financing obligation arrangements, wholly owned subsidiaries of the Company finance the cost of solar energy systems with investors for an initial term of 20 - 25 years. The solar energy systems are subject to Customer Agreements with an initial term of typically 20 years that automatically renew on an annual basis. These solar energy systems are reported under the line item solar energy systems, net in the consolidated balance sheets. As of June 30, 2018 and December 31, 2017, the cost of the solar energy systems placed in service under the financing obligations was $499.4 million and $464.2 million, respectively. The accumulated depreciation related to these assets as of June 30, 2018 and December 31, 2017 was $71.9 million and $63.7 million, respectively. The investors make a series of large up-front payments and, in certain cases, subsequent smaller quarterly payments (lease payments) to the subsidiaries of the Company. The Company accounts for the payments received from the investors under the arrangements as borrowings by recording the proceeds received as financing obligations. These financing obligations are reduced over a period of approximately 20 years by customer payments under the Customer Agreements, U.S. Treasury grants (where applicable), incentive rebates (where applicable), the fair value of the ITCs monetized (where applicable) and proceeds from the contracted resale of SRECs as they are received by the investor. Under this approach, the Company accounts for the Customer Agreements and any related U.S. Treasury grants or incentive rebates as well the resale of SRECs consistent with the Company’s revenue recognition accounting policies as described in Note 2, Summary of Significant Accounting Policies. Interest is calculated on the financing obligations using the effective interest rate method. The effective interest rate, which is adjusted on a prospective basis, is the interest rate that equates the present value of the estimated cash amounts, including ITCs, to be received by the investor over the lease term with the present value of the cash amounts paid by the investor to the Company, adjusted for amounts received by the investor. The financing obligations are nonrecourse once the associated assets have been placed in service and all the contractual arrangements have been assigned to the investor. Under the majority of the financing obligations, the investor has a right to extend its right to receive cash flows from the customers beyond the initial term in certain circumstances. Depending on the arrangement, the Company has the option to settle the outstanding financing obligation on the ninth or eleventh anniversary of the Fund inception at a price equal to the higher of (a) the fair value of future remaining cash flows or (b) the amount that would result in the investor earning their targeted return. In several of these financing obligations, the investor has an option to require repayment of the entire outstanding balance on the tenth anniversary of the Fund inception at a price equal to the fair value of the future remaining cash flows. In one arrangement the investor has a right, on June 30, 2019, to purchase all of the systems leased at a price equal to the higher of (a) the sum of the present value of the expected remaining lease payments due by the investor, discounted at 5%, and the fair market value of the Company’s residual interest in the systems as determined through independent valuation or (b) a set value per kilowatt applied to the aggregate size of all leased systems. Under all financing obligations, the Company is responsible for services such as warranty support, accounting, lease servicing and performance reporting to customers. As part of the warranty and performance guarantee with customers, the Company guarantees certain specified minimum annual solar energy production output for the solar energy systems leased to the customers, which the Company accounts for as disclosed in Note 2, Summary of Significant Accounting Policies.

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