Project assets as of October 31, 2022 and 2021 consisted of the following (in thousands):

The estimated useful lives of these project assets are 20 years for BOP and site construction, and four to seven years for modules. Project assets as of October 31, 2022 and 2021 included eight completed, commissioned installations generating power with respect to which the Company has a PPA with the end-user of power and site host with a net aggregate value of $125.2 million and $96.4 million as of October 31, 2022 and 2021, respectively. Certain of these assets are the subject of sale-leaseback arrangements with PNC and Crestmark.

Project assets as of October 31, 2022 and 2021 also include installations with carrying values of $107.7 million and $126.8 million, respectively, which are being developed and constructed by the Company in connection with projects for which we have entered into PPAs or projects for which we expect to secure PPAs or otherwise recover the asset value and which have not yet been placed in service.

Included in “Construction in progress” is the 2.3 MW Toyota project. It was determined in the fourth quarter of fiscal year 2021 that a potential source of renewable natural gas (“RNG”) at favorable pricing was no longer sufficiently probable and that market pricing for RNG had significantly increased, resulting in the determination that the carrying value of the project asset was no longer recoverable. Refer to Note 18. “Commitments and Contingencies” for more information regarding fuel risk exposure. Charges for the year ended October 31, 2022 were $22.1 million, which represents the carrying value of the project asset less the carrying value of inventory components that could be redeployed for alternative use. As this project is being constructed, only inventory components that can be redeployed for alternative use are being capitalized. The balance of costs incurred are being expensed as generation cost of revenues.

In the fourth quarter of fiscal year 2022, the Company made the decision not to proceed with development of the 7.4 MW and 1.0 MW Hartford projects given the then current economic profile of these projects. As a result, the Company recorded a $0.8 million impairment charge. The Company intends to seek modifications to the PPAs relating to these projects, however, there can be no assurance that such modifications will be acceptable to the counterparties (Eversource and United Illuminating) or approved by Connecticut regulators.

In the fourth quarter of fiscal year 2021, the Company recorded project asset impairment charges for (i) the Triangle Street Project, (ii) the LIPA Brookhaven and Clare Rose Projects, and (iii) the Toyota Project, which are further described as follows:

Fiscal Year 2020 Impairment Charges

In the fourth quarter of fiscal year 2020, the Company reviewed the Triangle Street Project and, as a result of output and revenue projections given then-current development plans, recorded an additional impairment charge of $2.4 million. The Triangle Street Project is used by the Company as a development platform for the Company’s advanced applications. Because we use the platform for development activities, generation revenue has been negatively impacted.

Impairment charges are recorded as cost of generation revenues in the Consolidated Statements of Operations and Comprehensive Loss.

Depreciation expense for project assets was $14.2 million, $13.7 million and $12.9 million for the years ended October 31, 2022, 2021 and 2020, respectively.

Project construction costs incurred for long-term project assets are reported as investing activities in the Consolidated Statements of Cash Flows. The proceeds received from the sale and subsequent leaseback of project assets are classified as “Cash flows from financing activities” within the Consolidated Statements of Cash Flows and are classified as a finance obligation within “Current portion of long-term debt” and “Long-term debt and other liabilities” on the Consolidated Balance Sheets (refer to Note 10. “Debt” for more information).