Summary of Significant Accounting Policies | Summary of Significant Accounting Policies Basis of Presentation The preparation of financial statements in accordance with U.S. generally accepted accounting principles (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates and such differences could be material. These financial statements have been prepared in accordance with the instructions to Form 10-Q and should be read in conjunction with the consolidated financial statements and notes thereto included in our annual report on Form 10-K for the year ended December 31, 2022, as filed with the SEC. In the opinion of management, all adjustments necessary to present fairly our financial position, results of operations and cash flows have been included. Our results of operations for the three- and nine-month periods ended September 30, 2023 and 2022, are not necessarily indicative of the results to be expected for the full year or any other future period. Certain information and footnote disclosures normally included in our annual consolidated financial statements have been condensed or omitted. Certain amounts in the prior years have been reclassified to conform to the current year presentation. The consolidated financial statements include our accounts and controlled subsidiaries, including the Operating Partnership. All material intercompany transactions and balances have been eliminated in consolidation. Following the guidance for non-controlling interests in Financial Accounting Standards Board Accounting Standards Codification (“ASC”) 810, Consolidation (“ASC 810”), references in this report to our earnings per share and our net income and stockholders’ equity attributable to common stockholders do not include amounts attributable to non-controlling interests. Consolidation We account for our investments in entities that are considered voting interest entities or variable interest entities (“VIEs”) under ASC 810 and assess on an ongoing basis whether we should consolidate these entities. We have established various special purpose entities or securitization trusts for the purpose of securitizing certain assets that are not consolidated in our financial statements as described below in Securitization of Financial Assets. Since we have assessed that we have power over and receive the benefits from those special purpose entities that are formed for the purpose of holding our assets on our balance sheet, we have concluded we are the primary beneficiary and should consolidate these entities under the provisions of ASC 810. We also have certain subsidiaries we deem to be voting interest entities that we control through our ownership of voting interests and accordingly consolidate. Certain of our equity method investments were determined to be interests in VIEs in which we are not the primary beneficiary, as we do not direct the significant activities of these entities, and thus we account for those investments as Equity Method Investments as discussed below. Our maximum exposure to loss through these investments is typically limited to their recorded values. However, we may provide financial commitments to these VIEs or guarantee certain of their obligations. Certain other entities in which we have equity investments have been assessed to be voting interest entities and as we exert significant influence rather than control through our ownership of voting interests, we do not consolidate them and thus account for them as equity method investments described below. Equity Method Investments We have made equity investments, typically in structures where we have a preferred return position. These investments are typically owned in holding companies (using limited liability companies (“LLCs”) taxed as partnerships) where we partner with either the operator of the project or other institutional investors. We share in the cash flows, income and tax attributes according to a negotiated schedule that typically does not correspond with our ownership percentages. Investors, if any, in a preferred return position typically receive a priority distribution of all or a portion of the project’s cash flows, and in some cases, tax attributes. Once the preferred return, if applicable, is achieved, the partnership “flips” and common equity investors, often the operator of the project, receive a larger portion of the cash flows, with the previously preferred investors retaining an on-going residual interest. Our equity investments in climate solutions projects are accounted for under the equity method of accounting. Under the equity method of accounting, the carrying value of these equity method investments is determined based on amounts we invested, adjusted for the equity in earnings or losses of the investee allocated based on the LLC agreement, less distributions received. For the LLC agreements that contain preferences with regard to cash flows from operations, capital events and liquidation, we reflect our share of profits and losses by determining the difference between our claim on the investee’s reported book value at the beginning and the end of the period, adjusted for distributions received and contributions made. This claim is calculated as the amount we would receive if the investee were to liquidate all of its assets at the recorded amounts determined in accordance with GAAP and distribute the resulting cash to creditors and investors in accordance with their respective priorities. This method is referred to as the hypothetical liquidation at book value method (“HLBV”). Our exposure to loss in these investments is limited to the amount of our equity investment, as well as receivables from or guarantees made to the same investee. Any difference between the amount of our investment and the amount of underlying equity in net assets at the time of our investment is generally amortized over the life of the assets and liabilities to which the difference relates. Cash distributions received from each equity method investment are classified as operating activities to the extent of cumulative earnings for each investment in our consolidated statements of cash flows. Our initial investment and additional cash distributions beyond the amounts that are classified as operating activities are classified as investing activities in our consolidated statements of cash flows. We typically recognize earnings one quarter in arrears for certain of these investments to allow for the receipt of financial information. We evaluate on a quarterly basis whether the current carrying value of our investments accounted for using the equity method have an other than temporary impairment (“OTTI”). An OTTI occurs when the estimated fair value of an investment is below the carrying value and the difference is determined to not be recoverable in the near term. First, we consider both qualitative and quantitative evidence whether there may be indicators of a loss in investment value below carrying value. After considering the weight of available evidence, if it is determined that there is an indication of loss in investment value, we will perform a fair value analysis. If the resulting fair value is less than the carrying value, we will determine if this loss in value is OTTI, and we will recognize any OTTI in the income statement as an impairment. This evaluation requires significant judgment regarding, but not limited to, the severity and duration of the impairment; the ability and intent to hold the securities until recovery; financial condition, liquidity, and near-term prospects of the issuer; specific events; and other factors. Commercial and Government Receivables Commercial and government receivables (“receivables”) include project loans and receivables. These receivables are separately presented in our balance sheet to illustrate the differing nature of the credit risk related to these assets. Unless otherwise noted, we generally have the ability and intent to hold our receivables for the foreseeable future and accordingly we classify them as held for investment. Our ability and intent to hold certain receivables may change from time to time depending on a number of factors including economic, liquidity and capital market conditions. At inception of the arrangement, the carrying value of receivables held for investment represents the present value of the note, lease or other payments, net of any unearned fee income, which is recognized as income over the term of the note or lease using the effective interest method. Receivables that are held for investment are carried at amortized cost, net of any unamortized acquisition premiums or discounts and include origination and acquisition costs, as applicable. Our initial investment and principal repayments of these receivables are classified as investing activities and the interest collected is classified as operating activities in our consolidated statements of cash flows. Receivables that we intend to sell in the short-term are classified as held-for-sale and are carried at the lower of amortized cost or fair value on our balance sheet, which is assessed on an individual asset basis. The purchases and proceeds from receivables that we intend to sell at origination are classified as operating activities in our consolidated statements of cash flows. Interest collected is classified as an operating activity in our consolidated statements of cash flows. Receivables from certain projects are subordinate to preferred investors in a project who are allocated the majority of such project’s cash in the early years of the investment. According, such receivables may include the ability to defer scheduled interest payments in exchange for increasing the receivable balance. We generally accrue this paid-in-kind (“PIK”) interest when collection is expected, and cease accruing PIK interest if there is insufficient value to support the accrual or we expect that any portion of the principal or interest due is not collectible. The change in PIK in any period is included in Change in accrued interest on receivables and investments line in the operating section of our statement of cash flows. We evaluate our receivables for an allowance as determined under ASC Topic 326 Financial Instruments- Credit Losses (“Topic 326”) and for our internally derived asset performance categories included in Note 6 to our financial statements in this Form 10-Q on at least a quarterly basis and more frequently when economic or other conditions warrant such an evaluation. When a receivable becomes 90 days or more past due, and if we otherwise do not expect the debtor to be able to service all of its debt or other obligations, we will generally consider the receivable delinquent or impaired and place the receivable on non-accrual status and cease recognizing income from that receivable until the borrower has demonstrated the ability and intent to pay contractual amounts due. If a receivable’s status significantly improves regarding the debtor’s ability to service the debt or other obligations, we will remove it from non-accrual status. We determine our allowance based on the current expectation of credit losses over the contractual life of our receivables as required by Topic 326. We use a variety of methods in developing our allowance, including discounted cash flow analysis and probability-of-default/loss given default (“PD/LGD”) methods. In developing our estimates, we consider our historical experience with our and similar assets in addition to our view of both current conditions and what we expect to occur within a period of time for which we can develop reasonable and supportable forecasts, typically two years. For periods following the reasonable and supportable forecast period, we revert to historical information when developing assumptions used in our estimates. In developing our forecasts, we consider a number of qualitative and quantitative factors in our assessment, which may include a project’s operating results, loan-to-value ratio, any cash reserves, the ability of expected cash from operations to cover the cash flow requirements currently and into the future, key terms of the transaction, the ability of the borrower to refinance the transaction, other credit support from the sponsor or guarantor and the project’s collateral value. In addition, we consider the overall economic environment, the climate solutions sector, the effect of local, industry, and broader economic factors, such as unemployment rates and power prices, the impact of any variation in weather and the historical and anticipated trends in interest rates, defaults and loss severities for similar transactions. For those assets where we record our allowance using a discounted cash flow method, we have elected to record the change in allowance due solely to the passage of time through the provision for loss on receivables in our income statement. For assets where the obligor is a publicly rated entity, we consider the published historical performance of entities with similar ratings in developing our estimate of an allowance, making adjustments determined by management to be appropriate during the reasonable and supportable forecast period. We have made certain loan commitments that are within the scope of Topic 326. When estimating an allowance for these loan commitments we consider the probability of certain amounts to be funded and apply either a discounted cash flow or PD/LGD methodology as described above. We charge off receivables against the allowance, if any, when we determine the unpaid principal balance is uncollectible, net of recovered amounts. Any provision we record for an allowance is a non-cash reconciling item to cash from operating activities in our consolidated statements of cash flows. Real Estate Real estate consists of land or other real property and its related lease intangibles, net of accumulated amortization. Our real estate is generally leased to tenants on a triple net lease basis, whereby the tenant is responsible for all operating expenses relating to the property, generally including property taxes, insurance, maintenance, repairs and capital expenditures. Certain real estate transactions may be characterized as “failed sale-leaseback” transactions as defined under ASC Topic 842, Leases , and thus are accounted for as financing transactions similarly to our commercial receivables as described above in Government and Commercial Receivables. For our real estate lease transactions that are classified as operating leases, the scheduled rental revenue typically varies during the lease term and thus rental income is recognized on a straight-line basis, unless there is considerable risk as to collectability, so as to produce a constant periodic rent over the term of the lease. Accrued rental income is the aggregate difference between the scheduled rents that vary during the lease term and the income recognized on a straight-line basis and is recorded in other assets. Expenses, if any, related to the ongoing operation of leases where we are the lessor, are charged to operations as incurred. Our initial investment is classified as investing activities and income collected for rental income is classified as operating activities in our consolidated statements of cash flows. When our real estate transactions are treated as an asset acquisition with an operating lease, we typically record our real estate purchases at cost, including acquisition and closing costs, which is allocated to each tangible and intangible asset acquired on a relative fair value basis. The fair value of the tangible assets of an acquired leased property is determined by valuing the property as if it were vacant, and the “as-if-vacant” value is then allocated to land, building and tenant improvements, if any, based on the determination of the fair values of these assets. The as-if-vacant fair value of a property is typically determined by management based on appraisals by a qualified appraiser. In determining the fair value of the identified intangibles of an acquired property, above-market and below-market in-place lease values are valued based on the present value (using an interest rate that reflects the risks associated with the leases acquired) of the difference between (i) the contractual amounts to be paid pursuant to the in-place leases, and (ii) management’s estimate of fair market lease rates for the corresponding in-place leases, measured over a period equal to the remaining term of the lease, including renewal periods reasonably certain of being exercised by the lessee. The capitalized off-market lease values are amortized as an adjustment of rental income over the term used to value the intangible. We also record, as appropriate, an intangible asset for in-place leases. The value of the leases in place at the time of the transaction is equal to the potential income lost if the leases were not in place. The amortization of this intangible occurs over the initial term unless management believes that it is reasonably certain that the tenant would exercise the renewal option, in which case the amortization would extend through the renewal period. If a lease were to be terminated, all unamortized amounts relating to that lease would be written off. Investments Investments are debt securities that meet the criteria of ASC 320, Investments-Debt and Equity Securities . We have designated our debt securities as available-for-sale and carry these securities at fair value on our balance sheet. Unrealized gains and losses, to the extent not considered to be credit related, on available-for-sale debt securities are recorded as a component of accumulated other comprehensive income (“AOCI”) in equity on our balance sheet. When a security is sold, we reclassify the AOCI to earnings based on specific identification. Our initial investment and principal repayments of these investments are classified as investing activities and the interest collected is classified as operating activities in our consolidated statements of cash flows. We evaluate our investments for impairment on at least a quarterly basis, and more frequently when economic or market conditions warrant such an evaluation. Our impairment assessment is a subjective process requiring the use of judgments and assumptions. Accordingly, we regularly evaluate the extent and impact of any credit deterioration associated with the financial and operating performance and value of the underlying project. We consider several qualitative and quantitative factors in our assessment. The primary factor in our assessment is the current fair value of the security, while other factors include changes in the credit rating, performance of the underlying project, key terms of the transaction, the value of any collateral and any support provided by the sponsor or guarantor. To the extent that we have identified an impairment for a security, intend to hold the investment to maturity, and do not expect that we will be required to sell the security prior to recovery of the amortized cost basis, we will recognize only the credit component of the unrealized loss in earnings by recording an allowance against the amortized cost of the asset as required by Topic 326. We determine the credit component using the difference between the security’s amortized cost basis and the present value of its expected future cash flows, discounted using the effective interest method or its estimated collateral value. Any remaining unrealized loss due to factors other than credit is recorded in AOCI. To the extent we hold investments with a fair value less than the amortized cost and we have made the decision to sell the security or it is more likely than not that we will be required to sell the security prior to recovery of its amortized cost basis, we recognize the entire portion of the impairment in earnings. Premiums or discounts on investment securities are amortized or accreted into interest income using the effective interest method. Securitization of Financial Assets We have established various special purpose entities or securitization trusts for the purpose of securitizing certain financial assets. We determined that the trusts used in securitizations are VIEs, as defined in ASC 810. When we conclude that we are not the primary beneficiary of certain trusts because we do not have power over those trusts’ significant activities, we do not consolidate the trust. We typically serve as primary or master servicer of these trusts; however, as the servicer, we do not have the power to make significant decisions impacting the performance of the trusts. We account for transfers of financial assets to these securitization trusts as sales pursuant to ASC 860, Transfers and Servicing (“ASC 860”), when we have concluded the transferred assets have been isolated from the transferor (i.e., put presumptively beyond the reach of the transferor and its creditors, even in bankruptcy or other receivership) and we have surrendered control over the transferred assets. When we are unable to conclude that we have been sufficiently isolated from the securitized financial assets, we treat such trusts as secured borrowings, retaining the assets on our balance sheet and recording the amounts due to the trust investor as non-recourse debt. For transfers treated as sales under ASC 860, we have received true-sale-at-law and non-consolidation legal opinions for all of our securitization trust structures to support our conclusion regarding the transferred financial assets. When we sell financial assets in securitizations, we generally retain interests in the form of servicing rights and residual assets, which we refer to as securitization assets. Gain or loss on the sale of financial assets is calculated based on the excess of the proceeds received from the securitization (less any transaction costs) plus any retained interests obtained over the cost basis of the assets sold. For retained interests, we generally estimate fair value based on the present value of future expected cash flows using our best estimates of the key assumptions of anticipated losses, prepayment rates, and current market discount rates commensurate with the risks involved. Cash flows related to our securitizations at origination are classified as operating activities in our consolidated statements of cash flows. We initially account for all separately recognized servicing assets and servicing liabilities at fair value and subsequently measure such servicing assets and liabilities using the amortization method. Servicing assets and liabilities are amortized in proportion to, and over the period of, estimated net servicing income with servicing income recognized as earned. We assess servicing assets for impairment at each reporting date. If the amortized cost of servicing assets is greater than the estimated fair value, we will recognize an impairment in net income. We account for our other retained interests in securitized financial assets, the residual assets, similar to available-for-sale debt securities and carry them at fair value, with changes in fair value recorded in AOCI. Income related to the residual assets is recognized using the effective interest rate method and included in securitization income in our income statement. Our residual assets are evaluated for impairment on a quarterly basis under Topic 326. A residual asset is impaired if its fair value is less than its carrying value. The credit component of impairments, if any, are recognized by recording an allowance against the amortized cost of the asset. For changes in expected cash flows, we will calculate a new yield based on the current amortized cost of the residual assets and the revised expected cash flows. This yield is used prospectively to recognize our income related to these assets. Cash and Cash Equivalents Cash and cash equivalents include short-term government securities, certificates of deposit and money market funds, all of which had an original maturity of three months or less at the date of purchase. These securities are carried at their purchase price, which approximates fair value. Restricted Cash Restricted cash includes cash and cash equivalents set aside with certain lenders primarily to support obligations outstanding as of the balance sheet dates. Restricted cash is reported as part of other assets in our consolidated balance sheets. Refer to Note 3 to our financial statements in this Form 10-Q for disclosure of the balances of restricted cash included in other assets. Convertible Notes We have issued convertible and exchangeable senior notes (together, “Convertible Notes”) that are accounted for in accordance with ASC 470-20, Debt with Conversion and Other Options , and ASC 815, Derivatives and Hedging (“ASC 815”) . Under ASC 815, issuers of certain convertible or exchangeable debt instruments are generally required to separately account for the conversion or exchange option of the debt instrument as either a derivative or equity, unless it meets the scope exemption for contracts indexed to, and settled in, an issuer’s own equity. Since our conversion and exchange options are both indexed to our equity and can only be settled in our common stock, we have met the scope exemption, and therefore, we are not separately accounting for the embedded conversion or exchange options. The initial issuance and any principal repayments are classified as financing activities and interest payments are classified as operating activities in our consolidated statements of cash flows. If converted or exchanged, the carrying value of each Convertible Note is reclassified into stockholders’ equity. Derivative Financial Instruments We use derivative financial instruments, including interest rate swaps and collars, to manage, or hedge, our interest rate risk exposures associated with new debt issuances and anticipated refinancings of existing debt, to manage our exposure to fluctuations in interest rates on floating-rate debt, and to optimize the mix of our fixed and floating-rate debt. Our objective is to reduce the impact of changes in interest rates on our results of operations and cash flows. The fair values of our interest rate derivatives designated and qualifying as effective cash flow hedges are reflected in our consolidated balance sheets as a component of other assets (if in an unrealized asset position) or accounts payable, accrued expenses and other (if in an unrealized liability position) and in net unrealized gains and losses in AOCI as described below. The cash settlements of our interest rate swaps, if any, are classified as operating activities in our consolidated statements of cash flows. The interest rate derivatives we use are intended to be designated as cash flow hedges and are considered highly effective in reducing our exposure to the interest rate risk that they are designated to hedge. This effectiveness is required in order to qualify for hedge accounting. Instruments that meet the required hedging criteria are formally designated as hedging instruments at the inception of the derivative contract. Derivatives are recorded at fair value. If a derivative is designated as a cash flow hedge and meets the highly effective threshold, the change in the fair value of the derivative is recorded in AOCI, net of associated deferred income tax effects and is recognized in earnings at the same time as the hedged item. For any derivative instruments not designated as hedging instruments, changes in fair value would be recognized in earnings in the period that the change occurs. We assess, both at the inception of the hedge and on an ongoing basis, whether the derivatives designated as cash flow hedges are highly effective in offsetting the changes in cash flows of the hedged items. We do not hold derivatives for trading purposes. Any collateral posted or received as credit support against derivative positions are netted against those derivatives in our balance sheets. Interest rate derivative contracts contain a credit risk that counterparties may be unable to fulfill the terms of the agreement. We attempt to minimize that risk by evaluating the creditworthiness of our counterparties, who are limited to major banks and financial institutions, and do not anticipate nonperformance by the counterparties due to their requirement to post collateral. We have entered into certain capped call transactions to mitigate the economic dilution that may result from the conversion or exchange of certain of our Convertible Notes. These transactions are freestanding equity-linked derivative instruments that qualify for the exemption for contracts indexed to, and settled in, an issuer’s own equity found in ASC 815, and accordingly the payment of the option premium was recorded as a reduction of Additional Paid-in-Capital within our Statement of Stockholders’ Equity. Income Taxes We elected and qualified to be taxed as a REIT for U.S. federal income tax purposes, commencing with our taxable year ended December 31, 2013. We also have taxable REIT subsidiaries (“TRS”) that are taxed separately, and that will generally be subject to U.S. federal, state and local income taxes as well as taxes of foreign jurisdictions, if any. To qualify as a REIT, we must meet on an ongoing basis several organizational and operational requirements, including a requirement that we currently distribute at least 90% of our REIT’s net taxable income before dividends paid, excluding capital gains, to our stockholders. As a REIT, we are not subject to U.S. federal corporate income tax on that portion of net income that is currently distributed to our owners. We account for income taxes under ASC 740, Income Taxes (“ASC 740”) for our TRS using the asset and liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to the differences between the consolidated financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates in effect for the year in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities from a change in tax rates is recognized in earnings in the period when the new rate is enacted. We evaluate any deferred tax assets for valuation allowances based on an assessment of available evidence including sources of taxable income, prior years taxable income, any existing taxable temporary differences and our future investment and business plans that may give rise to taxable income. We treat any tax credits we receive from our equity investments in renewable energy projects as reductions of federal income taxes of the year in which the credit arises. Any deferred tax impacts resulting from transfers of assets to or from our TRS are recorded as an adjustment to additional paid-in capital, as it is a transfer amongst entities under common control. We apply ASC 740 with respect to how uncertain tax positions should be recognized, measured, presented, and disclosed in the financial statements. This guidance requires the accounting and disclosure of tax positions taken or expected to be taken in the course of preparing our tax returns to determine whether the tax positions are “more likely than not” to be sustained by the applicable tax authority. We are required to analyze all open tax years, as defined by the statute of limitations, for all major jurisdictions, which includes U.S. federal and certain states. Equity-Based Compensation We have adopted equity incentive plans which provide for grants of stock options, stock appreciation rights, restricted stock units, shares of restricted common stock, phantom shares, dividend equivalent rights, long-term incentive-plan units (“LTIP Units”) and other restricted limited partnership units issued by our Operating Partnership and other equity-based awards. From time to time, we may grant equity or equity-based awards under our equity incentive plans as compensation to our senior management team, independent directors, employees, advisors, consultants and other personnel. Certain awards earned under each plan are based on achieving various performance targets, which are generally earned between 0% and 200% of the initial target, depending on the extent to which the performance target is met. In addition to performance targets, income or gain must be allocated by our |