Summary of significant accounting policies | 2. Summary of significant accounting policies Basis of presentation and principles of consolidation The accompanying unaudited condensed consolidated financial statements include the results of the Company and its wholly owned subsidiaries and have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial statements and pursuant to Form 10-Q and Article 10 of Regulation S-X. In the opinion of management, all adjustments of a normal recurring nature have been made that are considered necessary for a fair statement of our financial position as of March 31, 2024, and December 31, 2023, our results of operations for the three months ended March 31, 2024 and 2023, and our cash flows for the three months ended March 31, 2024 and 2023. The condensed consolidated balance sheet as of December 31, 2023 has been derived from the Company’s audited consolidated financial statements but does not include all disclosures required by accounting principles generally accepted in the United States of America. Operating results for the three months ended March 31, 2024 are not necessarily indicative of the results that may be expected for the year ending December 31, 2024. Intercompany balances and transactions have been eliminated in consolidation. Certain information and disclosures normally included in the notes to annual financial statements prepared in accordance with U.S. GAAP have been omitted from these interim financial statements pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Therefore, these unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023 (our "2023 Annual Report"). We currently operate in one business segment, the manufacturing and servicing of solar tracker systems . Liquidity We have incurred cumulative losses since inception and have a history of cash outflows from operations. As of March 31, 2024, we had $ 14.0 million of cash on hand, $ 45.7 million of working capital and approximately $ 64.9 million of remaining capacity available for future sales of our common stock under our ATM program as defined and described further in Note 4 below. There can be no assurance that we will be able to sell any additional shares of our common stock under the ATM program and no assurance regarding the price at which we will be able to sell such shares, and any sales of our common stock under the ATM program may be at prices that result in additional dilution to our existing stockholders. On December 22, 2023, we received notification from The Nasdaq Stock Market LLC (“Nasdaq”) that we were not in compliance with the requirement to maintain a minimum closing bid price of $ 1.00 per share, as set forth in Nasdaq Listing Rule 5450(a)(1), because the closing bid price of the Company’s common stock was below $ 1.00 per share for 30 consecutive business days. The notification does not impact the listing of our common stock on the Nasdaq Global Market at this time. In accordance with Nasdaq Listing Rule 5810(c)(3)(A), we have a period of 180 calendar days from the date of notification, or until June 19, 2024, to regain compliance with the minimum bid price requirement. During this period, our common stock will continue to trade on the Nasdaq Global Market. If at any time before June 19, 2024 the bid price of our common stock closes at or above $ 1.00 per share for a minimum of ten consecutive business days, Nasdaq will provide written notification that we have achieved compliance with this minimum bid price requirement. In the event we do not regain compliance by June 19, 2024, we may be eligible for an additional 180 calendar day compliance period to demonstrate compliance with the minimum bid price requirement. To qualify for the additional 180-day period, we may be required to meet the continued listing requirements for market value of publicly held shares and all other initial listing standards (with the exception of the bid price requirement) and transfer our listing to the Nasdaq Capital Market. In addition, we will need to provide written notice to Nasdaq of our intention to cure the deficiency during the second compliance period by effecting a reverse stock split, if necessary. If we do not qualify for the second compliance period or fail to regain compliance during the second 180-day period, then Nasdaq will notify us that our common stock is subject to delisting. As of March 31, 2024, we were not in compliance with the minimum liquidity covenant in our existing Senior Secured Revolving Credit Facility (the "Credit Facility") which prevented us from borrowing under the Credit Facility prior to its termination on April 30, 2024. Also, as of March 31, 2024, we had a material contractual obligation that could require us to make additional capital contributions of up to $ 1.6 million to Alpha Steel, as described further in Note 3, "Equity method investment". The most notable incentive program impacting our U.S. business has historically been the investment tax credit ("ITC") for solar energy projects, which allows taxpayers to offset their U.S. federal income tax liability by a certain percentage of their cost basis in solar energy systems placed in service for commercial use. The Inflation Reduction Act of 2022, passed by the U.S. Congress and signed into law by President Biden on August 16, 2022, expanded and extended the tax credits and other tax benefits available to solar energy projects and the solar energy supply chain. ITCs have been extended for such projects through at least 2032 and, depending on the location of a particular project and its ability to satisfy certain labor and domestic content requirements, the ITC percentage can range between 30 % and 50 %. U.S. manufacturers of specific solar components are now eligible to claim production tax credits as an alternative to the ITC. Implementing regulations for this law are, in certain cases, still being finalized and the impact of these regulations continue to be evaluated by developers of new solar projects and manufacturers of solar components. Our investment in and commitments made to Alpha Steel will allow us to obtain certain benefits as a result of this new production tax credit program. We have taken steps to expand and diversify our manufacturing partnerships and have adjusted our modes of transportation to mitigate the impact of headwinds that might arise in the global supply chain and logistics markets. As an example, we modified our ocean freight from previously using charter shipments to now using containerized shipments as costs in the container market began to decrease starting in 2022. We continue to monitor the logistics markets and will continue to evaluate our use of various modes of transportation when warranted to optimize our transportation costs. Additionally, from February 2022 to September 2023, we utilized a related-party consulting firm to support us in making improvements to our processes and performance in various areas, including design, sourcing, logistics, pricing, software and our distributed generation business. For further information regarding this consulting firm, see Note 16, "Related party transactions" below. Similar to previous periods, we continue to evaluate our opportunities in 2024 to address existing market challenges, our cost structure and our historical use of cash. Further, in 2023, we introduced a new mounting solution to support the installation and use of U.S.-manufactured thin-film modules, Pioneer, our 1P solar tracker solution became certified, and we introduced SUNOPS, a cloud-based, tracker agnostic solar asset monitoring solution allowing asset owners and managers to evaluate the operation and performance of their solar deployments. Additionally, we have seen improvements in the logistics markets and easing of supply chain constraints since 2022. These factors contributed to us having positive gross profit during each quarter in 2023, a first since our IPO in April 2021. In accordance with Accounting Standards Codification ("ASC") 205-40, Going Concern, we have evaluated whether there are conditions and events, considered in the aggregate, which raise substantial doubt about our ability to continue as a going concern within one year after the date our condensed consolidated financial statements are issued. Management believes that our existing cash on hand, including cash received in April 2024 as a result of our agreement with a major customer as discussed further in Note 18, "Subsequent events" below, as well as the continuing impact of certain of the actions described above and our expectations of (i) improved market conditions, (ii) the expected timing of customer project activity, including activity related to certain large project awards received in 2023, and (iii) positive results in recent periods from our efforts to increase our direct product margins, will allow us to grow profitably and generate positive cash flow from operations during the next twelve months in amounts that will be sufficient, along with our other available resources such as our existing working capital and, if conditions become more conducive, the remaining capacity available for future sales of our common stock under our ATM program, to fund our operations for at least one year from the date of issuance of the condensed consolidated financial statements. While there are already many underlying drivers of growth in the solar industry, the expected positive impact on demand for our products, or the timing of construction activity by existing customers and solar project developers, could take longer than expected to occur. In addition, domestic and international market conditions could deteriorate significantly from what we currently expect, and regulatory and international trade policies could become more stringent as a result of (i) findings from an ongoing investigation by the U.S. Department of Commerce (the Solar Circumvention Investigation") in response to a petition by Auxin Solar, Inc. of claims related to alleged circumvention of U.S. antidumping and countervailing duties ("AD/CVD") by solar manufacturers in certain Southeast Asian countries, (ii) enforcement of the Uyghur Forced Labor Prevention Act ("UFLPA") passed by the U.S. Congress and signed into law by President Biden on December 23, 2021, by U.S. Customs and Border Protection ("CBP'), and (iii) other factors, which may result in a need for us to issue additional debt or obtain new equity financing to adequately fund our existing operations beyond the next twelve months. We continue to actively explore options to obtain additional sources of capital through the issuance of new debt, asset financing or other potential measures for our longer-term needs. However, we may be unable to obtain any desired additional financing on terms favorable to us, or at all, depending on market and other conditions, which could result in curtailment of our current operations and our ability to further invest in our products and new technology. The ability to raise additional financing depends on numerous factors, some of which that are outside of our control, including macroeconomic factors such as the impact of inflation, the level of interest rates, supply chain or other effects from the ongoing conflicts in the Ukraine and the Middle East, general market conditions, the health of financial institutions (including recent bankruptcies and financial difficulties involving certain regional banks and related impacts that have occurred and continue to occur in the banking industry), investors' and lenders' assessments of our prospects and the prospects of the solar industry in general and the ability of our common stock to continue to trade in active markets. Use of estimates Preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported revenue and expenses during the period. Estimates are used for calculating the measure of progress of our solar tracker projects and deriving the standalone selling prices of the individual performance obligations when determining amounts to recognize for revenue, estimating allowances for credit losses and slow-moving and obsolete inventory, determining useful lives of long-lived assets and the estimated fair value of those assets for impairment assessments, and estimating the fair value of investments, stock compensation awards, warranty liabilities and federal and state taxes, including tax valuation allowances, as well as other contingencies. We base our estimates on historical experience and anticipated results, trends, and various other assumptions that we believe are reasonable under the circumstances, including assumptions as to future events. Actual results could differ from those estimates due to risks and uncertainties. Concentration of credit risk Financial instruments that potentially subject the Company to concentrations of credit risk are primarily cash and accounts receivable. We regularly maintain cash balances with various financial institutions that exceed federally insured amounts, but we have experienced no losses associated with these amounts to date. We also took action in early 2023 to reallocate cash balances between different financial institutions based on our assessment as to the financial health of certain institutions. We extend credit to customers in the normal course of business, often without requiring collateral. We also perform credit analyses and monitor the financial health of our customers to reduce credit risk. The Company’s accounts receivables are derived from revenue earned from customers primarily located in the U.S. and Australia. No countries other than the U.S. and Australia accou nted for 10 % or more of our revenue. Most of our customers are project developers, solar asset owners and engineering, procurement and construction (“EPC”) contractors that design and build solar energy projects. We typically rely on a small number of customers that account for a large portion of our revenue each period and our outstanding receivables at each period end. Cash and cash equivalents We consider all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. Certain of our cash equivalents include deposits in money market funds that invest primarily in short-term securities issued or guaranteed by the U.S. government or its agencies or instrumentalities and contain no restrictions on immediate redemption. These deposits totaled $ 9.3 million at March 31, 2024 and $ 13.9 million at December 31, 2023 . Interest earned on cash equivalents is included in interest income, which is reported net of interest expense in our condensed consolidated statements of comprehensive loss . Restricted cash Cash balances that are legally, contractually or otherwise restricted as to withdrawal or usage are considered restricted cash . Accounts receivable, net Trade receivables are recorded at invoiced amounts, net of allowances for credit losses, and do not bear interest. We generally do not require collateral from our customers; however, in certain circumstances, we may require letters of credit, other collateral, additional guarantees or advance payments. The allowance for credit losses is based on the lifetime expected credit loss of our customer accounts. To assess the lifetime expected credit loss, we utilize a loss rate method that takes into consideration historical experience and certain other factors, as appropriate, such as credit quality and current economic or other conditions that may affect a customer's ability to pay. Provisions for credit losses are included as a component of our selling and marketing expenses. Receivables arising from revenue recognized in excess of billings represents our unconditional right to consideration before customers are invoiced due to the level of progress obtained as of period end on our contracts to procure and deliver tracker systems and related equipment. Further information may be found below in our revenue recognition policy . Inventories, net Inventories are stated at the lower of cost or net realizable value, with costs computed on a first-in, first-out basis. The Company periodically reviews its inventories for excess and obsolete items and adjusts carrying costs to estimated net realizable values when they are determined to be less than cost. Impairment We review our long-lived assets that are held for use for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable or that its useful life may be shorter than previously expected. If such impairment indicators are present or other factors exist that indicate the carrying amount of the asset may not be recoverable, we determine whether an impairment has occurred through the use of an undiscounted cash flow analysis of the asset at the lowest level for which identifiable cash flows exist. If an impairment has occurred, we recognize a loss for the difference between the carrying amount and the fair value of the asset, which in most cases is estimated based upon Level 3 unobservable inputs. If the asset is determined to have a remaining useful life shorter than previously expected, an adjustment for the shorter remaining life will be made for purposes of recognizing future depreciation expense. Assets are classified as held for sale when we have a plan, approved by the appropriate levels of management, for disposal of such assets, as well as other considerations, and those assets are stated at the lower of carrying value or estimated fair value less estimated costs to sell. Intangible assets, net Intangible assets are recorded at fair value when acquired in connection with a business combination and consist of developed technology in the form of software tools, licenses, and intellectual property, which are amortized over the period of their estimated useful lives, generally 2.5 - 3.0 years, using the straight-line method. Costs incurred to renew or extend the term of a recognized intangible asset, if any, are expensed as incurred. We evaluate intangible assets for impairment using the method described above under "Impairment". Goodwill We recognize goodwill as the excess of the purchase price over the estimated fair value of the identified assets and liabilities acquired in a business combination accounted for using the acquisition method. Goodwill is not amortized but is subject to a periodic assessment for impairment at least annually, or whenever events and circumstances indicate an impairment may exist. Our assessments may include qualitative factors such as current or expected industry and market conditions, our overall financial performance, share price trends, market capitalization and other company-specific events. We operate in one segment, being the consolidated entity, which we have also determined is the reporting unit for goodwill impairment. No impairment of goodwill was recognized as of March 31, 2024 or 2023 . Equity method investment We use the equity method of accounting for investments in which we have the ability to exercise significant influence, but not control, over operating and financial policies of the investee. Our proportionate share of the net income or loss of these investees is included in our condensed consolidated statements of comprehensive loss. Judgment regarding the level of influence over each equity method investment includes considering key factors such as our ownership interest, legal form of the investee, representation on the board of directors or managers, participation in policy-making decisions and material intra-entity transactions. We account for distributions received from equity method investees under the “nature of the distribution” approach based on the nature of the activity or activities of the investee that generated the distribution as either a return on investment (classified as cash inflows from operating activities) or a return of investment (classified as cash inflows from investing activities). We evaluate equity method investments for impairment whenever events or changes in circumstances indicate that the carrying amount of the investment might not be recoverable. Factors considered by the Company when reviewing an equity method investment for impairment include the length of time and the extent to which the fair value of the equity method investment has been less than its cost, the investee’s financial condition and near-term prospects and the intent and ability to hold the investment for a period of time sufficient to allow for anticipated recovery. An impairment that is other-than temporary is recognized in the period identified. We made an accounting policy election that, upon the sale of our equity method investments, we will recognize contractual contingent gains arising from earnout provisions and project escrow releases when such amounts are realizable in periods subsequent to the disposal date. Warranty Typically, the sale of solar tracker projects includes parts warranties to customers as part of the overall price of the product. We provide standard assurance type warranties for our products for periods generally ranging from five to ten years . We also accrue for costs relating to remediation efforts involving product issues we believe require correction. We record a provision for estimated warranty and remediation expenses in cost of sales, net of amounts recoverable from manufacturers under their warranty obligations to us. When historical claims information relating to our equipment is not sufficient, we will base our estimates on industry studies involving the nature and frequency of product failure rates for similar parts used by our competitors, as well as other related businesses. We do not maintain general or unspecified reserves; all warranty reserves are related to specific projects. All actual or estimated material costs incurred for warranty or remediation services in subsequent periods are charged to those established reserves. While we periodically monitor our warranty activities and claims, if actual costs incurred were to be different from our estimates, we would recognize adjustments to our warranty reserves in the period in which those differences arise or are identified. Stock-based compensation We recognize compensation expense for all share-based payment awards made, including stock options and restricted stock units ("RSUs"), based on the estimated fair value of the award on the grant date. We calculate the fair value of stock options using the Black-Scholes option pricing model for awards with service-based vesting or through use of a lattice model or a Monte Carlo simulation for stock option and RSU awards with market conditions. The fair value of RSUs with service or performance-based vesting is based on the estimated fair value of the Company's common stock on the date of grant. We consider the closing price of our stock, as reported on the Nasdaq Global Market, to be the fair value of our stock on the grant date. Forfeitures are accounted for as they occur. For service-based awards, stock-based compensation is recognized using the straight-line attribution approach over the requisite service period. For performance-based awards, stock-based compensation is recognized based on graded vesting over the requisite service period when the performance condition is probable of being achieved. Stock compensation expense for market-based awards is recognized over the derived service period determined in the valuation model, inclusive of any vesting conditions. Revenue recognition Product revenue is derived from the sale of solar tracker systems and customized components for those systems, individual part sales for certain specific transactions and the sale of term-based software licenses. Term-based licensed software is deployed on the customers’ own servers and has significant standalone functionality. Service revenue includes revenue from shipping and handling services, engineering consulting and pile testing services, our subscription-based enterprise licensing model and maintenance and support services in connection with the term-based software licenses. Our subscription-based enterprise licensing model typically has contract terms ranging from one to two years and consists of subscription fees from the licensing of subscription services. Our hosted on-demand service arrangements do not provide customers with the right to take possession of the software supporting the hosted services. Support services include ongoing security updates, upgrades, bug fixes, and maintenance. We recognize revenue when promised goods or services are transferred to customers in an amount that reflects the consideration to which we expect to be entitled to in exchange for those goods or services by following a five-step process: (1) identify the contract with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when or as the Company satisfies a performance obligation, as further described below. Identify the contract with a customer: A contract with a customer exists when (i) the Company enters into an enforceable contract with a customer that defines each party’s rights regarding the products and services to be transferred and identifies the payment terms related to these products and services, (ii) the contract has commercial substance, and (iii) the Company determines that collection of substantially all consideration for products and services that are transferred is probable based on the customer’s intent and ability to pay the promised consideration. In assessing the recognition of revenue, we also evaluate whether two or more contracts should be combined and accounted for as one contract and if the combined or single contract should be accounted for as multiple performance obligations which could change the amount of revenue and profit (loss) recorded in a period. Change orders may include changes in specifications or design, manner of performance, equipment, materials, scope of work, and/or the period of completion of the project. We analyze change orders to determine if they should be accounted for as a modification to an existing contract or a new stand-alone contract. Contracts we enter into with our customers for sale of solar tracker systems are generally under two different types of arrangements: (1) purchase agreements and equipment supply contracts (“Purchase Agreements”), and (2) sale of individual parts for those systems. Change orders from our customers are generally modifications to existing contracts and are included in the total estimated contract revenue when it is probable that the change order will result in additional value that can be reliably estimated and realized. Identify the performance obligations in the contract: We enter into contracts that can include various combinations of products and services, which are either capable of being distinct and accounted for as separate performance obligations or as one performance obligation since the majority of tasks and services are part of a single project or capability. However, determining whether products or services are considered distinct performance obligations that should be accounted for separately versus together may sometimes require significant judgment. Our Purchase Agreements typically include two performance obligations: 1) our solar tracker systems or customized components of those systems, and 2) shipping and handling services. The deliverables included as part of our solar tracker systems are predominantly accounted for as one performance obligation, as these deliverables are part of a combined promise to deliver a project. The revenue for shipping and handling services will be recognized over time based on progress in meeting shipping terms of the arrangements, as this faithfully depicts the Company’s performance in transferring control. Revenue for stand-alone engineering consulting and pile testing services is recognized at a point in time upon completion of the services performed. Sales of individual parts of our solar tracker systems for certain specific transactions include multiple performance obligations consisting of individual parts of those systems. Revenue is recognized for parts sales at a point in time when the obligations under the terms of the contract with our customer are satisfied. Generally, this occurs with the transfer of control of the asset, which is in line with shipping terms. Determine the transaction price: The transaction price is determined based on the consideration to which we will be entitled in exchange for transferring services to the customer. Such amounts are typically stated in the customer contract, and to the extent that we identify variable consideration, we will estimate the variable consideration at the onset of the arrangement as long as it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. The majority of our contracts do not contain variable consideration provisions as a continuation of the original contract. None of our contracts contain a significant financing component. Taxes collected from customers and remitted to governmental authorities are not included in revenue . Allocate the transaction price to performance obligations in the contract: Once we have determined the transaction price, we allocate the total transaction price to each performance obligation in a manner depicting the amount of consideration to which we expect to be entitled in exchange for transferring the good(s) or service(s) to the customer. We allocate the transaction price to each performance obligation identified in the contract on a relative standalone selling price basis. We use the expected cost-plus margin approach based on hardware, labor, and related overhead cost to estimate the standalone selling price of our solar tracker systems, customized components of those systems, and individual parts for certain specific transactions. We also use the expected cost-plus margin approach based on expected third-party shipping and transportation costs to estimate the standalone selling price of our shipping, handling and logistics performance obligations. We use the adjusted market assessment approach for all other performance obligations. Recognize revenue when or as the Company satisfies a performance obligation: For each performance obligation identified, we determine at contract inception whether we satisfy the performance obligation over time or at a point in time. The performance obligations in the contracts for our solar tracker systems and customized components of those systems are satisfied over time as work progresses, utilizing an input measure of progress determined by cost-to-cost measures on these projects as this faithfully depicts our performance in transferring control. Additionally, our performance does not create an asset with an alternative use, due to the highly customized nature of the product, and we have an enforceable right to payment for performance completed to date. Our performance obligations for individual part sales for certain specific transactions are recognized at a point in time as and when control transfers based on the Incoterms for the contract. Our performance obligations for engineering consulting and pile testing services are recognized at a point in time upon completion of the services. Our performance obligations for term-based software licenses are recognized at a point in time as and when control transfers, either upon delivery to the customer or the software license start date, whichever is later. Our performance obligations for shipping and handling services are satisfied over time as the services are delivered over the term of the contract. We recognize revenue for subscription and other services on a straight-line basis over the contract period. With regard to support r |