Table of Contents The loss of, or events affecting, one of our major customers could reduce our sales and have an adverse effect on our business, financial condition and results of operations. For the fiscal year ended December 31, 2023, one customer accounted for approximately 40% of total net revenues. Further, as of December 31, 2023, amounts due from one customer represented approximately 40% of the total accounts receivable balance. Our customers’ decisions to purchase our products are influenced by a number of factors outside of our control, including, among others, retail energy prices, the macroeconomic environment, and government regulation and incentives. Although we have agreements with some of our largest customers, these agreements generally do not have long-term purchase commitments and are generally terminable by either party after a relatively short notice period. In addition, these customers may decide to no longer use, or to reduce the use of, our products and services for other reasons that may be out of our control. We may also be affected by events impacting our large customers that result in their decreasing their orders with us or impairing their ability to pay for our products. The loss of, or events affecting, one or more of our large customers has had from time to time, and could in the future have a material adverse effect on our business, financial condition and results of operations. Our energy systems, including our storage solutions, IQ8 microinverters and Ensemble OS technology, may not achieve broader market acceptance, which would prevent us from increasing our revenue and market share. If we fail to achieve broader market acceptance of the Enphase Energy System, including international acceptance of our storage solutions, IQ8 microinverters, ACM products and Ensemble OS technology, there would be an adverse impact on our ability to increase our revenue, gain market share and achieve and sustain profitability. Our ability to achieve broader market acceptance for our products and services will be impacted by a number of factors, including: • our ability to produce energy systems that compete favorably against other solutions on the basis of price, quality, reliability and performance; • our ability to timely introduce and complete new designs and timely qualify and certify our products; • whether installers, system owners and solar financing providers will continue to adopt our systems, which have a relatively limited history with respect to reliability and performance; • whether installers, system owners and solar financing providers will adopt our storage solution, which is a relatively new technology with a limited history with respect to reliability and performance; • the ability of prospective system owners to obtain long-term financing for solar PV installations based on our product platform on acceptable terms or at all; • our ability to develop products, systems and services that comply with local standards and regulatory requirements, as well as potential in-country manufacturing requirements; and • our ability to develop and maintain successful relationships with our customers and suppliers. In addition, our ability to achieve increased market share will depend on our ability to increase sales to established solar installers, who have traditionally sold central or string inverters, or who currently sell DC-to-DC optimizers. These installers often have made substantial investments in design, installation resources and training in traditional central or string inverter systems or DC optimizers, which may create challenges for us to achieve their adoption of our solutions. If our products contain manufacturing or software defects, our business and financial results could be harmed. We design and make complex products and they may contain undetected or latent errors or defects. Complex hardware and software systems, such as our products, can often contain undetected errors when first introduced or as new versions are released. In the past, we have experienced latent defects only discovered once the microinverters or batteries are deployed in the field. Changes in our supply chain or the failure of our suppliers to otherwise provide our third-party contract manufacturers with components or materials that meet our specifications could introduce defects into our products. As we grow our product volumes, the chance of manufacturing defects could increase. In addition, new product introductions or design changes made for the purpose of cost reduction, performance improvement or improved reliability could introduce new design defects that may impact the performance and life of our products. Any design or manufacturing defects or other failures of our products to Enphase Energy, Inc. | 2023 Form 10-K | 24