Up to 39,534,884 Shares of Common Stock This prospectus relates to the registration of the resale or other disposition of up to 39,534,884 shares of our common stock by YA II PN, LTD(“Yorkville”). Yorkville is also referred to in this prospectus as the Selling Securityholder. The shares of our common stock to which this prospectusrelates have been or may be issued by us to Yorkville (i) pursuant to a standby equity purchase agreement, dated as of January 27, 2026, by andbetween us and Yorkville (the “SEPA”), and (ii) upon conversion of a convertible debenture issued by us on March 6, 2026 to Yorkville (the “YADebenture”). Such shares of common stock include (i) up to 25,000,000 shares of common stock that we may, at our discretion, elect to issue and sellto Yorkville from time to time after the date of this prospectus pursuant to the SEPA (the “SEPA Shares”) and (ii) up to 14,534,884 shares of commonstock that may be issued to Yorkville upon conversion by Yorkville of the YA Debenture (the “Debenture Shares” and, collectively with theConversion Shares, the “Offered Securities”). We are not selling any securities under this prospectus and will not receive any of the proceeds from the sale of our common stock by the SellingSecurityholder. Prior to the date of this prospectus, we received (i) proceeds of $1,710,000 in connection with our sale and issuance to Yorkville onJanuary 27, 2026 of a convertible promissory note in the aggregate principal amount of $1,900,000 as a pre-paid advance under the SEPA and (ii)proceeds of $9,000,000 from the issuance and sale by us to Yorkville of the YA Debenture; and we may receive proceeds from sales of common stockthat we may elect to make to Yorkville pursuant to the SEPA, if any, from time to time after the date of this prospectus. The net proceeds from sales, ifany, under the SEPA, will depend on the frequency and prices at which we sell shares of common stock to Yorkville after the date of this prospectus.See “PROSPECTUS SUMMARY - The Standby Equity Purchase Agreement” on page 4 of this prospectus for a description of the SEPA and YADebenture and “SELLING SECURITYHOLDER” on page 109 of this prospectus for additional information regarding the Selling Securityholder. The Selling Securityholder may sell or otherwise dispose of the common stock described in this prospectus in a number of different ways and atvarying prices. Yorkville is an “underwriter” within the meaning of Section 2(a)(11) of the Securities Act of 1933, as amended (the “Securities Act”),only with respect to advances under the SEPA (“Advances”), and any profits on the sales of shares of our common stock by Yorkville acquired underthe SEPA and any discounts, commissions, or concessions received by Yorkville are deemed to be underwriting discounts and commissions under theSecurities Act. If any underwriters, dealers, or agents are involved in the sale of any of the securities, their names and any applicable purchase price,fee, commission, or discount arrangement between or among them will be set forth, or will be calculable from the information set forth, in anyapplicable prospectus supplement. Yorkville is not an “underwriter” within the meaning of Section 2(a)(11) of the Securities Act with respect to theshares of our common stock issuable to Yorkville upon conversion by Yorkville of the YA Debenture. We will pay the expenses incurred in registeringunder the Securities Act the offer and sale of the shares of the common stock to which this prospectus relates by the Selling Securityholder, includingour legal and accounting fees. See “Plan of Distribution” on page 124 of this prospectus for more information. No securities may be sold withoutdelivery of this prospectus and any applicable prospectus supplement describing the method and terms of the offering of such securities. You shouldcarefully read this prospectus and any applicable prospectus supplement before you invest in our securities. We engaged Northland Capital Markets (“Northland”) as our placement agent in connection with the SEPA. We have agreed to pay Northland a cashfee of 5.0% based upon the aggregate gross proceeds received from the sales of convertible promissory notes and common stock that we elect to maketo Yorkville pursuant to the SEPA. See “Plan of Distribution” on page 124 of this prospectus for additional information regarding this arrangement. Shares of our common stock are listed on the Nasdaq Global Market (“Nasdaq”) under the symbol “SPWR”. On May 29, 2026, the closing price ofour common stock was $1.03. We are an “emerging growth company” as defined under U.S. federal securities laws and, as such, have elected to comply with reduced publiccompany reporting requirements. This prospectus complies with the requirements that apply to an issuer that is an emerging growth company. Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties described in the section titled“Ri