Orion Energy Systems Inc美股招股说明书(2026-01-29版)

PRELIMINARY PROSPECTUS SUPPLEMENT(To Prospectus dated March10, 2023) Shares of Common Stock We are offeringshares of our common stock, no par value per share (the “Common Stock”). The purchase price ofeach share of Common Stock is $per share. Our Common Stock is listed on the NASDAQ Capital Market under the symbol “OESX.” The last reported sale price ofour Common Stock on the NASDAQ Capital Market on January28, 2026 was $17.27per share. As of the date of this prospectus supplement, the aggregate market value of our Common Stock held by non-affiliates, orthe public float, pursuant to General Instruction I.B.6 of Form S-3 was approximately $62.4million, which was calculated basedon 3,378,948 shares of our Common Stock outstanding held by non-affiliates as of the date of this prospectus supplement and ata price of $18.46 per share, the last reported sale price for our Common Stock on December10, 2025. We have not sold anysecuritiespursuant to General Instruction I.B.6 of Form S-3during the prior 12-calendar month period that ends on and includesthe date of this prospectus supplement (excluding this offering). Accordingly, based on the foregoing, we are currently eligibleunder General Instruction I.B.6 of Form S-3 to offer and sell shares of our Common Stock having an aggregate offering price ofup to approximately $20.8million.Pursuant to General Instruction I.B.6 of Form S-3, in no event will we sell securities in apublic primary offering with a value exceeding more than one-third of our public float in any 12-month period so long as ourpublic float remains below $75.0million. Investing in our Common Stock involves significant risk. You should read this prospectussupplement and the accompanying prospectus carefully before you make your investment decision.See the sections entitled “RiskFactors” beginning on pageS-11 of this prospectus supplement, theaccompanying prospectus, and the other documents we file or have filed with the Securities andExchange Commission that are incorporated by reference in this prospectus supplement and in theaccompanying prospectus, for more information. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapprovedof the securities or determined if this prospectus supplement is truthful or complete. Any representation to the contraryis a criminal offense. Per ShareTotalOffering Price$$Underwriting discounts and commissions(1)$$Proceeds, before expenses, to us$$ (1)Consists of a cash fee of 7.0% of the aggregate gross proceeds in this offering. We have also agreed to reimburse Craig-Hallum Capital Group LLC (the “Underwriter”) for certain expenses incurred in connection with this offering. See“Underwriting” beginning on page S-33 of this prospectus supplement for additional information with respect to thecompensation we will pay the Underwriter. Delivery of the shares offered hereby is expected to be made on or about, 2026, subject to satisfaction of certaincustomary closing conditions. Sole Managing UnderwriterCraig-Hallum Table of Contents TABLE OF CONTENTS Prospectus Supplement About This Prospectus SupplementCautionary Note Regarding Forward-Looking StatementsWhere You Can Find More InformationProspectus Supplement SummaryThe OfferingRisk FactorsUse of ProceedsDilutionDescription of Securities Being OfferedUnderwritingLegal MattersExperts About This ProspectusSpecial Note Regarding Forward-Looking StatementsOrion Energy Systems, Inc.Risk FactorsUse of ProceedsSecurities To Be OfferedDescription of Debt SecuritiesDescription of Capital StockDescription of WarrantsDescription of Subscription RightsDescription of Stock Purchase Contracts and Stock Purchase UnitsWhere You Can Find More InformationPlan of DistributionLegal MattersExperts Table of Contents ABOUT THIS PROSPECTUS SUPPLEMENT This document consists of two parts. The first part is this prospectus supplement, which describes the specific terms of the securities we areoffering. The second part is the accompanying prospectus, which gives more general information, some of which may not apply to this offering. Thisprospectus supplement and the information incorporated by reference in this prospectus supplement may add to, update and change informationcontained in, or incorporated by reference into, the accompanying prospectus. To the extent there is a conflict between the information contained in thisprospectus supplement, on the one hand, or in any document incorporated by reference herein that was filed with the Securities and ExchangeCommission (“SEC”) before the date of this prospectus supplement, on the other hand, you should rely on the information in this prospectussupplement. If any statement in one of these documents is inconsistent with a statement in another document having a later date, for example, adocument incorporated by reference in this prospectus supplement or the accompanying prospectus, the statement in the document having the later datemodifi