Solaris Energy Infrastructure, Inc.

Item 1.01. Entry into a Material Definitive Agreement. On September 22, 2026, Solaris Energy Infrastructure, Inc. (the “Company”), Solaris Energy Infrastructure, LLC, a subsidiary of the Company (the “Issuer”), and the subsidiary guarantors named therein (the “Subsidiary Guarantors”) entered into a purchase agreement (the “Purchase Agreement”) with MUFG Securities Americas Inc., as representative of the several initial purchasers named therein (collectively, the “Initial Purchasers”), pursuant to which the Issuer agreed to sell to the Initial Purchasers $1.25 billion aggregate principal amount of the Issuer’s 7.000% Senior Notes due 2032 (the “Notes”) in a private placement (the “Offering”) conducted pursuant to Rule 144A and Regulation S under the Securities Act of 1933, as amended. The Offering was upsized to $1.25 billion in aggregate principal amount of Notes from the original offering size of $1.0 billion in aggregate principal amount of Notes. The Notes will mature on April 1, 2032. The Notes will be issued at par for total net proceeds of approximately $1,227.2 million, after deducting the Initial Purchasers’ discount and estimated offering expenses. The closing of the issuance of the Notes is expected to occur on October 1, 2026, subject to customary closing conditions. The Issuer intends to use the net proceeds from the Offering for general corporate purposes, growth capital expenditures and to pay fees and expenses related to the Offering. The Purchase Agreement contains customary representations, warranties and agreements of the Company, the Issuer and the Subsidiary Guarantors and customary conditions to closing, indemnification rights, obligations of the parties and termination provisions. The foregoing description of the Purchase Agreement is qualified in its entirety by reference to the full text of the Purchase Agreement, a copy of which is filed as Exhibit 10.1 to this Current Report on Form 8-K and is incorporated herein by reference.

Item 8.01. Other Events. On September 22, 2026, the Company issued a press release announcing the pricing of the Notes described in Item 1.01 of this Current Report on Form 8-K. A copy of the press release is attached as Exhibit 99.1 to this Current Report on Form 8-K and incorporated herein by reference.