SEI Solaris Energy Infrastructure Inc

As filed with the U.S. Securities and Exchange Commission on November 18, 2024

Registration No. 333-     

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-3

REGISTRATION STATEMENT

Under

THE SECURITIES ACT OF 1933

Solaris Energy Infrastructure, Inc.

(Exact name of registrant as specified in its charter)

9651 Katy Freeway, Suite 300

Houston, Texas 77024

(281) 501-3070

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Kyle S. Ramachandran

President & Chief Financial Officer

9651 Katy Freeway, Suite 300

Houston, Texas 77024

(281) 501-3070

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Douglas E. McWilliams

Jackson A. O’Maley

Vinson & Elkins L.L.P.

845 Texas Avenue, Suite 4700

Houston, Texas 77002

(713) 758-2222

Approximate date of commencement of proposed sale to the public: From time to time after this registration statement becomes effective.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. ☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box: ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. ☐

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of Securities Act. ☐

The Registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act, or until the registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

EXPLANATORY NOTE

This registration statement consists of two prospectuses, covering the registration of:

The information in this prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any state where the offer or sale is not permitted.

Subject to completion, dated November 18, 2024

PROSPECTUS

Solaris Energy Infrastructure, Inc.

$500,000,000

Class A Common Stock

Preferred Stock

From time to time we may offer and sell the following securities:

The aggregate initial offering price of all securities sold by us under this prospectus will not exceed $500,000,000.

We may offer and sell these securities from time to time in amounts, at prices and on terms to be determined by market conditions and other factors at the time of our offerings. We may offer and sell these securities through agents, through underwriters or dealers or directly to one or more purchasers, including existing stockholders. This prospectus provides you with a general description of these securities and the general manner in which we will offer the securities. Each time securities are offered, we will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement may also add, update or change information contained in this prospectus.

Our Class A common stock is traded on the New York Stock Exchange under the symbol “SEI.”

You should read carefully this prospectus, the documents incorporated by reference in this prospectus and any prospectus supplement before you invest. See “Risk Factors” beginning on page 2 of this prospectus for information on certain risks related to the purchase of our securities.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is     , 2024.

TABLE OF CONTENTS

You should rely only on the information contained in this prospectus, any prospectus supplement and the documents we have incorporated by reference herein. We have not authorized any dealer, salesperson or other person to provide you with additional or different information. If anyone provides you with different or inconsistent information, you should not rely on it. This prospectus and any prospectus supplement are not an offer to sell or the solicitation of an offer to buy any securities other than the securities to which they relate and are not an offer to sell or the solicitation of an offer to buy securities in any jurisdiction to any person to whom it is unlawful to make an offer or solicitation in that jurisdiction. You should not assume that the information contained in this prospectus is accurate as of any date other than the date on the front cover of this prospectus, or that the information contained in any document incorporated by reference is accurate as of any date other than the date of the document incorporated by reference, regardless of the time of delivery of this prospectus or any sale of a security. Our business, financial condition, results of operation and prospects may have changed since that date.

i

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we have filed with the U.S. Securities and Exchange Commission (the “SEC”) using a “shelf” registration process. Under this shelf registration process, we may, from time to time, offer and sell any combination of the securities described in this prospectus in one or more offerings. This prospectus generally describes Solaris Energy Infrastructure, Inc. and the securities we may offer. Each time securities are offered by means of this prospectus, we will provide a prospectus supplement that will contain specific information about the terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. We may also add or update in the prospectus supplement (and in any related free writing prospectus that we may authorize to be provided to you) any of the information contained in this prospectus or in the documents that we have incorporated by reference into this prospectus. Please read this prospectus, any applicable prospectus supplement and any related free writing prospectus, together with the information incorporated herein by reference as described under the heading “Where You Can Find More Information,” carefully before buying any of the securities being offered.

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or are incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under the heading “Where You Can Find More Information.”

Unless context otherwise requires, references in this prospectus to the “Company,” “we,” “our,” “us” or like terms refer to Solaris Energy Infrastructure, Inc. and its subsidiaries and predecessors.

ii

WHERE YOU CAN FIND MORE INFORMATION

We have filed a registration statement with the SEC under the Securities Act of 1933, as amended (the ”Securities Act”), that registers the offer and sale of the securities covered by this prospectus. The registration statement, including the exhibits attached thereto and incorporated by reference therein, contains additional relevant information about us. In addition, we file annual, quarterly and other reports and other information with the SEC. The SEC maintains a website that contains reports, proxy and information statements and other information regarding issuers that file electronically with the SEC. Our SEC filings are available on the SEC’s website at www.sec.gov.

The SEC allows us to “incorporate by reference” the information we have filed with the SEC. This means that we can disclose important information to you without actually including the specific information in this prospectus by referring you to other documents filed separately with the SEC. The information incorporated by reference is an important part of this prospectus. Information that we later provide to the SEC, and which is deemed to be “filed” with the SEC, will automatically update information previously filed with the SEC, and may update or replace information in this prospectus and information previously filed with the SEC.

We incorporate by reference the documents listed below and any filings we make with the SEC under Sections 13(a), 13(c), 14, or 15(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) (excluding information deemed to be furnished and not filed with the SEC), after the date on which the registration statement was initially filed with the SEC (including all such documents that we may file with the SEC after the date the registration statement was initially filed and prior to the effectiveness of the registration statement) until all offerings under the registration statement of which this prospectus forms a part are completed or terminated:

These reports contain important information about us, our financial condition and our results of operations.

We make available free of charge on or through our website, solaris-energy.com, our filings with the SEC pursuant to Section 13(a) or 15(d) of the Exchange Act as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC. We make our website content available for information purposes only. Information contained on our website is not incorporated by reference into this prospectus and does not constitute a part of this prospectus.

You may obtain copies of any of the documents incorporated by reference in this prospectus from the SEC through the SEC’s website at the address provided above. You also may request a copy of any document incorporated by reference in this prospectus (including exhibits to those documents specifically incorporated by reference in this prospectus), at no cost, by contacting us at:

Solaris Energy Infrastructure, Inc.

Attention: Investor Relations

9651 Katy Freeway, Suite 300

Houston, Texas 77024

(281) 501-3070

iii

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and the documents incorporated by reference herein include “forward-looking statements” within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act, which involve risks, uncertainties and assumptions. Statements that are predictive in nature, that depend upon or refer to future events or conditions or that include the words “believe,” “expect,” “anticipate,” “intend,” “estimate,” “could,” “may,” “continue,” “predict,” “potential” and other expressions that are predictions of or indicate future events and trends and that do not relate to historical matters identify forward-looking statements. Our forward-looking statements include statements about our business strategy, our industry, our future profitability, our expected capital expenditures and the impact of such expenditures on our performance, management changes, current and potential future long-term contracts, the costs of being a publicly traded corporation, our capital programs and our future business and financial performance. In addition, our forward-looking statements address the various risks and uncertainties associated with extraordinary market environments and the expected impact on our businesses, results of operations and earnings.

A forward-looking statement may include a statement of the assumptions or bases underlying the forward-looking statement. We believe that we have chosen these assumptions or bases in good faith and that they are reasonable. You are cautioned not to place undue reliance on any forward-looking statements. You should also understand that it is not possible to predict or identify all such factors and should not consider the following list to be a complete statement of all potential risks and uncertainties. Factors that could cause our actual results to differ materially from the results contemplated by such forward-looking statements include:

iv

All forward-looking statements speak only as of the date of this prospectus. You should not place undue reliance on our forward-looking statements. Although forward-looking statements reflect our good faith beliefs at the time they are made, forward-looking statements involve known and unknown risks, uncertainties and other factors, including the factors described under Item 1A, “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2023 and under Part II, Item 1A. “Risk Factors” of our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2024, June 30, 2024 and September 30, 2024 this prospectus and in our other filings with the SEC, which may cause our actual results, performance or achievements to differ materially from anticipated future results, performance or achievements expressed or implied by such forward-looking statements. We undertake no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events, changed circumstances or otherwise, unless required by law.

v

ABOUT SOLARIS ENERGY INFRASTRUCTURE, INC.

Solaris Energy Infrastructure, Inc. and its consolidated subsidiaries provide mobile and scalable equipment-based solutions for use in distributed power generation as well as the management of raw materials used in the completion of oil and natural gas wells. Headquartered in Houston, Texas, Solaris serves multiple U.S. end markets, including energy, data centers, and other commercial and industrial sectors. Solaris delivers these offerings through its Solaris Logistics Solutions and Solaris Power Solutions business segments.

Our principal executive offices are located at 9651 Katy Freeway, Suite 300, Houston, Texas 77024, and our telephone number is (281) 501-3070. Our website address is solaris-energy.com. The information on our website is not part of this prospectus.

1

RISK FACTORS

An investment in our securities involves a significant degree of risk. Before you invest in our securities, you should carefully consider those risk factors included in our most recent Annual Report on Form 10-K, any subsequently filed Quarterly Reports on Form 10-Q and any subsequently filed Current Reports on Form 8-K, each of which is incorporated herein by reference, and those risk factors that may be included in any applicable prospectus supplement, together with all of the other information included in this prospectus, any prospectus supplement and the documents we incorporate by reference, in evaluating an investment in our securities. If any of these risks were actually to occur, our business, financial condition or results of operations could be materially adversely affected. Additional risks not presently known to us or that we currently believe are immaterial may also significantly impair our business operations and financial condition. Please read “Cautionary Statement Regarding Forward-Looking Statements.”

2

USE OF PROCEEDS

Unless otherwise specified in an accompanying prospectus supplement, we will use the net proceeds we receive from the sale of the securities covered by this prospectus for general corporate purposes, which may include, among other things, paying or refinancing all or a portion of our indebtedness at the time, funding acquisitions, capital expenditures and working capital.

The actual application of the net proceeds from the sale of any particular offering of securities using this prospectus will be described in the applicable prospectus supplement relating to such offering.

3

DESCRIPTION OF CAPITAL STOCK

Under our amended and restated certificate of incorporation, as amended, our authorized capital stock consists of 600,000,000 shares of Class A common stock, $0.01 par value per share 180,000,000 shares of Class B common stock, $0.00 par value per share (“Class B common stock”), and 50,000,000 shares of preferred stock, $0.01 par value per share. As of the date of this prospectus, there were 30,455,600 shares of our Class A common stock outstanding, 30,136,749 shares of our Class B common stock outstanding and no shares of our preferred stock outstanding.

The following description of capital stock is based upon our amended and restated certificate of incorporation, our amended and restated bylaws, as amended, and applicable provisions of law. We have summarized certain portions of our amended and restated certificate of incorporation and amended and restated bylaws below. The summary is not complete and is subject to, and is qualified in its entirety by express reference to, the provisions of applicable law and to our amended and restated certificate of incorporation and amended and restated bylaws, which are filed as exhibits to the registration statement of which this prospectus is a part.

Class A Common Stock

Voting Rights. Holders of shares of Class A common stock are entitled to one vote per share held of record on all matters to be voted upon by the stockholders. The holders of shares of Class A common stock do not have cumulative voting rights in the election of directors.

Dividend Rights. Holders of shares of our Class A common stock are entitled to ratably receive dividends when and if declared by our board of directors out of funds legally available for that purpose, subject to any statutory or contractual restrictions on the payment of dividends and to any prior rights and preferences that may be applicable to any outstanding preferred stock.

Liquidation Rights. Upon our liquidation, dissolution, distribution of assets or other winding up, the holders of shares of Class A common stock are entitled to receive ratably the assets available for distribution to the stockholders after payment of liabilities and the liquidation preference of any of our outstanding shares of preferred stock.

Other Matters. The shares of Class A common stock have no preemptive or conversion rights and are not subject to further calls or assessment by us. There are no redemption or sinking fund provisions applicable to the Class A common stock. All outstanding shares of our Class A common stock, including the Class A common stock offered in this offering, are fully paid and non-assessable.

Class B Common Stock

Generally. Each member of Solaris Energy Infrastructure, LLC (“Solaris LLC”) has received one share of Class B common stock for each unit of Solaris LLC (the “Solaris LLC Unit”) that it holds. Accordingly, each member of Solaris LLC has a number of votes in the Company equal to the aggregate number of Solaris LLC Units that it holds.

Voting Rights. Holders of shares of our Class B common stock are entitled to one vote per share held of record on all matters to be voted upon by the stockholders. Holders of shares of our Class A common stock and Class B common stock vote together as a single class on all matters presented to our stockholders for their vote or approval, except with respect to the amendment of certain provisions of our amended and restated certificate of incorporation that would alter or change the powers, preferences or special rights of the Class B common stock so as to affect them adversely, which amendments must be adopted by a majority of the votes entitled to be cast by the holders of the shares affected by the amendment, voting as a separate class, or as otherwise required by applicable law.

4

Dividend and Liquidation Rights. Holders of our Class B common stock do not have any right to receive dividends, unless the dividend consists of shares of our Class B common stock or of rights, options, warrants or other securities convertible or exercisable into or redeemable for shares of Class B common stock paid proportionally with respect to each outstanding share of our Class B common stock, and a dividend consisting of shares of Class A common stock or of rights, options, warrants or other securities convertible or exercisable into or redeemable for shares of Class A common stock on the same terms is simultaneously paid to the holders of Class A common stock. Holders of our Class B common stock do not have any right to receive a distribution upon the Company’s liquidation or winding up.

Redemption Right. Each Member of Solaris LLC has received one share of Class B common stock for Solaris LLC Unit that it holds. Accordingly, each member of Solaris LLC has a number of votes in the Company equal to the aggregate number of Solaris LLC Units that it holds. Pursuant to the second amended and restated limited liability company agreement of Solaris LLC, as amended from time to time (the “Solaris LLC Agreement”), each holder of Solaris LLC Units has the right to redeem his or her Solaris LLC Units, together with an equal number of shares of Class B common stock, for shares of Class A common stock (or cash at the Company’s election, subject to customary conversion rate adjustments for stock splits, stock dividends and reclassifications).

Preferred Stock

Our amended and restated certificate of incorporation authorizes our board of directors, subject to any limitations prescribed by law, without further stockholder approval, to establish and to issue from time to time one or more classes or series of preferred stock, par value $0.01 per share, covering up to an aggregate of 50,000,000 shares of preferred stock. Each class or series of preferred stock will have the powers, preferences, rights, qualifications, limitations and restrictions determined by the board of directors, which may include, among others, dividend rights, liquidation preferences, voting rights, conversion rights, preemptive rights and redemption rights. Except as provided by law or in a preferred stock designation, the holders of preferred stock will not be entitled to vote at or receive notice of any meeting of stockholders.

Anti-Takeover Effects of Provisions of Our Amended and Restated Certificate of Incorporation,

Our Amended and Restated Bylaws and Delaware Law

Certain provisions of Delaware law and certain provisions of our amended and restated certificate of incorporation and our amended and restated bylaws described below could make it more difficult for a third party to acquire the Company by means of a tender offer, a proxy contest or otherwise; or removal of our incumbent officers and directors. These provisions may also have the effect of preventing changes in our management. It is possible that these provisions could make it more difficult to accomplish or could deter transactions that stockholders may otherwise consider to be in their best interest or in our best interests, including transactions that might result in a premium over the market price for our shares.

These provisions, summarized below, are expected to discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed to encourage persons seeking to acquire control of us to first negotiate with us. We believe that the benefits of increased protection and our potential ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure us outweigh the disadvantages of discouraging these proposals because, among other things, negotiation of these proposals could result in an improvement of their terms.

Delaware Law

Our amended and restated certificate of incorporation provides that we are not governed by Section 203 of the Delaware General Corporation Law (“DGCL”), which, in the absence of such provisions, would have

5

imposed additional requirements regarding mergers and other business combinations. Section 203 of the DGCL prohibits a Delaware corporation, including those whose securities are listed for trading on the New York Stock Exchange, from engaging in any business combination with any interested stockholder for a period of three years following the date that the stockholder became an interested stockholder, unless:

Our Amended and Restated Certificate of Incorporation and Our Amended and Restated Bylaws

Certain provisions of our amended and restated certificate of incorporation and amended and restated bylaws may delay or discourage transactions involving an actual or potential change in control or change in our management, including transactions in which stockholders might otherwise receive a premium for their shares, or transactions that our stockholders might otherwise deem to be in their best interests. Therefore, these provisions could adversely affect the price of our Class A common stock.

Among other things, our amended and restated certificate of incorporation and amended and restated bylaws:

6

Corporate Opportunity

Under our amended and restated certificate of incorporation, to the extent permitted by law:

Forum Selection

Our amended and restated certificate of incorporation provides that unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware will, to the fullest extent permitted by applicable law, be the sole and exclusive forum for:

Our amended and restated certificate of incorporation also provides that any person or entity purchasing or otherwise acquiring any interest in shares of our capital stock will be deemed to have notice of, and to have consented to, this forum selection provision. Although we believe these provisions benefit us by providing increased consistency in the application of Delaware law for the specified types of actions and proceedings, the provisions may have the effect of discouraging lawsuits against our directors, officers, employees and agents.

7

The enforceability of similar exclusive forum provisions in other companies’ certificates of incorporation has been challenged in legal proceedings, and it is possible that, in connection with one or more actions or proceedings described above, a court could rule that this provision in our amended and restated certificate of incorporation is inapplicable or unenforceable.

The choice of forum provisions summarized above are not intended to, and would not, apply to suits brought to enforce any liability or duty created by the Securities Act or the Exchange Act or other claim for which the federal courts have exclusive jurisdiction. To the extent that any such claims may be based upon federal law claims, Section 27 of the Exchange Act creates exclusive federal jurisdiction over all suits brought to enforce any duty or liability created by the Exchange Act or the rules and regulations thereunder. Furthermore, Section 22 of the Securities Act creates concurrent jurisdiction for federal and state courts over all suits brought to enforce any duty or liability created by the Securities Act or the rules and regulations thereunder. Stockholders may be subject to increased costs to bring these claims, and the choice of forum provisions could have the effect of discouraging claims or limiting investors’ ability to bring claims in a judicial forum that they find favorable.

Limitation of Liability and Indemnification Matters

Our amended and restated certificate of incorporation limits the liability of our directors for monetary damages for breach of their fiduciary duty as directors, except for liability that cannot be eliminated under the DGCL. Delaware law provides that directors of a company will not be personally liable for monetary damages for breach of their fiduciary duty as directors, except for liabilities:

Any amendment, repeal or modification of these provisions will be prospective only and would not affect any limitation on liability of a director for acts or omissions that occurred prior to any such amendment, repeal or modification.

Our amended and restated bylaws also provide that we will indemnify our directors and officers to the fullest extent permitted by Delaware law. Our amended and restated bylaws also permit us to purchase insurance on behalf of any officer, director, employee or other agent for any liability arising out of that person’s actions as our officer, director, employee or agent, regardless of whether Delaware law would permit indemnification. We have entered into indemnification agreements with each of our current directors and officers and intend to enter into indemnification agreement with any future directors and officers. These agreements require us to indemnify these individuals to the fullest extent permitted under Delaware law against liability that may arise by reason of their service to us, and to advance expenses incurred as a result of any proceeding against them as to which they could be indemnified. We believe that the limitation of liability provision that is in our amended and restated certificate of incorporation and the indemnification agreements will facilitate our ability to continue to attract and retain qualified individuals to serve as directors and officers.

Transfer Agent and Registrar

The transfer agent and registrar for our Class A common stock is Equiniti Trust Company, LLC.

Listing

Our Class A common stock is listed on the NYSE under the symbol “SEI.”

8

PLAN OF DISTRIBUTION

We may sell securities described in this prospectus and any accompanying prospectus supplement through underwriters, through broker-dealers, in “at the market offerings,” within the meaning of Rule 415(a)(4) of the Securities Act to or through a market maker or into an existing trading market on an exchange or otherwise, through agents, on one or more exchanges, directly to one or more purchasers, including existing stockholders, through a combination of any of the foregoing methods of sale, or through any other method permitted by applicable law.

We will prepare a prospectus supplement for each offering that will disclose the terms of the offering, including the name or names of any underwriters, dealers, or agents, the purchase price of the securities and the proceeds to us from the sale, any underwriting discounts, and other items constituting compensation to underwriters, dealers, or agents.

We will fix a price or prices of our securities at:

We may change the price of the securities offered from time to time.

If we use underwriters or dealers in the sale, they will acquire the securities for their own account, and they may resell these securities from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price, or at varying prices determined at the time of sale. The securities may be offered to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more of such firms. Unless otherwise disclosed in the prospectus supplement, the obligations of the underwriters to purchase securities will be subject to certain conditions precedent, and the underwriters will be obligated to purchase all of the securities offered by the prospectus supplement if any of the securities are purchased. Any initial public offering price and any discounts or concessions allowed or re-allowed or paid to dealers may be changed from time to time.

We may sell the securities through agents designated by us from time to time. We will name any agent involved in the offering and sale of the securities for which this prospectus is delivered, and disclose any commissions payable by us to the agent or the method by which the commissions can be determined, in the prospectus supplement. Unless otherwise indicated in the prospectus supplement, any agent will be acting on a best efforts basis for the period of its appointment.

Offers to purchase securities may be solicited directly by us and the sale thereof may be made by us directly to institutional investors or others, who may be deemed to be underwriters within the meaning of the Securities Act with respect to any resale thereof. The terms of any such sales will be described in the prospectus supplement relating thereto. We may use electronic media, including the internet, to sell offered securities directly.

We may engage in at-the-market offerings and offer our securities into an existing trading market in accordance with Rule 415(a)(4) under the Securities Act on the terms described in the prospectus supplement relating thereto. Underwriters, dealers, and agents who participate in any at-the-market offerings will be described in the prospectus supplement relating thereto.

We may agree to indemnify underwriters, dealers, and agents who participate in the distribution of securities against certain liabilities to which they may become subject in connection with the sale of the securities, including liabilities arising under the Securities Act.

9

Certain of the underwriters and their affiliates may be customers of, may engage in transactions with and may perform services for us or our affiliates in the ordinary course of business.

A prospectus and accompanying prospectus supplement in electronic form may be made available on the websites maintained by the underwriters. The underwriters may agree to allocate a number of securities for sale to their online brokerage account holders. Such allocations of securities for internet distributions will be made on the same basis as other allocations. In addition, securities may be sold by the underwriters to securities dealers who resell securities to online brokerage account holders.

To the extent required, this prospectus may be amended or supplemented from time to time to describe a specific plan of distribution. The place and time of delivery for the securities in respect of which this prospectus is delivered will be set forth in the accompanying prospectus supplement.

In connection with offerings of securities under the registration statement of which this prospectus forms a part and in compliance with applicable law, underwriters, brokers, or dealers may engage in transactions that stabilize or maintain the market price of the securities at levels above those that might otherwise prevail in the open market. Specifically, underwriters, brokers, or dealers may over-allot in connection with offerings, creating a short position in the securities for their own accounts. For the purpose of covering a syndicate short position or stabilizing the price of the securities, the underwriters, brokers, or dealers may place bids for the securities or effect purchases of the securities in the open market. Finally, the underwriters may impose a penalty whereby selling concessions allowed to syndicate members or other brokers or dealers for distribution of the securities in offerings may be reclaimed by the syndicate if the syndicate repurchases previously distributed securities in transactions to cover short positions, in stabilization transactions or otherwise. These activities may stabilize, maintain, or otherwise affect the market price of the securities, which may be higher than the price that might otherwise prevail in the open market, and, if commenced, may be discontinued at any time.

10

LEGAL MATTERS

The validity of the issuance of the securities offered in this prospectus will be passed upon for us by Vinson & Elkins L.L.P., Houston, Texas. If certain legal matters in connection with an offering of the securities made by this prospectus and a related prospectus supplement are passed upon by counsel for the underwriters of such offering, that counsel will be named in the applicable prospectus supplement related to that offering.

EXPERTS

The consolidated financial statements of Solaris Oilfield Infrastructure, Inc. (n/k/a Solaris Energy Infrastructure, Inc.) as of December 31, 2023 and 2022 and for each of the three years in the period ended December 31, 2023 and the independent registered public accounting firm’s report on management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2023 incorporated by reference in this Prospectus and in the Registration Statement have been so incorporated in reliance on the reports of BDO USA, P.C., an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

The financial statements of Mobile Energy Rentals, LLC as of December 31, 2023 and December 31, 2022, and for the year ended December 31, 2023 and the period from February 23, 2022 (inception) to December 31, 2022 incorporated by reference in this Prospectus and in the Registration Statement have been so incorporated in reliance on the report of BDO USA, P.C., independent auditors, given on the authority of said firm as experts in auditing and accounting. The report on the financial statements contains an explanatory paragraph regarding Mobile Energy Rentals, LLC’s ability to continue as a going concern.

11

The information in this prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any state where the offer or sale is not permitted.

Subject to completion, dated November 18, 2024

PROSPECTUS

Solaris Energy Infrastructure, Inc.

12,294,549 Shares of Class A Common Stock

The securities to be offered and sold using this prospectus includes 12,294,549 shares of Class A common stock, par value $0.01 per share (the “Class A common stock”) issuable upon redemption of units in Solaris Energy Infrastructure, LLC, together with an equal number of shares of our Class B common stock, par value $0.00 per share (the “Class B common stock”). These shares of Class A common stock may be offered and sold by the selling stockholders named in this prospectus or in any supplement to this prospectus from time to time in accordance with the provisions set forth under “Plan of Distribution.”

The selling stockholders may sell the shares of Class A common stock offered by this prospectus from time to time on any exchange on which the shares of Class A common stock are listed on terms to be negotiated with buyers. They may also sell the shares of Class A common stock in private sales or through dealers or agents. The selling stockholders may sell the shares of Class A common stock at prevailing market prices or at prices negotiated with buyers. The selling stockholders will be responsible for any commissions due to brokers, dealers or agents. We will be responsible for all other offering expenses. We will not receive any of the proceeds from the sale by the selling stockholders of the shares of Class A common stock offered by this prospectus.

Our Class A common stock is traded on the New York Stock Exchange under the symbol “SEI.”

You should read carefully this prospectus, the documents incorporated by reference in this prospectus and any prospectus supplement before you invest. See “Risk Factors” beginning on page 2 of this prospectus for information on certain risks related to the purchase of our securities.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is     , 2024.

TABLE OF CONTENTS

You should rely only on the information contained in this prospectus, any prospectus supplement and the documents we have incorporated by reference herein. We and the selling stockholders have not authorized any dealer, salesperson or other person to provide you with additional or different information. If anyone provides you with different or inconsistent information, you should not rely on it. This prospectus and any prospectus supplement are not an offer to sell or the solicitation of an offer to buy any securities other than the securities to which they relate and are not an offer to sell or the solicitation of an offer to buy securities in any jurisdiction to any person to whom it is unlawful to make an offer or solicitation in that jurisdiction. You should not assume that the information contained in this prospectus is accurate as of any date other than the date on the front cover of this prospectus, or that the information contained in any document incorporated by reference is accurate as of any date other than the date of the document incorporated by reference, regardless of the time of delivery of this prospectus or any sale of a security. Our business, financial condition, results of operation and prospects may have changed since that date.

i

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we have filed with the U.S. Securities and Exchange Commission (the “SEC”) using a “shelf” registration process. Under this shelf registration process, the selling stockholders named in this prospectus or any supplement to this prospectus may, from time to time, offer and sell the Class A common stock described in this prospectus in one or more offerings. This prospectus generally describes Solaris Energy Infrastructure, Inc. and the Class A common stock that the selling stockholders may offer. Each time securities are offered by means of this prospectus, the selling stockholders are required to provide a prospectus supplement that will contain specific information about the terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. We may also add or update in the prospectus supplement (and in any related free writing prospectus that we may authorize to be provided to you) any of the information contained in this prospectus or in the documents that have been incorporated by reference into this prospectus. Please read this prospectus, any applicable prospectus supplement and any related free writing prospectus, together with the information incorporated herein by reference as described under the heading “Where You Can Find More Information,” carefully before buying any of the securities being offered.

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or are incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under the heading “Where You Can Find More Information.”

Unless context otherwise requires, references in this prospectus to the “Company,” “we,” “our,” “us” or like terms refer to Solaris Energy Infrastructure, Inc. and its subsidiaries and predecessors.

ii

WHERE YOU CAN FIND MORE INFORMATION

We have filed a registration statement with the SEC under the Securities Act of 1933, as amended (the ”Securities Act”), that registers the offer and sale of the securities covered by this prospectus. The registration statement, including the exhibits attached thereto and incorporated by reference therein, contains additional relevant information about us. In addition, we file annual, quarterly and other reports and other information with the SEC. The SEC maintains a website that contains reports, proxy and information statements and other information regarding issuers that file electronically with the SEC. Our SEC filings are available on the SEC’s website at www.sec.gov.

The SEC allows us to “incorporate by reference” the information we have filed with the SEC. This means that we can disclose important information to you without actually including the specific information in this prospectus by referring you to other documents filed separately with the SEC. The information incorporated by reference is an important part of this prospectus. Information that we later provide to the SEC, and which is deemed to be “filed” with the SEC, will automatically update information previously filed with the SEC, and may update or replace information in this prospectus and information previously filed with the SEC.

We incorporate by reference the documents listed below and any filings we make with the SEC under Sections 13(a), 13(c), 14, or 15(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) (excluding information deemed to be furnished and not filed with the SEC), after the date on which the registration statement was initially filed with the SEC (including all such documents that we may file with the SEC after the date the registration statement was initially filed and prior to the effectiveness of the registration statement) until all offerings under the registration statement of which this prospectus forms a part are completed or terminated:

These reports contain important information about us, our financial condition and our results of operations.

We make available free of charge on or through our website, solaris-energy.com, our filings with the SEC pursuant to Section 13(a) or 15(d) of the Exchange Act as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC. We make our website content available for information purposes only. Information contained on our website is not incorporated by reference into this prospectus and does not constitute a part of this prospectus.

You may obtain copies of any of the documents incorporated by reference in this prospectus from the SEC through the SEC’s website at the address provided above. You also may request a copy of any document incorporated by reference in this prospectus (including exhibits to those documents specifically incorporated by reference in this prospectus), at no cost, by contacting us at:

Solaris Energy Infrastructure, Inc.

Attention: Investor Relations

9651 Katy Freeway, Suite 300

Houston, Texas 77024

(281) 501-3070

iii

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and the documents incorporated by reference herein include “forward-looking statements” within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act, which involve risks, uncertainties and assumptions. Statements that are predictive in nature, that depend upon or refer to future events or conditions or that include the words “believe,” “expect,” “anticipate,” “intend,” “estimate,” “could,” “may,” “continue,” “predict,” “potential” and other expressions that are predictions of or indicate future events and trends and that do not relate to historical matters identify forward-looking statements. Our forward-looking statements include statements about our business strategy, our industry, our future profitability, our expected capital expenditures and the impact of such expenditures on our performance, management changes, current and potential future long-term contracts, the costs of being a publicly traded corporation, our capital programs and our future business and financial performance. In addition, our forward-looking statements address the various risks and uncertainties associated with extraordinary market environments and the expected impact on our businesses, results of operations and earnings.

A forward-looking statement may include a statement of the assumptions or bases underlying the forward-looking statement. We believe that we have chosen these assumptions or bases in good faith and that they are reasonable. You are cautioned not to place undue reliance on any forward-looking statements. You should also understand that it is not possible to predict or identify all such factors and should not consider the following list to be a complete statement of all potential risks and uncertainties. Factors that could cause our actual results to differ materially from the results contemplated by such forward-looking statements include:

iv

All forward-looking statements speak only as of the date of this prospectus. You should not place undue reliance on our forward-looking statements. Although forward-looking statements reflect our good faith beliefs at the time they are made, forward-looking statements involve known and unknown risks, uncertainties and other factors, including the factors described under Item 1A, “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2023 and under Part II, Item 1A. “Risk Factors” of our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2024, June 30, 2024 and September 30, 2024, this prospectus and in our other filings with the SEC, which may cause our actual results, performance or achievements to differ materially from anticipated future results, performance or achievements expressed or implied by such forward-looking statements. We undertake no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events, changed circumstances or otherwise, unless required by law.

v

ABOUT SOLARIS ENERGY INFRASTRUCTURE, INC.

Solaris Energy Infrastructure, Inc. and its consolidated subsidiaries provide mobile and scalable equipment-based solutions for use in distributed power generation as well as the management of raw materials used in the completion of oil and natural gas wells. Headquartered in Houston, Texas, Solaris serves multiple U.S. end markets, including energy, data centers, and other commercial and industrial sectors. Solaris delivers these offerings through its Solaris Logistics Solutions and Solaris Power Solutions business segments.

Our principal executive offices are located at 9651 Katy Freeway, Suite 300, Houston, Texas 77024, and our telephone number is (281) 501-3070. Our website address is solaris-energy.com. The information on our website is not part of this prospectus.

1

RISK FACTORS

An investment in our securities involves a significant degree of risk. Before you invest in our securities, you should carefully consider those risk factors included in our most recent Annual Report on Form 10-K, any subsequently filed Quarterly Reports on Form 10-Q and any subsequently filed Current Reports on Form 8-K, each of which is incorporated herein by reference, and those risk factors that may be included in any applicable prospectus supplement, together with all of the other information included in this prospectus, any prospectus supplement and the documents we incorporate by reference, in evaluating an investment in our securities. If any of these risks were actually to occur, our business, financial condition or results of operations could be materially adversely affected. Additional risks not presently known to us or that we currently believe are immaterial may also significantly impair our business operations and financial condition. Please read “Cautionary Statement Regarding Forward-Looking Statements.”

2

USE OF PROCEEDS

We will not receive any proceeds from the sale of the Class A common stock offered under this prospectus. Any proceeds from the sale of Class A common stock under this prospectus will be received by the selling stockholders. However, pursuant to the Registration Rights Agreement, dated May 17, 2017, by and among us, Solaris Energy Infrastructure, LLC and each of the holders set forth on the signature pages thereto (the “Registration Rights Agreement”), we will pay the expenses, other than the underwriting discounts and commissions, associated with the sale of Class A common stock by the selling stockholders pursuant to this prospectus.

3

DESCRIPTION OF CAPITAL STOCK

Under our amended and restated certificate of incorporation, as amended, our authorized capital stock consists of 600,000,000 shares of Class A common stock, $0.01 par value per share 180,000,000 shares of Class B common stock, $0.00 par value per share (“Class B common stock”), and 50,000,000 shares of preferred stock, $0.01 par value per share. As of the date of this prospectus, there were 30,455,600 shares of our Class A common stock outstanding, 30,136,749 shares of our Class B common stock outstanding and no shares of our preferred stock outstanding.

The following description of capital stock is based upon our amended and restated certificate of incorporation, our amended and restated bylaws, as amended, and applicable provisions of law. We have summarized certain portions of our amended and restated certificate of incorporation and amended and restated bylaws below. The summary is not complete and is subject to, and is qualified in its entirety by express reference to, the provisions of applicable law and to our amended and restated certificate of incorporation and amended and restated bylaws, which are filed as exhibits to the registration statement of which this prospectus is a part.

Class A Common Stock

Voting Rights. Holders of shares of Class A common stock are entitled to one vote per share held of record on all matters to be voted upon by the stockholders. The holders of shares of Class A common stock do not have cumulative voting rights in the election of directors.

Dividend Rights. Holders of shares of our Class A common stock are entitled to ratably receive dividends when and if declared by our board of directors out of funds legally available for that purpose, subject to any statutory or contractual restrictions on the payment of dividends and to any prior rights and preferences that may be applicable to any outstanding preferred stock.

Liquidation Rights. Upon our liquidation, dissolution, distribution of assets or other winding up, the holders of shares of Class A common stock are entitled to receive ratably the assets available for distribution to the stockholders after payment of liabilities and the liquidation preference of any of our outstanding shares of preferred stock.

Other Matters. The shares of Class A common stock have no preemptive or conversion rights and are not subject to further calls or assessment by us. There are no redemption or sinking fund provisions applicable to the Class A common stock. All outstanding shares of our Class A common stock, including the Class A common stock offered in this offering, are fully paid and non-assessable.

Class B Common Stock

Generally. Each member of Solaris Energy Infrastructure, LLC (“Solaris LLC”) has received one share of Class B common stock for each unit of Solaris LLC (the “Solaris LLC Unit”) that it holds. Accordingly, each member of Solaris LLC has a number of votes in the Company equal to the aggregate number of Solaris LLC Units that it holds.

Voting Rights. Holders of shares of our Class B common stock are entitled to one vote per share held of record on all matters to be voted upon by the stockholders. Holders of shares of our Class A common stock and Class B common stock vote together as a single class on all matters presented to our stockholders for their vote or approval, except with respect to the amendment of certain provisions of our amended and restated certificate of incorporation that would alter or change the powers, preferences or special rights of the Class B common stock so as to affect them adversely, which amendments must be adopted by a majority of the votes entitled to be cast

4

by the holders of the shares affected by the amendment, voting as a separate class, or as otherwise required by applicable law.

Dividend and Liquidation Rights. Holders of our Class B common stock do not have any right to receive dividends, unless the dividend consists of shares of our Class B common stock or of rights, options, warrants or other securities convertible or exercisable into or redeemable for shares of Class B common stock paid proportionally with respect to each outstanding share of our Class B common stock, and a dividend consisting of shares of Class A common stock or of rights, options, warrants or other securities convertible or exercisable into or redeemable for shares of Class A common stock on the same terms is simultaneously paid to the holders of Class A common stock. Holders of our Class B common stock do not have any right to receive a distribution upon the Company’s liquidation or winding up.

Redemption Right. Each Member of Solaris LLC has received one share of Class B common stock for Solaris LLC Unit that it holds. Accordingly, each member of Solaris LLC has a number of votes in the Company equal to the aggregate number of Solaris LLC Units that it holds. Pursuant to the second amended and restated limited liability company agreement of Solaris LLC, as amended from time to time (the “Solaris LLC Agreement”), each holder of Solaris LLC Units has the right to redeem his or her Solaris LLC Units, together with an equal number of shares of Class B common stock, for shares of Class A common stock (or cash at the Company’s election, subject to customary conversion rate adjustments for stock splits, stock dividends and reclassifications).

Preferred Stock

Our amended and restated certificate of incorporation authorizes our board of directors, subject to any limitations prescribed by law, without further stockholder approval, to establish and to issue from time to time one or more classes or series of preferred stock, par value $0.01 per share, covering up to an aggregate of 50,000,000 shares of preferred stock. Each class or series of preferred stock will have the powers, preferences, rights, qualifications, limitations and restrictions determined by the board of directors, which may include, among others, dividend rights, liquidation preferences, voting rights, conversion rights, preemptive rights and redemption rights. Except as provided by law or in a preferred stock designation, the holders of preferred stock will not be entitled to vote at or receive notice of any meeting of stockholders.

Anti-Takeover Effects of Provisions of Our Amended and Restated Certificate of Incorporation,

Our Amended and Restated Bylaws and Delaware Law

Certain provisions of Delaware law and certain provisions of our amended and restated certificate of incorporation and our amended and restated bylaws described below could make it more difficult for a third party to acquire the Company by means of a tender offer, a proxy contest or otherwise; or removal of our incumbent officers and directors. These provisions may also have the effect of preventing changes in our management. It is possible that these provisions could make it more difficult to accomplish or could deter transactions that stockholders may otherwise consider to be in their best interest or in our best interests, including transactions that might result in a premium over the market price for our shares.

These provisions, summarized below, are expected to discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed to encourage persons seeking to acquire control of us to first negotiate with us. We believe that the benefits of increased protection and our potential ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure us outweigh the disadvantages of discouraging these proposals because, among other things, negotiation of these proposals could result in an improvement of their terms.

5

Delaware Law

Our amended and restated certificate of incorporation provides that we are not governed by Section 203 of the Delaware General Corporation Law (“DGCL”), which, in the absence of such provisions, would have imposed additional requirements regarding mergers and other business combinations. Section 203 of the DGCL prohibits a Delaware corporation, including those whose securities are listed for trading on the New York Stock Exchange, from engaging in any business combination with any interested stockholder for a period of three years following the date that the stockholder became an interested stockholder, unless:

Our Amended and Restated Certificate of Incorporation and Our Amended and Restated Bylaws

Certain provisions of our amended and restated certificate of incorporation and amended and restated bylaws may delay or discourage transactions involving an actual or potential change in control or change in our management, including transactions in which stockholders might otherwise receive a premium for their shares, or transactions that our stockholders might otherwise deem to be in their best interests. Therefore, these provisions could adversely affect the price of our Class A common stock.

Among other things, our amended and restated certificate of incorporation and amended and restated bylaws:

6

Corporate Opportunity

Under our amended and restated certificate of incorporation, to the extent permitted by law:

Forum Selection

Our amended and restated certificate of incorporation provides that unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware will, to the fullest extent permitted by applicable law, be the sole and exclusive forum for:

7

Our amended and restated certificate of incorporation also provides that any person or entity purchasing or otherwise acquiring any interest in shares of our capital stock will be deemed to have notice of, and to have consented to, this forum selection provision. Although we believe these provisions benefit us by providing increased consistency in the application of Delaware law for the specified types of actions and proceedings, the provisions may have the effect of discouraging lawsuits against our directors, officers, employees and agents. The enforceability of similar exclusive forum provisions in other companies’ certificates of incorporation has been challenged in legal proceedings, and it is possible that, in connection with one or more actions or proceedings described above, a court could rule that this provision in our amended and restated certificate of incorporation is inapplicable or unenforceable.

The choice of forum provisions summarized above are not intended to, and would not, apply to suits brought to enforce any liability or duty created by the Securities Act or the Exchange Act or other claim for which the federal courts have exclusive jurisdiction. To the extent that any such claims may be based upon federal law claims, Section 27 of the Exchange Act creates exclusive federal jurisdiction over all suits brought to enforce any duty or liability created by the Exchange Act or the rules and regulations thereunder. Furthermore, Section 22 of the Securities Act creates concurrent jurisdiction for federal and state courts over all suits brought to enforce any duty or liability created by the Securities Act or the rules and regulations thereunder. Stockholders may be subject to increased costs to bring these claims, and the choice of forum provisions could have the effect of discouraging claims or limiting investors’ ability to bring claims in a judicial forum that they find favorable.

Limitation of Liability and Indemnification Matters

Our amended and restated certificate of incorporation limits the liability of our directors for monetary damages for breach of their fiduciary duty as directors, except for liability that cannot be eliminated under the DGCL. Delaware law provides that directors of a company will not be personally liable for monetary damages for breach of their fiduciary duty as directors, except for liabilities:

Any amendment, repeal or modification of these provisions will be prospective only and would not affect any limitation on liability of a director for acts or omissions that occurred prior to any such amendment, repeal or modification.

Our amended and restated bylaws also provide that we will indemnify our directors and officers to the fullest extent permitted by Delaware law. Our amended and restated bylaws also permit us to purchase insurance on behalf of any officer, director, employee or other agent for any liability arising out of that person’s actions as our officer, director, employee or agent, regardless of whether Delaware law would permit indemnification. We have entered into indemnification agreements with each of our current directors and officers and intend to enter into indemnification agreement with any future directors and officers. These agreements require us to indemnify these individuals to the fullest extent permitted under Delaware law against liability that may arise by reason of their service to us, and to advance expenses incurred as a result of any proceeding against them as to which they

8

could be indemnified. We believe that the limitation of liability provision that is in our amended and restated certificate of incorporation and the indemnification agreements will facilitate our ability to continue to attract and retain qualified individuals to serve as directors and officers.

Transfer Agent and Registrar

The transfer agent and registrar for our Class A common stock is Equiniti Trust Company, LLC.

Listing

Our Class A common stock is listed on the NYSE under the symbol “SEI.”

9

REDEMPTION OF SOLARIS LLC UNITS AND CLASS B COMMON STOCK

Solaris LLC’s limited liability company agreement provides for a single class of units we refer to as “Solaris LLC Units.” Each holder of Solaris LLC Units (a “Solaris LLC Unit Holder”) has received one share of our Class B common stock for each Solaris LLC Unit held by such Solaris LLC Unit Holder. Pursuant to the Solaris LLC Agreement, each Solaris LLC Unit Holder has the right to redeem his or her Solaris LLC Units, together with an equal number of shares of our Class B common stock, for shares of our Class A Common Stock (or cash at our election, subject to customary conversion rate adjustments for stock splits, stock dividends and reclassifications). As holders exchange their Solaris LLC Units and Class B common stock for Class A common stock, our relative interest in Solaris LLC will increase.

The selling stockholders will each generally bear his or her own expenses in connection with a redemption, except that, subject to a limited exception, we are required to pay any transfer taxes, stamp taxes or duties or other similar taxes in connection with such a redemption.

10

SELLING STOCKHOLDERS

The selling stockholders named below may offer to sell from time to time in the future up to an aggregate of 12,294,549 shares of our Class A common stock, par value $0.01 per share (“Class A common stock”) under this prospectus, including 12,294,549 shares of Class B common stock redeemable, together with an equal number of Solaris LLC Units, on a one for one basis for shares of our Class A common stock.

The term “selling stockholders” includes the stockholders listed in the table below and their permitted transferees and assignees or other successors.

Except as described in the footnotes to the following table and under the subsection below entitled “—Material Relationships with Selling Stockholders,” none of the persons named in the table set forth below has held any position or office with, been employed by, or otherwise has had a material relationship with us or any of our affiliates during the three years prior to the date of this prospectus.

The following table sets forth information as of the date of this prospectus by each selling stockholder regarding (i) the beneficial ownership of shares of our Class A common stock and our Class B common stock and (ii) the number of shares of our Class A common stock that may from time to time be offered or sold pursuant to this prospectus, assuming each selling stockholder has redeemed all Solaris LLC Units, together with an equal number of shares of our Class B common stock, beneficially owned by him or her for an equivalent number of shares of our Class A common stock. The information regarding shares of our Class A common stock and our Class B common stock beneficially owned after the offering assumes the sale of all shares of our Class A common stock offered by the selling stockholders (including shares of Class B common stock redeemable, together with an equal number of Solaris LLC Units, on a one for one basis for shares of our Class A common stock) and that the selling stockholders do not acquire any additional shares of our Class A common stock or our Class B common stock.

No offer or sale under this prospectus may be made by a stockholder unless that holder is listed in the table below, in a supplement to this prospectus or in an amendment to the related registration statement that has become effective. We may supplement or amend this prospectus to include additional selling stockholders.

The following table sets forth information relating to the selling stockholders as of the date of this prospectus, based on information supplied to us by the selling stockholders on or prior to that date and information filed with the SEC. We have not sought to verify such information. The selling stockholders may hold or acquire at any time shares of our Class A common stock or our Class B common stock in addition to the shares offered by this prospectus and may have acquired additional shares of our Class A common stock or our Class B common stock since the date on which the information reflected herein was provided to us. Additionally, the selling stockholders may have sold or transferred some or all of their shares of our Class A common stock or our Class B common stock in transactions exempt from the registration requirements of the Securities Act since such date. Other information about the selling stockholders may also change over time. The following table sets forth the maximum number of shares of our Class A common stock that may be sold by the selling stockholders identified below under this prospectus. Because the selling stockholders may offer all or some of their shares of our Class A common stock or our Class B common stock from time to time, we cannot estimate the number of shares of our Class A common stock or our Class B common stock that will be held by the selling stockholders upon the termination of any particular offering by such selling stockholders. The selling stockholders are not obligated to sell any of the shares of Class A common stock offered by this prospectus. The selling stockholders reserve the right to accept or reject, in whole or in part, any proposed sale of shares. The selling stockholders may also offer and sell less than the number of shares of Class A common stock indicated. The selling

11

stockholders are not making any representation that any shares of Class A common stock covered by this prospectus will or will not be offered for sale.

12

Material Relationships with Selling Stockholders

Our material relationships with the additional selling stockholders listed herein and their affiliates are set forth in the section entitled “Related Party Transactions” of our definitive proxy statement on Schedule 14A filed with the SEC on April 4, 2024, which such information is incorporated herein by reference.

Any applicable prospectus supplement, amendment or other permissible disclosure document will also disclose whether any of the selling stockholders has held any position or office with, has been employed by or otherwise has had a material relationship with us during the three years prior to the date of this prospectus supplement.

13

PLAN OF DISTRIBUTION

The selling stockholders may sell securities described in this prospectus and any accompanying prospectus supplement through underwriters, through broker-dealers, through agents, on one or more exchanges, directly to one or more purchasers, through a combination of any of the foregoing methods of sale, or through any other method permitted by applicable law.

In addition, the selling stockholders may from time to time sell securities in compliance with Rule 144 under the Securities Act, if available, or pursuant to other available exemptions from the registration requirements under the Securities Act, rather than pursuant to this prospectus. In such event, the selling stockholders may be required by the securities laws of certain states to offer and sell the shares of common stock only through registered or licensed brokers or dealers.

We will not receive any of the proceeds from the offering by the selling stockholders of the shares of Class A common stock offered under this prospectus. If the shares are sold through underwriters or broker-dealers, we will not be responsible for underwriting discounts or commissions or agents’ commissions.

The selling stockholders may set the price or prices of our securities at:

The selling stockholders may change the price of the securities offered from time to time.

The selling stockholders may act independently of us in making decisions with respect to the timing, manner and size of each of their sales.

From time to time, the selling stockholders may pledge or grant a security interest in some or all of the securities in respect of which this prospectus is delivered. If a selling stockholder defaults in performance of its secured obligations, the pledged or secured parties may offer and sell the securities from time to time by this prospectus. The selling stockholders also may transfer the securities in other circumstances. The number of securities beneficially owned by a selling stockholder will decrease as and when it transfers its securities or defaults in performing obligations secured by the securities. The plan of distribution for the securities offered and sold under this prospectus will otherwise remain unchanged, except that the transferees, distributees, pledgees, affiliates, other secured parties or other successors in interest will be selling stockholders for purposes of this prospectus.

Broker-dealers or other persons may receive discounts or commissions from the selling stockholders, or they may receive commissions from purchasers of the shares of common stock for whom they acted as agents, or both. Any of such discounts or commissions might be in excess of those customary in the types of transactions involved. Broker-dealers or other persons engaged by the selling stockholders may allow other broker-dealers or other persons to participate in resales. If a broker-dealer purchases securities as a principal, it may resell the securities for its own account under this prospectus. A distribution of the securities by the selling stockholders may also be effected through the issuance by the selling stockholder or others of derivative securities, including warrants, exchangeable securities, forward delivery contracts and the writing of options.

If the selling stockholders sell the securities in respect of which this prospectus is delivered in an underwritten offering, the underwriters may acquire the securities for their own account and resell the securities from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. In any such event described above in this paragraph, we will

14

set forth in a supplement to this prospectus the names of the underwriters and the terms of the transactions, including any underwriting discounts, concessions or commissions and other items constituting compensation of the underwriters and broker-dealers. The underwriters from time to time may change any public offering price and any discounts, concessions or commissions allowed or reallowed or paid to broker-dealers. Unless otherwise set forth in a supplement to this prospectus, the obligations of the underwriters to purchase the securities will be subject to certain conditions, and the underwriters will be obligated to purchase all of the securities specified in the supplement if they purchase any of the securities.

If a prospectus supplement so indicates, the selling stockholders may authorize agents, underwriters or dealers to solicit offers by certain institutional investors to purchase these securities to which such prospectus supplement relates, providing for payment and delivery on a future date specified in such prospectus supplement. There may be limitations on the minimum amount that may be purchased by any such institutional investor or on the number of these securities that may be sold pursuant to such arrangements. Agents, dealers or underwriters will not have any responsibility in respect of the validity of such arrangements or such institutional investors thereunder.

The aggregate proceeds to the selling stockholders from the sale of the securities will be the purchase price of the units less the aggregate agents’ discounts or commissions, if any, and other expenses of the distribution not borne by us. The selling stockholders and any agent, broker or dealer that participates in sales of securities offered by this prospectus may be deemed “underwriters” under the Securities Act and any profits, commissions or other consideration received by any agent, broker or dealer may be considered underwriting discounts or commissions under the Securities Act.

The selling stockholders may offer the shares of Class A common stock covered by this prospectus into an existing trading market on the terms described in the prospectus supplement relating thereto. Underwriters or agents could make sales in privately negotiated transactions and/or any other method permitted by law, including sales deemed to be an “at the market” offering as defined in Rule 415 promulgated under the Securities Act, which includes sales made directly on or through the New York Stock Exchange, the existing trading market for our common stock, or sales made to or through a market maker other than on an exchange. Underwriters and agents who participate in any at-the-market offerings will be described in the prospectus supplement relating thereto.

Any of the selling stockholders’ underwriters or agents or any of either of their affiliates may be customers of, engage in transactions with and perform services for us, and/or the selling stockholders or their affiliates in the ordinary course of business.

We and the selling stockholders expect to agree to indemnify each other against certain liabilities, including liabilities under the Securities Act. In addition, the selling stockholders may agree to indemnify any underwriters, broker-dealers and agents against, or contribute to any payments the underwriters, broker-dealers or agents may be required to make with respect to, civil liabilities, including liabilities under the Securities Act.

We have informed the selling stockholders that during such time as they may be engaged in a distribution of the shares of common stock covered by this prospectus they are required to comply with Regulation M under the Exchange Act. With exceptions, Regulation M prohibits the selling stockholders, any affiliated purchasers and other persons who participate in such a distribution from bidding for or purchasing, or attempting to induce any person to bid for or purchase, any security that is the subject of the distribution until the entire distribution is complete.

We have informed each selling stockholder that they are legally required to deliver copies of this prospectus in connection with any sale of securities made under this prospectus in accordance with applicable prospectus delivery requirements.

15

To the extent required, this prospectus may be amended or supplemented from time to time to describe a specific plan of distribution. The place and time of delivery for the securities in respect of which this prospectus is delivered will be set forth in the accompanying prospectus supplement.

In connection with offerings of securities under the registration statement of which this prospectus forms a part and in compliance with applicable law, underwriters, brokers, or dealers may engage in transactions that stabilize or maintain the market price of the securities at levels above those that might otherwise prevail in the open market. Specifically, underwriters, brokers, or dealers may over-allot in connection with offerings, creating a short position in the securities for their own accounts. For the purpose of covering a syndicate short position or stabilizing the price of the securities, the underwriters, brokers, or dealers may place bids for the securities or effect purchases of the securities in the open market. Finally, the underwriters may impose a penalty whereby selling concessions allowed to syndicate members or other brokers or dealers for distribution of the securities in offerings may be reclaimed by the syndicate if the syndicate repurchases previously distributed securities in transactions to cover short positions, in stabilization transactions or otherwise. These activities may stabilize, maintain, or otherwise affect the market price of the securities, which may be higher than the price that might otherwise prevail in the open market, and, if commenced, may be discontinued at any time.

16

LEGAL MATTERS

The validity of the issuance of the securities offered in this prospectus will be passed upon for us by Vinson & Elkins L.L.P., Houston, Texas. If certain legal matters in connection with an offering of the securities made by this prospectus and a related prospectus supplement are passed upon by counsel for the underwriters of such offering, that counsel will be named in the applicable prospectus supplement related to that offering.

EXPERTS

The consolidated financial statements of Solaris Oilfield Infrastructure, Inc. (n/k/a Solaris Energy Infrastructure, Inc.) as of December 31, 2023 and 2022 and for each of the three years in the period ended December 31, 2023 and the independent registered public accounting firm’s report on management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2023 incorporated by reference in this Prospectus and in the Registration Statement have been so incorporated in reliance on the reports of BDO USA, P.C., an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

The financial statements of Mobile Energy Rentals, LLC as of December 31, 2023 and December 31, 2022, and for the year ended December 31, 2023 and the period from February 23, 2022 (inception) to December 31, 2022 incorporated by reference in this Prospectus and in the Registration Statement have been so incorporated in reliance on the report of BDO USA, P.C., an independent auditors, given on the authority of said firm as experts in auditing and accounting. The report on the financial statements contains an explanatory paragraph regarding Mobile Energy Rentals, LLC’s ability to continue as a going concern.

17

PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

Set forth below are the expenses (other than underwriting discounts and commissions) expected to be incurred in connection with the offering of the securities registered hereby.

Solaris Energy Infrastructure, Inc.

Our amended and restated certificate of incorporation provides that a director or officer, as applicable, will not be liable to the corporation or its stockholders for monetary damages to the fullest extent permitted by the DGCL. In addition, if the DGCL is amended to authorize the further elimination or limitation of the liability of directors or officer, then the liability of a director or officer, as applicable, of the corporation, in addition to the limitation on personal liability provided for in our certificate of incorporation, will be limited to the fullest extent permitted by the amended DGCL. Our amended and restated bylaws will provide that the corporation will indemnify, and advance expenses to, any officer or director to the fullest extent authorized by the DGCL.

Section 145 of the DGCL provides that a corporation may indemnify directors and officers as well as other employees and individuals against expenses, including attorneys’ fees, judgments, fines and amounts paid in settlement in connection with specified actions, suits and proceedings whether civil, criminal, administrative, or investigative, other than a derivative action by or in the right of the corporation, if they acted in good faith and in a manner they reasonably believed to be in or not opposed to the best interests of the corporation and, with respect to any criminal action or proceeding, had no reasonable cause to believe their conduct was unlawful. A similar standard is applicable in the case of derivative actions, except that indemnification extends only to expenses, including attorneys’ fees, incurred in connection with the defense or settlement of such action and the statute requires court approval before there can be any indemnification where the person seeking indemnification has been found liable to the corporation. The statute provides that it is not exclusive of other indemnification that may be granted by a corporation’s certificate of incorporation, bylaws, disinterested director vote, stockholder vote, agreement or otherwise.

Our amended and restated certificate of incorporation also contains indemnification rights for our directors and our officers. Specifically, our amended and restated certificate of incorporation provides that we shall indemnify our officers and directors to the fullest extent authorized by the DGCL. Furthermore, we may maintain insurance on behalf of our officers and directors against expense, liability or loss asserted incurred by them in their capacities as officers and directors.

II-1

We have obtained directors’ and officers’ insurance to cover our directors, officers and some of our employees for certain liabilities.

We have entered into written indemnification agreements with our directors and executive officers. Under these agreements, if an officer or director makes a claim of indemnification to us, either a majority of the independent directors or independent legal counsel selected by the independent directors must review the relevant facts and make a determination whether the officer or director has met the standards of conduct under Delaware law that would permit (under Delaware law) and require (under the indemnification agreement) us to indemnify the officer or director.

The following documents are filed as exhibits to this registration statement, including those exhibits incorporated herein by reference to a prior filing of Solaris Energy Infrastructure, Inc. under the Securities Act or the Exchange Act as indicated in parentheses:

II-2

The undersigned registrant hereby undertakes:

provided, however, that paragraphs (a)(i), (a)(ii) and (a)(iii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the SEC by the registrant pursuant to Section 13 or 15(d) of the Exchange Act that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

II-3

The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act, each filing of our annual report pursuant to Section 13(a) or 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

Insofar as indemnification for liabilities arising under the Securities Act, as amended, may be permitted to directors, officers or persons controlling the registrant pursuant to the provisions set forth or described in Item 15 of this registration statement, or otherwise, the registrant has been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is therefore unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of their counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by them is against public policy as expressed in the Securities Act, and will be governed by the final adjudication of such issue.

The undersigned registrant hereby undertake that:

The undersigned registrant hereby undertakes to file an application for the purpose of determining the eligibility of the trustee to act under subsection (a) of Section 310 of the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”) in accordance with the rules and regulations prescribed by the Commission under Section 305(b)(2) of the Trust Indenture Act.

II-4

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Houston, State of Texas, on November 18, 2024.

Each person whose signature appears below appoints William A. Zartler, Kyle S. Ramachandran and Christopher M. Powell, and each of them, any of whom may act without the joinder of the other, as his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and in his name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement and any Registration Statement (including any amendment thereto) for this offering that is to be effective upon filing pursuant to Rule 462(b) under the Securities Act of 1933, as amended, and to file the same, with all exhibits thereto, and all other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents full power and authority to do and perform each and every act and thing requisite and necessary to be done, as fully to all intents and purposes as he or she might or would do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or any of them or their or his substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed below by the following persons in the capacities indicated below as of November 18, 2024.

II-5

II-6

Exhibit 5.1

Tel + 1.713.758.2222 Fax + 1.713.758.2346

November 18, 2024

Solaris Energy Infrastructure, Inc.

9651 Katy Freeway, Suite 300

Houston, Texas 77024

Ladies and Gentlemen:

We have acted as counsel for Solaris Energy Infrastructure, Inc., a Delaware corporation (the “Company”), and certain of its subsidiaries with respect to certain legal matters in connection with the preparation and filing of a Registration Statement on Form S-3 (the “Registration Statement”) filed on or about the date hereof with the U.S. Securities and Exchange Commission (the “Commission”) in connection with the registration by the Company under the Securities Act of 1933, as amended (the “Securities Act”), of the offer and sale (a) by the Company, from time to time, pursuant to Rule 415 under the Securities Act, of up to $500 million of (i) shares of Class A common stock, par value $0.01 per share, of the Company (the “Common Stock”) and (ii) shares of preferred stock, par value $0.01 per share, of the Company, in one or more series (the “Preferred Stock” and, together with the Common Stock, the “Securities”); and (b) by the selling stockholders named in the Registration Statement (the “Selling Stockholders”), that may redeem shares of the Company’s Class B common stock, par value $0.00 per share, along with a limited liability company unit of Solaris Energy Infrastructure, LLC, a Delaware limited liability company (“Solaris LLC”) for a share of Common Stock of the Company, of up to 12,294,549 shares of Common Stock (the “Redemption Common Stock”).

We have also participated in the preparation of a Prospectus relating to the Securities (the “Primary Prospectus”) and a Prospectus relating to the Redemption Common Stock (the “Secondary Prospectus” and, together with the Primary Prospectus, the “Prospectuses”) each of which is contained in the Registration Statement to which this opinion is an exhibit.

In connection with the opinions expressed herein, we have examined, among other things, the (i) the Amended and Restated Certificate of Incorporation, as amended, and the Amended and Restated Bylaws, as amended, of the Company, (ii) the Second Amended and Restated Limited Liability Company Agreement of Solaris LLC, dated as of May 11, 2017, as amended (the “Solaris LLC Agreement”), (iii) the Registration Statement, (iv) the Prospectuses and (v) the records of corporate proceedings that have occurred prior to the date hereof with respect to the Registration Statement. We have also reviewed such questions of law as we have deemed necessary or appropriate. As to matters of fact relevant to the opinions expressed herein, and as to factual matters arising in connection with our examination of corporate documents, records and other documents and writings, we have relied upon certificates and other communications of corporate officers of the Company, without further investigation as to the facts set forth therein.

In connection with rendering the opinions set forth below, we have assumed that (i) all information contained in all documents reviewed by us is true and correct; (ii) all signatures on all documents examined by us are genuine; (iii) all documents submitted to us as originals are authentic and all documents submitted to us as copies conform to the originals of those documents; (iv) the Registration Statement and any subsequent amendments (including additional post-effective amendments), will have become effective and comply with all applicable laws; (v) all Securities will be issued and sold in compliance with applicable federal and state securities laws and in the manner specified in the Registration Statement and the applicable prospectus supplement to the applicable Prospectus; (vi) one or more prospectus supplements to the applicable Prospectus will have been prepared and filed with the Commission describing the Securities offered thereby; (vii) a definitive purchase, underwriting or similar agreement with respect to any Securities offered will have been duly authorized and validly executed and delivered by the Company and the other parties thereto; (viii) any securities issuable upon conversion, exchange or exercise of any Preferred Stock being offered will have been duly authorized, created and, if appropriate, reserved for issuance upon such conversion, exchange or exercise; (ix) the Redemption Common Stock will have been issued in accordance with the Solaris LLC Agreement; and (x) the Redemption Common Stock will be sold in the manner set forth in the Registration Statement and the Secondary Prospectus.

Based upon the foregoing, and subject to the assumptions, qualifications, limitations, and exceptions set forth herein, we are of the opinion that:

				November 18, 2024

We express no opinions concerning the enforceability of indemnification provisions to the extent they purport to relate to liabilities resulting from or based upon negligence or any violation of federal or state securities or blue sky laws.

The foregoing opinions are limited to the Delaware General Corporation Law and Delaware Limited Liability Company Act (including the applicable provisions of the Delaware Constitution and the reported judicial decisions interpreting these laws) and the federal laws of the United States of America, and we are expressing no opinion as to the effect of the laws of any other jurisdiction, domestic or foreign.

We hereby consent to the filing of this opinion as an exhibit to the Registration Statement and to the use of our name in the Prospectuses forming a part of the Registration Statement under the caption “Legal Matters.” In giving this consent, we do not admit that we are within the category of persons whose consent is required under Section 7 of the Securities Act.

Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We hereby consent to the incorporation by reference in the Prospectus constituting a part of this Registration Statement of our reports dated February 27, 2024, relating to the consolidated financial statements and the effectiveness of internal control over financial reporting of Solaris Oilfield Infrastructure, Inc. (n/k/a Solaris Energy Infrastructure, Inc.) (the Company) appearing in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023.

We also consent to the reference to us under the caption “Experts” in the Prospectus.

/s/ BDO USA, P.C.

Houston, Texas

November 18, 2024

Exhibit 23.2

Consent of Independent Auditor

We hereby consent to the incorporation by reference in the Prospectus constituting a part of this Registration Statement of Solaris Energy Infrastructure, Inc. of our report dated July 25, 2024, relating to the financial statements of Mobile Energy Rentals, LLC (the Company), appearing in Solaris Energy Infrastructure, Inc.’s Current Report on Form 8-K filed November 18, 2024. Our report contains an explanatory paragraph regarding the Company’s ability to continue as a going concern.

We also consent to the reference to us under the caption “Experts” in the Prospectus.

/s/ BDO USA, P.C.

Houston, Texas

November 18, 2024

Exhibit 107

Calculation of Filing Fee Tables

Form S-3

(Form Type)

Solaris Energy Infrastructure, Inc.

(Exact Name of Registrant as Specified in its Charter)

Table 1: Newly Registered Securities