NET POWER (NYSE: NPWR) to withdraw MISO interconnection request after cost update

Rhea-AI Filing Summary

NET POWER Inc. reported that on December 29, 2025 it notified the Midcontinent Independent System Operator (MISO) that it intends to withdraw its request to interconnect a proposed project, after MISO provided updated estimates showing significantly higher expected network upgrade costs. The company still holds its site lease in the northern MISO region and is exploring other ways to develop clean, firm power generation facilities at that location.

NET POWER stated that it has not capitalized any significant costs related to the MISO interconnection request and does not expect this withdrawal to have a material adverse impact on its financial condition or results of operations.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of report (Date of earliest event reported): December 29, 2025

NET POWER INC.

(Exact name of registrant as specified in its charter)

Delaware

001-40503

98-1580612

(State or other jurisdiction of incorporation)

(Commission File Number)

(IRS Employer Identification No.)

320 Roney St., Suite 200 Durham, North Carolina						27701
(Address of principal executive offices)						(Zip Code)

(919) 287-4750

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o			Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
o			Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
o			Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
o			Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Class A Common Stock, par value $0.0001 per share

NPWR

The New York Stock Exchange

Warrants, each exercisable for one share of Class A Common Stock at a price of $11.50

NPWR WS

The New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company x

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 13(a) of the Exchange Act. o

Item 7.01 Regulation FD Disclosure.

On December 29, 2025, Net Power Inc. (the “Company”) notified the Midcontinent Independent System Operator, Inc. (“MISO”) of its intent to withdraw its request for interconnection after receiving updated information from MISO indicating significantly higher anticipated network upgrade costs associated with the proposed interconnection. The Company continues to hold its site lease in northern MISO and is assessing alternative ways to develop clean firm power generation facilities at this site.

The Company has not capitalized any significant costs related to the MISO Interconnection Request to date and does not expect the withdrawal to have a material adverse impact on the Company’s financial condition or results of operations.

The information set forth in this Item 7.01 of this Current Report on Form 8-K is being furnished herewith, and shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section and shall not be incorporated by reference in any filing with, the Securities and Exchange Commission under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference therein.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Dated:

January 5, 2026

NET POWER INC.

By:

/s/ Daniel J. Rice IV

Name:

Daniel J. Rice IV

Title:

Chief Executive Officer

FAQ

What did NET POWER Inc. (NPWR) disclose in this 8-K filing?

NET POWER Inc. disclosed that it notified the Midcontinent Independent System Operator (MISO) of its intent to withdraw a prior interconnection request after updated information showed significantly higher anticipated network upgrade costs.

Why is NET POWER (NPWR) withdrawing its MISO interconnection request?

The company is withdrawing its request after receiving updated information from MISO that indicated significantly higher anticipated network upgrade costs associated with the proposed interconnection.

Does NET POWER expect a financial impact from withdrawing the MISO interconnection request?

NET POWER stated that it has not capitalized any significant costs related to the MISO interconnection request and does not expect the withdrawal to have a material adverse impact on its financial condition or results of operations.

Is NET POWER abandoning its planned project site in northern MISO?

No. The company continues to hold its site lease in northern MISO and is assessing alternative ways to develop clean firm power generation facilities at this site.

What part of the power grid does MISO cover in relation to NET POWER’s plans?

MISO, the Midcontinent Independent System Operator, is the grid operator with which NET POWER had filed an interconnection request; the company is withdrawing that request but retaining its site lease in the northern MISO region.

Is the information in this NET POWER disclosure considered filed or furnished?

The company stated that the information in this Regulation FD disclosure is being furnished, not filed, and therefore is not subject to the liabilities of Section 18 of the Securities Exchange Act of 1934.