UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE ~~13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934~~

13a-16 OR 15d-16 UNDER

THE SECURITIES EXCHANGE ACT OF 1934

For the month of July 2022

Commission File Number 001-13314

Huaneng Power International, Inc.

(Translation of registrant’s name into English)

Huaneng Power International, Inc.

Huaneng Building,

6 Fuxingmennei Street,

Xicheng District,

Beijing, 100031 PRC

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F. Form 20-F x Form 40-F ¨

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ¨

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ¨

This Form 6-K consists of:

AAn ~~copy~~announcement ofregarding ~~monthly~~issue ~~return~~ of ~~equity~~super ~~issuer~~short-term ondebentures ~~movements in securities~~ of Huaneng Power International, Inc.(the "Registrant"), ~~submitted~~made by the Registrant on July 48, 2022.

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SIGNATURES

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, thereunto duly authorized.

	HUANENG POWER INTERNATIONAL, INC.
	By:	/s/ Huang Chaoquan
	Name:	Huang Chaoquan
	Title:	Company Secretary
Date: July 6, 2022
Date: July 8, 2022

~~Monthly~~- ~~Return~~3 ~~for Equity Issuer and Hong Kong Depositary Receipts listed under Chapter 19B of the Exchange Listing Rules on Movements in Securities~~-

~~For~~Hong Kong Exchanges and Clearing Limited and The Stock Exchange of Hong Kong Limited take no responsibility for the ~~month~~contents ~~ended:~~of 30this ~~June~~announcement, make ~~2022~~no ~~Status:~~representation ~~New~~as ~~Submission~~to its accuracy or completeness and expressly disclaim any liability whatsoever for any loss howsoever arising from or in reliance upon the whole or any part of the contents of this announcement.

To(Stock Code: ~~Hong Kong Exchanges and Clearing Limited~~902)

Name of Issuer:	Huaneng Power International, Inc.
Date Submitted:	04 July 2022

OVERSEAS REGULATORY ANNOUNCEMENT ISSUE OF SUPER SHORT-TERM DEBENTURES

IThis announcement is made pursuant to Rule 13.10B ~~Movements~~of inthe ~~Authorised~~Rules /Governing ~~Registered~~the ~~Share~~Listing ~~Capital~~of Securities on The Stock Exchange of Hong Kong Limited (the “Listing Rules”).

1. Type of shares	Ordinary shares		Class of shares	Class H			Listed on SEHK (Note 1)			Yes
Stock code	00902		Description	H shares listed in Hong Kong and ADR listed in New York
		Number of authorised/registered shares			Par value			Authorised/registered share capital
Balance at close of preceding month		4,700,383,440			RMB	1		RMB	4,700,383,440
Increase / decrease (-)								RMB
Balance at close of the month		4,700,383,440			RMB	1		RMB	4,700,383,440

As resolved at the 2021 annual general meeting of Huaneng Power International, Inc. (the “Company”) held on 28 June 2022, the Company has been given a mandate to issue super short-term debentures (in either one or multiple tranches on rolling basis) with a principal amount of up to RMB30 billion (which means that the outstanding principal balance of the super short-term debentures in issue shall not exceed RMB30 billion at any time within the period as prescribed therein) within the period from approval obtained at 2021 annual general meeting to the conclusion of the 2022 annual general meeting.

2. Type of shares	Ordinary shares		Class of shares	Class A			Listed on SEHK (Note 1)			No
Stock code	600011		Description	A Shares listed on The Shanghai Stock Exchange ("SSE")
		Number of authorised/registered shares			Par value			Authorised/registered share capital
Balance at close of preceding month		10,997,709,919			RMB	1		RMB	10,997,709,919
Increase / decrease (-)								RMB
Balance at close of the month		10,997,709,919			RMB	1		RMB	10,997,709,919

The Company has recently completed the issue of the fifth tranche of the Company’s super short- term debentures for 2022 (the “Debentures”). The total issuing amount was RMB3 billion with a maturity period of 29 days whereas the unit face value is RMB100 and the interest rate is 1.54%.

~~Total~~China ~~authorised/registered~~CITIC ~~share~~Bank ~~capital~~Corporation atLimited and Bank of Communications Co., Ltd. acted as the ~~end~~lead ofunderwriters to form the ~~month:~~underwriting ~~RMB~~syndicate 15for the Debentures,~~698~~ which were placed through book- building and issued in the domestic bond market among banks. The proceeds from the Debentures will be used to supplement the working capital of the Company,~~093,359~~ adjust debts structure and repay bank loans and the debt due.

~~Page~~The 1 relevant documents in respect of 6the Debentures are posted on China Money and Shanghai Clearing House at websites of www.chinamoney.com.cn and www.shclearing.com, respectively.

~~II.~~- ~~Movements~~4 ~~in Issued Shares~~-

1. Type of shares	Ordinary shares		Class of shares	Class H	Listed on SEHK (Note 1)	Yes
Stock code	00902		Description	H shares listed in Hong Kong and ADR listed in New York
Balance at close of preceding month		4,700,383,440
Increase / decrease (-)
Balance at close of the month		4,700,383,440

The Debentures do not constitute any transaction under Chapter 14 and Chapter 14A of the Listing Rules.

2. Type of shares	Ordinary shares		Class of shares	Class A	Listed on SEHK (Note 1)	No
Stock code	600011		Description	A shares listed on SSE
Balance at close of preceding month		10,997,709,919
Increase / decrease (-)
Balance at close of the month		10,997,709,919

By Order of the Board
Huaneng Power International, Inc.
Huang Chaoquan

Company Secretary

~~Page~~As 2 at the date of 6this announcement, the directors of the Company are:

~~III.~~Zhao ~~Details~~Keyu of(Executive ~~Movements~~Director) inZhao ~~Issued~~Ping ~~Shares~~(Executive Director) Huang Jian (Non-executive Director) Wang Kui (Non-executive Director) Lu Fei (Non-executive Director) Teng Yu (Non-executive Director) Mi Dabin (Non-executive Director) Cheng Heng (Non-executive Director) Li Haifeng (Non-executive Director) Lin Chong (Non-executive Director) Xu Mengzhou (Independent Non-executive Director) Liu Jizhen (Independent Non-executive Director) Xu Haifeng (Independent Non-executive Director) Zhang Xianzhi (Independent Non-executive Director) Xia Qing (Independent Non-executive Director

~~(A).~~Beijing, ~~Share Options (under Share Option Schemes of~~ the ~~Issuer) Not applicable~~PRC

~~(B).~~9 ~~Warrants~~July ~~to Issue Shares of the Issuer which are to be Listed Not applicable~~2022

~~(C).~~- ~~Convertibles~~5 ~~(i.e. Convertible into Issue Shares of the Issuer which are to be Listed) Not applicable~~-

(D). Any other Agreements or Arrangements to Issue Shares of the Issuer which are to be listed, including Options (other than Share Options Schemes) Not applicable

(E). Other Movements in Issued Share Not applicable

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IV. Information about Hong Kong Depositary Receipt (HDR) Not applicable

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V. Confirmations

We hereby confirm to the best knowledge, information and belief that, in relation to each of the securities issued by the issuer during the month as set out in Part III and IV which has not been previously disclosed in a return published under Main Board Rule 13.25A / GEM Rule 17.27A, it has been duly authorised by the board of directors of the listed issuer and, insofar as applicable:

(Note 2)

(i) all money due to the listed issuer in respect of the issue of securities has been received by it;

(ii) all pre-conditions for listing imposed by the Rules Governing the Listing of Securities on The Stock Exchange of Hong Kong Limited under "Qualifications of listing" have been fulfilled;

(iii) all (if any) conditions contained in the formal letter granting listing of and permission to deal in the securities have been fulfilled;

(iv) all the securities of each class are in all respects identical (Note 3);

(v) all documents required by the Companies (Winding Up and Miscellaneous Provisions) Ordinance to be filed with the Registrar of Companies have been duly filed and that compliance has been made with other legal requirements;

(vi) all the definitive documents of title have been delivered/are ready to be delivered/are being prepared and will be delivered in accordance with the terms of issue;

(vii) completion has taken place of the purchase by the issuer of all property shown in the listing document to have been purchased or agreed to be purchased by it and the purchase consideration for all such property has been duly satisfied; and

(viii) the trust deed/deed poll relating to the debenture, loan stock, notes or bonds has been completed and executed, and particulars thereof, if so required by law, have been filed with the Registrar of Companies.

Submitted by: Huang Chaoquan Title: Secretary to the Board of Directors (Director, Secretary or other Duly Authorised Officer)

Notes

1. SEHK refers to Stock Exchange of Hong Kong.

2. Items (i) to (viii) are suggested forms of confirmation which may be amended to meet individual cases. Where the issuer has already made the relevant confirmations in a return published under Main Board Rule 13.25A / GEM Rule 17.27A in relation to the securities issued, no further confirmation is required to be made in this return.

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3. “Identical” means in this context:

• the securities are of the same nominal value with the same amount called up or paid up;

• they are entitled to dividend/interest at the same rate and for the same period, so that at the next ensuing distribution, the dividend/interest payable per unit will amount to exactly the same sum (gross and net); and

• they carry the same rights as to unrestricted transfer, attendance and voting at meetings and rank pari passu in all other respects.

4. If there is insufficient space, please submit additional document.

5. In the context of repurchase of shares:

• “shares issuable to be listed on SEHK” should be construed as “shares repurchased listed on SEHK”; and

• “stock code of shares issuable (if listed on SEHK)” should be construed as “stock code of shares repurchased (if listed on SEHK)”; and

• “type of shares issuable” should be construed as “type of shares repurchased”; and

• “issue and allotment date” should be construed as “cancellation date”

6. In the context of redemption of shares:

• “shares issuable to be listed on SEHK” should be construed as “shares redeemed listed on SEHK”; and

• “stock code of shares issuable (if listed on SEHK)” should be construed as “stock code of shares redeemed (if listed on SEHK)”; and

• “type of shares issuable” should be construed as “type of shares redeemed”; and

• “issue and allotment date” should be construed as “redemption date”

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