SC 13D/A

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 13D

(Amendment No. 5)*

Under the Securities Exchange Act of 1934

TransAlta Corporation

__________________________________________________________________________________

(Name of Issuer)

Common Shares, no par value

__________________________________________________________________________________

(Title of Class of Securities)

89346D107

________________________________________________________________________________

(CUSIP Number)

John Staikos

Senior Vice President and General Counsel

LS Power Equity Advisors, LLC

1700 Broadway, 35th Floor

New York, New York 10019

212-615-3441

______________________________________________________________

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

February 12, 2008

_________________________________________________________________________

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of sections 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. [  ]

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Section 240.13d-7 for other parties to whom copies are to be sent.

(Continued on followings pages)

(Page 1 of 14 Pages)

*     The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934, as amended (the "Exchange Act") or otherwise subject to the liabilities of that section of the Exchange Act but shall be subject to all other provisions of the Exchange Act (however, see the Notes).

 CUSIP No. 89346D107  13D  Page 2 of 14 Pages

1.	Names of Reporting Persons. LSP Penn Holdings, LLC
2.	Check the Appropriate Box if a Member of a Group (See Instructions)  (a) [   ]  (b) [X]
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e) [   ]
6.	Citizenship or Place of Organization Delaware
Number of Shares Beneficially Owned by Each Reporting Person with		7.	Sole Voting Power 0
		8.	Shared Voting Power 16,782,400
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 16,782,400
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 16,782,400
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)                                                                                                              [   ]
13.	Percent of Class Represented by Amount in Row (11) 8.3%
14.	Type of Reporting Person (See Instructions) OO

 CUSIP No. 89346D107  13D  Page 3 of 14 Pages

1.	Names of Reporting Persons. LSP Penn Holdings II, LLC
2.	Check the Appropriate Box if a Member of a Group (See Instructions)  (a) [   ]  (b) [X]
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e) [   ]
6.	Citizenship or Place of Organization Delaware
Number of Shares Beneficially Owned by Each Reporting Person with		7.	Sole Voting Power 0
		8.	Shared Voting Power 16,782,400
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 16,782,400
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 16,782,400
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)                                                                                                              [   ]
13.	Percent of Class Represented by Amount in Row (11) 8.3%
14.	Type of Reporting Person (See Instructions) OO

 CUSIP No. 89346D107  13D  Page 4 of 14 Pages

1.	Names of Reporting Persons. LS Power Partners, L.P.
2.	Check the Appropriate Box if a Member of a Group (See Instructions)     (a) [   ]     (b) [X]
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)  [   ]
6.	Citizenship or Place of Organization Delaware
Number of Shares Beneficially Owned by Each Reporting Person with		7.	Sole Voting Power 0
		8.	Shared Voting Power 16,782,400
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 16,782,400
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 16,782,400
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)                                                                                                                   [   ]
13.	Percent of Class Represented by Amount in Row (11) 8.3%
14.	Type of Reporting Person (See Instructions) PN

 CUSIP No. 89346D107  13D  Page 5 of 14 Pages

1.	Names of Reporting Persons. LS Power Partners II, L.P.
2.	Check the Appropriate Box if a Member of a Group (See Instructions)     (a) [   ]     (b) [X]
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)  [   ]
6.	Citizenship or Place of Organization Delaware
Number of Shares Beneficially Owned by Each Reporting Person with		7.	Sole Voting Power 0
		8.	Shared Voting Power 16,782,400
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 16,782,400
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 16,782,400
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)                                                                                                                   [   ]
13.	Percent of Class Represented by Amount in Row (11) 8.3%
14.	Type of Reporting Person (See Instructions) PN

 CUSIP No. 89346D107  13D  Page 6 of 14 Pages

1.	Names of Reporting Persons. Luminus Management, LLC
2.	Check the Appropriate Box if a Member of a Group (See Instructions)     (a) [   ]     (b) [X]
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)          [   ]
6.	Citizenship or Place of Organization Delaware
Number of Shares Beneficially Owned by Each Reporting Person with		7.	Sole Voting Power 0
		8.	Shared Voting Power 16,782,400
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 16,782,400
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 16,782,400
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)                                                                                                                   [   ]
13.	Percent of Class Represented by Amount in Row (11) 8.3%
14.	Type of Reporting Person (See Instructions) PN

 CUSIP No. 89346D107  13D  Page 7 of 14 Pages

1.	Names of Reporting Persons. Luminus Asset Partners, L.P.
2.	Check the Appropriate Box if a Member of a Group (See Instructions)     (a) [   ]     (b) [X]
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)  [   ]
6.	Citizenship or Place of Organization Delaware
Number of Shares Beneficially Owned by Each Reporting Person with		7.	Sole Voting Power 0
		8.	Shared Voting Power 16,782,400
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 16,782,400
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 16,782,400
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)                                                                                                                   [   ]
13.	Percent of Class Represented by Amount in Row (11) 8.3%
14.	Type of Reporting Person (See Instructions) PN

 CUSIP No. 89346D107  13D  Page 8 of 14 Pages

1.	Names of Reporting Persons. Luminus Energy Partners Master Fund, Ltd.
2.	Check the Appropriate Box if a Member of a Group (See Instructions)     (a) [   ]     (b) [X]
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) WC
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)  [   ]
6.	Citizenship or Place of Organization Bermuda
Number of Shares Beneficially Owned by Each Reporting Person with		7.	Sole Voting Power 0
		8.	Shared Voting Power 16,782,400
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 16,782,400
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 16,782,400
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)                                                                                                                   [   ]
13.	Percent of Class Represented by Amount in Row (11) 8.3%
14.	Type of Reporting Person (See Instructions) OO

 CUSIP No. 89346D107  13D  Page 9 of 14 Pages

1.	Names of Reporting Persons. LPCO Investments S.a.r.l.
2.	Check the Appropriate Box if a Member of a Group (See Instructions)     (a) [   ]     (b) [X]
3.	SEC USE ONLY
4.	Source of Funds (See Instructions) OO
5.	Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d) or 2(e)  [   ]
6.	Citizenship or Place of Organization Luxembourg
Number of Shares Beneficially Owned by Each Reporting Person with		7.	Sole Voting Power 0
		8.	Shared Voting Power 16,782,400
		9.	Sole Dispositive Power 0
		10.	Shared Dispositive Power 16,782,400
11.	Aggregate Amount Beneficially Owned by Each Reporting Person 16,782,400
12.	Check if the Aggregate Amount in Row (11) Excludes Certain Shares (See Instructions)                                                                                                                 [   ]
13.	Percent of Class Represented by Amount in Row (11) 8.3%
14.	Type of Reporting Person (See Instructions) OO

 CUSIP No. 89346D107  13D  Page 10 of 14 Pages

This Amendment No. 5 (this "Amendment") amends and supplements the Schedule 13D initially filed on June 27, 2007 (the "Original Filing") and amended on October 23, 2007, December 7, 2007, December 14, 2007 and January 16, 2008 by the Reporting Persons relating to the Common Shares, no par value (the "Shares"), of TransAlta Corporation, a corporation incorporated under the Canada Business Corporations Act (the "Issuer"). Information reported in the Original Filing remains in effect except to the extent that it is amended, restated or superseded by information contained in this Amendment, Amendment No. 1, Amendment No. 2, Amendment No. 3 or Amendment No. 4. Capitalized terms used but not defined in this Amendment have the respective meanings set forth in the Original Filing.

Item 3. Source and Amount of Funds or Other Consideration

Item 3 is hereby amended and supplemented as follows:

As of February 11, 2008, the Reporting Persons are deemed to beneficially own an aggregate of 16,782,400 Shares, as detailed in Item 5.  The aggregate purchase price for such Shares was $441,560,466.031 (exclusive of brokerage commissions and fees), which amount has come, (1) with respect to the LS Power Entities, from working capital and/or from borrowings pursuant to margin accounts maintained in the ordinary course of business with the previously identified financial institution, and (2) with respect to the Luminus Entities, from working capital.

Item 4. Purpose of Transaction.

Item 4 is hereby amended and supplemented as follows:

On February 12, 2008, certain of the Reporting Persons issued a press release relating to the upcoming Annual and Special Meeting of Shareholders of the Issuer.

A copy of the press release is included as Exhibit 7.5 hereto and is incorporated herein by reference.

Item 5. Interest in Securities of the Issuer.

Items 5(a) and 5(b) are hereby amended and restated as follows:

Reporting Persons	Number of Shares with Sole Voting and Dispositive Power	Number of Shares with Shared Voting and Dispositive Power	Aggregate Number of Shares Beneficially Owned	Percentage of Class Beneficially Owned
LSP Penn Holdings, LLC†	0	16,782,400	16,782,400	8.3%
LSP Penn Holdings II, LLC†	0	16,782,400	16,782,400	8.3%
LS Power Partners, L.P.	0	16,782,400	16,782,400	8.3%
LS Power Partners II, L.P.	0	16,782,400	16,782,400	8.3%
Luminus Management, LLC	0	16,782,400	16,782,400	8.3%
Luminus Asset Partners, L.P.†	0	16,782,400	16,782,400	8.3%
Luminus Energy Partners Master Fund, Ltd.†	0	16,782,400	16,782,400	8.3%
LPCO Investments S.à.r.l.	0	16,782,400	16,782,400	8.3%

†  LSP Holdings currently holds 60,700 Shares and LSP Holdings II currently holds 60,700 Shares, purchased between January 16, 2008 and February 11, 2008, which are expected to be transferred to and held by LPCO.Luminus Energy Fund currently holds 533,950 shares and Luminus Asset Partners currently holds 34,950 shares, purchased between November 29, 2007 and February 11, 2008, which are expected to be transferred to and held by LPCO.

By virtue of the relationships among the Reporting Persons described herein, the Reporting Persons may be deemed to constitute a "group," which "group" may be deemed to beneficially own an aggregate of 16,782,400 Shares, representing approximately 8.3% of the outstanding Shares. The percentages used herein are based on the 202,200,000

1 For purposes of calculating the aggregate purchase price, transactions in Shares executed in Canadian Dollars since the most recent filing on Schedule 13D on January 16, 2008 have been converted to US Dollars at a current market exchange rate of 1 CAD to 1.00428 USD.

 CUSIP No. 89346D107  13D  Page 11of 14 Pages

Shares reported to be issued and outstanding as of October 22, 2007 by the Issuer in its Report of Foreign Issuer on Form 6-K, filed with the Securities and Exchange Commission on October 24, 2007.

Items 5(c) is hereby amended and supplemented as follows:

All transactions in the Shares effected by the Reporting Persons since the most recent filing on Schedule 13D on January 16, 2008 are set forth in Annex E attached hereto and incorporated herein by reference.

Item 7. Material to be Filed as Exhibits.

Exhibit Number	Description
7.5	Press release, dated February 12, 2008

 CUSIP No. 89346D107  13D  Page 12 of 14 Pages

SIGNATURE

After reasonable inquiry and to the best of the knowledge and belief of the undersigned, the undersigned certifies that the information set forth herein is true, complete and correct.

Dated: February 12, 2008

LSP Penn Holdings, LLC
By:	/s/ Darpan Kapadia
Name:	Darpan Kapadia
Title:	Managing Director
LSP Penn Holdings II, LLC
By:	/s/ Darpan Kapadia
Name:	Darpan Kapadia
Title:	Managing Director
LS Power Partners, L.P.
By:	/s/ Darpan Kapadia
Name:	Darpan Kapadia
Title:	Managing Director
LS Power Partners II, L.P.
By:	/s/ Darpan Kapadia
Name:	Darpan Kapadia
Title:	Managing Director
Luminus Management, LLC
By:	/s/ Paul Segal
Name:	Paul Segal
Title:	President

 CUSIP No. 89346D107  13D  Page 13 of 14 Pages

Luminus Asset Partners, L.P.
By:	/s/ Paul Segal
Name:	Paul Segal
Title:	President
Luminus Energy Partners Master Fund, Ltd.
By:	/s/ Paul Segal
Name:	Paul Segal
Title:	Director
LPCO Investments S.à.r.l.
By:  Paul Segal, as attorney-in-fact
By:	/s/ Paul Segal
Name:	Paul Segal

 CUSIP No. 89346D107  13D  Page 14 of 14 Pages

ANNEX E to SCHEDULE 13D/A

Party Effecting Transaction	Date	Buy/Sell	Quantity	Average Price (US$)*	Currency
LSP Holdings	1/18/08	Buy	10,700	31.2331	CAD
LSP Holdings	1/22/08	Buy	25,000	30.0397	USD
LSP Holdings	1/23/08	Buy	25,000	29.5410	USD
LSP Holdings II	1/18/08	Buy	10,700	31.2331	CAD
LSP Holdings II	1/22/08	Buy	25,000	30.0397	USD
LSP Holdings II	1/23/08	Buy	25,000	29.5410	USD

*Transactions in Shares executed in Canadian Dollars have been converted to US Dollars using a current market exchange rate of 1 CAD to 1.00428 USD. Average price is net of brokerage fees and commissions.

EX-99

Exhibit 7.5

LUMINUS MANAGEMENT ALERTS TRANSALTA SHAREHOLDERS TO FEBRUARY 25 RECORD DATE FOR 2008 ANNUAL AND SPECIAL MEETING OF SHAREHOLDERS

Urges Shareholders To Take Steps To Ensure Ability To Vote At April 22 Meeting

New York, February 12, 2008 – Luminus Management, LLC and LS Power (collectively “Luminus Group”), TransAlta Corporation’s (TSX: TA) (NYSE: TAC) largest shareholder, today noted that TransAlta has set a record date of February 25, 2008 and a meeting date of April 22, 2008 for its upcoming Annual and Special Meeting of Shareholders according to a February 11, 2008 filing by TransAlta with Canadian securities regulators.

Luminus Group, the beneficial holder of approximately 8% of TransAlta’s shares, has put forth various shareholder proposals for inclusion in TransAlta’s Management Proxy Circular for the 2008 Annual and Special Meeting, including a proposal that reserves Luminus Group’s right to nominate directors for election at that meeting.  Luminus Group intends to announce its director nominees shortly.

Luminus Group urges TransAlta shareholders to take the necessary steps with their custodial banks and brokerage firms to ensure they have the ability to vote at the upcoming Annual and Special Meeting.  TransAlta shareholders should pay particular attention to any shares presently held in swap arrangements or in margin accounts.  In order to ensure that TransAlta shareholders have the ability to vote, they should begin the process of promptly unwinding any swap accounts to allow sufficient time before the February 25 record date.  Likewise, Luminus Group is also recommending that TransAlta shareholders with any shares held in margin accounts that may be loaned by a broker should move the shares into a cash account in advance of the February 25 record date.  Shareholders also interested in adding to their ownership of TransAlta should complete any such purchases by February 20 to allow for trade settlement by the record date, permitting them to vote those shares at the Annual and Special Meeting.

For more information, please visit www.ImproveTransAlta.com

About the Luminus Group:

Luminus Management

Founded in 2002, Luminus Management is the Investment Advisor to two investment partnerships – Luminus Energy Partners Master Fund, Ltd. and Luminus Asset Partners, LP.  Luminus Management focuses primarily on investing in independent power and utility securities.  The investment partnerships to which Luminus Management is Investment Advisor have approximately $1.4 billion of equity under management.

LS Power

Founded in 1990, LS Power is a fully integrated development, investment and asset management group with a proven track record of successful development activities, operations management and commercial contract origination and optimization.  As a developer, LS Power has successfully developed gas-fired facilities and coal-fired facilities representing over 7,000 MW of total capacity, and is currently developing more than 6,000 MW of coal, natural gas and renewable power generation facilities. LS Power currently owns and manages three natural gas-fired power generation facilities representing approximately 1,765 MW.  LS Power has purchased eighteen power generation projects with approximately 11,800 MW of generation capacity and manages two investment funds with approximately $4.3 billion of committed equity capital.

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________________________________________________________________________

The foregoing includes, refers to or incorporates by reference certain statements that are “forward-looking statements”. All statements, other than statements of historical fact, in the foregoing that address activities, events or developments, proposed acquisitions, dispositions and financings that may occur in the future, including TransAlta’s future growth, results of operations, performance and business prospects and opportunities, and the assumptions underlying any of the foregoing, are forward-looking statements. These statements generally can be identified by use of forward-looking words such as “may”, “will”, “expect”, “estimate”, “anticipate”, “believe”, “project”, “should”, or “continue” or the negative thereof or similar variations. Forward-looking statements are based upon a number of assumptions and are subject to a number of known and unknown risks and uncertainties, many of which are beyond the Luminus Group’s control, that could cause actual results to differ materially from those that are disclosed in or implied by such forward-looking statements. These risks and uncertainties include, among other things, risks related to: business risks; cost of fuels to produce electricity, legislative or regulatory developments, competition, global capital markets activity, changes in prevailing interest rates, currency exchange rates, inflation levels, plant availability, and general economic conditions. There can be no assurance that the expectations of the Luminus Group will prove to be correct.

Although the forward-looking statements contained in the foregoing are based upon what the Luminus Group believes are reasonable assumptions, there can be no assurance that actual results will be consistent with these forward-looking statements.

All forward-looking statements in the foregoing speak as of January 16, 2008.  The Luminus Group shall have no duty and does not undertake to update any such forward-looking statements whether as a result of new information, future events or otherwise.

The information concerning TransAlta contained in the foregoing has been taken from or is based upon publicly available documents or records on file with Canadian securities regulatory authorities and other public sources.

The foregoing does not constitute a solicitation of a proxy, consent or authorization for or with respect to any meeting of, or action by vote, written consent or otherwise by, TransAlta’s shareholders. Any such solicitation, if made, will be made only in compliance with applicable law.

# # #

Media Contacts:

Sard Verbinnen & Co.

Paul Caminiti/Dan Gagnier/Lesley Bogdanow

212-687-8080

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