September 21,
2005


Mail Stop 6010

Thomas H. Werner
Chief Executive Officer
SunPower Corporation
430 Indio Way
Sunnyvale, California 94085

Re:	SunPower Corporation
	Registration Statement on Form S-1
	Filed August 25, 2005
	         File No. 333-127845
Dear Mr. Werner:
      We have reviewed your filing and have the following
comments.
Where indicated, we think you should revise your document in
response
to these comments.  If you disagree, we will consider your
explanation as to why our comment is inapplicable or a revision is
unnecessary.  Please be as detailed as necessary in your
explanation.
In some of our comments, we may ask you to provide us with
information so we may better understand your disclosure.  After
reviewing this information, we may raise additional comments.
      Please understand that the purpose of our review process is
to
assist you in your compliance with the applicable disclosure
requirements and to enhance the overall disclosure in your filing.
We look forward to working with you in these respects.  We welcome
any questions you may have about our comments or any other aspect
of
our review.  Feel free to call us at the telephone numbers listed
at
the end of this letter.
General
1. Please confirm that any preliminary prospectus you circulate
will
include all non-Rule 430A information. This includes the price
range
and related information based on a bona fide estimate of the
public
offering within that range. Also note that we may have additional
comments after you include this information.

Graphics
2. Please clarify whether you are currently selling the solar
panels
shown in the graphics on the inside front cover page, or whether
those panels will not be shipped until 2006 as disclosed on page
66.
Also, please explain to us how you selected the conventional 150
watt
solar panel to compare with your company`s product.

3. Please revise the artwork so that it places greater emphasis on
the products that SunPower actually manufactures and sells, and
less
emphasis on the application in which those products are used, such
as
the residential solar system shown in the top half of the inside
front cover page and the power plant shown in the top half of your
inside back cover page.  Although we will not object if the
artwork
includes references to applications in which your products are
used,
the artwork should focus primarily upon your products rather than
on
those applications.

Cover Page
4. Please revise to briefly describe the extent to which you will
be
controlled by Cypress following the offering.  Quantify the number
of
shares that Cypress will own and the percentage of total votes
that
Cypress will control.

Summary, page 1

Our Company, page 1

5. The disclosure in the summary should be a balanced presentation
of
your business.  Revise to indicate your historical losses, your
accumulated deficit, and the fact that you have only been selling
solar cells since late 2004.  Also expand to balance the
disclosure
of your strengths with a realistic picture of the challenges you
face, many of which are identified in your risk factors section.

6. Please provide us independent, objective support for your
statements regarding your leadership position and the "superior"
performance of your products, including the ability of your solar
cells to "generate up to 50% more power per unit" area than
conventional solar cells and your "efficient use of silicon."
Also
revise the filing so that the basis for each statement is clear
from
the context of your disclosure.

Market Opportunity, page 1
7. With respect to the statistics cited here and throughout your
prospectus, please tell please tell us whether the industry
sources
consented to your use of their data and whether any reports were
prepared specifically for your use.  Also tell us whether you are
aware of or sought any contradictory data.

8. In the last paragraph on page 1 you describe the benefits of
solar
power systems as an energy source.  Please balance the description
of
the benefits of solar power with equally prominent disclosure of
its
shortcomings.

Our Strengths, page 2
9. In the third bullet point, where you describe efficient silicon
utilization, please quantify your efficiency levels and compare
them
to the efficiency levels maintained by conventional silicon cells.
Provide independent objective support for your quantifications.

Our Strategy, page 2

10. In the second bullet point and throughout the prospectus,
please
describe what it means to operate certain amount of megawatt per
year
production lines so that investors who may not be familiar with
your
industry may understand this term in context.

Our Relationship with Cypress Semiconductor Corporation, page 3

11. Please expand your disclosure of your various agreements with
Cypress to discuss the nature of the financial terms of such
agreements so that investors can understand the impact of such
agreements on your operations.  For example, on page 88 you
describe
such terms to be at cost or alternatively at the rate charged to
other Cypress departments.

Use of proceeds, page 4
12. We note that you intend to use the net proceeds from the
offering
for the expansion of your manufacturing capacity and for general
corporate purposes.  Here and on page 35, please revise to
quantify
the portion of the proceeds of the offering to be used for each
purpose indicated.  Refer to Item 504 of Regulation S-K.

Risk Factors, page 9
As long as Cypress controls us..., page 26
13. Please revise to quantify the percentage of voting control
that
Cypress will have following the offering.

Our proposed agreements with Cypress..., page 28
14. Please quantify the limited amount of shares you can sell
after
this offering before triggering your obligations to indemnify
Cypress
for tax liabilities and quantify the potential tax liabilities
upon
such a sale.

Use of Proceeds, page 35
15. Please revise to disclose any proceeds to be paid to
affiliates
pursuant to the separation agreements or otherwise.

Management`s Discussion and Analysis, Page 42
Overview, page 43
16. Here and elsewhere in your filing as appropriate, please
expand
your discussion of your financing activities with Cypress to
explain
how Cypress`s Class A shares will be converted into Class B
Shares.
Also, explain how the minority equity interest was "retired" in
the
November 2004 merger.

Six Months Ended June 30, 2004 and 2005, page 50
17. Where changes in financial statement amounts are attributable
to
several factors, each factor should be separately quantified and
discussed to the extent practicable. As an example, we note your
disclosure that cost of revenue increased in the six months ended
June 30, 2005 due primarily to higher volumes of production and
higher costs and volumes of raw materials, among other reasons.
Please revise your results of operations and your discussion of
liquidity and capital resources accordingly.


Total Revenue, page 50

18. We see that your revenues increased 654% in the six months
ended
June 30, 2005, primarily due to strong demand for and commercial
introduction of your solar cells.  Given the material increase in
revenues, please revise your disclosures to include an analysis of
the underlying reasons and factors contributing to the increase,
as
required by SAB Topic 13.B.  In addition, where possible quantify
the
reasons for changes in this and other financial statement line
items.

19. We note from your disclosures on page 14 that you entered into
material supply agreements with Conergy and Solon.  Please revise
Management`s Discussion and Analysis to quantify and discuss any
actual or expected impact of this agreement on your results of
operations, liquidity and capital resources.


Year Ended December 31, 2003 and 2004, page 51

20. We see you have presented the sum of the financial data for
SunPower Corporation for the period from January 1, 2004 to
November
8, 2004, your pre-merger period, and from November 9, 2004 to
December 31, 2004, your post-merger period and note you are
including
these combined amounts to improve the comparative analysis.
Notwithstanding your current presentation, please also discuss the
nature of and reason for any material trends, events and
transactions
that occurred within each of the referenced combined periods.  For
example, discuss why research and development expenses and
selling,
general and administrative expenses during the November 9, 2004 to
December 31, 2004 period decreased significantly as a percentage
of
sales.

Business, page 59
Our Manufacturing, page 69
21. We note that you have entered into contracts for the supply of
polysilicon.  Please revise your disclosure to briefly describe
the
material terms of these agreements.  Also file these agreements as
exhibits to the registration statement, or tell us why they are
not
required to be filed.  Refer to Item 601(b)(10)(ii)(B)) of
Regulation
S-K.

Facilities, page 73
22. Please revise to indicate whether you expect to finalize the
agreement in principle with Cypress extending the lease for your
primary production facility in the Philippines prior to completion
of
the offering.  Please also file the agreement as an exhibit to the
registration statement.

Management, Page 74
Board of Directors, page 75
23. You state you intend to have five or six directors, three of
whom
are independent.  As you currently have five directors, please
explain whether you intend to add new directors prior to the
completion of this offering.  Also tell us whether you view the
directors who are employees of Cypress as independent, and if so,
explain why.

Related Party Transactions, page 82
24. We note your disclosure that you retired 14.9 million shares
of
common stock in exchange for the issuance of 2.5 million shares of
Cypress stock to former stockholders and Mr. Rodgers.  Please
revise
to provide this disclosure on an individual basis for each
participant in the transaction for whom disclosure pursuant to
Item
404 of Regulation S-K is required.  Please present the dollar
value
of this transaction and quantify the amount of each person`s
interest
in the transaction.

25. Please explain how you determined members of the board of
directors who approved the 2004 reorganization and the January 18,
2005 transactions were "non-Cypress."

26. Please disclose whether the March 2005 and July 2005
transactions
were arms-length transactions.  Describe who the members of the
board
of directors were at that time.

Indemnification for Environmental Matters, page 87
27. Please briefly explain what facilities you have or had other
than
the Sunnyvale or Philippines facilities subject to this
environmental
indemnification.  Please explain whether the liabilities assumed
under the third bullet point are limited by their relation to your
facilities.


Tax Sharing Agreement, page 87
28. It would appear that Cypress will receive benefits from
including
SunPower on its consolidated tax returns, but that SunPower`s tax
calculations for filing separately would not include such benefit
under the terms of this Tax Sharing Agreement.  Please disclose
whether the treatment under this agreement is beneficial to
SunPower
in this respect.

Master Transition Services Agreement, page 88
29. You describe the rates at which Cypress will charge you for
services under the Master Transition Services Agreement at either
"cost" or at the rate charged by other Cypress departments or
subsidiaries using these services. Explain which amount will be
used
in different circumstances. Explain how appropriate allocations of
salary and benefits will be determined for "cost" purposes.  Also,
explain why other subsidiaries would not be paying "cost" for
these
services, and whether they would be paying more or less otherwise.

Description of Capital Stock, page 94
30. Please briefly explain the reasons for your reincorporation
from
California to Delaware.

Underwriting, page 105
31. Please identify any members of the underwriting syndicate that
will engage in any electronic offer, sale or distribution of the
shares and describe their procedures to us.   If you become aware
of
any additional members of the underwriting syndicate that may
engage
in electronic offers, sales or distributions after you respond to
this comment, promptly supplement your response to identify those
members and provide us with a description of their procedures.
Briefly describe any electronic distribution in the filing.
Also, in your discussion of the procedures, tell us how your
procedures ensure that the distribution complies with Section 5 of
the Securities Act.  In particular:
* the communications used;
* the availability of the preliminary prospectus;
* the manner of conducting the distribution and sale, like the use
of
indications of interest or conditional offers; and
* the funding of an account and payment of the purchase price.
Finally, tell us whether you or the underwriters have any
arrangements with a third party to host or access your preliminary
prospectus on the Internet.  If so, identify the party and the
website, describe the material terms of your agreement and provide
us
with a copy of any written agreement.  Provide us also with copies
of
all information concerning your company or prospectus that has
appeared on their website.  Again, if you subsequently enter into
any
arrangements like this, promptly supplement your response.

Financial Statements, page F-1

Consolidated Statements of Operations, page F-5

32. We believe that the portion of deferred stock compensation
expense attributable to cost of revenues should be deducted in
determining gross profit.  Accordingly, please revise this
Statement
and other sections of your filing to include that portion of the
expense in the cost of revenues section of the income statement.
Please note that, with regard to the remainder of the stock
compensation expense, we do not object to your current
presentation.

33. We see disclosures on page 45 that you do not record
amortization
expense in separate functional categories of your Statement of
Operations.  Please tell us why it is appropriate to not include
any
amortization in your cost of revenues during the periods
presented.
Note the guidance at SAB Topic 11(B).  Revise the filing, as
necessary, based on our comment.

Consolidated Statements of Shareholders` Equity (Deficit), page F-
6

34. We see in 2005 you issued $4.5 million of warrants in
connection
with promissory notes.  Please tell us why this transaction
decreased
equity.  Revise the filing, as necessary, based on our comment.

Note 1. The Company and Summary of Significant Accounting
Policies,
page F-9

Revenue Recognition, page F-12

35. Please revise your disclosure to describe your revenue
recognition policy with greater specificity.  To the extent that
policy differs among significant product lines (i.e. solar
electric
power products and imaging and infrared detectors, etc.), please
make
your disclosure product line specific.  Also, please address your
revenue recognition policy as it relates to various marketing
venues
used by the company (i.e. direct sales representatives and
distributors). Also, if the policies and sales practices vary in
different parts of the world those differences should be
discussed.

Note 2.  Cypress Step Acquisition of SunPower, page F-17

36. We see that effective November 9, 2004, SunPower became a
wholly
owned subsidiary of Cypress when Cypress exchanged Cypress common
stock for all outstanding shares of SunPower common stock.  We
also
see the determination of the fair value of SunPower`s net assets
as
of May 24, 2002 and November 8, 2004 resulted in valuation
adjustments (intangible assets and related deferred income taxes)
aggregating $3.7 million and $23.2 million, respectively.  Please
revise the note to specifically disclose how you valued the May
2002
and November 2004 consideration issued on each of the referenced
dates.  Tell us how the valuations complied with generally
accepted
accounting principles.  Also, tell us how you concluded the excess
of
the fair value of the consideration issued over SunPower`s net
assets
on these dates only required the recognition of intangible assets
and
did not impact the historical carrying value of any other
SunPower`s
assets and liabilities.  We may have further comments after
reviewing
your response.

37. We see that you recorded an $18.1 million push down adjustment
related to purchased technology.   Describe to us and revise the
filing to disclose the types of technology you recorded, including
the various stages of development (if applicable).  Discuss the
factors you considered pertinent in concluding that the technology
should be capitalized.

38. Refer to disclosures in your Consolidated Statements of
Shareholders` Equity (Deficit).  Please tell us how you allocated
the
push down effect between additional paid in capital and
accumulated
deficit, citing any authoritative literature upon which you relied
to
support the allocations.  Also, tell us why you believe the
balances
in your accumulated deficit account properly reflect changes in
your
ownership.  Specifically, tell us why the pre "purchase" deficit
balance was carried forward.  We may have further comments after
reviewing your response.

Note 4. Balance Sheet Components, page F-20

39. We see that the fair value of your property held for sale was
determined by estimated market prices provided by a third party.
Please revise the filing to identify the appraisal firm under
"Experts" and include their consent in this registration
statement.
Alternatively, you may state in revised disclosure that management
considered a number of factors, including valuations or
appraisals,
when estimating fair value.  Regardless of your decision, your
disclosure should clearly indicate that management is responsible
for
the valuation.  Please revise as appropriate.

Note 5. Income Taxes, page F-22

40. Please revise to provide a reconciliation using percentages or
dollar amounts of reported income tax expense to income tax
expense
that would have been reported using statutory rates.  Refer to
paragraph 47 of SFAS 109.

41. We see you are subject to a tax holiday in the Philippines.
Please revise the note to include the dollar and per share effects
of
the holiday as required by SAB Topic 11(c).

Note 8. Customer Advances, page F-25

42. Please describe to us the significant terms and conditions
related to the customer advances received for expansion of your
manufacturing facility.  Specifically address why these payments
are
properly classified as an operating cash flow, citing any
authoritative literature upon which you relied.  Also, disclose
the
balance subject to repayment and the actual or expected repayment
terms.

Note 9. Debt, page F-25

43. We see you indicate that several of your notes were repaid
during
the periods presented.  Please revise your debt footnote
disclosure
to specifically indicate those debt instruments that were
converted
to equity and those that were repaid with cash.

Note 10. Redeemable Convertible Preferred Stock and Shareholders`
Equity, page F-27

Common Stock, page F-29

44. We see that in March 2005 you issued 35.2 million class A
shares
to Cypress in exchange for the cancellation of $58 million of debt
held by Cypress.  Please tell us and revise the filing to disclose
the nature of the 2005 cash inflow of $19.6 million in your
statement
of cash flows.  It is not clear to us if the inflow is related to
the
aforementioned exchange transaction.


Stock Option Program, page F-32

45. Please provide us with an itemized chronological schedule
detailing each issuance of your ordinary shares, stock options and
warrants since June 2004 through the date of your response.
Include
the following information for each issuance or grant date:

* Number of shares issued or issuable in the grant
* Purchase price or exercise price per share
* Any restriction or vesting terms
* Management`s fair value per share estimate
* How management determined the fair value estimate
* Identity of the recipient and relationship to the company
* Nature and terms of any concurrent transactions with the
recipient
* Amount of any recorded compensation element and accounting
literature relied upon

In the analysis requested above, highlight any transactions with
unrelated parties believed by management to be particularly
evident
of an objective fair value per share determination.  Progressively
bridge management`s fair value per share determinations to the
current estimated IPO price per share.  Also, indicate when
discussions were initiated with your underwriters.  We will delay
our
assessment of your response pending inclusion of the estimated IPO
price in the filing.

Exhibits
46. We note your intention to file a number of exhibits, including
your legal opinion, by amendment.  Because we may have comments on
these exhibits, and on the related disclosure, please file the
exhibits allowing adequate time for their review.

*   *   *   *   *


As appropriate, please amend your registration statement in
response
to these comments.  You may wish to provide us with marked copies
of
the amendment to expedite our review.  Please furnish a cover
letter
with your amendment that keys your responses to our comments and
provides any requested information.  Detailed cover letters
greatly
facilitate our review.  Please understand that we may have
additional
comments after reviewing your amendment and responses to our
comments.

      We urge all persons who are responsible for the accuracy and
adequacy of the disclosure in the filing to be certain that the
filing includes all information required under the Securities Act
of
1933 and that they have provided all information investors require
for an informed investment decision.  Since the company and its
management are in possession of all facts relating to a company`s
disclosure, they are responsible for the accuracy and adequacy of
the
disclosures they have made.

      Notwithstanding our comments, in the event the company
requests
acceleration of the effective date of the pending registration
statement, it should furnish a letter, at the time of such
request,
acknowledging that:

?	should the Commission or the staff, acting pursuant to
delegated
authority, declare the filing effective, it does not foreclose the
Commission from taking any action with respect to the filing;

?	the action of the Commission or the staff, acting pursuant to
delegated authority, in declaring the filing effective, does not
relieve the company from its full responsibility for the adequacy
and
accuracy of the disclosure in the filing; and

?	the company may not assert staff comments and the declaration
of
effectiveness as a defense in any proceeding initiated by the
Commission or any person under the federal securities laws of the
United States.

	In addition, please be advised that the Division of
Enforcement
has access to all information you provide to the staff of the
Division of Corporation Finance in connection with our review of
your
filing or in response to our comments on your filing.

      We will consider a written request for acceleration of the
effective date of the registration statement as confirmation of
the
fact that those requesting acceleration are aware of their
respective
responsibilities under the Securities Act of 1933 and the
Securities
Exchange Act of 1934 as they relate to the proposed public
offering
of the securities specified in the above registration statement.
We
will act on the request and, pursuant to delegated authority,
grant
acceleration of the effective date.


We direct your attention to Rules 460 and 461 regarding requesting
acceleration of a registration statement.  Please allow adequate
time
after the filing of any amendment for further review before
submitting a request for acceleration.  Please provide this
request
at least two business days in advance of the requested effective
date.

      You may contact Eric Atallah at (202) 551-3663 or in his
absence, Jay Webb at (202) 551-3603 if you have questions
regarding
comments on the financial statements and related matters.  Please
contact Jay Mumford at (202) 551-3637 or me at (202) 551-3625 with
any other questions.

      Sincerely,




								Mary Beth Breslin
								Attorney-Advisor


cc:	Jorge del Calvo, Esq.
	Davina K. Kaile, Esq.
	Stephen M. Wurtzburg, Esq.





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Thomas H. Werner
SunPower Corporation
September 21, 2005
Page 1