EXHIBIT 31

CERTIFICATION PURSUANT TO SECTION 302


I, Charles In, certify that:

1.   I have reviewed this Form 10-Q of SGreenTech Group Limited
     (formerly Alderwood Acquisition Corporation).

2.   Based on my knowledge, this report does not contain any
     untrue statement of a material fact or omit to state a material
     fact necessary to make the statements made, in light of the
     circumstances under which such statements were made, not
     misleading with respect to the period covered by this report;

3.   Based on my knowledge, the financial statements, and other
     financial information included in this report, fairly present
     in all material respects the financial condition, results of
     operations and cash flows of the registrant as of, and for,
     the periods presented in this report;

4.   The registrant's other certifying officer(s) and I are
     responsible for establishing and maintaining disclosure
     controls and procedures (as defined in Exchange Act Rules 13a-15(e)
     and 15d-15(e)) and internal control over financial reporting (as
     defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the
     registrant and have:

a)   Designed such disclosure controls and procedures,or caused such
     disclosure controls and procedures to be designed under our
     supervision, to ensure that material information relating to the
     registrant, including its consolidated subsidiaries, is made known
     to us by others within those entities, particularly during the period
     in which this report is being prepared;

b)   Designed such internal control over financial reporting, or caused
     such internal control over financial reporting to be designed under
     our supervision, to provide reasonable assurance regarding the
     reliability of financial reporting and the preparation of financial
     statements for external purposes in accordance with generally
     accepted accounting principles;

c)   Evaluated the effectiveness of the registrant's disclosure
     controls and procedures and presented in this report our
     conclusions about the effectiveness of the disclosure
     controls and procedures, as of the end of the period covered
     by this report based on such evaluations; and

d)   Disclosed in this report any change in the registrant's
     internal control over financial reporting that occurred
     during the registrant's most recent fiscal quarter (the
     registrant's fourth fiscal quarter in the case of an
     annual report) that has materially affected, or is reasonably
     likely to materially affect, the registrant's internal control
     over financial reporting; and

5.   The registrant's other certifying officer(s) and I have disclosed,
     based on our most recent evaluation, to the registrant's auditors
     and the audit committee of registrant's board of directors (or
     persons performing the equivalent functions):

a)   All significant deficiencies and material weaknesses in the design
     or operation of internal control over financial reporting  which
     are reasonably likely to adversely affect the registrant's ability
     to record, process, summarize and report financial information; and

b)   Any fraud, whether or not material, that involves management or
     other employees who have a significant role in the registrant's
     internal control over financial reporting.

      Date: August 14, 2011             /s/  Charles In

                                          Chief Financial Officer and
                                          Principal Accounting Officer

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