Power of Attorney – Alcoa

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS that each of the undersigned Directors of
Alcoa Inc. (the “Company”) hereby constitutes and appoints
CHARLES D. MCLANE, JR., GRAEME W. BOTTGER, PETER HONG and DONNA C. DABNEY, or
any of them, his or her true and lawful attorneys-in-fact and agents, with full
power of substitution, to do any and all acts and things and to execute any and
all instruments that said attorneys-in-fact and agents, or any of them, may deem
necessary or advisable or may be required:

(1) To enable the Company to comply with the Securities Exchange Act of
1934, as amended (the “1934 Act”), and any rules, regulations or requirements of
the Securities and Exchange Commission (the “Commission”) in respect thereof, in
connection with the filing under the 1934 Act of the Company’s Annual Report on
Form 10-K for the year ended December 31, 2010 (the “2010 Annual Report”),
including specifically, but without limiting the generality of the foregoing,
power and authority to sign the name of each of the undersigned in the capacity
of Director of the Company to the 2010 Annual Report to be filed with the
Commission and to any instruments or documents filed as part of or in connection
with the 2010 Annual Report, including any amendments or supplements thereto;

(2) To enable the Company to comply with the Securities Act of 1933, as
amended (the “1933 Act”), and any rules, regulations or requirements of the
Commission in respect thereof, in connection with the registration under the
1933 Act during 2011 of the offer and sale or delivery of shares of common stock
of the Company to be issued under the 2009 Alcoa Stock Incentive Plan (the “2009
Plan”), the 2004 Alcoa Stock Incentive Plan (the “2004 Plan”) or the Alcoa Stock
Incentive Plan (the “Stock Incentive Plan”), including specifically, but without
limiting the generality of the foregoing, power and authority to sign the name
of each of the undersigned in the capacity of Director of the Company to any
registration statement on Form S-8, or on such other form as may be appropriate,
to be filed with the Commission in respect of said shares and the 2009 Plan, the
2004 Plan or the Stock Incentive Plan, or any of them, to any and all
pre-effective amendments, post-effective amendments and supplements to any such
registration statement, and to any instruments or documents filed as part of or
in connection with any such registration statement or any such amendments or
supplements thereto; and

(3) To enable the Company to comply with the 1933 Act, and any rules,
regulations or requirements of the Commission in respect thereof, in connection
with the registration under the 1933 Act during 2011 of the offer and sale or
delivery of shares of common stock of the Company to be issued under the
Company’s employee savings plans (together with interests in such plans),
including, without limitation, the Alcoa Retirement Savings Plan for Bargaining
Employees, the Alcoa Retirement Savings Plan for Salaried Employees, the Alcoa
Retirement Savings Plan for Hourly Non-Bargaining Employees, the Alcoa
Retirement Savings Plan for Mill Products Employees, the Alcoa Retirement
Savings Plan for Fastener Systems and Commercial Windows Employees, the Alcoa UK
Holdings Limited 2002 Inland Revenue Approved Share Incentive Plan, the Alcoa
Employee Share Plan and employee savings plans sponsored by the Company or its
subsidiaries or entities acquired by the Company from time to time (the
“Plans”), including specifically, but without limiting the generality of the
foregoing, power and authority to sign the name of each of the undersigned in
the capacity of Director of the Company to any registration statement on Form
S-8, or on such other form as may be appropriate, to be filed with the
Commission in respect of said shares and the Plans (or interests in such Plans),
or any of them, to any and all pre-effective amendments, post-effective
amendments and supplements to any such registration statement, and to any
instruments or documents filed as part of or in connection with any such
registration statement or any such amendments or supplements thereto;

and granting unto each of said attorneys-in-fact and agents full power and
authority to do and perform each and every act and thing requisite and necessary
to be done, as fully to all intents and purposes as the undersigned might or
could do in person, and each of the undersigned hereby ratifies and confirms all
that said attorneys-in-fact and agents, or any of them, shall do or cause to be
done by virtue hereof.

1

This power of attorney will be governed by and construed in accordance with
the laws of the Commonwealth of Pennsylvania. The execution of this power of
attorney is not intended to, and does not, revoke any prior powers of attorney.

IN WITNESS WHEREOF, each of the undersigned has subscribed these presents
this 21st day of January 2011.