


                                                                    Exhibit 5.1

April 30, 1997

The AES Corporation
1001 North 19th Street
Arlington, Virginia 22209

Re:      Registration Statement on Form S-8

Dear Sirs:

                  We have served as counsel to The AES  Corporation,  a Delaware
corporation (the  "Company"),  in connection with the filing by the Company of a
Registration  Statement  on Form S-8  (the  "Registration  Statement")  with the
Securities and Exchange Commission, covering up to 281,374 shares (the "Shares")
of common stock,  par value $.01 per share, of the Company to be issued and sold
pursuant to the Company's Stock Option Plan for Outside Directors (the "Plan").

                  In rendering  this  opinion,  we have  examined the  Company's
Certificate of Incorporation  and By-laws,  each as amended to date,  minutes of
proceedings  and consents of the Board of Directors of the Company,  the form of
Company  common stock  certificate,  and originals or copies of such  documents,
instruments,  records,  and certificates of public officials and officers of the
Company as we have deemed  necessary.  In connection with such  examination,  we
have assumed the  genuineness  of all  signatures  and the  authenticity  of all
documents  submitted  to  us as  copies,  and  we  have  also  made  such  other
investigations of fact and law as we have deemed relevant in connection with the
opinion set forth below.  In  rendering  this  opinion,  we have relied upon the
accuracy of the certificates, documents, instruments,  certificates, and records
we have examined as to the matters of fact covered thereby.

                  Based on the foregoing, we are of the opinion that the Shares,
when issued and sold in accordance with the terms of the Plan including, without
limitation,  payment of the purchase  price  therefor,  will be duly and validly
issued, fully-paid and non-assessable.

                  We hereby  consent the filing of this opinion as an exhibit to
the Registration Statement.

Sincerely,

Chadbourne & Parke LLP
