Ameresco, Inc. — Director's Dealing 2011

May 24, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Ameresco, Inc. (AMRC)
CIK: 0001488139
Period of Report: 2011-05-23

Reporting Person: Derrington Keith A (Executive Vice President)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-05-23	Class A Common Stock	M	400	$2.75	Acquired	400	Direct
2011-05-23	Class A Common Stock	S	400	$15.00	Disposed	0	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2011-05-23	Stock Option (right to purchase)	$2.75	M	400	Disposed	2014-06-25	Class A Common Stock (400)	Direct

Footnotes

F1: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 8, 2011.

F2: Of the shares subject to the option, 20% vested on June 25, 2005, and the remainder vested in 16 equal quarterly installments thereafter.