Ameresco Declares Commercial Operations of Historic RNG Plant

91^st Ave Biogas-to-Renewable Natural Gas Facility (largest in the US)

FRAMINGHAM, MA and PHOENIX, AZ – April 18, 2019 – Ameresco, Inc. (NYSE:AMRC), a leading energy efficiency and renewable energy company, today announced that it achieved commercial operations in early 2019 at its 91st Ave renewable natural gas (RNG) plant located in Phoenix, Arizona. Now operational, this plant is the largest wastewater treatment biogas-to-RNG facility of its kind in the US and is capable of processing 3,250 standard cubic feet per minute (scfm) of raw digester gas produced at the wastewater treatment plant (WWTP).

The 91^st Ave WWTP is owned by the sub-regional operating group (SROG) member cities: Phoenix, Glendale, Mesa, Scottsdale and Tempe and is operated by the City of Phoenix.

In February 2017, Ameresco and the City of Phoenix hosted a ceremonial groundbreaking event for the start of this multi-million-dollar wastewater treatment biogas utilization project. Now almost exactly 2 years later, Ameresco, the City of Phoenix and the SROG partners are celebrating the start-up of this monumental project.

“This innovative partnership allows us to turn waste into resource by converting biogas, a byproduct of wastewater treatment, into renewable energy,” said Phoenix Mayor Kate Gallego. “This not only benefits our regional economy, but also reduces greenhouse gas emissions. Phoenix has set ambitious sustainability and renewable energy goals, and this kind of public-private partnership will help us get there.”

“This project exemplifies innovation in action and is a model for municipalities across the globe,” said Mike Bakas, Executive Vice President of Ameresco. “We commend the City of Phoenix and the SROG member cities for both their commitment to sustainability and their initiative to derive economic benefit from a previously undervalued asset: biogas from wastewater. We’re thrilled to be a long-term partner to the City of Phoenix and proud to help the region reduce its reliance on fossil fuels.”

A ribbon-cutting ceremony is scheduled for April 25, 2019 with Phoenix Mayor Kate Gallego, Ameresco and SROG City officials as the invited speakers for this historic event.

About the City of Phoenix

Phoenix is the capital and largest city in the State of Arizona. With approximately 1,563,025 inhabitants, Phoenix is the fifth most populous city nationwide, the most populous state capital in the United States, and the only state capital with a population of more than a million residents. The City of Phoenix is the anchor of the Phoenix metropolitan area, also known as the Valley of the Sun, which in turn is a part of the Salt River Valley. In addition, Phoenix is the county seat of Maricopa County and is one of the largest cities in the United States by land area. The area is known for high-end resorts, Jack Nicklaus-designed golf courses and vibrant nightclubs, but the city’s biggest attraction may be the sunshine and winter warmth. For more information, visit Phoenix.gov.

About Ameresco, Inc.

Founded in 2000, Ameresco, Inc. (NYSE:AMRC) is a leading independent provider of comprehensive services, energy efficiency, infrastructure upgrades, asset sustainability and renewable energy solutions for businesses and organizations throughout North America and Europe. Ameresco’s sustainability services include upgrades to a facility’s energy infrastructure and the development, construction and operation of renewable energy plants. Ameresco has successfully completed energy saving, environmentally responsible projects with Federal, state and local governments, healthcare and educational institutions, housing authorities, and commercial and industrial customers. With its corporate headquarters in Framingham, MA, Ameresco has more than 1,000 employees providing local expertise in the United States, Canada, and the United Kingdom. For more information, visit www.ameresco.com.

The announcement of achieving commercial operations for an energy asset is not necessarily indicative of the timing or amount of revenue from the energy asset, of the company’s overall revenue for any particular period or of trends in the company’s overall total assets in development or operation. This project was included in our previously reported assets in development as of December 31, 2018.