Exhibit 99.1 FOR IMMEDIATE RELEASE Ameresco Reports Fourth Quarter and Full Year 2023 Financial Results Awarded Project Backlog Conversion Drives Significant Q4 Revenue and Profit Growth Record Total Project Backlog of nearly $4B, with$520M in New Awards in Q4 717 MWe of Assets in Development, with 63 MWe Placed into Operation in the Quarter Guiding to 38% Adj. EBITDA Growth at the Midpoint for 2024 Full Year and Fourth Quarter 2023 Financial Highlights: • Revenues of $1,374.6 million and$441.4 million • ...