Our Clients Lead
the Nation in Energy Efficiency

  • Massachusetts (#1)
    8 years in a row
  • California (#2)
  • Rhode Island (#3)
  • Vermont (#4)
  • Connecticut (#5)
  • New York (#6)
  • Minnesota (#8)

Learn More About Where We Work

Prime Contractor for Delivering Cost-Effective EE Programs

Hiker and views from Camel’s Hump Mountain in Huntington, VT

Staff Spotlight: Gretchen Calcagni

As a consultant at Optimal, Gretchen provides research, analytical, and project management support for clients.

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Gretchen Calcagni head shot

Nationally Recognized Energy Efficiency Consultants

Since 1996, Optimal Energy has provided a full range of energy efficiency consulting services to investor and municipally owned utilities, program administrators, state and federal energy offices, regulatory commissions, advisory councils, and advocacy groups. Read more…