Energy Efficiency

Energy efficiency is an important and economical tool to reduce energy costs, decrease greenhouse gas emissions and reliance on fossil fuels, manage energy demand, and create clean energy jobs. With close to one-third of Maine’s emissions attributed to buildings, efficiency improvements in energy consumption for heating, cooling, weatherization, appliances, and lighting technologies can aid in reducing energy needs, costs, and associated emissions. The American Council for an Energy-Efficient Economy ranked Maine fifth and the most improved among all states for state energy efficiency policies and programs that save energy, advance equity, and produce environmental and economic benefits.

The two primary state agencies that provide support for energy efficiency technology adoption are the Efficiency Maine Trust (Efficiency Maine) and the Maine State Housing Authority (MaineHousing). Efficiency Maine is Maine’s quasi-state agency and independent administrator for programs to improve energy efficiency for low-income, residential, commercial, and industrial participants. MaineHousing is an independent authority created by the Maine State Legislature to address problems of unsafe, unsuitable, overcrowded, and unaffordable housing including clean heating and weatherization. The Governor’s Energy Office works closely with both Efficiency Maine and MaineHousing to ensure robust coordinated efforts between the three entities for the deployment of energy efficient technologies in an equitable, economical, and efficient manner. 

Energy Efficiency Goals

Heat Pumps 

Maine has long been a national outlier for reliance on oil and is currently the most heating oil dependent state for home heating in the nation with 56.1% of households using fuel oil for their primary home heating source (U.S. EIA and U.S. Census Bureau).

Heat pumps provide energy efficient heating and cooling to Maine’s homes and businesses in addition to decreasing the state’s high reliance on fossil fuels for heating. Pursuant to 35-A MRSA § 10119 signed in 2019, Maine's Climate Action Plan -- Maine Won't Wait -- seeks to achieve the required goal for the installation of 100,000 new heat pumps by 2025 with 15,000 new heat pumps being provided to income-eligible households. This goal will ensure that by 2030, 130,000 homes will be using 1-2 heat pumps (i.e., partial-home heat pump systems) and an additional 115,000 homes will be using whole-home heat pump systems.

In 2023, Maine achieved its goal for the installation of 100,000 new heat pumps two years ahead of schedule. To continue Maine’s momentum, Governor Mills also unveiled a new target for the installation of another 175,000 additional heat pumps in Maine by 2027. This new goal will bring the number of heat pumps installed in Maine homes, businesses, and public buildings during Governor Mills’ time in office to 275,000. If this target is achieved, Maine would have more than 320,000 heat pumps in total installed across the state.


Weatherization benefits a building’s energy efficiency through the installation of insulation to retain indoor temperature and air sealing, weather-stripping, caulking, and more to reduce air leakage through the building envelope. Maine has approximately 570,000 homes, with over half of owned and two-thirds of rented dwellings built in 1960 or earlier suffering from energy inefficient weatherization.

Pursuant to 35-A MRSA § 10104 as amended in 2021, Maine's Climate Action Plan -- Maine Won't Wait -- seeks to double the pace of home weatherization so that by 2025, 17,500 additional homes and businesses will be weatherized, with an end goal of 35,000 homes and businesses weatherized by 2030. These goals include at least 1,000 low-income residential units per year.

Rebates, Incentives, and Energy Efficiency Programs

Efficiency Maine Residential Programs

Efficiency Maine offers a variety of rebates and incentives for residential energy efficiency projects such as high efficiency heating systems, hot water heaters, weatherization, electric vehicles, lighting, and more. Enhanced incentives are available for income qualifying households. 

Efficiency Maine Commercial and Industrial Programs

Efficiency Maine has programs for businesses of all sizes, including multifamily buildings with five units or more and Maine’s largest energy customers. 

  • The Commercial and Industrial (C&I) Prescriptive Program offers fixed-price financial incentives for a predefined list of “off-the-shelf,” widely available efficiency measures. Typical measures promoted through this program include lighting fixtures, heating and cooling systems, and sector specific solutions (e.g., compressed air equipment, agricultural equipment, etc.).
  • The Commercial & Industrial (C&I) Custom Program incentivizes tailored energy efficiency and distributed generation projects that require site-specific engineering analyses and/or projects with energy conservation measures that are not otherwise covered by the C&I Prescriptive Program incentives. The C&I Custom Program is primarily designed to overcome the barriers conforming Maine’s larger businesses and institutions when making investments in complex energy efficiency and distributed generation projects.  
MaineHousing Energy Programs 

If you cannot afford to heat your home, pay electric bills, or would benefit from energy improvements such as new insulation or a new heating system, help may be available from MaineHousing programs. Lower income households may qualify for heating assistance and energy improvements at no cost to them. Moderate-income households may qualify for low-cost energy loans. 

  • MaineHousing’s Heat Pump Program pays for the cost and installation of a heat pump for eligible Maine homeowners. Heat pumps are a popular and efficient tool to help heat homes in cold climates. They can help save on heating costs if used in the correct way. 
  • MaineHousing’s Weatherization Program provides grants to low-income homeowners and renters to reduce energy costs by improving home energy efficiency. MaineHousing offers this program to consumers through Community Action Program agencies, who screen people for eligibility as part of the HEAP application process. 
  • MaineHousing’s Central Heating Improvement Program (CHIP) provides grants to repair or replace central heating systems that serve low-income households.

View the Energy Assistance Programs page for a compressive list of all energy programs offered by MaineHousing

Building Codes 

Building codes provide standards for building construction and maintenance throughout the state that promote safety, sustainability, public health, and more. In particular, energy codes establish standards for energy efficiency, embodied carbon, beneficial electrification, weatherization, and more. The Bureau of Building Codes and Standards (BBCS) was created in 2010 under Title 25 §2372 to provide administrative and technical support to the Technical Building Codes and Standards Board. The BBCS also provides non-binding technical interpretation of the codes for professionals and the public. The Maine Uniform Building and Energy Code (MUBEC) is the statewide building and energy code that is comprised of codes from the International Code Council (ICC) and the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)