About Maine’s RPS
Maine’s Renewable Portfolio Standard (RPS), in place since 1999, establishes the minimum portion of electricity sold in Maine that must come from renewable sources such as wind, solar, hydro, and biomass, among others. In 2019, Governor Mills signed legislation that increased Maine’s RPS to 80 percent by 2030. In 2025, Governor Mills signed legislation increasing the RPS to 90 percent by 20230 and establishing a new Clean Energy Standard (CES) to achieve 100 percent clean energy by 2040. For more information about Maine’s renewable and clean energy standards, visit this page.
Background
The Maine Department of Energy Resources (DOER) is required by law to review, in consultation with the Maine Public Utilities Commission (PUC), the status and impacts of the State’s portfolio requirements every three years. This review must be completed through a public process and consider the benefits and costs associated with the policy, including impacts on energy prices, greenhouse gas emissions, and the State’s economy.
The most recent study on Maine’s RPS published in 2024 demonstrated that the policy has helped to suppress electricity costs by expanding production of local renewable energy and reducing the state’s reliance on imported fossil fuels. Since 2011, Maine’s RPS is estimated to have saved ratepayers more than $21 million annually in electricity costs, driven more than $100 million in direct investment, and supported over 1,000 jobs.
Maine’s 2027 RPS Assessment
Throughout 2026, DOER will conduct another review and assessment of Maine’s RPS with multiple opportunities for public participation and feedback. The 2027 RPS Assessment will be submitted to the Maine Legislature by March 31, 2027.
The PUC also produces an annual summary of the State’s RPS implementation and compliance pursuant to State law. The PUC RPS reports are available here.