Renewable Portfolio Standards - Energy Efficiency Component

May 15, 2024



Established in 1998 and subsequently revised several times, Connecticut's renewables portfolio standard (RPS) requires each electric supplier and each electric distribution company wholesale supplier to obtain at least 48% of its retail load by using renewable energy by January 1, 2030. Specific to energy efficiency, the RPS creates a "carve-out" that requires each electric supplier and each electric distribution company wholesale supplier to obtain at least 4% of its retail load by using combined heat and power (CHP) systems and energy efficiency by 2018.

Electric Demand and Energy Reduction Standard

Within the renewable portfolio standard, separate portfolio standards are required for energy resources classified as "Class I," "Class II," or "Class III." Class III resources eligible for the energy efficiency carve-out include: (1) customer-sited CHP systems, with a minimum operating efficiency of 50%, installed at commercial or industrial facilities in Connecticut on or after January 1, 2006; (2) systems that recover waste heat or pressure from commercial and industrial processes installed on or after April 1, 2007; (3) electricity savings from conservation and load management programs that started on or after January 1, 2006, provided that on or after January 1, 2014, no such programs supported by ratepayers shall be eligible; and (4) any demand-side management project awarded a contract under Conn. Gen. Stat. §16-243m. The revenue from these credits must be divided between the customer and the state Conservation and Load Management Fund, depending on when the Class III systems are installed, whether the owner is residential or nonresidential, and whether the resources received state support.

Electric providers must meet the standard with at least 4% Class III sources by 2018, and thereafter, according to the following schedule:

Year Percentage of Retail Load Covered by Class III RECs
2018 4%
2019 4%
2020 4%
2021 4%
2022 5%
2023 5%
2024 5%
2025 4%
2026 4%
2027 4%
2028 4%
2029 4%
2030 and Thereafter 4%

According to a 2023 PURA decision regarding 2022 compliance (the most recent information available), all utilities or retail providers that must meet the 4% requirement had either met it in 2022 or paid an alternative compliance payment for each REC it chose not to earn from energy efficiency programs.

Program Administrator Type

Energy efficiency and demand-side management programs that provide compliance with the standard are managed by Connecticut's electric utilities. The Connecticut Energy Efficiency Board, appointed by the Connecticut Public Utility Regulatory Authority (PURA) oversees the Connecticut Energy Efficiency Fund, which provides funding for the utilities and other providers' programs.

Cost-Effectiveness and Program Evaluation

To evaluate the cost effectiveness of its efficiency and demand reduction activities, Connecticut law specifies the use of the Utility Cost Test (UCT), which is one of the five "California tests" from the California Standard Practice Manual as its primary test for measuring the cost-effectiveness of energy efficiency programs. Connecticut also uses the Total Resource Cost test (TRC).

Special Provisions (Class III REC Banking)

In its most recent Conservation and Load Management Plan, the Connecticut Department of Energy and Environmental Protection authorized the development of a Business and Energy Sustainability (BES) Program that allowed customers to self-direct program funds to projects of their own choosing. For more information, please visit

In addition, per the rules of Connecticut's RPS, utilities and other providers subject to the Class III energy efficiency requirements are allowed to meet a portion of their requirements with Class III RECs that are "banked" from a prior year. For more information about banking provisions in the Connecticut RPS, please visit the DSIRE Connecticut RPS page.

Program Overview

Implementing Sector: State
Category: Regulatory Policy
State: Connecticut
Incentive Type: Energy Efficiency Resource Standard
Web Site:
Start Date:
Eligible Renewable/Other Technologies:
  • Combined Heat & Power
  • Yes; specific technologies not identified
Electric Sales Reduction: 4% of retail load must be met with Class III Resources by 2018


Name: Conn. Gen. Stat. § 16-245a et seq.
Date Enacted: 1998 (subsequently amended)
Effective Date: 7/1/1998


Name: Donna Devino
Organization: CT Public Utilities Regulatory Authority PURA
Address: 10 Franklin Square
New Britain CT 06051
Phone: (860) 827-2873

This information is sourced from DSIRE; the most comprehensive source of information on incentives and policies that support renewables and energy efficiency in the United States. Established in 1995, DSIRE is operated by the N.C. Clean Energy Technology Center at N.C. State University.