State seal of Connecticut

Connecticut’s Renewable Portfolio Standard (RPS) is intended to increase use of renewable resources in the state by establishing the minimum amount of renewable energy that the state’s electricity providers must sell in a given year. This legally-established renewable energy procurement goal gradually increases over time to meet the overall target of 23% renewable power by 2020. This policy also includes requirements for energy efficiency, which are described, but not considered for calculations on this and subsequent pages.

The state profile below explores the design of this policy, highlighting the factors that influence the success of Connecticut’s RPS goals and the tradeoffs inherent to it. Once you’re comfortable with the information on this page, you can evaluate the policy’s expected viability with the RPS Feasibility Calculator. You can also use the calculator to change the policy requirements, trajectory, cost cap, and more, to see how altering Connecticut’s policy design affects its success.

RPS Snapshot


  • 23% of the state’s retail electric sales from must be from renewable sources by 2020, subject to the cost cap
  • Allows consideration of small hydroelectric, trash-to-energy and some biomass
  • Implicit ‘cost cap’ defined by compliance payments


Carve-outs can create economic opportunities in the state by introducing new or promising technologies into the market. However, these standards limit the utilities’ ability to substitute between renewable energy sources, potentially increasing the cost of the policy. Connecticut’s RPS allows for utilities to meet up to 3 percentage points of the total renewable energy goal in each year with power from hydroelectric, trash-to-energy and some biomass sources.

RPS Progress

Compare the goal established in the RPS to what is being achieved.

Energy Details

Grid Mix

The following chart compares the variety of sources currently used to generate Connecticut’s electricity. The color of each bar is indicative of the carbon intensity of each source.

Cost Cap Details

Connecticut does not have an explicit cost cap. However, by allowing alternative compliance payments (ACPs), Connecticut sets an effective cap on the premium a utility will be willing to pay for renewable energy. The RPS sets this cap at $55/MWh. If the renewable energy premium exceeds this cap, the utility would prefer to meet the standard by making the lower cost alternative compliance payments. Using the RPS Feasibility Calculator you can make adjustments to cost of alternative compliance, determining how this impacts the provision of renewable power and the overall viability of the RPS.

Historic retail prices (¢ / kWh)

The above chart presents historical data from the Energy Information Administration (EIA) on the price at which residential customers can purchase electricity. Typically, states set explicit cost caps relative to the retail price (as opposed to the lower wholesale price).



Connecticut’s RPS is governed primarily by Senate Bill 1138, enacted on June 5, 2013. The law was originally enacted in 1998, but subsequently has been revised into its current form. The legislation requires that each electricity wholesale supplier in the state purchase 23% of its retail load from renewable sources (of Class I and II) by January 1, 2020. The sources defined as Class I and Class II materials can be used in combination to meet the 23% RPS requirement, with a fixed portion of 3% from either Class I or II throughout the schedule, and a ramp-up to 30% from Class I by 2020. Renewable Energy Credits (RECs) can be used to satisfy requirements.

The statute also requires with an additional 4% of its retail load required to be accounted for using energy efficiency measures, combined heat and power (CHP) or waste heat systems by 2010 and thereafter. These are considered Class III sources. The feasibility calculator does not consider the costs or benefits of this program

RPS Technical Details

Eligible Technologies

(Class I) Solar Thermal Electric, Photovoltaics, Landfill Gas, Wind, Biomass, Hydroelectric, Geothermal Electric, Fuel Cells, Low E Renewables, Anaerobic Digestion, Tidal Energy, Wave Energy, Ocean Thermal, Fuel Cells using Renewable Fuels;

(Class II) Municipal Solid Waste, other biomass, river hydropower;

(Class III) CHP/Cogeneration, energy efficiency and conservation measures

Geographic Eligibility Providers may purchase electricity generated using Connecticut’s defined Class I or Class II resources within ISO New England, the regional independent system operator, as well as from New York, Pennsylvania, New Jersey, Maryland, and Delaware.
Percent of Total Load 93.4%
Technology Requirements Up to 3 percentage points of the total renewable obligation can come from Class II sources
Sectors Investor-Owned Utility, Retail Suppliers. (Municipal Utilities must develop own RPS)
Penalty ACPs of $55/MWh


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