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Renewable Portfolio Standards Fact Sheet

State Policy Resources

Renewable Portfolio Standards: An Effective Policy to Support Clean Energy Supply

Last updated April 2009

A Renewable Portfolio Standard (RPS) provides states with a mechanism to increase renewable energy generation using a cost-effective, market-based approach that is administratively efficient. An RPS requires electric utilities and other retail electric providers to supply a specified minimum amount of customer load with electricity from eligible renewable energy sources. The goal of an RPS is to stimulate market and technology development so that, ultimately, renewable energy will be economically competitive with conventional forms of electric power. States create RPS programs because of the energy, environmental, and economic benefits of renewable energy and sometimes other clean energy approaches, such as energy efficiency and combined heat and power (CHP).1

How Does a Renewable Portfolio Standard Encourage Clean Energy?

An RPS creates market demand for renewable and clean energy supplies. Currently, states with RPS requirements mandate that between 4 and 30 percent of electricity be generated from renewable sources by a specified date. While RPS requirements differ across states, there are generally three ways that electricity suppliers can comply with the RPS:

What Are the Benefits of a Renewable Portfolio Standard?

The policy benefits of an RPS are the same as those from renewable energy and CHP:

Because it is a market-based program, an RPS also has several operational benefits:

Which States Have Established Renewable Portfolio Standards?

As of March 2009, RPS requirements or goals have been established in 33 states plus the District of Columbia (see Figure 1). Thirteen of these states include CHP or waste heat recovery as an eligible resource, and Arizona explicitly includes renewable fueled CHP systems. More than 2,300 megawatts (MW) of new renewable energy capacity through 2003 was attributable to RPS programs.3 As of February 2009, the Union of Concerned Scientists projects that state standards will provide support for 76,750 megawatts (MW) of new renewable power by 2025—an increase of 570 percent over total 1997 U.S. levels (excluding hydro).4

Tremendous diversity exists among these states with respect to the minimum requirements of renewable energy, implementation timing, and eligible technologies and resources (see Figure 2).

Figure 1. States With RPS Requirements
This image shows a map of the United States and displays all states that have renewable portfolio standard (RPS) laws or goals as of January 2008. The District of Columbia and 25 different states passed RPS laws; the 25 states include the following: Alabama, California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Iowa, Massachusetts, Maryland, Maine, Minnesota, Montana, North Carolina, New Hampshire, New Jersey, New Mexico, Nevada, New York, Oregon, Pennsylvania, Rhode Island, Texas, Washington, and Wisconsin. Four states have RPS goals rather than a mandatory requirement; these states are: Missouri, North Dakota, Virginia, and Vermont.

Source: Database of State Incentives for Renewable Energy (DSIRE) last accessed March 2009, www.dsireusa.org Exit EPA.


In Progress

States with RPS

In Progress

States with RPS Goals

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What Are the Key Features of a Renewable Portfolio Standard?

States have tailored their RPS requirements to satisfy particular policy objectives, electricity market characteristics, and renewable resource potential. Consequently, there is wide variation in RPS rules from state to state with regard to the minimum requirement of renewable energy, implementation timing, eligible technologies and resources, and other policy design details. The key features of effective RPS requirements are outlined below in the following sections.

Goals and Objectives. To produce the best RPS design for the state, it is important to articulate goals and objectives early in the process. Clear goals serve as a guide for design choices and avoid protracted rule implementation debate. There can be multiple goals for an RPS, and some states aim for a broader set of objectives than others. Examples of broader goals and objectives include local, regional, or global environmental benefits; local economic development goals; hedging fossil fuel price risks; and advancing specific technologies.

Figure 2. State RPS Requirements

State Target (% of electricity sales) Specific Provisions
(% of electric sales)
AZ 15% by 2025 4.5% by 2012 from distributed energy resources
CA 20% by 2010  
CO IOUs 20% by 2020; electric cooperatives and municipal utilities 10% by 2020 IOUs: 0.4% solar by 2020
CT 27% by 2020 4% Energy Efficiency and CHP by 2010
DC 20% by 2020 0.4% solar by 2022
DE 20% by 2019 2.005% solar by 2019
HI 20% by 2020  
IA 105 MW by 2025  
IL 25% by 2025 18.75% wind by 2013
MA Class I: 4% by 2009 (+1%/year after); Class II: 3.6% renewable, 3.5% waste energy by 2009; APS: 5% by 2020 increasing by 0.25% each year after. Class II: 3.6% renewable, 3.5% waste energy by 2009
MD 20% by 2022 2% solar by 2022
ME 30% by 2000; 10% new by 2017  
MI 10% by 2015  
MN Xcel Energy (utility) 30% by 2020; other utilities 25% by 2025 Xcel Energy: 25% wind
MO 15% by 2021 0.3% solar retail sales by 2021
MT 15% by 2015  
ND* 10% by 2015  
NH 23.8% by 2025 - 16.3% new 0.3% solar by 2025
NJ 22.5% by 2021 2.12% from solar by 2021
NM IOUs: 20% by 2020; rural electric cooperatives 10% by 2020 Wind: 4%; solar: 4%; biomass and geothermal: 2%; distributed renewables: 3% by 2020 (IOU only)
NV 20% by 2015 1% solar by 2015
NY 24% by 2013 0.154% customer-sited by 2013
OH 25% by 2025 (12.5% renewable energy) 1% solar by 2025
OR Large utilities (>3% state’s total electricity sales) 25% by 2025 Smaller utilities 5-10% by 2025 (depending on size)
PA 18% by May 31, 2021 (8% renewable energy) 0.5% solar by 2025
RI 16% by 2020  
SD* 10% by 2015  
TX 5,880 MW by 2015 At least 500 MW from renewables other than wind
UT* 20% by 2025  
VA* 12% of 2007 sales by 2022  
VT* 20% by 2017; Total incremental energy growth between 2005-2012 to be met with new renewables (10% cap)  
WA 15% by 2020  
WI 10% by December 31, 2015  

* States with RPS goals not mandatory requirements.
Source: Database of State Incentives for Renewable Energy (DSIRE), accessed March 2009, www.dsireusa.org Exit EPA.

Applicability. RPS requirements are most commonly applied to investor-owned utilities and electric service providers. It is unusual for mandatory RPS requirements to extend to municipal utilities and cooperatives, as these entities are predominately self-regulated. However, some states have included provisions for municipal utilities and cooperatives to voluntarily join the RPS program or to "self certify."

Eligibility. States are finding that defining which energy resources and technologies qualify as eligible under RPS requirements (see Figure 3) can be a complex process. Eligibility usually depends on whether or not an energy resource or technology supports the goals and objectives established for the RPS. Issues that states typically have considered include:

Figure 3: Eligible Technologies Under State RPS Requirements

Energy Source AZ CA CO CT DE DC HI IA IL MA MD ME MI MN MOa MT NC NDa NH NJ NM NV NY OH OR PA RI SD TX UT VAa VTa WA WI
Biofuels
Biomass
CHP/Waste Heat c                                        
Energy Efficiency                                                  
Fuel Cellsb                       d                            
Geothermal            
Hydro
Landfill Gas
Municipal Waste                                  
Ocean Thermal                                  
Photovoltaics
Solar Thermal Electric        
Tidal                        
Waste Tire                                                              
Wave                        
Wind

a States with RPS goals not mandatory requirements.
b Renewable CHP systems are eligible; fossil-fueled CHP systems are not eligible.
c Includes only those states that allow fuel cells using nonrenewable energy sources of hydrogen. Some states allow only renewable fuel cells (Arizona, California, Colorado, Delaware, Massachusetts, Maryland, Missouri, New Mexico, New York, Rhode Island, South Dakota, Utah, Wisconsin) as eligible technologies.
Source: Database of State Incentives for Renewable Energy (DSIRE), accessed March 2009.

Structure. The structure of an RPS can influence investor confidence, the ability of markets to develop, and opportunities for project developers and investors to recover capital investments. The critical structural elements include:

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Elements of a Successful Policy

Based on the experiences of states that have instituted an RPS, a number of best practices have emerged for designing and implementing an effective RPS. These best practices include:

EPA Assistance Available

The U.S. Environmental Protection Agency (EPA) CHP Partnership is a voluntary program that seeks to reduce the environmental impact of power generation by promoting the use of cost-effective CHP. The Partnership helps states identify opportunities for policy developments (energy, environmental, economic) to encourage energy efficiency through CHP. The Partnership can provide information and assistance to states considering including CHP or waste heat recovery in their RPS requirements.

EPA's Green Power Partnership provides assistance to renewable generators in marketing RECs and helps educate potential REC buyers about resources. The Partnership may be of assistance to states that employ RECs as a compliance measure for their RPS requirements but also allow for purchase and retirement of RECs for organizational "green power" designation.

Additional Resources

EPA has created The Clean Energy-Environment Guide to Action. The Guide provides an overview of clean energy supply technology options and, in addition to RPSs, presents a range of policies that states have adopted to encourage continued growth of clean energy technologies and energy efficiency.

The Database of State Incentives for Renewable Energy (DSIRE) Exit EPA is a comprehensive source of information on state, local, utility, and selected federal incentives that promote renewable energy.

The National Association of Regulatory Utility Commissioners' report, The Renewable Portfolio Standard: A Practical Guide (PDF), (139 pp, 284K, About PDF) Exit EPA provides detailed guidance on designing and implementing an RPS.

For more information, contact:

Katrina Pielli
U.S. Environmental Protection Agency
Climate Protection Partnerships Division
Phone: 202-343-9610
e-mail: Katrina Pielli (pielli.katrina@epa.gov)


Notes:
1 CHP is the simultaneous generation of electric and thermal energy from a single fuel source.
2 A REC is a tradable right to claim the environmental and other attributes associated with 1 megawatt-hour of renewable electricity from a specific generation facility.
3 Petersick, T. (2004). State Renewable Energy Requirements and Goals: Status Through 2003. U.S. Energy Information Administration, www.eia.doe.gov/oiaf/analysispaper/rps/index.html Exit EPA.
4 UCS. Renewable Electricity Standards at Work in the States (February 2009). http://www.ucsusa.org/assets/documents/clean_energy/RES_in_the_States_Update.pdf (PDF) (2 pp, 246K, About PDF) Exit EPA

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