Responsible Purchasing Network

Green Power: Overview

Welcome to the Responsible Purchasing Guide for Green Power. This Guide is designed to help institutions understand and compare green power based on sound analysis of environmental impacts and on concerns regarding cost, quality, and supply of green power.

Below we provide an overview of each section of the Guide: Social & Environmental Issues; Best Practices; Cost, Quality, & Supply; Policies; Specifications; Standards; Products; Handy Facts; Definition; and Credits & Endnotes.

This Guide covers electricity procurement from grid-delivered green power and renewable energy certificates (RECs). It does not cover: 1) on-site generation; 2) the purchase of equity stakes in green power generation capacity; and 3) the purchase of carbon offsets. Contact RPN for guidance on these items – 301-891-3683.

(Presentations from the RPN webinar - Green Power can be downloaded at the bottom of this page.)

Social & Environmental Issues

The social & environmental issues section discusses how electric utilities in the United States consume around one billion tons of coal, six trillion cubic feet of natural gas, and 77 million barrels of oil and emit over 2.4 billion tons of carbon dioxide each year. Fossil fuel power plants also emit large volumes of sulfur dioxide, nitrogen oxides, and mercury. U.S. coal power plants produce around 100 million tons of solid waste annually. Nuclear plants are the largest non-fossil form of electricity and produce over 2,000 tons of high-level radioactive waste each year. Coal and uranium mines degrade air and water quality, can be dangerous workplaces, and often severely impair both the ecosystem functioning and aesthetic beauty of natural areas. Thermal power plants in the United States (primarily coal and nuclear) use 200 billion gallons of water each day. Electricity from green power sources, such as solar, wind, and hydro mitigate these problems and deliver significant environmental, economic, and security benefits.

Best Practices

The best practices section discusses ways to increase energy conservation, improve energy efficiency, and purchase green power. Begin by forming a Green Power Team with staff from purchasing, management, facilities, public relations, and other relevant departments. The Team will be responsible for implementing, tracking, and reporting on the green power program. Develop an inventory of electricity consumption and the related social and environmental effects. Data from this baseline can be compared with subsequent years to assess progress and identify areas for improvement. Set realistic but ambitious goals for energy conservation and efficiency and green power procurement. Adopt a policy that reflects these goals with deadlines and benchmarks. Rely on leading standards such as Green-e Energy and EcoLogo to verify the quality and validity of green power products. Purchase green power after collecting information on available products, and issuing a request for proposals and a contract. Publish an annual report highlighting successes and addressing challenges.

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Cost, Quality, & Supply

The cost, quality, & supply section discusses differences between 1) conventional and green power, 2) various forms of green power, 3) and the leading green power products available to institutions. In 2005, commercial customers paid an average price of $86 per megawatt hour (MWh) for 1.3 billion MWh of electricity, totaling $110 billion and representing roughly 1/3 of all electricity produced in the United States. For conventional fuel sources, electricity from coal and nuclear power plants are the least expensive, although many costs, such as CO2 emissions for coal plants and liability insurance for nuclear plants, are not paid for by the utilities and not included in the price of electricity. The most cost competitive forms of green power are hydro, landfill gas, wind, and geothermal. In optimal locations, production costs for these forms of green power are similar to conventional electricity. There are qualitative differences in the way green power is produced and sold, which institutions should consider when making a purchasing decision. Green power is available across the nation in both grid-delivered form and through renewable energy certificates (RECs).


The policies section contains over 15 green power policies from leading institutions. Policies for purchasing green power typically require energy conservation and efficiency, assign responsibilities for implementing and tracking the green power program, and specify the type and volume of green power the institution will purchase. Ideally, policies will also require certifications, such as Green-e Energy and EcoLogo, for all green power purchased.


The specifications section contains over 25 sample green power bid and contract specs used by leading institutions. Establishing a green power policy demonstrates a commitment to buying cleaner electricity, but with or without a policy, environmental attributes can be incorporated into bid and contract specifications.


The standards section discusses and compares leading green power standards. Green-e Energy and EcoLogo are the two leading standards for green power. For renewable energy certificates (RECs), the EcoPower Standard is also available, and for small hydropower generation there is the Low Impact Hydropower Certification. The U.S. Green Building Council LEED program awards points for green power use by buildings.


The products section contains a searchable database of green power products certified by Green-e Energy and EcoLogo. Both grid-delivered green power and renewable energy certificates (RECs) are listed.

Handy Facts

The handy facts section provides a referenced set of facts and findings pertaining to green power.


The definitions section provides a glossary of terms used throughout the Guide.

Credits & Endnotes

The credits & endnotes section lists the people responsible for writing, reviewing, and editing this Guide along with a listing of sources referenced.

Webinar Presentations

RPN Webinar - Green Power, April 8, 2008

RPN - Green Power Guide Overview

RPN - Environmental Problems with Electricity Production

Think Energy - Renewable Energy

Green-E Energy - Standard and Certification

Wisconsin - Green Power Purchase

Pennsylvania - Green Power Purchase

Creative Commons License This work by the Responsible Purchasing Network is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.

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