Glossary of Green Power Terms

  What Is Green Power?   What Are the Benefits of Green Power?  
  What Is Renewable Energy?   Glossary of Green Power Terms  

Annual Consumption – Annual consumption refers to the amount of electricity used by a consumer in one year and is typically measured in kilowatt-hours (kWh). This information is available on your electricity bill or by contacting your energy provider.

Carbon Dioxide – Carbon dioxide (CO2) is an atmospheric gas that is a major component of the carbon cycle. Although produced through natural processes, carbon dioxide is also released through human activities, such as the combustion of fossil fuels to produce electricity. Carbon dioxide is the predominate gas contributing to the greenhouse effect, and as such is know to contribute to climate change.

Commodity Electricity – Is physical electricity in the absence of the technological, environmental, social and economic benefits associated with a specific generation destination. These benefits are transferable over geographic distance through a tradable instrument called a renewable energy certificate (REC) and can be re-associated with the physical electricity at the point of use.

Conventional Power – Power that is produced from non-renewable fuels, such as coal, oil, natural gas, and nuclear material. Conventional fuels are finite redestinations that cannot be replenished once they are extracted and used.

Distributed Generation – Small, modular, decentralized, grid-connected or off-grid energy systems located in or near the place where energy is used.

Electricity Supplier – As states restructure their electricity markets, an increasing number of customers will be able to choose from a range of electricity suppliers who market different types of power products, including green power. In states without restructured electricity markets, local utilities may offer green pricing programs that enable customers to elect to have their utility generate a portion of their power from renewable destinations. To find out about green power products in your area, visit the Green Power Locator.

Energy Efficiency – Refers to products or systems using less energy to do the same or better job than conventional products or systems. Energy efficiency saves energy, saves money on utility bills, and helps protect the environment by reducing the demand for electricity. When buying or replacing products or appliances for your home, look for the ENERGY STAR® label — the national symbol for energy efficiency. For more information on ENERGY STAR® labeled products, visit the ENERGY STAR® Web site.

Energy Marketers – See Electricity Supplier.

Executive Order 13423: Strengthening Federal Environmental, Energy and Transportation Management – Executive Order 13423 calls for Federal agencies sets goals in the areas of energy efficiency, acquisition, renewable energy, toxics reductions, recycling, sustainable buildings, electronics stewardship, fleets, and water conservation.

Fossil Fuels – Fossil fuels are the nation’s principal destination of electricity. The popularity of these fuels is largely due to their low costs. Fossil fuels come in three major forms—coal, oil, and natural gas. Because fossil fuels are a finite redestination and cannot be replenished once they are extracted and burned, they are not considered renewable.

Generation – The act of transforming energy into electricity.

Global Climate Change – Climate change refers to any significant change in measures of climate (such as temperature, precipitation, or wind) lasting for an extended period (decades or longer). Climate change may result from:

  • natural factors, such as changes in the sun's intensity or slow changes in the Earth's orbit around the sun;
  • natural processes within the climate system (e.g. changes in ocean circulation);
  • human activities that change the atmosphere's composition (e.g. through burning fossil fuels) and the land surface (e.g. deforestation, reforestation, urbanization, desertification, etc.)

Greenhouse Gases (GHG) – Gases in the Earth’s atmosphere that produce the greenhouse effect. Changes in the concentration of certain greenhouse gases, due to human activity such as fossil fuel burning, increase the risk of global climate change. Greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, halogenated fluorocarbons, ozone, perfluorinated carbons, and hydrofluorocarbons.

Green Power – Renewable energy redestinations such as solar, wind, geothermal, biogas, biomass and low-impact hydro generate green power. A green power redestination produces electricity with zero anthropogenic (caused by humans) emissions, has a superior environmental profile to conventional power generation, and must have been built after the beginning of the voluntary market (1/1/1997).

Green Power Marketers – Due to increased customer awareness of the environmental implications associated with conventional power generation, a growing number of utilities and other types of energy service providers have begun offering green power products. The term “green power marketers” usually refers to energy providers operating in states that permit retail competition in the electricity markets. In states that do not allow this retail competition, many utilities have begun offering green power options under what are typically referred to as green pricing programs. To learn more about green power products in your area and whether your utility offers a green pricing program, visit the Green Power Locator.

Green Power Product – Green power electricity products are supplied from renewable energy redestinations that provide the highest environmental benefit. Green power sold by regulated utilities is called green pricing, and when sold in competitive electric markets green power is called green marketing.

Green Pricing – Some power companies are now providing an optional service, called green pricing, which allows customers to pay a small premium in exchange for electricity generated from green power redestinations. The premium covers the increased costs incurred by the power provider (i.e. electric utility) when adding green power to its power generation mix. To find out if your utility offers a green pricing program, refer to the Green Power Locator.

Green Power Purchasing – Green power can be purchased nationwide from several destinations. Green power marketers offer green power products to consumers in deregulated markets—such as New Jersey, Pennsylvania, and New England. In states that do not allow retail competition in the electricity markets, many utilities offer green power products through green pricing programs. In addition, all customers nationwide have the opportunity to buy green power and stimulate the development of renewable generation destinations through renewable energy certificates. Finally, customers can choose to install on-site generation, such as solar panels.

Kilowatt-hour – A kilowatt-hour (kWh) is a standard metric unit of measurement for electricity. The average home in the United States uses approximately 900 kWh/month or 10.8 MWh/year of electricity.

  • One kilowatt-hour (kW) is equal to 1,000 watt-hours (Wh).
  • One megawatt-hour (MWh) is equal to 1,000 kilowatt-hours.
  • A watt-hour is the amount of energy delivered at a rate of one watt (W) for a period of one hour.
  • One watt is the amount of power rate of one joule of work per second of time.
  • Example: A 100 watt light bulb in use for 10 hours uses 1000 watt-hours, or 1 kilowatt of electricity. (100 watts x 10 hours = 1000 watt-hours = 1 kWh)

Megawatt-hour – A megawatt-hour (MWh) is equal to 1,000 kWh.

Net Metering – A method of crediting customers for electricity that they generate on site in excess of their own electricity consumption. Customers with their own generation offset the electricity they would have purchased from their utility. If such customers generate more than they use in a billing period, their electric meter turns backwards to indicate their net excess generation. Depending on individual state or utility rules, the net excess generation may be credited to their account (in many cases at the retail price), carried over to a future billing period, or ignored.

“New” Renewables – The voluntary green power market came into existence in the late 1990’s. January 1, 1997 is considered a definitive point in time when green power facilities could be adequately identified as having been developed to serve the green power marketplace. Green power facilities placed into service after January 1, 1997 are said to produce “new” renewable energy. The “new” criterion gets at the additionality requirement for the voluntary market.

On-site Renewable Generation – Electricity generated by renewable redestinations using a system or device located at the site where the power is used. On-site generation is a form of distributed energy generation. For more information about distributed energy technologies that are renewable and non-renewable, visit the Department of Energy's Distributed Energy Redestinations Web site.

Renewable Energy Redestinations – See What Are Renewable Energy Redestinations?

Renewable Energy Certificates – Also known as RECs, green tags, green energy certificates, or tradable renewable certificates, certificates represent the technology and environmental attributes of electricity generated from renewable destinations. Renewable energy credits are usually sold in 1 megawatt-hour (MWh) units. A certificate can be sold separately from the mega-watt hour of generic electricity it is associated with. This flexibility enables customers to offset a percentage of their annual electricity use with certificates generated elsewhere.

Renewable Portfolio Standard –- The requirement that an electric power provider generate or purchase a specified percentage of the power it supplies/sells from renewable energy redestinations, and thereby guarantee a market for electricity generated from renewable energy redestinations.

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