Why Buy Green Power?
In This Section
- EPA's mission is to protect human health and the environment. Purchasing green power and renewable energy helps accomplish this goal by avoiding most of the environmental impacts associated with traditional power generation, such as emissions of the following gases:
- Carbon dioxide (CO2) is a product of fossil fuel combustion. Burning fossil fuels releases carbon that has been stored underground for millions of years into the atmosphere. The carbon in these fossil fuels is transformed into carbon dioxide—the predominant gas contributing to the greenhouse effect—during the combustion process and contributes to the potential for global warming.
- Methane (CH4) is a greenhouse gas that remains in the atmosphere for approximately 9-15 years. Although carbon dioxide is more prevalent in the atmosphere (there is approximately 200 times more carbon dioxide than methane in the atmosphere), methane is more than 20 times more effective in trapping heat than carbon dioxide over a 100-year period. Sources of methane include organic waste decomposition in municipal solid waste landfills and agricultural production. Methane is also emitted during the production and transport of coal, natural gas, and oil.
- Nitrogen oxides (NOx) is the generic term for a group of highly reactive gases, all of which contain nitrogen and oxygen in varying amounts. Nitrogen oxides form during fuel combustion, the primary sources being motor vehicles, electric utilities, and other industrial, commercial, and residential sources. These emissions contribute to smog, global warming, and a number of human respiratory hazards. Nitrogen oxides can also lead to acid rain, as emissions react with other substances in the air to form acids which fall to earth as precipitation.
- Nitrous oxide (N2O) is a greenhouse gas with an atmospheric lifetime of approximately 120 years. Nitrous oxide is about 310 times more effective in trapping heat in the atmosphere than CO2 over a 100-year period. The primary sources of human-influenced emissions of nitrous oxide are agricultural soil management, animal manure management, sewage treatment, mobile and stationary fuel combustion, adipic acid production, and nitric acid production. Nitrous oxide is also emitted naturally from a wide variety of biological sources.
- Sulfur dioxide (SO2) is emitted when burning fossil fuels, such as coal or oil, or when extracting gasoline from oil or metals from ores. Over 65 percent of sulfur dioxide released to the air, or more than 13 million tons per year, comes from electric utilities, especially those that burn coal. As with nitrogen oxides, sulfur dioxide emissions are associated with a number of harmful respiratory effects and react with other substances in the air, causing acid rain.
- Sulfur hexafluoride (SF6) is a potent greenhouse gas primarily used as an electrical insulator in high voltage equipment that transmits and distributes electricity. Gas leaks occur from aging equipment, and gas losses can occur from equipment maintenance and servicing. Because of its great ability to trap heat in the atmosphere and its life span of 3,200 years, even a relatively small amount of SF6 can have a significant impact on our climate.
- Furthermore, the production cycle of conventional fossil fuels causes additional environmental harm in the form of resource extraction and processing of fossil fuels.
- Purchasing green power can help reduce America’s dependence on foreign fuel sources because green power is a domestic energy source, whereas conventional power is in part produced from imported fossil fuels, such as petroleum or natural gas.
- Renewable fuels are inexhaustible and can be used so that fossil fuels are kept in reserves for times of need.
- Green power provides a hedge against risks posed by electricity price instability. Wind, geothermal, hydro, and solar energy are not subject to the rise and fall of fuel costs and therefore they can offer a fixed price over the long term.
- Buying green power supports the U.S. share of the growing renewable market, with the potential for billions of dollars to be invested in the U.S. economy and to enlarge the job market.
Energy Independence and Security Act of 2007
In December 2007, Congress and former President George W. Bush established aggressive new requirements for federal energy management with the signing of the Energy Independence and Security Act of 2007 (EISA). EISA is a comprehensive energy bill that includes numerous provisions designed to improve energy and water efficiency and stimulate the use of renewable energy among federal agencies. While EISA does not contain specific green power purchase requirements for federal agencies, Section 523 requires that agencies meet 30 percent of their hot water demand for each new building or major renovation through the use of solar hot water heaters.
Executive Order 13423
The U.S. Department of Energy published final renewable energy guidance for Executive Order (EO) 13423 in January 2008. EO 13423 requires that 50 percent of current renewable energy purchases come from new renewable sources—sources that have been developed after January 1, 1999. While the Energy Policy Act of 2005 (EPAct 2005) set renewable energy goals, EO 13423 is the first federal mandate to require agencies to purchase a certain percentage of new renewable energy.
During FY 2007, agencies continued to receive credit toward their energy reduction goal from purchases of qualified electric and non-electric renewable energy sources. From FY 2008 through FY 2011, the credit will gradually be reduced to zero. Purchases of renewable energy or Renewable Energy Certificates (RECs) may only contribute up to 60 percent of the annual energy reduction goal for FY 2008, and will gradually be reduced to zero by FY 2012. Long-term REC purchases of 10 years or more of renewable energy that contribute to the development of new renewable energy resources could only contribute up to 80 percent of the annual energy reduction goal for FY 2008 and will gradually be reduced to zero in FY 2012.
The phase out for counting renewable energy and REC purchases toward energy intensity goals does not impact how agencies count these purchases toward renewable energy goals.
Signed into law on August 8, 2005 , EPAct 2005 dictates the following:
- Each federal agency must consume renewable energy in amounts no less than:
- 3 percent in FY 2007 through FY 2009
- 5 percent in FY 2010 through FY 2012
- 7.5 percent in FY 2013 and thereafter
Superseded by EO 13423, EO 13123's renewable energy requirements focused on installation of solar units:
- Expand use of renewable energy at federal facilities, striving to have 2,000 solar energy units installed by 2000 and 20,000 units installed by 2010. Learn more about EPA's EO 13123 energy reduction and greenhouse gas emission reduction requirements.
Through EPA's green power purchasing, the Agency has made several important commitments to ensure that it leads by example and shares its experience. EPA's outreach efforts related to the Agency's green purchasing serve to:
- Educate the public on the importance of purchasing renewable energy.
- Demonstrate federal commitment to green power.
- Reinforce importance of social responsibility.