Green energy is a term describing what is considered to be environmentally friendly, typically non-polluting, sources of power and energy, some sources may use it interchangeably with renewable energy (see #Definition below). Additionally, some governments have drafted very specific definitions of green energy or an equivalent term which may be eligible for special subsidies or support in order to promote the technology.
Green energy is commonly thought of in the context of electricity, heating, and cogeneration, and is becoming increasingly available. Consumers, businesses, and organizations may specifically purchase green energy in order to support further development, help reduce the environmental impacts associated with conventional electricity generation, and increase their nation’s energy independence.
Definition
Several definitions have been put forth for the term. These include:
- A popular term for energy produced from renewable energy resources or, sometimes, from clean (low-emitting) energy sources.[1]
- Green energy comes from a source which does not produce pollutants; for example, solar, wind and wave energies.[2]
- Energy that is produced and used in ways that produce less air pollution and other environmental impacts.[3]
- "environmentally friendly" energy generated from sources such as hydro (water), solar (sun), biomass (landfill) or wind.[4]
Related terms
Green power can refer specifically to electricity generated from "green" sources.
The term brown energy has been introduced by some such as the The John Ray Initiative to contrast with green energy.[5]
Alternative energy is another, sometimes equivalent, term to renewable energy. Both terms indicate sources that are non-polluting non-fossil fuel sources. Both are Buzzwords, and they differ by highlighting the environmentally friendly aspect versus the non-traditional aspect.
Since the term indicates low-pollution and environmental soundness, green energy sources are also clean technologies.
Energy sources
Green energy includes natural energetic processes that can be harnessed with little pollution. Anaerobic digestion, geothermal power, wind power, small-scale hydropower, solar power, biomass power, tidal power and wave power fall under such a category. Some versions may also include power derived from the incineration of waste.
Some organizations have specifically classified nuclear power as green energy such as cleantech.com[6]. However, even the Nuclear Energy Institute has avoided the issue of directly classifying nuclear as green energy - a public awareness campaign launched for nuclear power uses the catch phrase clean air energy.[7]
Likewise, medium or large-scale hydroelectric power or sources of air pollution such as burning biomatter or petroleum, consume water and are often excluded from the label 'green energy'.
Renewable energy certificates (Green certificates, or green tags) are currently the most convenient way for consumers and businesses to support "green power". Over 35 million homes in Europe, and 1 million in the United States, are purchasing such certificates.
No power source is entirely impact-free. All energy sources require energy and gives rise to some degree of pollution from manufacture of the technology.
Purchasing green energy through the electrical grid
In several countries with common carrier arrangements, electricity retailing arrangements make it possible for consumers to purchase green electricity from either their utility or a green power provider. The customer typically pays a small premium.
When energy is purchased from the electricity network, the power reaching the consumer will not necessarily be generated from green energy sources. The local utility company, electric company or state power pool buys their electricity from electricity producers who may be generating from fossil fuel, nuclear or renewable energy sources. In many countries green energy currently provides a very small amount of electricity, generally contributing less than 2 to 5% to the overall pool.
By participating in a green energy program a consumer may be having an effect on the energy sources used and ultimately might be helping to promote and expand the use of green energy.
They are also making a statement to policy makers that they are willing to pay a price premium to support renewable energy. Green energy consumers either obligate the utility companies to increase the amount of green energy that they purchase from the pool (so decreasing the amount of non-green energy they purchase), or directly fund the green energy through a green power provider. If insufficient green energy sources are available, the utility must develop new ones or contract with a third party energy supplier to provide green energy, causing more to be built. However, there is no way the consumer can check whether or not the electricity bought is "green" or otherwise.
In some countries such as the Netherlands, electricity companies guarantee to buy an equal amount of 'green power' as is being used by their green power customers. The Dutch government exempts green power from pollution taxes, which means green power is hardly any more expensive than other power.
Abuses
In countries where suppliers are legally obliged to purchase a proportion of their electricity from renewable sources (for example under the Renewables Obligation in the United Kingdom), there is a danger that energy suppliers may sell such green electricity under a premium 'green energy' tariff, rather than sourcing additional green electricity supplies.[8] Where a Renewable Energy Certificate or similar scheme is in operation it is also possible for the energy supplier to sell the green electricity to the consumer, and also sell the certificate to another supplier who has failed to meet their quota, rather than 'retiring' the certificate from the marketplace. In other cases green energy tariffs may involve carbon offsetting rather than purchasing or investing in renewable energy.[9][10]
Certification schemes to minimise these and similar questionable practices are in place or are being developed in a few countries.[11]
International standards
The World Wide Fund for Nature and several green electricity labelling organizations have created the Eugene Green Energy Standard under which national green electricity certification schemes can be accredited to ensure that the purchase of green energy leads to the provision of additional new green energy resources.[12]
Purchasing green energy through the gas grid
The market for heating is mostly serviced by gas and oil rather than electric power, due to the high cost per kilowatt of electricity in many countries. Distribution of cheap renewable electric power via the electrical grid has made it possible in many countries for the average consumer to choose renewable electric power, and in the same manner bionatural gas may in future be made available to the average consumer via the existing natural gas grid. [13][14]
Local green energy systems
Those not satisfied with the third-party grid approach to green energy via the power grid can install their own locally-based renewable energy system. Renewable energy electrical systems from solar to wind to even local hydro-power in some cases, are some of the many types of renewable energy systems available locally. Additionally, for those interested in heating and cooling their dwelling via renewable energy, geothermal heat pump systems that tap the constant temperature of the earth, which is around 7 to 15 degrees Celsius a few feet underground, are an option and save money over conventional natural gas and petroleum-fueled heat approaches.
United States
The advantage of this approach in the United States is that many states offer incentives to offset the cost of installation of a renewable energy system. Individuals are usually assured that the electricity they are using is actually produced from a green energy source that they control.
Once the system is paid for, the owner of a renewable energy system will be producing their own renewable electricity for essentially no cost and can sell the excess to the local utility at a profit.
DOE, the U.S. Environmental Protection Agency (EPA), and the Center for Resource Solutions (CRS) [15] recognizes the voluntary purchase of electricity from renewable energy sources (also called renewable electricity or green electricity) as green power .
DOE selected six companies for its 2007 Green Power Supplier Awards, including Constellation NewEnergy; 3Degrees; Sterling Planet; SunEdison; Pacific Power and Rocky Mountain Power; and Silicon Valley Power. The combined green power provided by those six winners equals more than 5 billion kilowatt-hours per year, which is enough to power nearly 465,000 average U.S. households.
The EPA recognized the West Division of Macy's Inc., the Timberland Company, and the City of Chico, California, for their on-site generation of solar power, and also recognized New York University and six companies for purchasing green power. The EPA also named the City of Bellingham, Washington, and six more companies as their Green Power Partners of the Year.
Among all the companies, PepsiCo stands out as a partner of the year, because three of its bottling companies were also honored for buying green power. In addition, CRS awarded its Market Development Awards to the Western Washington Green Power Campaign, Clif Bar, and two individuals: John Schaeffer and Bill Spratley.
Throughout the country, more than half of all U.S. electricity customers now have an option to purchase some type of green power product from a retail electricity provider. Roughly one-quarter of the nation's utilities offer green power programs to customers, and voluntary retail sales of renewable energy in the United States totaled more than 12 billion kilowatt-hours in 2006, a 40% increase over the previous year.
See also
Alternative propulsion
Ashden Awards
Blue energy
Clean Energy Trends
Efficient energy use
Electric vehicle
Energy conservation
Energy efficiency
Energy Globe Awards
Feed-in Tariff
Global warming
Green energy certification schemes
Green banking
International Sustainable Energy Agency
Oil phase-out
Plug-in hybrid
Renewable energy
Renewable heat
The Clean Tech Revolution
V2G
National articles
Category:Green electricity by country
External links
EnviroDaq 100 Clean Tech Index Stock Index for Clean Tech and Green Energy companies listed on the London Stock Exchange.
U.S. Dept. of Energy's Green Power Network
US EPA: Green Power Partnership
Case Study: Green electricity in Darmstadt, Germany
Why Is It Better to Buy Green Electricity?
Association for Environment Conscious Building: The Green Electricity Illusion
Related journals
International Journal of Green Energy
Renewable Energy World
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