Green energy

From Wikipedia, the free encyclopedia

It has been suggested that this article or section be merged into Renewable energy. (Discuss)

A solar trough array is an example of green energy

The term Green energy is used to describe sources of energy which are considered environmentally friendly and non-polluting.

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. Renewable energy certificates (Green certificates, or green tags) have been one way for consumers and businesses to support green energy. Over 35 million homes in Europe, and 1 million in the United States, are purchasing such certificates.^{[citation needed]}

Additionally, some governments have drafted very specific definitions for green energy or similar terms which may be eligible for subsidies or other support for specific technologies.

[edit] Definition

Several working definitions used for green energy. These include:

An alternate term for renewable energy.
Energy generated from sources which do not produce pollutants (e.g. solar, wind and wave energies).^[1]
Energy generated from sources which are considered environmentally friendly (e.g. hydro (water), solar (sun), biomass (landfill) or wind).^[2]
Energy generated from sources which produce low amounts of pollution.^[3]
Energy that is produced and used in ways that produce relatively less environmental impacts.^[4]

[edit] Related terms

Because the green energy sources are often low-polluting and environmentally sound, they are also considered clean technologies.

Alternative energy is another term which is often used interchangeably with renewable energy. It suggests a non-polluting, non-fossil-fuel source.

Green power is sometimes used in reference to electricity generated from "green" sources.^[5]

Brown energy is sometimes used to contrast non-renewable or polluting energy sources with green energy.^[6]

[edit] Green sources

A wind turbine at Greenpark, Reading, England, generating green electricity for approx 1000 homes.

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 definitions may also include power derived from the incineration of waste.

Some organizations have specifically classified nuclear power as green energy.^[7]

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'.^{[citation needed]}

No power source is entirely impact-free. All energy sources require energy and give rise to some degree of pollution from manufacture of the technology.^{[citation needed]}

[edit] 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 (renewable electricity) from either their utility or a green power provider.

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.

[edit] 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]

[edit] 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]

[edit] 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.^{[citation needed]} Distribution of renewable electric power via the electrical grid has made it possible in many countries for consumers 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]

[edit] Local green energy systems

Main article: Microgeneration

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.

[edit] 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.

[edit] Green energy and labelling by region

[edit] European Union

Directive 2004/8/EC of the European Parliament and of the Council of 11 February 2004 on the promotion of cogeneration based on a useful heat demand in the internal energy market^[15] includes the article 5 (Guarantee of origin of electricity from high-efficiency cogeneration).

[edit] United Kingdom

See Green electricity in the United Kingdom for further information.

[edit] France

Over 75% of french electricity comes from nuclear power plants.^[16] ^[17] France is the largest net exporter of electricity in the world.^[16] Electricity exports generate over 3 billion euros of revenue a year for France.^[16] French electricity costs are among the lowest in Europe.^[16] A major factor in the low cost of electricity in France is the use of a single reactor design, which allows for economies of scale.^[17] French CO2 emissions are among the lowest in the developed world, with 10 tons of CO2 equivalents per person per year.^[18] Danish citizens emit an average of 14 tons of CO2 equivalents per person per year.^[19] Even Iceland, with its abundance of geothermal energy for heating, has higher per Capita emissions at 10.4 tons of CO2 equivalents per Capita.^[20]

[edit] Spain

In Spain green energy is regulated by the Orden ITC/1522/2007.^[21]

Please help improve this section by expanding it.
Further information might be found on the talk page or at requests for expansion.

[edit] Portugal

Portugal is currently making huge investments in this field, it is to become one of the largest producers and users of this type of energies in Europe by 2010, says José Sócrates, the portuguese Prime-minister. Portugal has a great potential to produce solar, water, waves, geothermic and wind energies.

[edit] United States

DOE, the U.S. Environmental Protection Agency (EPA), and the Center for Resource Solutions (CRS)^[22] 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.