Green energy

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A solar trough array is an example of green energy

Green energy is a term describing what is thought to be environmentally friendly sources of power and energy. Typically, this refers to renewable and non-polluting energy sources.

Green energy includes natural energetic processes which 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.

More controversial is nuclear energy's claim to be green. It is possibly sustainable, arguably renewable and produces virtually no atmospheric pollution during the energy production stage. However nuclear waste is a pollutant, as well as the carbon dioxide and other greenhouse gases generated by the large amount of energy required by transport, mining and pre- and post-production. Hence, nuclear power is rarely included in official green energy schemes.

Likewise, medium or large-scale hydroelectric power or sources of air pollution such as burning biomatter or petroleum, are often excluded from the label 'green energy'.

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

In several countries, current electricity retailing arrangements make it possible for consumers to buy green electricity, either by purchasing their electricity from a generating company that uses only renewable technologies, or by buying from a general supplier who undertakes to buy at least as much power from renewable sources as their "green" customers purchase. Generally green electricity commands a price premium compared with standard supplies. Obviously this option is only available where common carrier arrangements have been put in place to allow competitive supply of power.

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.

1 Purchase of green energy
2 See also
- 2.1 National / Continental
3 External links
4 Related Journal
5 References

[edit] Purchase of green energy

[edit] Purchase of green energy through the electrical grid

In the USA,and Canada, residential and commercial customers can purchase Green Power from either their utility or a green power provider. Green energy is available through one of the many third-party energy suppliers that sell electricity made from renewable sources. The energy is delivered via the local electric utility. The customer simply pays a slight premium on their monthly utility bill for the Green Energy or directly purchases from a green power supplier.

When energy is purchased from the electricity network, there is no way of knowing that the power that reaches the home is from green energy sources. The local utility company, electric company or state power pool buys their electricity from electricity producers, ranging from coal and nuclear to large scale hydropower and green energy sources such as wind power and solar power. Most electricity has its source in non-renewable and polluting energy sources such as coal and nuclear. Green energy currently provides a very small amount of electricity, generally contributing less than 2 to 5 % to the overall pool from which utilities buy their electricity.

In order to make an impact, individuals who sign up for green energy either obligate the utility companies to increase the amount of green energy that they purchase from the pool and subsequently decrease 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. Although there is no guarantee that turning on a light will mean that, say, a wind turbine is providing the electricity, by participating in green energy programs a consumer is having an effect on the energy sources used and ultimately is 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.

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] Purchase of 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. 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 Renewable natural gas may in future be made available to the average consumer via the existing gas grid. ^[1]^[2]

[edit] Purchase of green energy through localized renewable systems

Those not satisfied with the third-party grid approach to green energy, that utilizes the power grid to deliver green energy, can still install their own locally-based renewable energy system. Renewable energy electrical systems from solar to wind to even local hydropower 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.

The advantage of this approach is that many US 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.