Green energy refers to the use of power that is not only more efficient than fossil fuel but that is friendly to the environment as well. Green energy is generally defined as energy sources that dont pollute and are renewable.

There are several categories of green energy. They are anaerobic digestion, wind power, geothermal power, hydropower on a small scale, biomass power, solar power and wave power. Waste incineration can even be a source of green energy.

Nuclear power plants claim that they produce green energy as well, though this source is fraught with controversy, as we all know. While nuclear energy may be sustainable, may be considered renewable and does not pollute the atmosphere while it is producing energy, its waste does pollute the biosphere as it is released.

The transport, mining and phases before and after production of nuclear energy does produce and release carbon dioxide and similar destructive greenhouse gases. When we read of green energy, therefore, we rarely see nuclear power included.

Those who support nuclear energy say that nuclear waste is not, in fact, released into our earths biosphere during its normal production cycle. They stress as well that the carbon dioxide that nuclear energy production releases is comparable, in terms of each kilowatt hour of electricity, to such sources of green energy as wind power.

As an example of the green energy production the average wind turbine, such as the one in Reading England, can produce enough energy daily to be the only energy source for 1000 households.

Many countries now offer household and commercial consumers to opt for total use of green energy. They do this one of two ways. Consumers can buy their electricity from a company that only uses renewable green energy technology, or they can buy from their general supplies such as the local utility company who then buys from green energy resources only as much of a supply as consumers pay for.

The latter is generally a more cost – efficient way of supplying a home or office with green energy, as the supplier can reap the economic benefits of a mass purchase. Green energy generally costs more per kilowatt hour than standard fossil fuel energy.

Consumers can also purchase green energy certificates, which are alternately referred to as green tags or green certificates. These are available in both Europe and the United States, and are the most convenient method for the average consumer to support green energy. More than 35 million European households and one million American households now buy these green energy certificates.

While green energy is a great step in the direction of keeping our environment healthy and our air as pollutant free as possible, it must be noted that no matter what the energy, it will negatively impact the environment to some extent.

Every energy source, green or otherwise, requires energy. The production of this energy will create pollution during its manufacture. Green energys impact is minimal, however.

Every day people do dozens of things that put more carbon dioxide into the atmosphere. This gas is the main perpetrator of climate change, yet activities like driving, heating your house, air travel, and electricity consumption, are hard to stop. Individuals that want to reduce their carbon footprint, the amount of carbon dioxide generated in a year, have the option of buying carbon offsets, often called renewable

energy credits, or RECs

Carbon offsets are projects that decrease the amount of greenhouse gases (GHG) like carbon dioxide in the air to counterbalance the amount that an individual has emitted. These projects can include, but aren’t limited to planting trees (carbon sequestration), erecting wind turbines or solar panels, reducing methane (a greenhouse gas more potent, but less common than carbon dioxide), or updating manufacturing processes to use less fossil fuel.

To offset the average US household energy consumption of 10,656 kWh per year, 3Phases, a large wind company in the Midwest, charges $213.00. 3Phases will use this money to produce, in theory, 10,656 kWh extra in wind energy by building that many more turbines. This new renewable energy will be added to the grid in the place of conventional energy, like coal. The pricing of carbon offsets for alternative energy firms is based on the price difference between fossil fuel energy production and the alternative energy production per kilowatt hour.

In all cases, the money from the offset purchase must instigate additional reductions by the company. Otherwise, the price of the credit will not accurately reflect the amount of GHG reductions it caused. Community Energy Inc., a Pennsylvania-based organization operating in New Jersey, is one of several companies doing the same thing.

As offset purchases have become more popular, journalists and researchers have raised the alarm and cautioned consumers about offsets that do little more than make you feel good. The major concern centers on additionality. Carbon mitigation is only additional if it occurs at a level above the baseline level, also called ‘business as usual’. Ideally, the offset you buy should initiate extra reductions that could not have happened without the money you spent. Additionality is hard to measure: large firms are already working to reduce their GHG-producing activities, and offset purchases, especially small ones, may not actually instigate enough new activity to fully offset the promised amount of kilowatt hours.

A recent New York Times article publicized these problems. To many environmentalists, the carbon-neutral campaign is a sign of the times, easy on the sacrifice and big on the consumerism, Andrew Revkin reported in his piece Carbon Neutral Is Hip, but Is It Green? Revkin quotes Denis Hayes, a leading sustainability activist and expert; the worst of the carbon-offset programs resemble the Catholic Church’s sale of indulgences back before the Reformation, he says. Instead of reducing their carbon footprints, people take private jets and stretch limos, and then think they can buy an indulgence to forgive their sins.

In the past year, researchers discovered that Al Gore, director of the climate change documentary An Inconvenient Truth, has a carbon footprint twenty times the national average; his mansion consumes almost 221,000kWh (kilowatt hours) a year. Gore buys offsets to legitimize this enormous fossil fuel consumption, but many question if his offset purchase actually exempts him from his climate change sin.

Citizens in China use an average of 6 carbon tons per year, and in India, the average is less than half that. In the United States, however, the average person generates around 25 carbon tons per year. Many environmentalists feel we should be reducing our carbon consumption by taking big steps to change our personal and organizational habits and use different technologies and/ or fuels, instead of taking the easier path of changing nothing, and spending money to transfer the reduction responsibility to others. Different offset providers have different pricing schemes, which further complicates the issue of additionality.

Most people familiar with the offset market, including offset providers, encourage individuals first to take steps to reduce the amount of energy they use before making an offset purchase. Conserving electrical energy by turning off lights and computers at night, buying fuel-efficient appliances and vehicles, and being an informed consumer about the food you buy can all make significant reductions in your carbon footprint.After taking these steps, only carbon offsets can mitigate the remaining GHG emissions, allowing individuals to go completely carbon neutral.

In summary, trees don’t reduce carbon, they sequester it for as long as they live. Energy conservation is probably the best way to lower your carbon footprint.

Carbon offsets essentially fund additional carbon reduction that would not happen otherwise.

Individuals and institutions have 3 ways to lighten their carbon footprint:

1) Reduce your own energy consumption

2) Replace dirty energy with clean

3) Facilitate and fund energy conservation by others, particularly those who cannot afford to do it themselves

You think you understand renewable energy credits. You’re sure you understand Carbon Offsets. You are fuzzy on the details about how they differ and when the purchase of one or the other might be appropriate. Never fear! This article explains the key differences, and similarities, between the two.

The first difference is the way that offsets and Renewable Energy Credits (RECs) are measured. Carbon offsets are measured in metric tons of C02 or C02 Equivalent. Renewable Energy Credits are measured in kilowatt hours, which are a standard electricity measurement metric. A kilowatt hour is the amount of work that can be performed by one kilowatt of energy in one hour.

Picture a lonely, dim lightbulb hanging from the ceiling that turns on for one hour each day by which you feverishly darn socks in a carbon constrained world; that’s a watt, and for the privilege of its use, you’ll be charged for 1/1000 kwh of electricity each day. These days, you probably use a several kwh per day.

The second difference between carbon offsets and renewable energy credits is that renewable energy credits only come from renewable energy projects (solar, wind geothermal, biofuels, etc.) while carbon offsets can come from all different kinds of projects, including renewable energy generation, that reduce the level of greenhouse gases that are entering the atmosphere.

To put it another way, RECs are primarily concerned with promoting the generation of clean energy, while carbon offsets are primarily concerned with preventing the emissions that enter the atmosphere.

They are both systems that have developed to deal with global warming systematically, but they have different approaches. RECs are forward looking, focused on building a clean energy economy and providing an extra incentive for the creation of renewable energy, while carbon offsets are oriented in the present, dealing with preventing greenhouse gases from entering the atmosphere right now.

Because of these different measurement systems and the different foci of the two programs, RECs and carbon offsets have different precision rates when it comes to carbon. Carbon offsets are all about exactitude, and many of the discussions about the efficacy of offsets center around the degree of certainty a buyer has that the exact amount of carbon s/he has paid for is actually being prevented or captured. RECs, on the other hand, are measured in kilowatt hours, and the carbon content of that ’saved’ kwh differs depending on the location of the project and the quality of the local electricity.

The dirtier the local electricity, the more carbon an REC ’saves.’ Different utilities around the country use different mixes of energy sources, from coal to natural gas to renewables, to create electricity. These sources vary widely in their carbon content. To make matters even more confusing, a utility might even change the mix it uses depending on the time of day- when peak load sets in they might have to rely on dirtier power sources than they would otherwise.

So, it’s impossible to say exactly how much carbon a clean kwh of renewable energy ‘offsets.’ The closest we can get is to use the ‘emissions factor’ for energy from the local utility, which is the average emissions for the mix of sources that the utility uses to create power, and multiply it by the number of kilowatt hours to produce an estimate of the carbon saved per kilowatt. But it will always be an estimate.

This is not to say that RECs are no good. They are an extremely effective way to promote clean energy because they give the providers and extra incentive to keep creating clean energy and we need all the incentives we can get to move toward a clean energy economy. RECs just aren’t the most accurate way to offset carbon. I highly recommend using RECs to offset electricity use, because your electric bills will have a record of the exact number of kwh you used, and you can buy RECs to account for all the dirty emissions your plugged-in Macbook caused. Then, you can buy carbon offsets to cover all your driving and flying.

‘But what about renewable carbon offsets?’, you say. ‘Those seem like the best of both worlds!’ I’m getting there. Those are good to, and if you really value the promotion of clean energy despite some of the accuracy issues, you can buy renewable energy offsets. Many times offsets will actually come from the exact same projects as the RECs, but the nice thing about buying the offset version instead of buying RECs and doing the calculations yourself is that someone else, hopefully a third party verifier, is determining how much carbon each kwh of clean energy replaced. So you don’t have to! Rest easy, and lay off the carbon guilt.