Have you ever wondered how the electricity in your home is generated? Is it powered by coal, hydro, perhaps wind or a mixture of sources?

If you live in the USA, there's an easy way to determine this using the EPA's Power Profiler.

The Power Profiler will first ask for your ZIP code, followed by your electric utility. It will then generate results of the sources used and display related greenhouse gas emissions such as Nitrogen Oxide, Sulfur Dioxide and Carbon Dioxide. You'll also be shown a comparison with the national average.

For example, I entered a Portland (Oregon) ZIP code - 97202. There's only one local provider - Portland General Electric Company. It turns out that Portlanders score pretty well in comparison to the national average with 48.6% of electricity generated coming from hydro compared to a 6.5% national average. In relation to coal, Portland's share is 34.4% compared to the national average of 49.6%.

Given Portland's progressive nature, I was expecting to see a little more in terms of non-hydro renewable energy such solar and wind; which only make up 2.3% compared to a national average of 2.1%.

It's a really interesting tool worth trying out!

So what can you do if you discover that most of your power is generated through filthy coal?

Many utilities have green programs where you can pay a little more (usually a couple of cents per kilowatt extra) and be "switched" to renewable energy in various percentages. For example, you may not want to take the full hit financially speaking, so you may be able to get onto a program where 25% of your power comes from renewable sources. It's usually a simple exercise only requiring a phone call, but there are a few pitfalls to watch out for; which I've mentioned in my article on buying green electricity.

If your local providers have no green programs whatsoever, you can also consider purchasing green tags, aka carbon offsets.