Consider energy consumer A: His mansion consumes more electricity every month than the average American household uses in an entire year.

The average household in America consumes 10,656 kilowatt-hours (kWh) per year, according to the Department of Energy. In 2006, this home devoured nearly 221,000 kWh—more than 20 times the national average.

Last August alone, it burned through 22,619 kWh—guzzling more than twice the electricity in one month than an average American family uses in an entire year. As a result of his energy consumption, his average monthly electric bill topped $1,359.

The extravagant energy use does not stop at his electric bill. Natural gas bills for the mansion and guest house averaged $1,080 per month last year.

In total, he paid nearly $30,000 in combined electricity and natural gas bills for his Nashville estate in 2006.

Consider energy consumer B: His 4,000-square-foot house is a model of environmental rectitude. Geothermal heat pumps located in a central closet circulate water through pipes buried 300 feet deep in the ground where the temperature is a constant 67 degrees; the water heats the house in the winter and cools it in the summer. Systems such as the one in this "eco-friendly" dwelling use about 25% of the electricity that traditional heating and cooling systems utilize. A 25,000-gallon underground cistern collects rainwater gathered from roof runs; wastewater from sinks, toilets and showers goes into underground purifying tanks and is also funneled into the cistern. The water from the cistern is used to irrigate the landscaping surrounding the four-bedroom home. Plants and flowers native to the high prairie area blend the structure into the surrounding ecosystem.

Energy consumer A: Al Gore.

Energy consumer B: George W. Bush.