I thought I'd share a link to a site that I've found particularly useful for a while now. The author goes by Mr. Electricity and the site can be found at http://michaelbluejay.com/electricity/.

Mr. Electricity used to take questions from readers, but has discontinued this option. However, this site still has tons of great information on how electricity is used in your home, how you can reduce your usage, and ultimately how you can save on your electric bill.

Electric usage is very simple when you look at the math. Watts = Volts x Amps. Volts and amps are listed on most electrical devices. You can then calculate the wattage for that particular device. Electric companies charge you by the kilowatt-hour (kWh) which is the number of kilowatts of electricity used on an hourly basis. So if you have a 1,000 watt device running for 1 hour, you just racked up 1 kWh. Or if you leave a 60 watt light bulb on for 2 hours, you’ve used 0.12 kWh. If you multiply that by your electric rate (displayed on your bill), you will be able to calculate the actual cost to run that device for that amount of time. I have used this site to help calculate my usage increase in December due to Christmas lights.

The site also goes into several electricity myths such as leaving the AC on all day is more efficient than leaving it off and then turning it on when you get home. It is conventional wisdom that this is true. People believe that it is more efficient to keep a house cooled to 75 degrees all day than it is to let it heat up and then cool it to 75 all in one shot. As Mr. Electricity explains, this is false because the house can only get so hot. If you leave your AC off, the house will reach a peak temperature. If you cool all day, the A/C will continually bring the temperature down, the house will reheat, and the AC will have to cool again. So, his point is that cooling the house to 75 degrees once is more efficient than doing it many times during the day.

Finally, another of my favorite sections of this site is the chart that gives you an approximate value on the electric usage of common household devices. Not surprisingly, anything that heats or cools (electric heat, oven, clothes dryer, central air) are high on the list. But you may be surprised to find out that your little coffee maker is using more electricity than your refrigerator. Or you might be surprised that: Running your AC 12 hours a day for three weeks uses more energy than leaving the refrigerator door open 24 hours a day for a whole year.

Have fun learning about electricity usage, and hopefully finding some ways to help reduce your own usage (and your bills).