Hey Mr. Green,

My 10-year-old electric water heater uses about 5,000 kilowatt-hours a year. Should I wait until it dies or replace it now? If the latter, what's the most energy-efficient water heater on the market?

Randi, in Putnam Valley, New York

Holy starry dynamo of night! Your water heater alone uses almost twice as much electricity as my entire house. At New York's average residential rate of 19.6 cents per kilowatt-hour, you could be spending $1,000 a year to feed that energy hog. I'd rather take cold showers with Dick Cheney and Mitch McConnell than shell out that much.

Depending on where your energy comes from, conventional electric water heaters can suck up even more fossil fuel energy than gas heaters since two-thirds or more of the fossil energy that makes electricity gets used up as heat and in transmission.

So, to replace or not to replace your electric water heater?

Read the entire story in Sierra Magazine, originally published on the Sierra Club website (www.sierraclub.org): http://sierraclub.org/sierra/2014-6-november-december/green-life/mr-green-should-i-replace-my-water-heater