Monday, January 28, 2008

Home Economics Noob

I brew my tea by the cup, boiling the water in a small electric kettle. I have always overfilled it slightly, so as to avoid any risk of not being able to fill my cup adequately. Last week I switched it up, so that now I may come up short once in a while, but I'll only rarely end up with too much.

I'm not really concerned with wasted water so much, but I'm worried the energy used to heat up the water might add up over time.

I figure I probably have an average of two cups a day when weekends and days I'm not working at home are factored in. So call it 700 cups a year. If I was overshooting by 20%, or two ounces, then that's 1400oz of water each year that I've been heating to boiling from room temperature.

A BTU is the energy it takes to heat a pound of water a single degree Fahrenheit. Each year I've been heating 87.5 pounds of water a whole 140 or so degrees, for a total of 12,250 unnecessary BTU each year, or about 13 million Joules.

My kettle is rated at 1000 watts, and since it is probably close to perfectly efficient (it's small and plastic, and the heating element is fully immersed), that means I'm wasting, uh...13,000...seconds. Each year.

That's three and a half hours! At minimum wage it would buy a nice lunch for two! I'm glad I've change my ways.


DU said...

Don't forget that 13e6 Joules is about 3.6 kWh. If electricity costs you about $.12 per kWh, the 43 cents saved could serve as the tip for that nice lunch.

Travis said...

See, that's what I was originally trying to calculate, but I got confused. Even with my actual electric rate, it's still only like sixty cents. A lousy tip.

DU said...

You did this whole thing in BTUs and then got confused by cents?

The waitron should be fall on their knees and thank GID for that $.60, after how late they were with my refills.