Thursday, October 11, 2007

Efficiency - the Name of the Game

Our low-flow showerhead just arrived yesterday. I need to get some teflon tape so I can install it this weekend. This will reduce water use in the shower from 2.5 gallons per minute down to between 1.2 and 1.4 gallons per minute. That's a 50% reduction in water used and a 50% reduction in energy to heat shower water.

I also just ordered an external 160 GB hard drive.

"How does this save energy?", you ask.

By buying this external hard drive and attaching it to my PC at home I will be able to turn off another computer. It's a massive old server with dual power supplies. It sounds like a jet taking off when you hit the power button. This old tank draws 500W of power and it's on 24/7. It serves as the file server for our house holding our music, pictures, videos, and other files.

By turning this machine off we save a lot of energy:

(500W/ 1000 W/kW) x 24 hours/day x 30.417* days/month = 365.004 kWh/month

365.004 kWh/month x 7.09 cents/kWh = $25.88/month in savings

* 365 days/yr divided by 12 months/yr = 30.417 days/month

In other words, this external hard drive completely pays for itself in 3 months. After it pays for itself, it's like an extra $25 a month in the bank compared to what I would have spent on the electric bill.

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