I’ve been working hard over the past couple of Months to improve the energy efficiency of our condo.  A part of this is unplugging stuff at night (in my case I turn off the power strip to cut power to the device).  Here is one way you can save energy and money.

If you are like me you have your cable modem in your house that is then connected to the wireless router so that you have wireless internet.  I’m just going to focus on my modem for this example and how shutting it off at night can save energy and money.

On the bottom of my modem it shows that it uses 12 volts and .75 amps.   To figure out the watts we would then multiply the two together using the conversion equation:

Volt X Amp = Watt

In this case the modem takes up 9 Watts:     9Watts = 12 Volts * .75 Amp

If we break this down, assuming that it is running nonstop through the day and night, it uses 216 watts during a 24 hour cycle.  This equates to 1512 Watts/week  and ultimately 78624 Watts/year.  I shut off my modem during the night and day when I’m not using it/at work.  This breaks down to 7 hours of it being on during the week and 15 on the weekends, with an average of  83 Watts used a day which breaks down to 585 Watts of usage a week.

Here is a table where I compare the usage:

This may not seem like a lot but you saved about 48 KW of energy per year, just by shutting off your modem at night.  Note that if you shut off your wireless router this will also increase the savings and decrease the energy usage.  There are a lot of “vampire electronics” in the home that just draw on power with standby lights and displays.  Run an inventory on your house and see if there are things you can shut off to save on the electricity bill.  I’ve been able to get my bill down to $17 doing this.  My goal is $15.   Note that I don’t have air conditioning.    If you have any good tips about saving energy please post them here.