Our Electricity

After being asked rhetorically a couple of times if I knew now much I paid for my electricity, and whether I knew how much power my fridge was using ($0.13/kWh, and I don’t know) I bought a “Kill-A-Watt” power meter to see where our $18/month in electricity usage was going… just out of curiosity.  It turns out that watching a movie costs abot $0.08 in electricity.  The Cold Box (beer) uses about $3/month worth of power.  The fridge itself, usually the largest power hog in a household, is close to half our usage at $8/month. Making a batch of coffee in the french press, using the electric kettle is about a penny.  The other big electricity users are the stove and oven, and the washer and dryer (though we hardly use the dryer).  They can’t be measured with this thing because they use 220V outlets, which are generally hidden away and inaccessible anyway.

After those miniscule numbers, I was amazed to discover that a day’s worth of computation (24 hours, including some research related number crunching by my laptop, my desk light, my backup disk, and my 30″ cinema display) came in at $0.50!  So, at least for me personally, at roughly $15/month my computer is by far my largest expenditure of electricity.  Interesting!

I’d love to build (and live in) a condo that tracked the water and power usage of each unit, and within each unit each outlet/faucet/etc, in real time, posted to the web, and displayed in the communal entryway.  Visibility goes a long way to influencing behavior.

3 thoughts on “Our Electricity”

  1. Very cool 🙂 I've been wanting a kill-a-watt meter for a while, but I have a hard time actually purchasing things! I can justify it more now that I have 4 fridges etc to test out. Data is awesome. I think some of my current tenants would be a bit off-put by a public display of each outlet and faucet, but my ideal tenant (like myself) would also love such open data!
    What about the trade-off of energy (embodied and maintaining) used to meter/track use vs. the efficiency gains for doing so? At the small, already efficient household level one would presumably lose by having a monitor running 24/7 to show use (as you mention your computer taking up the bulk of your personal electric supply). What size condo or office would it be justified for? (A rhetorical question, perhaps, due to the variability of factors involved…)

  2. There have been several studies showing that when people can see their energy usage in real time, they use less: meters installed in the entryway, instead of out back somewhere, MPG displays on the dash of a car, etc. Sometimes by significant margins. Here's a project in which someone re-wired their entire house for plug-by-plug monitoring. I think the Kill-A-Watt is easily worth the $30 (w/ free shipping from Amazon), especially if you want to use it across all of your units. Do you own the appliances, or do the tenants? At the very least, this could help you facilitate taking advantage of whatever rebate programs are available. Though I guess most of those are CA state things.

    I suspect that the energy costs involved in doing the monitoring would be very, very small, compared to the overall energy usage of the house – even a highly efficient house, and similarly for embodied energy. Ideally, each wall and light socket would just have a tiny wireless transmitter with a unique ID inside it, and there would be a receiver/data logger plugged in somewhere, that would either upload directly to a server somewhere, or periodically upload to your computer or smartphone when it was on. If this were standard, and mass produced, the additional cost would be small. Will be expensive to start with though…

    I have a fantasy about building an energy and resource efficient living space for green geeks in Boulder. So my fantasy tenants/co-owners are into having their data public 🙂

  3. There have been several studies showing that when people can see their energy usage in real time, they use less: meters installed in the entryway, instead of out back somewhere, MPG displays on the dash of a car, etc. Sometimes by significant margins. Here's a project in which someone re-wired their entire house for plug-by-plug monitoring. I think the Kill-A-Watt is easily worth the $30 (w/ free shipping from Amazon), especially if you want to use it across all of your units. Do you own the appliances, or do the tenants? At the very least, this could help you facilitate taking advantage of whatever rebate programs are available. Though I guess most of those are CA state things.

    I suspect that the energy costs involved in doing the monitoring would be very, very small, compared to the overall energy usage of the house – even a highly efficient house, and similarly for embodied energy. Ideally, each wall and light socket would just have a tiny wireless transmitter with a unique ID inside it, and there would be a receiver/data logger plugged in somewhere, that would either upload directly to a server somewhere, or periodically upload to your computer or smartphone when it was on. If this were standard, and mass produced, the additional cost would be small. Will be expensive to start with though…

    I have a fantasy about building an energy and resource efficient living space for green geeks in Boulder. So my fantasy tenants/co-owners are into having their data public 🙂

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