During a road trip this past Friday, I grabbed a magazine from the unread pile to catch up on some reading. Turns out my Outside subscription has expired. (I’ll get a renewal/resubscribe in after getting my next check – or I’ll go back to reading it online.) And it turns out I was way behind on my reading. The issue I grabbed was September 2008, which was great – it had an article that coincided nicely with the Hot, Flat, and Crowded book that I had read.
The article is the written exchange of two of the magazine’s editors in a competition to track their energy use. I had downloaded my electric bill about a month earlier, and I decided to join in the comparison a year late (and without the technological gadget). Without the special software, I would only be able to estimate my daily use. That’s still good enough for me to begin to understand how much power my wife and I use compared to other households.
First, I checked out PPL’s website, which lets consumers access special tools to understand their electricity use. I downloaded the account history and looked at the kilowatts used. Big increases in the winter months and valleys in the summer. Our rented half-double has no insulation (we’ve bugged the landlord about it to no avail – and without much opportunity to look for other options). That means the heating unit uses plenty of electricity trying to keep the old house warm during the cold winters. We topped out at 693 kilowatts in February 2008 – before we began dialing the thermostat way down during the day. Our best full month was July 2007 when we used 336 kilowatts.
An easy spreadsheet formula gave me the number of days in each billing period. From there, it was easy to track the average kilowatts per day. The Outside article (if you didn’t follow the link) says the average American household uses 30.25 kWh per day. The most we used was 23.1 kilowatts in February 2008, and our best month was 10.5 kilowatts in July 2007. The two competing editors fell between about 8 and 18 kilowatts. I have some work to stay in their league. My median was 14.86 kWh, and the mean was 15.28 kWh. There aren’t big fluctuations in our energy use except for a few key months when it really spikes.
I wondered what the trend was from year to year. I took a few minutes to reconfigure the chart to map out the monthly use over the course of 2007, 2008, and 2009 – and I checked the mean for each of the 12 months. So far in 2009, we’ve been below the monthly average every month except for January.
I’ve actually followed the average pretty closely for most of this year. August heat and air conditioners have driven up our electricity in the past – that’s something we haven’t done this year with a cooler summer. Look like the windows are staying open this year, and I’m looking for ideas on how to winterize.