As I guessed, I used about the same amount in 2008 as in 2007. I haven't done anything to reduce my usage since then, but I'm still thinking about it.

Every few months, ComEd includes with my bill an environmental disclosure pamphlet that lays out how its power was generated over the last twelve months. The most recent one covered the period up through September, 2008 and it broke down the sources as 60% nuclear, 34% coal, and a few percent from natural gas, hydro, and biomass. This seems to change quite a bit from pamphlet to pamphlet, which I'm guessing is because they're always buying their power from different sources.

It also provides a table that gives average amounts of emissions that those sources produced, per 1,000 kilowatt-hours. This lets me calculate my personal impact:

All this is interesting, but there’s more useful data in there waiting to be uncovered. Someone at Google put together a list of search terms that might be entered by someone with the flu, extracted a few years of search data, correlated that with the CDC’s disease data, and created Google Flu Trends. The idea is that when flu season hits and people start getting sick, they’ll start hunting for information and advice online. This will get noticed by Google and can provide useful data on where the flu seems to be hitting hardest. Additionally, since most people are likely to go online before they call their doctor or go to the hospital, trends might become apparent earlier through search data than through more traditional methods.

All in all, it’s a very clever way to take information which otherwise might get ignored, or used for a purely business-related purpose, and use it in a way that could help people. Get the backstory in this article at the New York Times.

My yearly usage has been going up, but seems to be leveling off. There was a big jump from 2005 to 2006 and a smaller one from 2006 to 2007. 2008 isn’t complete, of course, but I’m on track for about the same amount as 2007, unless something unusual happens.

Averaging out the data by month also leads to some insights. There seem to be two major seasonal effects at work. Running the AC in the summer has the biggest impact, causing spike in July and August. I also want to say that there’s a smaller bump in the winter due to the increased need for artificial light, but the data’s a little too uneven to say for sure. In particular, I’m not sure why it’s lower in September than in October, and why the trend is downward from October through December. Perhaps it’s because I’m often away for the last week or so of December.

The big picture is that I consume about 160 kWh per month, or 1,900 kWh per year. According to government statistics, the average household in Illinois consumes 770 kWh per month, and for the U.S. as a whole, that goes up to 920 kWh. I’m way below average, but I probably shouldn’t brag too much, since I have some built-in advantages which I can’t really take credit for. I don’t have to account for a washer, dryer, dishwasher, hot water, or heat. The only major appliances that show up on my electric bill are my refrigerator, my AC, and my 1400W espresso machine.

What could I do to get this figure lower? I’ve already replaced most of my bulbs with compact fluorescents. The only incandescents I still have either are used rarely, or are harder than the average bulb to replace (odd base sizes, on dimmer switches, or decorative bare bulbs).

My computer stays on (although asleep) all day. If I shut it off while I’m asleep or at work, I could probably save a few watts. Only a few though, since according to Apple in sleep mode it uses just over two watts, only slightly more than it uses when it’s off.

Addressing “vampire power” (devices such as power adapters which consume energy even if they’re not being actively used) might save me a few more watts. I have a bunch of little electronic devices that don’t get used very often, but stay plugged in all the time. If I plugged these into a single power strip then I could turn them off when I wasn’t using them. Something like a Kill A Watt meter, or its DIY equivalent, would allow me to measure how much power is actually getting used by these devices. I’m going to think about this and see if it would be practical for me. If I have to dig around under my desk half a dozen times a day just to save a few watts, it’s not going to be worth the effort.