Energy consumption

I’ve finally got enough data to start to look at patterns in my home energy use. For the past two years, I’ve been stashing data in an excel spreadsheet every time I got a bill from any utility provider. Electricity is the simplest, since they read the meter almost exactly once a month. I took the KW/h for each month in 2004-05 and 2005-06 and laid them out on this here chart:

It starts and ends in June. I did absolutely nothing to correct for the fact that some months are longer than one another. If it would make you happier to round february up by 6% and all the 31 day months down by 3%, you go ahead and do that. The reality would be even uglier, since I would have had to stash the “days since last reading” data in my little spreadsheet. I’ll start doing that now, but I haven’t for the past two years.

I also did nothing with “degree day” data, which is how the big boys figure out energy consumption data like this. Basically, take the degrees difference from some comfort temperature, on average, and multiply by the days. This gives you a number you can use when saying “okay, I burned more oil, but it was a colder winter.” My perfunctory search of the internet didn’t yield even a daily low/high chart for Providence, much less a nicely tabulated degree-day chart. If anyone finds me a table of such data, I’ll happily toss it in there and try to normalize.

So what do I see? I see that my energy consumption measures are having some significant impact, at least in the early summer! I’m not surprised that the winters are roughly equivalent. Our heating is oil based, so electrical is going to be the space heaters and the lights. However, these first few hot days have been cool enough in the house (with one notable exception) that I’ve felt no need to run a crapload of fans and AC units. I’m seeing about *half* the consumption from past year, which makes me feel *great*!

I did something similar with heating oil:

This one, since they fill the tank basically at random, I had to do in a cumulative fashion. I’m a little bummed to see no noticeable difference between last year and this year. Looking at the tank, it’s at about 140 / 280 gallons. That means we’re probably on track to burn just as much oil last year as this year, meaning that none of the innovations we put in place (insulation, new chimney liner, insulating pipes in the basement, “intelligent” thermostat) has done a lick of good.

Think, think, think.

— UPDATE —

I went over to ye-olde filing cabinet and pulled out the yellowing scraps of dead tree that the power company sends to me. Yes, I’m a pack rat. I added in the actual days comprising each meter reading, and boy am I ever glad that I did! Check this out:

So I even had a slight win over the fall, and my average daily consumption is an even bigger win than I though it was!

So, at our current “take home” cost of $0.18 / KWh, my relentless investment in insulation, fluorescent bulbs, and the like are saving, like, $1.44 a day!

Gross, huh?

— UPDATE, MARK 2!!!!! —

OMFG, the Weather Underground has so much data, I nearly wet myself in geeky bliss. Heating, cooling, degree days, barometric pressure in 5 minute increments going back 30 years!!!!. I haven’t even clicked “advanced search” yet, but it looks like they’ve set it up so I can dump out the exact data that I want. Ungh! Ungh! Ha! Wubba wubba wubba!