I last evaluated my long term power usage in April when I had 1 year of data. Those results were good, but they weren’t a real calendar year.
I’ll go ahead and do the same number analysis as I did then, then branch a bit since I have some more data I didn’t really look at then.
- Total Energy used in 2010: 10,292.23KWH ($476.53)
- Average Energy use per month: 857.69KWH ($39.71)
- Highest energy use day (amount): 2010-12-27 (61.19KWH)
- Highest energy use month (amount): December 2010 (1161.34KWH)
- Lowest energy use day (amount): 2010-08-06 (9.71kWH)
- Lowest energy use month (amount): September 2010 (570.83KWH)
- Mean (average) energy use per day: 28.2KWH (~ $1.31/day)
- Median energy use per day: 22.27KWH
- Mode (most common) energy use per day: 23KWH (had to round this)
- Highest energy use at a given time: 18.85kW (registered on 2010-11-21)
- Lowest Voltage Recorded: 115.5v (registered 2010-11-24)
- Highest Voltage Recorded: 125.9v (registered 2010-10-02)
- Average Voltage: 121.3v
- Number of rows in DB: 523,344
Now, one thing that came up was looking back at the April numbers, the median was WAY off. I recalculated and it’s much more reasonable now.
So, first off, I’ll admit, I’ve done very little since April to further reduce energy consumption in the house. Over 2010, I’ve done a fair amount. In Dec/January (completed the work in January), I replaced my server (which wasn’t too energy inefficient since it was an old Powerbook G4) with a Mac Mini Server, and a Drobo v2. The only other thing I’ve really done is install a SmartStrip SCG3 on the game room TV, PS3, Wii, and Cable Box. Doesn’t save me MUCH energy, but 11W saved adds up over time (.011KWH over 1 year is about 100KWH over the course of a year, or $4.65 at my cost per KWH). So yeah, given what I paid, it’ll take 5 years to make that back, but… every little bit counts. Though, what I JUST figured out is the Wii Remote Inductive Charger uses 20W, even when it’s not charging! No more just leaving it on I guess. =/
Early this year, I plan to replace my garage doors (original to the house, wood, don’t seal at all) with modern insulated steel doors. This should help with energy use a bit more, since the garage is below the bedrooms, and some of the HVAC ducting does run through the garage (though it is insulated). But since the garage is usually about 45-50F even in the winter, there’s obviously some heat being lost from the living spaces into the garage. I’ll be very interested to see if there’s much of an energy usage change once the doors are replaced. Hopefully that’ll happen by the end of February (once I have my tax return).
But, I digress a bit, so back to energy use.
There are a couple things that can be concluded from this chart. First, the Pacific Northwest is temperate. There aren’t a lot of really hot, or really cold days. This last year, we never hit 100°F (we had 9 days of 90°F or greater as a high), and only 19 days of 32°F or less. While the TED is great, it doesn’t let me see how much energy is JUST used by heating/cooling. So I can’t accurately figure out my Heating Degree Days (HDDs) and Cooling Degree Days (CDDs). Assuming over time the base load averages out, I had 4565 HDDs and 200 CDDs (in the US, HDDs and CDDs are calculated based on a 65°F base temperature). There’s more to it than that, but I’m not quite sure how to accurately figure that info out. Maybe I’ll come back to it.
Looking back at the numbers, and what I reported in April, here’s the analysis. I’m missing about 1.5 days of data, or 2,256 minutes, Or about 0.4%. Not too bad, but it’s up from April. My lowest month usage was (September 2010) was about 49% of the usage in the highest month (December 2010).
My voltage averages only 1.3v above 120v, which I’d think is pretty darn good. That’s a little more than 1%. Looking online, typical variance is 3-5%, and most products are designed to handle 10% variance. The highest variance was +5.9v, and -4.5v, which fall within ±5%.
Last but not least, I use 28.2KWH per day, or about $1.31/day. And about 857.69KWH ($39.71) per month, so a little less than $40/month. Considering I have no gas service, so all my HVAC, hot water, cooking, etc come from electricity, that isn’t bad at all. And given where power largely comes from in this part of the country (Hydro-Electric), my general carbon footprint is actually lower using all electricity than it would be if I was using gas.
So, here’s to 2011, and hopefully making further energy improvements. Garage doors are already on the table. I’d love to replace a major appliance (washer/dryer, refrigerator, or dishwasher) but that might require one die, so I’m not hoping for that. We are hoping in the next few years to replace our Aluminum frame windows in the house too, but that’s a fairly serious chunk of cash that will have to wait until some other debt is paid off (like, the HVAC system). All in good time. And I look forward to comparing 2011 energy use to 2010, and how to further reduce my energy usage.
In the next few days, I hope to post again with comparisons of the 2009 energy usage I have (April through December) with the 2010 data. From the general numbers, it looks like I’ve saved additional energy, but since there’s 3 extra months in 2010 that aren’t in my 2009 data, and temperatures are obviously not consistent from year to year (in the short term), I can’t just say “yes, I’m saving energy over last year”.
Stay tuned, and Happy 2011!