In November, my energy bill was $68
In December, $115
My electricity bill was $52 in November and $98 in December.
I keep my heat off, and have a small fan-forced heater in my bedroom.
What I’ve learned: When it’s friggin’ cold, that heater runs a lot. It also costs about $45 more for a 15 degree difference.
Some considerations I’ve made for this year, then:
- Put the heater and the window AC unit on a power strip. Switch the power strip off when I leave during the day; switch the power strip for the heater off at night when cold. Blankets work great in the winter (I’ve tried), and both units are digital and thus draw annoying (small) amounts of power to run small computers. I can live for 5 minutes when I get home without heat or AC; can’t sleep in a hot room, so I’ll run the AC at night.
- Consider shutting down the computer at night. This is annoying, but “Standby” mode uses less than 5 watts. That and the fan-force heater both contribute a lot of noise at night; the quiet is better.
Seriously, my power bill could hit about $30 or less if I knocked out the 250 watt computer and the 800 watt heater and the 1000 watt AC for about 10-20 hours a day. As it stands, there’s about 1050-1250 watts in use that don’t need to be in use.
Since the heater and computer will run for about 5 hours in the winter, that’s 1050 * 19 * 30 == 585000 == 585kWh potentially saved, although the heater runs about 30% of the time and thus it’s more like 490 * 19 * 30 == 279kWh, which actually makes sense. For reference, with the computer and heater running 24 hours a day, November’s power usage was 348kWh and December’s was 691kWh; the only change was the outside temperature, so the extra run time for the heater accounted for 343kWh (of a possible 576kWh for continuous running of the device, meaning it was using under 233kWh in November and thus running under 40% of the time). Thus, I can reduce my power usage by roughly 80% in the winter (other stuff used 115kWh).
Let’s take some stats for this.
Minus computer, AC, and heating, my base power usage is 115kWh.
24 hour heating and computer uptime accounts for roughly 233kWh. Heating in the cold month alone pushed up 343kWh; 100% heater utilization is 576kWh.
24 hour peak power computer uptime (250 watt PSU) would account for 180kWh; my computer probably actually draws 30 watts normally, around 21kWh.
The summer is more difficult. The air conditioner (9 amp * 110 V = 990W ~= 1kW) must run for 14 hours a day (5pm-7am) but the computer only 4 hours a day (5pm-10pm). Thus my summer savings would come to ((1000 * 7) + (250 * 19)) * 30 == 352kWh. In July I used 626kWh of electricity; not even yet as much as the heater, but close. Then again, I’m trying to bring down from 90-95 to around 78, about 12-17 degrees; not up from 30 to 78, around 48 degrees, so the AC has less work to do. The AC is bad at it.
The best I can do here is guess. If I guess 21kWh for the PC and 115kWh base, that’s 136kWh and the AC did 490kWh! If so, cutting that back by about a third would land me at 323kWh, plus the 136, giving 459kWh total in July.
So lessons learned:
- Heating is expensive.
- Air conditioning is more expensive.
- Leaving your computer on is not expensive.
Now think about those programmable thermostats. A few degrees warmer around midnight, when you’re likely asleep… a few degrees cooler around 5am, because you’ll wake up around 6… not much of a difference really, but shifting from 75 to 85 and then back will do wonders. The same in winter, shutting the heat completely off at night and between 10am and 5pm. Consider when you have a whole house to heat, too…
Here’s to the coming summer!
