Electricity usage breakdown by appliance
 

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My monthly usage in KWh is posted above. In the absence of use of A/C, furnace, or grid charging my car, I'm using 84-110KWh/mo. Btw, my bill ranges from $26-$36, which includes the $16/mo service charge.

In the interest of figuring out where I spend the ~100KWh/mo I use, I created a quick and dirty spreadsheet based on KaW readings. It breaks down the measurable electricity consumers in my house and how many KWh each uses in a month.

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Column A is total KWh for a 30.5 day month. I populate either column C for items where I measured Watts, or D and E for items where I measured KWh. You can see the formula for cell A15 in the formula bar. Column C is also very close to $/yr @ $0.12/KWh.

Excluding charging my car, I was able to account for 68KWh/mo, which is about two thirds of my usage. The rest of it must be mostly power tools and cooking.

Illumination: I figured four bulb-hours a day, times 13W per bulb. YMMV, but illumination really is a tiny contributor to my electric usage. If I want to make a dent in my electric consumption, I need to look elsewhere. The fridge seems like the easiest target, as it uses about a third of my electricity. Powering down my PC and internet when it's not in use would save another third, but I'm not going to do that.

I have a natural gas clothes dryer and hot water heater, so the total energy consumption of the dishwasher, laundry, and showers are not fully captured here.

Very nice break down. I can see why you'd want to go after the fridge!

Why no A/C on the list?

A/C season ended before I took the measurements this week and last.

I cool just my bedroom with a window A/C, and I set it on the floor in front of the window during cool weeks, when a fan in the window is plenty. It shows up in my Jun-Sep billings, which also coincides with the start of my car's grid charging, which was occasional at first, and is almost daily now.

Edit: having read a few other threads regarding other people's electricity consumption, it looks like I'm doing really, really well.

I'd like to see a similar breakdown for someone who uses 400+ KWh/mo. Where could it possibly go?

Yes, you are doing really, really well. After a 1.5 yrs of effort to reduce my family's electrical consumption, we're down to 180KWh per month for a family of 4. There is really nothing left except our 12 year old fridge (it uses around 50KWh/mo). A new energy star fridge could reduce our total by 20KWh per month or so. Other than that, my usage is stuck where it is.

Excellent. I wish I could what you're doing. Unfortunately, it's not going to be possible for me as I have central air and my wife would not like to have the A/C running in only one room of the house. A/C is my major consumer - 3.5 ton, 13 SEER unit (about 4.5 KW) that runs more than 1/2 the time during the summer. Second is probably the water heater (the house is all electric due to no gas availability here unless you have propane trucked in). I'm thinking about installing one of the new hydbrid heatpump water heaters. My total consumption is about 3000 KWh/mo.

3000KWh/mo?

= - O

That's $4300/yr for electricity! I wonder how much of that is for A/C. I hope your white roof and maybe other improvements knock at least a few hundred dollars off your electric bills.



Nice work, Knowbodies. On a per capita basis, you're ahead of me, despite your more challenging climate. I think I am likewise pretty close to stuck, myself. Though there's some room for improvement in my natural gas usage.

Well it's not quite that much. My usage is lower in Fall, Winter and Spring. And energy is about $0.10 a KWh here. I was going to have a 5 KW PV system installed, but it didn't pencil out even with the state rebates. Oh well, maybe when PV prices drop a lot (hopefully in the near future).

I'd like to do a similar per-appliance breakdown of my natural gas usage so I know where to try to conserve. I'll measure the dryer and oven next time I use them, but I have a feeling almost all of my gas is used for hot water, plus a big bump in the winter for the furnace.

I would love a DIY hybrid solar thermal hot water tank, and I'd also like to cancel my service with the gas company eventually. My goal is to use so little gas that it's not worth the $150/yr hookup fee or the $192/yr minimum billing. It's not going to happen any time soon, because I don't fancy replacing four of my major appliances just to save $150/yr. But IF I had solar hot water and all four gas appliances failed at the same time, or if I were doing new construction, I'd go for it.

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Another dense spreadsheet. Column E is the monthly service charge / hookup fee for each utility, and column D is the cost of energy + delivery.

Cell F3 is a lie. That's what my electric consumption's CO2 footprint would be on grid average electricity, but my utility offers a 100% renewable plan, so cell F3 should hold some value close to zero.

I find columns G&H very interesting. The CO2/MJ figures include petrol refining and electric transmission. The fact that petrol is so much more expensive than natural gas speaks to the relative scarcity of and lack of substitutes for the former.

A heat pump would need a CoP of 3.2 to match the energy cost of a 95% efficient natural gas furnace, or 3.1 to match the CO2 output. Hmm. Natural gas is good stuff.

At least in winter, you could consider doing something like this to reduce fridge power consumption. I've always loved this idea.

Resurrecting the California Cooler