Utilities Reduction Project Part I: Electricity

[Shawn Clark]

Now that summer is completely behind us, and I've been forced to turn on the heat for the freeze tonight and stowed the deck furniture in the shed, it is a good time to reassess/project my annual electrical consumption (as well as water and gas...but those will come later.)

I've not worried about electrical use that much until this past year. My electrical consumption reflected that while living down South in smaller homes. I was running 15,000-16,000 kWh/year for a family of four over much of the past decade. Even with Houston summers that's high. I did begin making some major CFL conversion when living in Houston and continued in Georgia before moving here to the Midwest. How much impact did this have? Well, I had gas water heating in Texas, but electric water heating in Georgia...yet after a reasonably thorough CFL convsersion my electric consumption was unchanged in Georgia. The electric water heating should have added 4,000 kwh/year or more. So while I didn't really note it at the time, I had made a signficant first step in reducing electrical power use.

I'm living in the Midwest now, with about 5,200 heating degree days/year and around 1,300 cooling degree days/yr. A few months after buying this home I realized that the utilities were running greater than I anticipated. I researched the previous owner's use and found to my horror that the two of them were consuming ~24,000 kwh/yr of electric. This and the purchase of a Prius and observation of the very low usage of some Priuschat members lit a fire under me to see what I could do to become more energy efficient without sacrificing comfort or doing anything really radical. I started with electricity, but progressed to natural gas and water/sewer as part of the effort.

There have been many aspects to the project: early on I focused on CFL's, then major appliance updrades (my appliances were aged...starter stuff from 15-18 years before), and better window shade/window opening/thermostat control. Additionally I did a fair bit of insulating, duct balancing, duct sealing, and window sealing. By Spring most of it was in place and my electric consumption was in the 450 kwh/month range.

We had an abnormally mild summer and by my estimates I used only 1,275 kwh for AC vs. up to 4,500 kwh budgeted. This yields a present estimate of ~7,000 kwh/year total. That's about 1,000 kwh/yr below my stretch goal of 8,000, but I have to credit much of that difference to a mild summer. I'm probably down about 5,000 kwh/year even after electric water heating is factored out. Without accounting for water heating I'm down by over 50% compared to my long term running average. Compared to the previous owners I'm down over 70%.

I started doing CFL conversion as soon as I moved in. By March of this year my major projects were complete with replacement/modification of most of the home's light fixtures. Total lighting savings are projected as around 2,000 kwh/year.

A major improvement came from a new refrigerator, front loading washer, and moisture sensing dryer in February. Together these are worth about 1,200 kwh/year.

The other major impact has come from slaying vampire loads. I've cut about 650 kwh/year by unplugging transformers and powerstripping various components.

Harder to quantify effects have been duct sealing, duct insulating, wall insulation, improved manual zone control, better shade/window opening strategy.

There is more to do and hopefully various items will compensate for warmer summers in the future. My PC's are energy hogs as are my old AC and air handler.

p.s. I still dry my clothes with the dryer and don't intend to stop. My newer washer and dryer greatly cut the energy consumption of drying clothes.

[fuzzy1]

Yikes, you've set a high bar that I will be very hard pressed to match.

My efforts three years ago reduced my home's usage from 10,600 kwh/year down to 9200, in an all-electric home with two people. This came from updated front loader washer, dishwasher, gap sealing of ceiling electrical fixtures, and some other small changes. The CFL transition began more than a decade earlier, but most of the lesser used lights were changed at this time. I'm hoping that another change at the tail end of last heating season, the installation of a single zone mini-split heat pump in the main living area, will knock total energy down to the 7000 - 7500 kwh/year range.

Heating degree days were 4400-4500 in the several years before these changes, 4800 and 4970 since. Cooling? What is that? :-)

The next targets are a new refrigerator (~400 kwh by itself, 800 if it is big enough to retire the separate chest freezer) and floor and ceiling insulation improvements. Replacement windows have been looked at, but at current prices the payback is longer than my life expectancy -- at birth! Solar and on-demand water heating are also overpriced at this time.

Water consumption was a bigger success. The new appliances above, a pair of low flow toilets, and two rain barrels (which are more valuable for conservation mind share than actual water collection) cut our water usage almost in half. Average use was 66 ccf/year before, 35 now.

[DaveinOlyWA]

8000 for a family of 4 in a decent sized house would be very impressive. i did 8200 KWH last year with 3 charging an EV, but we have gas heat and hot water. plus, we have very mild summers (this past summer not included!!) and mild winters. our house is pretty small only 1400 sq feet.

[cwerdna]

Do you have a Kill-A-Watt? If not, it helps a lot with identifying thing that you should really turn off when not in use (more than others) or unplug/put on a power strip, if they have high standby power consumption.

[fuzzy1]

Originally Posted by DaveinOlyWA

... i did 8200 KWH last year with 3 charging an EV...

Do you have an estimate of how much of that was the EV, vs. rest of house? My house is the same size, and I can crudely estimate my electric heat and hot water, but cannot compare with your EV mixed in.

BTW, finally saw a Zenn while walking in West Seattle today.

[Shawn Clark]

Originally Posted by fuzzy1

Yikes, you've set a high bar that I will be very hard pressed to match.

My efforts three years ago reduced my home's usage from 10,600 kwh/year down to 9200, in an all-electric home with two people.

Actually, in an all electric home that beats my present numbers hands down when looking at the big picture. You are probably using 2,000 kwh/year or so for water heating for two of you. But the real difference is that you are doing this with an electric heat pump while I'm heating with gas.

[fuzzy1]

Originally Posted by Shawn Clark

Actually, in an all electric home that beats my present numbers hands down when looking at the big picture. You are probably using 2,000 kwh/year or so for water heating for two of you. But the real difference is that you are doing this with an electric heat pump while I'm heating with gas.

OK, your total doesn't seem so difficult now. But with a pair of young-uns in the house, you have additional restrictions that I don't. And for percentage reduction from past usage, you are far ahead.

My numbers so far are for pure electric resistance heat, with a rare wood supplement. Most of the time I want to fire up the wood stove, the Puget Sound Clean Air Authority imposes a burn ban. The heat pump was added in late March, as the heating season was winding down, so this coming winter will be its first 'real' use.

Best guess is that my electric resistance heat has typically run 4000 kwh/year, and hot water a bit under 2000 kwh/year. We have run a cold house for decades, and my aging body is saying that it is time to run it warmer. The heat pump appeared to be the best way to do that without adding to our energy footprint.

[DaveinOlyWA]

Originally Posted by fuzzy1

Do you have an estimate of how much of that was the EV, vs. rest of house? My house is the same size, and I can crudely estimate my electric heat and hot water, but cannot compare with your EV mixed in.

BTW, finally saw a Zenn while walking in West Seattle today.

since Nov 2007 i have used 1938 KWH. so in a nutshell, i say, not very much and for the past year i have been plugging in at work so its been even less. i have used 650 KWH in the past 12 months.