So it is now 90 to 110? Have there been no other changes in use? electric hot water, stove or dryer?
J

I can say from experience that apparently little changes have significant effect...such as a 9 year old who turns 10 and for whatever reason starts taking 20 minute showers.

If owing to the tight economy you cut back on meals out, bear in mind that cooking at home might add a buck or two per day in range and AC costs (far less than even one restaurant tab)

You need a kWH meter and they are not very expensive. I use meters from EKM Metering (ekmmetering.com) and they are easy to install without changing any wiring. Just slip the current transformers over the wires to the unit and give it power. They also can report readings to a excel spreadsheet through the LAN which is what I do and it works good.

The problem is that if you're guessing you're probably off because I tried last year to guess at mine and because of the 2 stage heat I was off. I use much more electricity in the house than I should but after putting meters on large loads and using a Killawatt meter I have a good handle on where the energy is going.

I also put a data logger on the ground loop and it is a good idea because you can see the health of your system and calculate the heat generated with the information. I used a HOBO 4 channel logger.

When my system was being installed and wasn't finished it was turned on and with it running while the house was being finished last November and December we found that the loop temperatures were too low. It was determined that the unit would not heat the house so we had a third bore hole drilled. We had 2 300 ft bore holes for a 4 ton system and we drilled a third 300 ft hole. Now a year later our loop temperatures are good and we have plenty of heat. We use now about 25-30 kWH per day for a day like today which is an average temperature outside of 35 f to heat 4,800 sq-ft.

You need data.

John

I have the same kid, 10 in January. Give him a bottle of shampoo and a warm shower and hours later no more shampoo or hot water.

I have the answer but it has costs that may or may not have actually been justified but it was fun. I now have three water heaters. First one is heated by the GTHP, second is heated by Solar and the third is a GE heat pump hot water heater. I'm down to 20 cents a day even with my out of control 9 year old.

Stock up on travel sized shampoo, you'll save a fortune! Perhaps you could install a hot water shutoff at the heater, wait till he gets in the shower, run downstairs and turn it off after 1 minute. Do it enough times and he'll be a clean kid in record time.

I spent a couple summers at camp running a riflery program and a cabin of 10 kids. We had a gas water heater that would run the shower about 20 minutes. Each kid got 90 seconds and then 30 more after a spoken warning. At 121 seconds I would close the HW valve, reducing the shower temp from 100+ to the local artesian well temperature of 55. Out came the kid, in went the next kid.

An hour after the kids sacked out I'd take a proper shower after the tank recovered.

Navy vets might recognize the foregoing as "Navy" vs "Hollywood" showers.

Are you suggesting that young men use more shampoo than young women sporting waist length hair?
My wife still doesn't get it.......
j

Jongig,

How do you like the GE HPWH? Is it annoyingly noisy?

Of the two new ones that hit the market this fall, I prefer the GE's design not requiring a water pump, and it shows in a significantly higher EF rating than the Rheem. It is bested, and not by much, by the Steibel Eltron 80 gal unit, which is twice as expensive.

I have a Geyser external HPWH, and it works well. The install is a bit of a kluge, but it has the advantage of being able to be mated to just about any size tank, and in the event of a tank leak one can toss the offending tank and replace it at much lower cost.

She is assuming the shampoo is being used for hair

....it's not?!

I do like it. I've had it for about a month now and it was purchased also as a dehumidifier. I had looked at the Geyser and had plans to purchase it this winter when the GE showed up in a note from our electric company. I couldn't resist as it was $1,450 installed with a $300 rebate plus the Fed tax rebate.

My only complaint would be that it is noisy as it sits next to a 4 ton climatemaster GTHP and it's louder than the Climatemaster. It's not a problem since the area is my workshop. The fan has multiple stages and for our install it doesn't come on at full speed most of the time.

I'm down to 2 kWH per day for DHW and I'm pretty happy with that number. SInce I'm solar and Geothermal I've covered multiple bases and the water temperature going into the GE is usually 100 f or even higher.

John

Update for December 2009 bill (November usage)

Average temperature = 49 degrees
Average Electric usage per day = 18 KWH
Our total usage = 628 KWH (based on our bill)