Return to the Plumbing Forum | Post a Follow-Up

 o
Electric Hot Water Heater Monthly Kilowatt usage

Posted by mrmichaeljmoore (My Page) on
Tue, Jan 20, 09 at 21:26

I am trying to find out what my monthly Electric Hot Water Heater Kilowatt usage is....

I have a Whirlpool (made by American Water Heater) 50 Gallon water heater.

My electric company says the water heater can cost anywhere from $75-$90 a month.
That sounds really really high to me.

I know it may be tough to give an accurate number because of all the variables.....but if anyone has a ballpark figure that would be great.

Additional info:
Unit is 4 years old
50 Gallon
Temperature is set at approximately 120 degrees
Whirlpool brand (Purchased at Lowes)
Water heater is wrapped with an insulation blanket
Household has 2 adults, 1 2-year-old
No one home during the day
2 showers, 1 bath per day
Most laundry done with cold or warm water
Location: Fairfield, Connecticut

Thanks.
mike


Follow-Up Postings:

 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

why not go to Lowes and look at the yellow sticker on the side of your model--it gives an estimated annual cost. If your model isn't there, find one close to it...it may not be exact but it will be in the ball park.


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

The yellow sticker is as close as you will get unless you install a meter on it


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

Just another note here:

Virtually all electric water heaters are nearly 100% efficient. Some will have a little more insulation than others, but there just isn't a big difference in operating efficiency.

That said, you could have other issues such as high water usage (you should only be running 2.5 gal per minute through the shower head), a poorly performing recirculation system or very expensive electricity.

$75-$90 sounds very expensive to me... that's more than I pay for all of my gas per month (I pay $60 for heat, water heater, dryer and stove in central Indiana).

The Energy Guide for your water heater claims about 4,767 kwh a year for an annual cost of $410 at a cost per kwh of 8.6 cents.


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

The monthly killowatt usage for you water heater depends on how much hot water you draw out of it and the temperature setting. If you set the temp of the water to 120 F instead of 140 F you will have a lower killowatt usage. If you get 1.5 gpm showerheads instead of 2.5 - 5 gpm showerheads you will use less killowatts. If you own a fairly new low water usage washing machine and wash your clothes in cold water, you will use less killowatts.

So the bottom line is conserve your hot water usage and you will save on your electric bill. You have to remember also that uninsulated pipes, recirculating pump that runs all the time, long showers will use more hot water and increase your electric bill.

You must also remember electric hot water heater is probably the most expensive way to heat water.


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

You can figure the cost per hour WHILE it's heating.

Wattage / 1000 X your electric rate per KWH = cost for 1 hour of run-time.

Find the true cost/KWH of your power by dividing the $-amount of your bill by KWH used.
Example: $150.05 / 1246 KWH = $0.1204 per KWH

Example:
4500 watts / 1000 = 4.5 KW consumption per hour
4.5 KWH X $0.1204 / KWH = $0.5418 per hour

Of course, it doesn't heat continuously 24/7, but you can monitor how long it runs to recover from a shower or load of clothes, for example.


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

"You must also remember electric hot water heater is probably the most expensive way to heat water."

Given 100% heating efficiency, and the fact that electric tanks don't have a heat robbing flue like gas heaters, this seems a questionable statement.


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

local rates vary for electricity and for gas. By factors of two or three.

in some places, electric is the cheapest energy.
And also the greenest (hydro electricity).

I'd like to know what "100%" refers to. A hundred Per Cent of ? What?
Physicists will tell you that no process is perfect, no energy transfer is 100% efficient...

-david


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

David,

The "100% efficient" in this case indicates that virtually all of the heat generated by the electricity heats the water. In my post I said nearly 100%... given that no process is 100% efficient. But let's not split hairs here. The point is that electric water heaters, because of their design, don't have a significant difference from model to model in the amount of energy they use to heat the same amount of water. The biggest difference is the insulation jacket and the R value is generally pretty high on new electric heaters.

The question that the OP was hinting at seemed to be if the water heater was defective/energy hog/not efficient. The answer to that question is "No".

The other variables are:
1. the amount of hot water used (such as high flow showers)
2. the cost of electricity
3. The possibility of a malfunctioning/poorly designed recirculating system.

The cost of electricity vs other energy varies by region. In many regions, electricity is significantly more expensive than gas. Even the higher efficiency of electric appliances, electricity can cost considerably more than gas to do the same job. Again, that's not always true and you have to check local prices.

To answer the original question, the yellow sticker gives an approximation of the KWH used.

I looked it up online and The Energy Guide for the water heater claims about 4,767 kwh a year for an annual cost of $410 at a cost per kwh of 8.6 cents (approx $34 a month).

Multiply 4,767 by your cost per KWH (should be on your electric bill) to get an idea of estimated cost to run the heater in your area. This of course will vary based on your actual usage. However, there's nothing that the OP has said about his family/situation that would indicate significantly different hot water use than the government model. (This isn't a family of 8 teens who have a car wash business on the side, for example)

All of that said, $75-90 a month for a family of 3, one of which is 3yo, sounds completely unreasonable.


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

well, i went to flush the heater the other day and pulled back the water heater insulating blanket and found the yellow energy guide stickers on the tank (as someone mentioned above)....

According to tht sticker, my unit uses on average of about 4622 kilowatt hours per year.

In Fairfield County, Connecticut, current electtric prices are about .20 cents per kilowatt hour...

So a little math says 4622 * .20 = $924.40 for the year.
$924.40/12 months = about $77/month for my water heater.
That is almost half of my monthly electric bill. Total bill usually runs around $150-170 or so.

WOW. WOW. WOW.

I had no idea that that unit could really cost that much.

I know the sticker is just an estimate, but I imagine it's got to be at least in the ballpark....and I bet, if anything, it errs on the lower side.

SO.......

I guess I am either gonna consider going to a propane unit or possibly tankless. They have got to be cheaper.
The only thing that stinks is that the current electric unit is only about 4 years old. UGH.

just thought I'd put this update out there....

thanks.
mike


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

Holy Cow... 20 cents a kwh, I think we've found the problem.

Electric tankless will not save you any money. Don't do it.

However, propane may be a reasonable choice. Find out how much a gallon and I can help you figure it out.


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

Right now I am locked in at $4.39/gallon for propane through Suburban Propane. Yeah, I know....that's really high....but that was the market price at the time.
I locked in over last summer when oil/fuel prices were through the roof. Not sure what the market price is for propane now. I should call Suburban tomorrow....

Luckily, I use less than 250 gallons of propane a year. Propane is for the forced air furnace and cooking only. I have a pellet stove that provides the majority of heat.

.20 cents kilowatt hour......welcome to Fairfield County CT. this place is friggin crazy.


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

There was just a thread from a guy who was comparing electricity to propane for space heating.

His costs were:
LP is $2.06 per gallon
ELEC is 10.33 cents per kwh

Now, I understand how electricity could vary from location to location (I can't see 20 cents a kwh) but propane is propane.

What I can tell you from that post is that you would save about 28% over electricity. If you can get your propane costs down, it could make even more sense.

Let me know what you find out about propane costs and I will run the numbers for you.

Here is a link that might be useful: Cost Comparison


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

"Now, I understand how electricity could vary from location to location (I can't see 20 cents a kwh) but propane is propane."

If you include service charges it can easily hit those kind of rates.
Of course it looks better if you use more kW-hr to spread the service charges over, but that costs you even more.

Propane can be very high in some areas if it is not a popular fuel in that location.


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

Last month's electric bill:

29 days in billing cycle
787 Total kilowatts used
Bill: $157.25

157.25/787 = .1998
about 20 cents a kilowatt

I checked with Suburban Propane.
The current price per gallon for propane is $4.19.

boy, energy is expensive in Fairfield CT.


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

Electricity is costing you $5.86 per 100,000 BTU output

Propane would cost you
$4.93@85% efficiency
$4.41@95% efficiency

You would save about 24% using a condensing propane tankless heater.

You are getting totally screwed on energy costs and you should make noise with the regulatory agency. Other people are paying half of what you pay. There's no excuse for that other than nobody is watching.

Since you have an electric heater now, keep it connected and ready to be functional (turn on power and valve) in the event that propane gets ridiculous.


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

"You are getting totally screwed on energy costs and you should make noise with the regulatory agency. Other people are paying half of what you pay. There's no excuse for that other than nobody is watching."

"energy is expensive in Fairfield CT."

That says it all right there.
Location.


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

This is getting way off topic, but the real issue is deregulation. This was another state that bought the whole "deregulate the electric utility" BS and all it did was result in sky high prices -- same with Cal and a handful of other states.


 o
RE: Electric Hot Water Heater Monthly Kilowatt usage

If you are handy... ONLY, THIS IS RISKY. IT IS ELECTRICITY!

You can splice in a regular type alarm clock (with the hands NOT digital) to a leg of the electric after the thermostat or when it leaves the heater.

Start the hands at midnight.

As the HW turns on and off the hand will progress.

This will give you a running TIME that the HW is on > AND USING ELECTRICITY!

Multiply out by your KWH.

NOTE: use only one leg of power NOT BOTH or you will fry the clock (assuming 220/240 not 110/120 volts). If you look at the label OR how many circuit breakers you have, this will tell you how much vlotage and "legs"(power wires - 1 or 2)

tapalmer99b1@aol.com


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Plumbing Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here