dslreports logo
site
 
    All Forums Hot Topics Gallery
spc

spacer




how-to block ads


Search Topic:
uniqs
4010
share rss forum feed


Rod580sl

@bell.ca

Comparing Cost of Propane and electicity heating?

Does any one know of a better scientific way to compare cost of propane heat to cost of electrick heat?

This could be a little foggy and depends on furnace efficiency, insullation, etc. however I read a web post that indicated one gallon of propane generates equivalent energy to 27 kw of hydro. (Not sure wher 27 comes from)
So, to compare cost of hydro heating to propane one should calcluate for example how many kw used in a month, divide that by 27 which yields an equivalent number of gallons of propane - the cost of which can easily be calclulated by multiplying bythe cost of a gallon of propane.

Does this make sense? I am contemplating a new country home with limited capital funds and am trying to decision between Hydro heating and propane.

Thanks for any help



FiReSTaRT
Premium
join:2010-02-26
Canada

What kinda hydro? Resistive heating will be a buttrape, heat pump won't cut it in Canadian winters unless you go with geoexchange, but that will involve a lot of startup capital.


telco_mtl

join:2012-01-06
reply to Rod580sl

what part of canada, it all depends on how much you pay for electricity.



PSWired

join:2006-03-26
Annapolis, MD

1 recommendation

reply to Rod580sl

First, you need to know the efficiency of the propane furnace used for comparison. 80% on the low range, 95+% on the high range. This tells you how much of the propane heat content goes into your house and how much goes out the exhaust.

Insulation, thermostat setting, etc. don't matter for this comparison since they're constant between the heating fuels.

Assume you're comparing to electric resistance heating. This will be different than heat pump heating.

1 kilowatt-hour (kWh) is equal to 3412 BTU. Divide your cost per kWh for electricity (from your bill) by 3412 to figure out how much you pay for a BTU of room heat via electric resistance heating.

To find the cost per BTU for propane, multiply the number of BTUs in a gallon of propane (91,330) by the efficiency of the furnace. The result is the number of BTUs going toward heating your house per gallon of propane. Divide the cost per gallon of propane by this number to get the cost per BTU of room heat.



Rod580sl

@bell.ca

-In Sudbury northern Ontario, cost of a gallon of propane is $3.15
-On new construction assume maximum efficiency propane furnace acquired
-TOU in place but for illustration purposes assume cost of Hydro is .09/kwh

With these variables can you compute to arrive at comparison/BTU?



SparkChaser
Premium
join:2000-06-06
Downingtown, PA
kudos:3
Reviews:
·Verizon FiOS

1 edit

Your 27 is 27 X 3412 = 92124 BTU @ .09 = $2.43 electric

I gal =91330 @ $3.15

Now throw your efficiencies in there and guess what's going to go higher in the future. I'm guessing propane will climb faster if your hydro is really from hydro.
--
"Facts do not cease to exist because they are ignored." - Aldous Huxley

"When a true genius appears in the world, you may know him by this sign, that the dunces are all in confederacy against him." Jonathan Swift


pandora
Premium
join:2001-06-01
Outland
kudos:2
Reviews:
·ooma
·Google Voice
·Comcast
·Future Nine Corp..
reply to Rod580sl

Propane has 91,000 BTU per gallon +-, efficiency of a propane furnace is usually 90% or higher. Using 90% (which may be low), I get about 82,200 BTU per gallon. Propane number taken from - »www.flameengineering.com/Propane_Info.html converting 82,200 BTU to tons (dividing btu by 12,000 which is a ton) gives about 6.8 tons, if you are a bit over 90% at the furnace it's about 7 tons per gallon of propane.

A ton of electric heat is about 3.5 KWh. 7 tons of electric heat (to match a gallon of propane) would be 24.5 KWh.

In my area, propane costs $2.05 per gallon, and electricity costs .17 cents per KWh. An equivalent BTU of electricity to a gallon of propane would cost me about $4.17.

For me, resistive electric costs about double propane. Note, propane and electric prices vary considerably from area to area. You'll need to plug your numbers in yourself.

It costs $169 to install a 20KW electric heat capability in my air handler, plus several hundred for the 100 amp line. A 1,000 gallon propane tank costs $2,300.

The capital investment for propane vs resistive heat is generally higher. How much, varies by your area.

As a rule of thumb, assume a gallon of propane is about 7 tons, the same quantity of resistive electric heat requires a bit under 25 KWh. 1 gallon of propane vs 25 KWh of electricity. See which costs more.

I hope this was helpful.
--
Congress could mess up a one piece jigsaw puzzle.



Rod580sl

@bell.ca
reply to SparkChaser

Fascinating. No one at hydro or gas companies could/would provide this simple analysis.

To summarize my understanding:

-I how have NG and cost per CM delivery, storage all in is $.49/CM one CM producing 36,000 BTU.
-Propane here is at 3.15/Gal that produces 91,330 BTU
-Electric FA cost is .09 to max (at present of .11/Kwh)

On new build I cannot get NG and so was contemplating propane but clearly hydro is the unexpected better alternative.

-91,330 BTU of propane $3.15 (before factoring 100% efficiency)
-91,330 BTU of hydro (91330/3412 = 26.77 x .09) $2.41
Using current max TOU of .11 = $2.94 worse case at present
-91,330 BTU of NG gas (91330/36000 = 2.54 x .49) $1.26

Thanks



SparkChaser
Premium
join:2000-06-06
Downingtown, PA
kudos:3
reply to Rod580sl

Yes, for you electric looks better.


lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1
reply to Rod580sl

said by Rod580sl :

On new build I cannot get NG and so was contemplating propane but clearly hydro is the unexpected better alternative.

I live in a somewhat drafty suburban Ottawa home with an old and inefficient natural gas furnace. My Enbridge bill for January, coldest month this winter, was $176 which included gas for our inefficient water heater. I did some calculations, and even I could have lowered heating cost by using electricity during off-peak periods.

I have to replace both the gas furnace and the gas water heater later this year. I plan to install a second electric water heater which will turn on very early morning and also all weekend which are off-peak for us. I will also install a few small (300W-600W) infrared and convection heaters and small circulation fans for the family room, bedrooms and bathrooms.

Hopefully the more efficient gas furnace, more efficient gas water heater, and the complementary electric heating will lower our total bill by at least 25% each month.

agtle

join:2013-03-09
reply to Rod580sl

Are you certain about that $.09/kw/h? That sounds like an average of the regulated TOU supply rate; are you including delivery charges in there?

Where I am, delivery is around $.06/kw/h. And don't forget the DRC, which is I think about 2 cents/kw/h on top of that. 0.17/kw/h is my average, in Southern Ontario.



Cho Baka
Premium,MVM
join:2000-11-23
there
kudos:2
Reviews:
·TekSavvy DSL

said by agtle:

Are you certain about that $.09/kw/h? That sounds like an average of the regulated TOU supply rate; are you including delivery charges in there?

Where I am, delivery is around $.06/kw/h. And don't forget the DRC, which is I think about 2 cents/kw/h on top of that. 0.17/kw/h is my average, in Southern Ontario.

I'll second this.
--
The talented hawk speaks French.


cowboyro
Premium
join:2000-10-11
Shelton, CT
reply to pandora

said by pandora:

As a rule of thumb, assume a gallon of propane is about 7 tons, the same quantity of resistive electric heat requires a bit under 25 KWh.

TONS express the heat transfer capacity PER HOUR. As such, you cannot say that it's the equivalent of 25kWh, but the equivalent of 25kW.
You cannot compare power to energy...


LazMan
Premium
join:2003-03-26
canada

1 edit
reply to Cho Baka

I'll x3...

My TOU rate averages about the same as the OP... I'm served by (likely) the same utility (Hydro One) as he would be, if he's outside the service area of the municipal PUC... My effective rate is about double the 'electricity' cost, by the time transmission losses, account and customer fees, and other charges and fees are worked in.

Electric heat is the most efficient; but rarely the cheapest...

EDIT - To add real-world #'s...

I just pulled up my Jan '13 bill from Hydro One:

1101 kWh used... But they charge for 1202 ("corrected" for line losses...)

1202 kWh = 91.57 for the electricity... BUT

Add $87.81 for delivery, 7.82 for regulatory charges, 7.71 for debt retirement (don't ask... The "old" provincial utility up here managed to rack up mountains of debt, that we're still paying off)...

So before tax, that 1101 kWh cost $194.91, or an effective rate of 17.7 cents/kWh...

Now, we apply THAT # to the math you did...

91,330 BTU of Propane - $3.15
91,330 BTU of Electric - $2.41$4.74

Propane starts to look a lot better, doesn't it?



PSWired

join:2006-03-26
Annapolis, MD
reply to cowboyro

said by cowboyro:

said by pandora:

As a rule of thumb, assume a gallon of propane is about 7 tons, the same quantity of resistive electric heat requires a bit under 25 KWh.

TONS express the heat transfer capacity PER HOUR. As such, you cannot say that it's the equivalent of 25kWh, but the equivalent of 25kW.
You cannot compare power to energy...

Yeah, the units in this thread are all messed up.

POWER (btu/hr, kW, tons of refrigeration, etc.) units express the *rate* of energy delivery. Multiply by time to get the energy consumed.

ENERGY (btu, kWh, therms, etc.) units indicate the total amount of work that can be done, total amount of thermal change, etc. Divide by time to get power.

A particularly egregious error that I see on the forum regularly is using the "unit" kW/hr. A kilowatt is a unit of power. Dividing it by time creates a meaningless quantity. Most times this is used, the writer means kWh, or kilowatt-hour, which is a unit of energy--the amount of energy equivalent to a kilowatt consumed or produced over a one-hour period.

Oh, and while I'm on my pedantic rant, the ton is an especially confusing unit since it was originally derived from the thermal *energy* absorbed by a one ton block of ice. The unit today is used as a power unit corresponding to the refrigeration capacity needed to replace one ton of ice delivery per day.


cdru
Go Colts
Premium,MVM
join:2003-05-14
Fort Wayne, IN
kudos:7
reply to Rod580sl

said by Rod580sl :

On new build I cannot get NG and so was contemplating propane but clearly hydro is the unexpected better alternative.

-91,330 BTU of propane $3.15 (before factoring 100% efficiency)
-91,330 BTU of hydro (91330/3412 = 26.77 x .09) $2.41
Using current max TOU of .11 = $2.94 worse case at present
-91,330 BTU of NG gas (91330/36000 = 2.54 x .49) $1.26

If your budget allows, geoexchange (aka geothermal) could cut your electrical usage to 20% of that. Air sourced heat pumps may not be all that well suited depending on your exact location, but a typical geothermal heat pump should be able to have a COP of around 5, meaning for every $1 you put in, you get the equivalent of $5 resistance heat back.

Installation costs are significantly more than a conventional system although since its new construction it a little cheaper than a retrofit. It just depends on your usage as to how long your payback period is.