Propane or Electric back up?

[GT2]

I'm trying to explore the possibilitys for my wood and solar water, back up power.
2700 sf tight well insulated ranch style home in N Idaho. About 40,000 heat calc. Radiant in floor.
My two choices are propane ( $2.90 gal & rising ) and electric (.064 kwh & stable hydro ).
I have used several on line calculators and unless I have missed something electricity seems to be about 1/2 the cost?
I'm thinking of using a large instant hot water heater as a back up for the radiant.
I relies this will involve a large power supply infrastructure, but the up front cost of the unit is about half the cost of a propane unit.
Another variable is that I can help pay for electricity with solar and wind, I cannot however, make my own propane.
What am I missing?
Thanks, Tim

 

[Transit]

I have a friend in Monroe NY that replaced his oil heat with coal. This winter he used 4 tons at $175/ton. Something to think about.

 

[beenthere]

GT2
Enjoy your super low electric rates and go with that. It wouldn't be the case in the midwest. Don't know what you can do with coal in your neck of the woods.
I backup with propane. Had to use it only over one weekend this winter. So far the wood boiler has handled about the same size home that you have.

 

[AKwelder]

you may want to read the duty cycle on those instant hot water heaters. Not all of them are built the same.

May i ask why you are not looking at heat pumps if your electrical cost are so low.

And i am envious, we pay 32 cents a KWh

 

[robphillips00]

32 cents! Ouch. We pay about 12 here in southwest Texas, it was 8 less than 6 months ago. Lots of talk about another increase.
Propane is about 2.60 per gallon. We have lots of gas production here. You might give a look to summer prices on propane and get a tank large enough to carry you through.

 

[KTurner]

You say this is a backup, but not under what conditions you expect to use it. If this is mitigate some sort of outage, you should make sure your backup is not vulnerable to the same issues as your primary. I.e., if your primary is solar, a single event, such as a large storm, could disrupt both your primary solar and your backup electricity (downed power lines).

Also, storage. Electricity is very difficult/expensive to store, so you're dependent on your electrical provider to keep a constant supply flowing to you and you quickly feel any changes in price. Propane is very easy to store and it stores indefinitely. You could buy a large tank full of propane tomorrow and it'll be there for you years from now, with no recurring costs to keep it on hand. You own it. Doesn't matter if the mideast melts down into total war and the cost of all energy quadruples overnight.

Keith

 

[GT2]

You say this is a backup, but not under what conditions you expect to use it. If this is mitigate some sort of outage, you should make sure your backup is not vulnerable to the same issues as your primary. I.e., if your primary is solar, a single event, such as a large storm, could disrupt both your primary solar and your backup electricity (downed power lines).

Also, storage. Electricity is very difficult/expensive to store, so you're dependent on your electrical provider to keep a constant supply flowing to you and you quickly feel any changes in price. Propane is very easy to store and it stores indefinitely. You could buy a large tank full of propane tomorrow and it'll be there for you years from now, with no recurring costs to keep it on hand. You own it. Doesn't matter if the mideast melts down into total war and the cost of all energy quadruples overnight.

Keith

Good points Keith
"Back up" for me means I'm too lazy to go out and stoke the wood boiler:laughing:, or I,m not home and the wife couldn't be bothered. Also could be a bunch of cloudy days, so no help from the solar hot water.
I know electric/storage is expensive. That is not what I intend, other than short term. After that it would be gen power.
Point taken on the propane, however if the ME does melt and costs quad; as soon as that tank is empty it will mater!! ( applies to gen power too!).
Tim

 

[jinjimbob]

Use an electric heat pump water heater, it uses less than 1000W when running, mine runs fine on a generator.
You can put one inline with your solar heater.

 

[GT2]

you may want to read the duty cycle on those instant hot water heaters. Not all of them are built the same.

May i ask why you are not looking at heat pumps if your electrical cost are so low.

And i am envious, we pay 32 cents a KWh

AK, I'm not super informed on heat pumps. From what little I know I have been turned off by the complexity and the costs of such systems.
Tim

 

[JimRB]

You can see water heat pumps at Lowes, Home Depot or whatever big box retailer is in you area. Not to be smart but does a refridgerator or deep freezer turn you off due to the complexity? A house geothermal heat pump or a hot water heat pump is doing the same thing your fridge or freezer does. My geothermal has been serviced once in 13 years because the coil rusted out. My neighbors have replaced their heating systems at a similar age but I hope to get 30 years out of my system.