Generator for all electric home

Status
Not open for further replies.
Joined
Mar 21, 2004
Messages
29,553
Location
Near the beach in Delaware
The home in DE I have bought has two heat pumps each with electric backup. Prior homes in the Northeast were oil hot water. So this is a change. There is a 750 gallon buried propane tank used mainly for domestic hot water and two fireplaces.

One of the heating systems circuit breaker was 65 amps. I could see needing 100 amps just for heat. Then there is a well pump and refrig & freezer.

No basement so garage will be crowed with wife's car and workshop.

I am thinking I need 35kw to 40kw.

One idea is to get a diesel generator on a trailer and rent a storage space for it. Then how do you easily connect a portable 40kw generator to your home?
 
Big cord into a utility disconnect so you don't charge the rest of neighborhood. Farmers around here do it all the time to keep confinement operations going.
 
If you have a LP tank , consider an LP powered generator . Even if you have to add another LP tank .

Are you thinking of powering the whole house of just enough to " rude out a storm " ?

Easy to connect such a generator to your home . But doing it cheaply , safely & with in code is another matter .

Also , quickly and easily if power goes out at night in a pounding storm ( it most likely will ) .

Automatic transfer switches are easily obtainable , but not cheap .

Will you have the discipline to maintain it and exercise it once or twice a month ? If you go LP , at least you will not have to worry about fuel storage and fuel degrading with time .

You probably will not be able to DIY this . You may need some professional assistance , at least some where along the way .

Best of luck & stay safe , :)
 
Well riding out the storm will probably mean powering the first floor heat pump and it's electric booster coils if it's less than 30F.

I can forget the 2nd floor one as there are only guest bedroom on 2nd floor. Kids are gone.

But just that one heat pump system will require a large generator. And well pump, septic air pump and refrig/freezer.

That's the minimum to "rude" out the storm.

Clearly propane is an option. My tank should be large enough. HOA rules no above ground fuel tanks.

This is thinking in progress. I will bring my 8kw propane generator when I move.
 
Interesting to hear of an electric heat house in Delaware.

The cost of propane must be out of sight if they went that route over propane.

I would assume that natural gas is not an option if you are setup for propane?

I had an apartment in Central Texas that was all electric and the heat bill was insane. Mind you its not cold down here for long.
 
PP&L in southeast PA pushed all electric houses back in the 60's and 70's so there are many, many thousands in their service area. I know; I had one when I lived in Lancaster and had a heat pump installed to cut my bills.
 
Originally Posted By: andyd
Wabbout a wood or pellet stove as back up heat?


Very good idea .

Since you have a LP tank , Install one or more LP fired heaters / furnaces .

That would help reduce the size needed for the generator .

Wyr
God bless
 
How cold does it get there? The draw of the heat pumps should not be too scary, but the electric backup is. You may be better off adding some sort of alternative heat, rather than trying to power the entire heating system with a generator.

My dad just had a 22kw Generac installed, which was sized to run his entire house, including three heat pump air conditioners...however, his heat is provided by an oil boiler.
 
Originally Posted By: JustinH
Interesting to hear of an electric heat house in Delaware.

The cost of propane must be out of sight if they went that route over propane.

I would assume that natural gas is not an option if you are setup for propane?

I had an apartment in Central Texas that was all electric and the heat bill was insane. Mind you its not cold down here for long.


All except the very coldest days the heat pump will provide the heat, not electric coils.
 
What is the LRA (Locked Rotor Amperage) rating on the nameplate of the heat pump you want to run? This is the momentary inrush current needed to start the compressor. The RLA (Running Load Amperage) should also be listed on the nameplate, and it will be a small fraction of the LRA. Don't be surprised if the LRA exceeds the capacity of the breaker that protects the unit because we are talking about a momentary load.

When starting an inductive load, such as the compressor on a heat pump, the voltage will drop momentarily which results in more amperage at the same level of power output from your generator. I've read that covering 70% of your LRA load is considered acceptable for commercial applications, and that homeowners might be able to push that figure closer to 50%.

The bottom line here is that you are going to need to perform a load calculation, and that inductive loads like heat pumps cannot be treated the same way as resistive loads like a water heater or electric range. Installing a large, stationary generator is not normally a DIY project, so have some pros help you with this.
 
If you have money to burn fine. But what is the liklihood of loosing electricity for more than a few days. You should make an assessment of what level of comfort you expect for what period of time.

I am most concerned with winter and loss of electricity. So I have a propane heater with a 500 gal propane tank. I just want to stay warm and have some lioghts at night. Thats why I opted for a small 1800 wat generator. I keep enough food in the house for say a month (at least). If it gets much worse than that, you better get out your guns.

If you expect a generator to run for your survival..its probably a bad plan. Things can and do break down. Best to keep it simple.
 
Pellet stove still needs some electricity. If you have a gas fireplace already the install of a high efficiency fireplace with a blower would probably produce 30-40k btu with a electrical need of less than 250 watts. That would keep a floor of a modest home from freezing and the immediate room cozy and probably very economical over electric using zone heat unless propane is crazy high. I have a freestanding fireplace stove that does not require electricity at all for here in the country but does have a fan for higher efficiency.
 
Originally Posted By: Astro_Guy
What is the LRA (Locked Rotor Amperage) rating on the nameplate of the heat pump you want to run? This is the momentary inrush current needed to start the compressor. The RLA (Running Load Amperage) should also be listed on the nameplate, and it will be a small fraction of the LRA. Don't be surprised if the LRA exceeds the capacity of the breaker that protects the unit because we are talking about a momentary load.

When starting an inductive load, such as the compressor on a heat pump, the voltage will drop momentarily which results in more amperage at the same level of power output from your generator. I've read that covering 70% of your LRA load is considered acceptable for commercial applications, and that homeowners might be able to push that figure closer to 50%.

The bottom line here is that you are going to need to perform a load calculation, and that inductive loads like heat pumps cannot be treated the same way as resistive loads like a water heater or electric range. Installing a large, stationary generator is not normally a DIY project, so have some pros help you with this.


I understand the load concerns of starting an electric motor. But my real concern is when the electric booster coils kick in. It's all integrated and I am not sure there is any control of when it kicks in the booster coils.
 
Propane gas is heavier than air, and if you ever get a propane leak it will accumulate in low areas usually leading up to an explosion. There are detectors with alarms you can buy but they are not cheap.

Some type of propane furnace would make a lot of sense and go a long way in reducing the size of the generator you would need.
 
Originally Posted By: Astro_Guy
What is the LRA (Locked Rotor Amperage) rating on the nameplate of the heat pump you want to run? This is the momentary inrush current needed to start the compressor. The RLA (Running Load Amperage) should also be listed on the nameplate, and it will be a small fraction of the LRA. Don't be surprised if the LRA exceeds the capacity of the breaker that protects the unit because we are talking about a momentary load.

When starting an inductive load, such as the compressor on a heat pump, the voltage will drop momentarily which results in more amperage at the same level of power output from your generator. I've read that covering 70% of your LRA load is considered acceptable for commercial applications, and that homeowners might be able to push that figure closer to 50%.

The bottom line here is that you are going to need to perform a load calculation, and that inductive loads like heat pumps cannot be treated the same way as resistive loads like a water heater or electric range. Installing a large, stationary generator is not normally a DIY project, so have some pros help you with this.


You are absolutely 100% correct ! Especially LRA & RLA . I thought I had discussed this also ? I guess people just want to believe what they want to believe ?

Might also consider 1 or 2 Ductless Mini Split Heat Pumps . I have 2 that are around 12,000 BTU & they will run on 15 amp 120 VAC . You could huddle up in 2 rooms during an emergency & be pretty comfortable . Buy the highest SEER rating units you can afford . It will come with inverter drive ( VFD ) compressors & starting load is small .

We have a portable diesel 25 KVA generator at work . Before we got it , we used to rent a 45 KVA generator from CAT . Very nice !

The 45 KVA would probably work for you . If interested , check the commercial rental places . That is where the boss purchased the 25 KVA from .

Best wishes , :)
 
Last edited:
Originally Posted By: JimPghPA
Propane gas is heavier than air, and if you ever get a propane leak it will accumulate in low areas usually leading up to an explosion. There are detectors with alarms you can buy but they are not cheap.

Some type of propane furnace would make a lot of sense and go a long way in reducing the size of the generator you would need.

A alarm with CO and combustable gas is around $40. I need a new on for the camper:)
If the home has fireplaces it should have these.
 
Last edited:
Originally Posted By: Donald
Originally Posted By: Astro_Guy
What is the LRA (Locked Rotor Amperage) rating on the nameplate of the heat pump you want to run? This is the momentary inrush current needed to start the compressor. The RLA (Running Load Amperage) should also be listed on the nameplate, and it will be a small fraction of the LRA. Don't be surprised if the LRA exceeds the capacity of the breaker that protects the unit because we are talking about a momentary load.

When starting an inductive load, such as the compressor on a heat pump, the voltage will drop momentarily which results in more amperage at the same level of power output from your generator. I've read that covering 70% of your LRA load is considered acceptable for commercial applications, and that homeowners might be able to push that figure closer to 50%.

The bottom line here is that you are going to need to perform a load calculation, and that inductive loads like heat pumps cannot be treated the same way as resistive loads like a water heater or electric range. Installing a large, stationary generator is not normally a DIY project, so have some pros help you with this.


I understand the load concerns of starting an electric motor. But my real concern is when the electric booster coils kick in. It's all integrated and I am not sure there is any control of when it kicks in the booster coils.



You are talking about the electric resistance heat / emergency heat . Pretty simple mater to be able to disable it , should you need to . Any HVAC tech or electrician that knows controls should be able to install a manual " switch " to disable it .

Or you may be able to do so , partially or entirely by switching off the appropriate circuit breakers . Childs play . :)

Best of luck , :)
 
Originally Posted By: JimPghPA
Propane gas is heavier than air, and if you ever get a propane leak it will accumulate in low areas usually leading up to an explosion. There are detectors with alarms you can buy but they are not cheap.

Some type of propane furnace would make a lot of sense and go a long way in reducing the size of the generator you would need.


Propane heater / stove / furnace ! 100% correct ! Think I might have mentioned it too ?

A good idea even if you do it before the generator project .

Best of luck to you , :)
 
Status
Not open for further replies.
Back
Top