Generators, sizes and fuel options?

   / Generators, sizes and fuel options? #1  

stumblinhorse

Platinum Member
Joined
Jul 15, 2022
Messages
613
Location
Colorado Mountains
Tractor
Case Farmall 75C, Kubota L3130
It seems the power is not something that can be relied upon as much as it used to be. Seems like in bad weather getting the power back on takes longer than it used to. So I wanted to get some ideas of what people are using to keep critical items running to survive a bad storm. I already have the needed wiring etc to run “most“ of what I think I need and will be pulling some romex to make sure I get what I need on the correct circuit.

I like the idea of tying into my 300 gallon propane tank for fuel since that allows me to run for multiple days and not store fuel. But that means I need to modify connectivity to the house and lose a little efficiency of power generation, especially at my 8K elevation. So not sure which way to go.

Also I would like to understand the math on what size I need. Biggest draw for my set up is the well pump and pressure tank. Other items on the circuit are electric stove, fridge, propane boiler/pumps, outdoor boiler and microwave. So I think 10000 watts should be plenty. But not sure what considerations I need to figure in.

thanks for any insight.
 
   / Generators, sizes and fuel options? #2  
10k watts should be enough as long as you space out your loads. An electric stove can consume that much by itself if you turned on all the elements at the same time. I’d recommend something with electric start capability to make it more user friendly as you age and for your wife. Make sure you size the plumbing from the propane tank correctly. It’s not as straight forward as it would seem. It takes a pretty large pipe to keep up with the load especially with any distance involved.
 
   / Generators, sizes and fuel options?
  • Thread Starter
#3  
10k watts should be enough as long as you space out your loads. An electric stove can consume that much by itself if you turned on all the elements at the same time. I’d recommend something with electric start capability to make it more user friendly as you age and for your wife. Make sure you size the plumbing from the propane tank correctly. It’s not as straight forward as it would seem. It takes a pretty large pipe to keep up with the load especially with any distance involved.
It is better to set the generator closer to the propane source or to the plug to power the circuit? 30 feet between them
 
   / Generators, sizes and fuel options? #4  
Is your 10,000 watt estimate peek watts or continuous watts? There is about a 20% difference.

There is about a 3% drop in efficiency of internal combustion engines for every 1000 ft. of elevation rise. At 8000 ft. elevation there will be about a 24% drop on engine horse power.

Having the house and generator pulling propane from the same 300 gallon tank may not produce the the desired outcome very long.
 
   / Generators, sizes and fuel options? #5  
A 10KW generator will use 1 gal of propane per hour at 50% load. Depending on what else you do with your propane it might not last as long as you think it will. That is before the "penalty" you take in power for being at altitude.

We have a 6500 running watt (8K starting) and it will run everything but the cooktop/stove. We do not have the circuit wired in as a result. We have the well, sump, fridge, boiler (gas heat but electric for the pumps) and some lights/outlets wired in. For cooking in an extended outage we have an electric griddle that we can use to cook a lot of things.

Electric start is a must for an engine that big. I am still pretty fit, but pull starting my generator is a huge ask, and I do not think much longer until I simply cannot do it. Wife could absolutely not do it. Last time we had to start it the battery was dead. So I had to jump start it. Pain in the butt yes, but I could get it done.

Often I wish I had two generators. A smaller one to run when I do not need the well pump, which is most of the time. It would consume less fuel. Of course there is the pain to swap out generators when you want to shower or flush.

In any event if you can get 10K running watts at altitude that would power a good set of the basics plus some.

Make sure you keep oil on hand for oil changes in an outage.
 
   / Generators, sizes and fuel options? #6  
Also, generators put out less on propane than car gas...

A 300 gallon tank isn't all that big for a generator.

SR
 
   / Generators, sizes and fuel options?
  • Thread Starter
#7  
Is your 10,000 watt estimate peek watts or continuous watts? There is about a 20% difference.

There is about a 3% drop in efficiency of internal combustion engines for every 1000 ft. of elevation rise. At 8000 ft. elevation there will be about a 24% drop on engine horse power.

Having the house and generator pulling propane from the same 300 gallon tank may not produce the the desired outcome very long.
The house doesn’t pull propane during the winter. It is for the indoor boiler for DHW in the summer. Outdoor boiler provides all heating needs when running.

That is my concern with propane for the generator. The loss in efficiency, and same reason I don’t use it for winter heat ;)
 
   / Generators, sizes and fuel options?
  • Thread Starter
#8  
A 10KW generator will use 1 gal of propane per hour at 50% load. Depending on what else you do with your propane it might not last as long as you think it will. That is before the "penalty" you take in power for being at altitude.

We have a 6500 running watt (8K starting) and it will run everything but the cooktop/stove. We do not have the circuit wired in as a result. We have the well, sump, fridge, boiler (gas heat but electric for the pumps) and some lights/outlets wired in. For cooking in an extended outage we have an electric griddle that we can use to cook a lot of things.

Electric start is a must for an engine that big. I am still pretty fit, but pull starting my generator is a huge ask, and I do not think much longer until I simply cannot do it. Wife could absolutely not do it. Last time we had to start it the battery was dead. So I had to jump start it. Pain in the butt yes, but I could get it done.

Often I wish I had two generators. A smaller one to run when I do not need the well pump, which is most of the time. It would consume less fuel. Of course there is the pain to swap out generators when you want to shower or flush.

In any event if you can get 10K running watts at altitude that would power a good set of the basics plus some.

Make sure you keep oil on hand for oil changes in an outage.
1 gallon an hour is livable. I want to plan for 3-5 days without power and depending on the conditions I would not expect to run the generator 24 hours a day. So if I could plan for 18 hours at 1 gallon/hour for 5 days = 90 gallons as a max. I think that is a good start.

I also don’t need the well pump much or the stove For that matter. Maybe a 8k/6.5k is also enough if I ration/plan properly?
 
   / Generators, sizes and fuel options? #9  
I had a 20,000 watt natural gas Briggs and Stratton system installed about 2 1/2 years ago. It will run the whole house. I have two gas water heaters and a gas furnace. It came on twice this past weekend. The generator starts four seconds after the power goes out but doesn't transfer power for twenty seconds in case the line power does not stay off. My five ton A/C will pull it down some when it starts but it runs it without any problems. B&S has come out with a 26,000 watt generator now, may try to trade for one in the future.
 
   / Generators, sizes and fuel options? #10  
It would really help if you tried some of the online generator sizing calculators. for example
These often put in things like zip and you can add and subtract different things immediately.
 
 
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