Follow up on Ice Storm Gen Thread - How much power does a house take

[woodlandfarms]

I am looking to explore all the variables here, so all comments welcome.

Last blackout we had we pulled out the generator and plugged it into the house (We had a hard disconnect from the power grid so no back feeding). Generator is a 5000 watt system.

I turned off everything in the house, we are mostly CFL. My generator the meter is out so I have no idea how much I am pulling (another thread has shown me the parts, jsut need to find time to order).

What I am reading or should I say understanding is that my furnace which is electric pulls way too much for my generator, but I was wondering about a hot water heater (electric) and stove.

I was also wondering about off the grid people, I get heat is from a stove, but what about hot water, stoves and pumps. How does a solar system provide enough juice?

I did find this, maybe should start with this but how accurate do you find this guys chart?

How much electricity does my stuff use?


Am I going to broad on this?

 

[90cummins]

First thing you need to do is look at the data tag on all your appliances, furnace, fridge, water heater & stove if they are electric and all your lights and record.
Only then can your needs be determined.
90cummins

 

[GPintheMitten]

When you say your furnace is electric, do you mean resistance heating, or is it electric motor for the fan with oil , propane or gas?

 

[k0ua]

When you say electric furnace.. please define how it works.. Baseboard heat? Heat pump in emergency mode using the resistive heating element in the air handling column? Heat pump using the compressor? I don't know what an electric furnace is. You have to tell us what it is you are referencing or better yet read the data plate and tell us how many watts it uses. If more than 5000, it ain't gonna work. and it aint' gonna work for long if it is 5000. electric hot water heater is around 5000 watts per element. Stove depends on burner size, some are around 5000, some a bit less.. Most of these HUGE electrical load, you can forget.. 5000 watt genny is to provide lights, TV small appliances, some refrigiration/freezer and MAYBE. MAYBE if you submersible pump is small enough it will pump water for you. You often have to do load management. In other words turn off this to run that.

Your data plates on the appliances are your friends, or better yet get an amp probe or a Killlowat meter (probably the cheapest and easiest to understand) and start measuring the loads.

How does solar run these things? the only way to run huge loads is for a short time with your battery bank if you have one. Run something like a pump from battery/inverter system to pump water, and takes hours to recharge batteries back to that same state. All about exchange load for time. make sense? Here is an example. My load center in my house is 200 amp at 240 volt. So something short of 48 kilowatts is my possible load on the grid. That is a bunch of power.
Know of anyone that has enough solar panels to make 48 kilowatts? I sure don't.. The money is just not in most peoples pockets to buy that much solar capacity.

So they make compromises. First thing they do is get rid of the things that consume big bunches of power. Like my heat pump/air conditioning. Lets heat with wood or gas or something. We can sorta cool with a small fan.

Lets get rid of that electric hot water heater, and either have a solar hot water heating system with lots of storage for non sunny days, or a gas water heater and supplement it with solar water heating maybe. Lets cook with gas or propane and get rid of that huge electric hog of a electric stove. Heck an oven can use 10Kw by itself.

Change all the lighting to LED. Maybe even change out the refrigeration to gas or get small energy efficient electric refrigerator.

All sorts of strategies like that. And have a big as you can afford battery bank and inverter setup so you can make some big draws but have time for the solar to recharge it. This acts like a flywheel in mechanical terms. Heck some guys also have either wind power or hydroelectric power if they have a stream nearby they can harness. This can make up for when the sun does not shine..

It is all about what you are able to get along without or give up so that you can be self sustaining, whether you are trying to do it with solar or even a gas generator in an emergency power outage situation.

 

[Industrial Toys]

That's always been my irritation with people talking about going off grid, that don't have a clue about consumption. I couldn't care less about CFLs, LEDs and electronics. I want to heat my house, dry my clothes (in the winter) ,take a hot shower and cook a hot meal. Electrically, those things are HUGE loads!

I have seen it a few times. People make the decision to go solar PV and then in short order get that many (expensive) panels, and batteries again. I think someone misrepresented something to them! Next they are buying a Diesel Generator, that was never in the initial concept either!

If you are in a remote location with no utility power, that's one thing. But if the utility comes by your place, that's the cheapest (and easiest) power in my opinion. Then it's just a matter of conservation.

 

[General Lee]

The data tags on your appliances will tell you what they burn (watts). Before my whole gen install, I used a 5500 watt (8250 starting watts) portable genny. I plugged it into the panel. I did load management and got by fine. My water heater has 2 4500 watt heating elements, yours will be similar if you have an electric one. To shower I turned off every breaker except the hot water breaker. I let the heater get hot then shut off that breaker and turned on the breaker for the well pump. I'm pretty sure only one heating element runs at a time therefore it won't overload the 5000 watt genny.

Winter time I was able to run my oil furnace just fine, but A/C in the summer, Nope. You just have to be smart with your load management. Just run what you need. I had 3 fridges and a freezer on the 5500 watt genny and as long as they all weren't starting at the same time along with the hot water heater, I was good.

 

[Industrial Toys]

I have mentioned this before. I rewired my water heater for 110. Half the wattage, much less possibility of deposits forming on your elements. A friend told me this trick. I was skeptical but have noticed no difference in available hot water. Mind you I live alone with weekend company. She does her laundry here (as well as mine) and still have never had a shortage of hot water with a forty gallon heater.

 

[timswi]

I'm in the same boat with electric heat. Never tried to run my heat pump or backup electric furnace on the gen (mine's 8000) and I would never try..However I have run the well pump, hot water tank (electric), lights, TV's, computers and general stuff...I shut the breakers off that are power hogs (oven, HP, Furnace)...Common sense is all that is really needed and kill the main so you don't try to power the whole neighborhood, the gen won't even run and it can be an issue depending on if your facility lines are down.

Transfer switches are the ticket.. May get a meter version that the power company came up with. Don't really want to deal with one in the house as power outages are fairly infrequent around here. I'll just decide what I want to leave on.

I have a pellet stove, so that will break the chill in the winter and it is a light power user.

And yes, I'm a back feeder through a dedicated outlet and breaker in the garage and house panel and never had a problem--EVER....Let the flaming begin.

 

[MossRoad]

I am looking to explore all the variables here, so all comments welcome.

Last blackout we had we pulled out the generator and plugged it into the house (We had a hard disconnect from the power grid so no back feeding). Generator is a 5000 watt system.

I turned off everything in the house, we are mostly CFL. My generator the meter is out so I have no idea how much I am pulling (another thread has shown me the parts, jsut need to find time to order).

What I am reading or should I say understanding is that my furnace which is electric pulls way too much for my generator, but I was wondering about a hot water heater (electric) and stove.

I was also wondering about off the grid people, I get heat is from a stove, but what about hot water, stoves and pumps. How does a solar system provide enough juice?

I did find this, maybe should start with this but how accurate do you find this guys chart?

How much electricity does my stuff use?


Am I going to broad on this?

Try this link for some basic info...
Honda Generators - how much power do I need?

My generator will supply 30 amps @110v or 15 amps at 220v. No way can it run large electric appliances. I think many electric stove nowadays require 40A 220v breakers. Maybe even 50A. But I think that's rated for all burners and the oven on at the same time. I may be wrong. Electric water heaters pull like 20-30 amps @220v. No idea what an electric furnace (assuming electric coils in the furnace?) pulls.

Like you, gotta wonder how many amps they can pull from the batteries on a solar system and for how long on off-grid systems. I can see it on grid-tied. But not off-grid. Will be watching this thread. Always interesting stuff.

 

[MossRoad]

This thread's about loads, so no discussion regarding back feeding please. They always digress into a shouting match. Is been discussed to death.