Batteries V Generator.

[WillyP]

SO I am designing my new home (nothing isbuilt yet) I am leaning heavily towards having a propane gas generator for power back up as opposed to batteries. The reason is cost. I will have a grid tied system. I am mainly worried about power outages. I will have a large propane tank to power stoves and water heaters (I know I am cheating). It looks to cost under three thousand dollars for a generator and a battery backup system could cost as much easily. So my question is... Am I right? Will I save money in thelong run to just build a generator and automatic switching into the system?

 

[svetz]

It depends on your case and needs... but it sounds like you've run the numbers are they're probably spot on. Often times it makes sense convenience-wise to have some batteries to get you through short-term outages just so you're not out of propane when you need it.

When battery prices fall to where it makes sense you can get more and use the generator as a fallback for multiple days of no sun.

If you can get natural gas, it'll be cheaper/easier than trucking in propane (although check, some places shut off the gas for some emergencies (e.g., earthquakes)).

 

[John Frum]

What size generator?
You can combine batteries/inverter with an ice generator to have some critical circuits not even blip.
The less critical stuff can wait until you manually or automatically trigger the generator.
Running off a big standby generator 24/7 can get expensive if the outage is long duration.

 

[WillyP]

Well I am building in a pretty remote part of Maine. The heater will be all solar. But I don't want to be stuck without power for days if things get ugly after a heavy snowfall. I plan on having a huge propane tank, built into the yard. The kind they fill with a truck a few times a year. Chances are I will hardly ever use it. But if we lose power for days, when it is below zero outside, I don't want to have to chose between dying or taking my snow mobile to a hotel.

 

[WillyP]

It depends on your case and needs... but it sounds like you've run the numbers are they're probably spot on. Often times it makes sense convenience-wise to have some batteries to get you through short-term outages just so you're not out of propane when you need it.

When battery prices fall to where it makes sense you can get more and use the generator as a fallback for multiple days of no sun.

If you can get natural gas, it'll be cheaper/easier than trucking in propane (although check, some places shut off the gas for some emergencies (e.g., earthquakes)).

Somebody really needs to reinvent the battery. I mean let's face it even lithium ion batteries are fifty year old technology. Lead acid batteries were invented in the eighteen fifties. With all the advances we have made in tech, you would think somebody would come up with a new design, that works better and is smaller, cheaper would be a nice add on.

 

[John Frum]

Also its my understanding that residential standby generators are only good for ~1000 hours.

 

[svetz]

... With all the advances we have made in tech, you would think somebody would come up with a new design, that works better and is smaller, cheaper would be a nice add on.

It's pretty much the holy grail and tons of folks are working on it. Prices have been plummeting and advertised commercial systems are running ~$1/Wh installed (tesla powerwall is about $0.66/Wh)[although the advertising all has asterisks, so YMMV], but I've heard some DIYers are setting up batteries with BMSes for < $0.20/Wh. Battery prices are expected to continue to fall.

 

[Baz Ares]

Also its my understanding that residential standby generators are only good for ~1000 hours.

Cheap ones from home depot that have no pressure oil feeding and oil filter are what they be, short life some not worth repairing.
I have a few gens with over 3500 hrs and no major repairs need be done. That only cost 20% more doing them right.
As run on them on NG, and can use LP and last gas. They all get services done right. And loads on them are right only 50-60% total. I feel your understanding is a little off the way you posted.

BTW: A Car engine at idle is like 25 miles per hour idled. With a real oil pump and filter. As to wear and tear.
So, 1000 hrs is like 25000 miles. If this generator is a splash type oiling system (shit). I have a 2000 watt gen with over 1000hrs now.
Cheap shit, but works if used right.

My 9 and 15k's have real oil pumping systems and have both over 3500 hours with no major rebuilds/repairs.

These equal to a car running over 75,000 miles. My hope is to get over 100K. miles maybe get 175,000 miles. Before rebuilds, and I have parts now in my plan to do that when needed, as don't know if I can get them, then.

 

[theoldwizard1]

SO I am designing my new home (nothing is built yet) I am leaning heavily towards having a propane gas generator for power back up as opposed to batteries. The reason is cost. I will have a grid tied system.

With proper installation, you can still use your grid tie solar system to supplement your propane generator. Well, at least when the sun is shining.

 

[Elevation]

I live in town because I had to be on call 24/7 in my career before I retired. However, being an architecture major my house has natural gas heater, water heater, gas dryer, and I recommend a gas stove/oven. Also all of the light bulbs are LED. If you do these things you will greatly reduce your overall electrical power needs. You have the advantage of planning from the beginning. Look into SIPS / structurally insulated panels or 2x6 studs 24” on center which nets you 5 1/2” of insulation in the walls. Plan for no les than 12” in the ceilings, more is better. Double or triple pane windows. There are other ideas here, but running out of time right now.

 

[Elevation]

Oops in your case propane...

 

[WillyP]

I live in town because I had to be on call 24/7 in my career before I retired. However, being an architecture major my house has natural gas heater, water heater, gas dryer, and I recommend a gas stove/oven. Also all of the light bulbs are LED. If you do these things you will greatly reduce your overall electrical power needs. You have the advantage of planning from the beginning. Look into SIPS / structurally insulated panels or 2x6 studs 24” on center which nets you 5 1/2” of insulation in the walls. Plan for no les than 12” in the ceilings, more is better. Double or triple pane windows. There are other ideas here, but running out of time right now.

Thanks for responding. I plan on doing most of what you recommended. I'll be going with 2X10 walls not 2X6, It will be 16 inch centers due to structural concerns with the second floor. The ceiling between the first and second floor is going to have pex pipe in it and be insulated on the bottom. There will be wooden H beams for floor joists. So I will have a little space between floors (only ten inches high). It will have sprayed cellulose on the bottom and plywood on top with the pex attached by those metal fins. So under the second story floor will be a small heated space.

I really want gas (on demand) hot water heaters. I fear how I will safely vent it, without a heat loss... Any suggestions about that would be greatly appreciated.

Oh and the generator, will be solely for when power goes out. Any other time it will sit idle. I just want reliable electricity, if the grid goes down for a few days in the middle of winter.