Back-up Generator for Entire House

Submitted by ReadBonny t3_10500q5 in vermont

Hi all. Like many others, I lost power for 4 days over the holidays. We would like to have a back-up generator installed. My first thought was to get a propane powered one and I already have a consultation scheduled with a technician.

Our house is heated with oil and we have radiant floors. This means we would also have to have propane tanks installed for the generator, which is completely fine, just another step in the process.

I just discovered that there are also battery powered backup generators for whole homes. They also come with the ability to be charged via solar. Here is an example of the battery generators I am talking about. https://www.bluettipower.com/

Do you or do you know any Vermonters that have a similar system? How well does it work and would you recommend it over propane? Would the solar charging even work with our short cloudy winter days? Regarding cost, I am guessing the battery system might be a bit more expensive than propane since we will need multiple batteries for the entire home, but I might be wrong here.

It looks like there are a ton of accessories you can buy and additional batteries you would need to power an entire home for multiple days. We are looking to power the heat, our well/septic and some lights at night. We have a wood stove to help keep the house warm but would like the option to be able to leave the house for extended periods of time.

Would love to hear people's experiences! If there are other options for back-up generators that work, please share! Thank you

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whaletacochamp t1_j37ykef wrote

Not to be pedantic, but.....the batteries that you are talking about are quite literally backup batteries to power your house. They aren't "battery powered generators" since a battery powered generator would be kinda counterproductive.

Annnyway. Backup batteries work pretty well. Remember that they are always charged and ready to go, so you don't necessarily need sunny sky to have power. You DO need to have sunny sky to recharge them via solar, however. Capacity and time of coverage depends on the system and size of the system. My neighbors have a system and they were able to go two days - but I believe the batteries only run their well, boiler, septic pump, and a couple of lights.

Personally I wouldn't go with a propane generator unless you already have propane onsite. Just seems like a lot of extra peripherals and pain setting up delivery etc. With that being said, it is certainly the lowest maintenance option and probably best for someone who has limited knowledge/comfortability with small engines. You can also get ones that run off natural gas but since you heat with oil I'm guessing that's not an option.

We heat with propane and I'm planning on installing a generator right next to our propane tank for this exact reason. But if we didn't have propane I would just keep a big can of gas on hand all winter for the generator.

Be aware that if you are having a company come out and do the whole shebang they are going to cost quite a lot. You will have an incredibly good system that's easy to use at the end but it will not be cheap and they will likely have you on the hook for yearly maintenance (which is important but not cheap). So if you are at all familiar/comfortable with this sort of stuff it can be considerably cheaper to buy your own generator, pay an electrician to come out and do the wiring for you, and then just hook it up and start it up when you lose power. The company your working with will likely want to sell auto cut-over which is not cheap, but is wicked convenient.

NEVER RUN THE GENERATOR WITHIN 20' OF YOUR HOUSE (although any new generator will have a low oxygen/CO cutoff and some units are designed to be closer). NEVER BACK FEED A PANEL WITHOUT A TRANSFER SWITCH

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ReadBonny OP t1_j37z9wc wrote

Whoops sorry for the mistake. Clearly I'm new at this and still learning a lot. Appreciate the feedback. I agree that installing propane tanks just for a generator will be a pain. Would be great if the back-up battery solution worked for this reason.

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whaletacochamp t1_j38046o wrote

Most if not all solar companies will give free consultations and often free estimates or even quotes. I would definitely explore that! From what I have heard, I would avoid the Tesla system.

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ReadBonny OP t1_j381hse wrote

Thanks. And sigh, we already have starlink for internet. No need to purchase additional Elon products haha

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whaletacochamp t1_j381v0q wrote

Same lol.

How does it work for you? Works flawlessly for us knock on wood.

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ReadBonny OP t1_j384j7r wrote

It's incredible. No outages and we have tons of trees. We will eventually have fiber in our area so we will probably switch to that. Works better and fewer outaages than Comcast when we lived in Montpelier.

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Good_Kitty_Clarence t1_j38h8j0 wrote

Idk how others are getting so lucky with Starlink. We’ve had it for less than a year and are on our 3rd dish. The previous 2 malfunctioned. The most recent got water inside that caused it to short out. When the service is good, it’s good, but the issues with their shitty equipment is making me lose my mind!

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throwaway9384929 t1_j3ausij wrote

Agree with this, I had it for a very short period and it was borderline unusable, the wind blows the right way and it flat out wouldn’t work, clouds? Forget it no internet for you today

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Good_Kitty_Clarence t1_j3cefu9 wrote

Bummer. Our service is stable and works great… when it does. We’ve only lost service for brief periods of time during inclement weather. It’s the malfunction of the equipment (and the subsequent snail-paced troubleshooting/customer service) that is so frustrating to me. Our third dish in less than a year and a company that truly does not give the tiniest fraction of a fuck.

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whaletacochamp t1_j387j1d wrote

We had HughesNet before this which was borderline fraud for what we paid and what we got.

We also have a ton of trees (literally live in the woods) including one huge one that obstructs a good portion of dishy to the point where the app says expect an outage every two minutes (during the leafed parts of the year that is) and the only time I ever have issues is quick two seconds lags on Teams or Zoom meetings with a lot of people.

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syphax t1_j38g2o9 wrote

>https://www.bluettipower.com/

Me 3. StarLink is magic for us. Doesn't change my opinion of Elon much, though.

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Real-Pierre-Delecto2 t1_j3817aj wrote

Had a Tesla powerwall for years with never an issue nor have I ever heard of other issues with them. Keeps the house going for about 24hr before I have to fire up the genny. Most often the only way I know we have had an outage is because the Tesla app tells me about it.

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Most-Analysis-4632 t1_j3btzca wrote

Same here. Flawless switchovers. We have two Powerwalls, got conservative with our usage after day one, and got to day three with 20% left.

Interestingly, Suncommon wouldn’t install just one battery. They told me there can be a spike-induced glitch with a single, where the crossover fails. It’s probably super rare, but I thought it interesting that they won’t install singles.

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8valvegrowl t1_j38ksmv wrote

This is such a complicated topic, since there are so many variables.

u/whaletacochamp has hit on a lot of great topics to think about.

I'm no expert by any means, but I take a key interest in energy (I'm a physicist, so it is a thing I think about a lot, I guess).

You managed 4 days without power, so I'm pretty sure you now have a good idea of what your needs are for the household, so make a list of priorities and for how long it would need to be an option.

Data is your friend here. First, track your normal energy usage globally; look at the use in the house over a year, but best to log it over a few years to account for variations. Pretty easy to do with your electric billing. Next, look at energy requirements for the things that are important to make the house function, for example, Refrigerator, well and sump pump, heat sources, basic lights. Some can be measured directly with a Kill-A-Watt meter in an outlet, others might take some math (like calculating several 15W LED's on a light circuit).

I'll reiterate u/whaletacochamp here, you NEED a transfer switch to prevent power flow when you switch between an islanding power system versus the power grid.

Moving on...

Weigh the Pros/Cons of every system (I'll list a few):

Battery Backup*:

Pros-

Cost: Can range from pretty cheap cost upfront (but there may be hidden costs for a turn-key system from a place like GMP), to very costly upfront (and later, if not well-designed).

Maintenance: Low/No Maintenance.

Readiness: Always ready/generally seamless back up (Charged up via grid before failure**, or with solar/wind to add to the system post-failure).

Lifetime: This is a wildcard, as the systems are pretty new, but claim to have a 15-20 year lifetime.

*This highly depends on how you set your battery up and any agreements you have with the electric grid provider. Lots of research is required to have a fully independent battery system, but the grid provider cannot touch your 'saved' energy.

**There is always the possibility, although small, that the grid is using your battery prior to grid failure, so it's not guaranteed it will be fully operational at any given time.

Neutral -

Power: Scalability costs money, and there are less installers with experience.

Cons-

Depending on the battery distribution scheme, your household power consumption may mean it lasts less than 24-48 hours. If you only power key sub-systems, or are willing to shutdown breakers, this might go further; especially if you can recharge the battery via solar or wind).

It's a black-box system, unless you build it yourself, or like to hack (ymmv, caveat emptor).

Standalone Gas Generator:

I'd only recommend small gas generators in an emergency, but a small contractor-type generator that can do 3000W-5000W is a nice thing to have. Have several heavy-duty power cords to plug in and a place to set it outside the house while it runs, you can run a few things in the house directly. I have a small Honda 4000W that can easily run at nominal load for 24 hours on a tank of gas.

Use ethanol free gas, start it twice a year to make sure it runs well. Change the oil once a year. Keep a clean run of ethanol free gas in a 2 gallon can and it's all good for an emergency situation for a few days. This is a great option for less than $1000.

Full House LPG/Diesel/NG:

These are expensive to install, but can easily be sized to run your whole house as long as there is fuel. A smaller scale system isn't that much cheaper to build.

If you have the infrastructure to supply them with fuel types, it's not a bad thing to think about, especially LPG or NG.

Pros-

Power: Easy to scale to full house requirements, smaller range between minimum and maximum power costs. Lots of installers out there with experience in setting these up.

Proven reliability/lifetime with maintenance: Over a century old technology, just more bells and whistles.

Cons-

Cost: Really steep if there is no fuel on-site, plus maintenance costs. Reliant on fuel costs/supply.

Maintenance: Minimum of annual professional maintenance to check engine/generator. Can be cheaper if you know a thing or two about engines or generators. Same goes for repair costs.

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whaletacochamp t1_j38n6k5 wrote

Damn this is a ton of good info. I almost went into the generator maintenance stuff but figured OP wasn't even considering a route where that would matter.

Another really good idea is to call your electric provider and chat with them. They may very well have recommendations, programs, contractors they like to work with, etc.

I'm pretty much in the same boat as OP currently but have LPG onsite. Just a tricky run to the house and not enough money to get the infrastructure setup and generator purchased...

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8valvegrowl t1_j38vpin wrote

Thanks! You posted a ton of good points as well.

I think this is a topic a lot of us think about, and it's really hard to get good information without a lot of marketing fluff from all the industry players. Luckily there are lots of smart folks here in VT that are willing to share thoughts and ideas.

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whaletacochamp t1_j38yhi9 wrote

For sure. I bet a lot of folks are thinking about it right now especially

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amnias t1_j3812jg wrote

Just get a gas generator with 7500 running watts and hook it up to the breaker panel (hire an electrician if you don't know how). It'll run the whole house and one with an 8gal tank can run for about 10 hours. (My house has 2 furnaces, the fridge, and all lights and outlets running the whole time). If you want the microwave or electric range you'll want something a little larger, probably 10k+ running watts.

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ReadBonny OP t1_j38d8ya wrote

Thanks. We will also look into this. Sounds like it might be the easiest solution. Will keep on researching!

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EscapedAlcatraz t1_j39yz1a wrote

Here's a budget option: a dual fuel portable Westinghouse model 5300 generator ($650), Reliance indoor transfer switch ($450), electrician to install this panel (~$800 or so), a 100 lb propane bottle or two from Lowes ($200 each). So for around $2,000 you can keep the critical items running like your refrigerator, boiler / furnace, lights and microwave oven and get through several days of an outage without a lot of hardship and without having to manage the shelf life issues associated with a gasoline appliance.

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lavransson t1_j3c38m8 wrote

Great plan. Question: is there any long-term storage issues with LPG? Would you recommend storing the tanks in the shed and lug them out only when you need them?

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EscapedAlcatraz t1_j3ed6nu wrote

No storage issues whatsoever. I keep spare barbecue tanks in the shed at all times. That’s a great plan. It might also be worthwhile to chain the generator to something solid nearby while in use. During extended power outages generators are desirable acquisitions and they’re outside running unattended.

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lavransson t1_j3c3s2h wrote

Also, is it safe and practical to transport a 100 lb tank? I’m reading that this weighs 170 lbs when full and should only be transported upright. So you’d need a pickup truck and a way to keep it secure. And 2+ strong people on both ends of the trip to load and unload.

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EscapedAlcatraz t1_j3c58be wrote

Propane has an indefinite shelflife. You might want to go with 40 pound bottles of propane. These are the type you would see on the front of a travel trailer. Three or four of these would be easier to move around and transport.

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mosessmiley t1_j396dn4 wrote

I just did this. $16.99 for a 30 amp breaker, 17.99 for interlock kit, 124 for 20’ of 8/3/g, 67 for outside plug. I had a gen and cord.

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lavransson t1_j3c31rd wrote

Curious why you went with a 30amp breaker. A lot of these portable generators have a 50amp outlet. Thanks for any tips, as I’m looking to install something similar.

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mosessmiley t1_j3domcp wrote

Mine has a 30 which is why. If I ever get a bigger genset it’s a pretty easy change.

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Dire88 t1_j3aqr1a wrote

You can buy dual fuel generators.

I have a 10,000 watt portable generator that runs on gasoline or propane. Gasoline has slightly higher output, but running on propane means not having to worry about winterizing fuel every year. Changing fuel type can be done in a few minutes.

Install a generator interlock kit on the panel.

Small concrete pad, enclose it with a locking door. Install a 120v and a 240v plug, 120v is on the main panel and has constant power to keep a battery tender hooked up. 240v is on the interlock breaker for backfeed.

10k is enough to run most items in an effecient house. I can run my well pump and water heater for showers, and keep the fridge/freezer going. Realistically, it's all I need since we use wood heat.

For a fraction of the cost of a Generac.

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2q_x t1_j380x0a wrote

GMP has a program for battery backups. That's probably the most turnkey solution. You basically let the grid use you as a battery. If there is an outage, it isolates current to your home.

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Most-Analysis-4632 t1_j3bu86p wrote

And I’m not sure about 2023, but the fed tax rebate was 30% in 2022. That applies to battery backup as long as it’s solar-only-recharged.

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happyonthehill802 t1_j386a1k wrote

Propane standby generators are great if the cost doesnt scare you. Since you already burn fuel oil for heat, maybe you can find a diesel standby generator.

Battery banks are expensive. As is solar. This is an investment, and understanding the life span of batteries is also very important before you make a decision. If you go this route do some research on grants related to renewable energy.

The cheapest option is a portable generator, which can also be powered by propane, and a transfer switch.

For the amount of times we lose power a year (in my rural town, i see 2 - 4 per year avg), i would just get a portable generator and be very diligent with fuel treatment, or run it on propane.

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Loudergood t1_j39md7u wrote

Yeah, I went with solar but no battery as the return just didn't appear to be there.

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thomaschazzard t1_j387aob wrote

We have a 10Kw solar array integrated with a Tesla Powerwall. We heat our house with a Fujitsu heat pump.

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BudsKind802 t1_j38aihg wrote

I bought a 15kW propane Generac a few years ago, and there's a couple things to consider....

I would recommend going with a professional. If your neighbor helps hook it up directly to your power without a transfer switch, you're gonna have a bad time.

That professional can help you size the right generator, and the right fuel amount needed to run it. I use some big electric heat pumps, well water, etc etc for electric and already had propane water and stove and so I ended up upgrading to 300 gallon tanks. Propane lasts a long time so I don't have to refill the tanks more than once a year.

Run time is important. If you're OK having a few day's worth of backup, batteries are fine. We just lost power for 5 days and the propane lasted me the whole time. My neighbor's powerwall made it 3 days.

Price is also important. Batteries will run you less money in the short term, although they may have a shorter life than a generator with the wear if you have multiple outages per year. For my generator setup I paid about $12k for installation, propane work, electrical work, and the generator.

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-_Stove_- t1_j37xlrh wrote

You're going to spend a ton of money supporting your house (how big? what features?) with those little portable powerbanks.

Re: Solar- yes it works, but we're far away from the sun up here in the winter. And don't forget to keep snow and ice away.

My suggestion: Figure out your total power needs, and consider if you need *everything* running during a blackout.

Personally, I've got a battery backup for my house, with a secondary charge circuit to charge via a small propane genny if the batteries run low (should take about a week). Propane isn't as energy dense as oil/diesel, but the shelf life is perfect, and no clogged carbs/injectors if it's been sitting for...a while.

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Real-Pierre-Delecto2 t1_j384687 wrote

Wow ya those things are insanely expensive and not very powerful either. Two for the well just for starters as it seems for 240v you need to have two of them sadly.

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whaletacochamp t1_j37ys3q wrote

> Propane isn't as energy dense as oil/diesel, but the shelf life is perfect, and no clogged carbs/injectors if it's been sitting for...a while.

This is definitely the selling point for propane. Just kinda sucky if you don't already have propane on site.

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ReadBonny OP t1_j37ygqn wrote

Our home is 3 bed 2 bath and approximately 2400 sq ft. Built in 2006 so it's newer and fairly energy efficient. What type of back-up battery do you have?

We understand it will be expensive and have prepared financially for the cost. Bare minimum requirements would probably be heat, water and septic. We can live without the rest.

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whaletacochamp t1_j37yywy wrote

Water is only an issue if you're on a well (which it sounds like you probably are) and septic is only an issue if you have some sort of ejector pump or macerator or something along those lines. Many many septic systems are gravity fed (you just need water to flush the toilet)

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ReadBonny OP t1_j380s1v wrote

Yes we are on a well and we have a mound septic system. We need electricity to run the pump chamber so it won't back-up. But this is all fairly new to me so I might be wrong. Lived in Montpelier before this and always had municipal plumbing.

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whaletacochamp t1_j38346h wrote

It’s definitely a big change moving from municipal to rural.

If you have any question call out the septic company (the folks who would pump your tank) and they’ll be happy to tell you all about it.

What part of the state are you in now? I highly recommend Working Dog Septic if you’re in Franklin county or norther Chittenden.

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ReadBonny OP t1_j385atf wrote

We're in Washington County. Pooping outside in the snow was rough and we would prefer to poop inside :)

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whaletacochamp t1_j386yp5 wrote

Chat with whoever is your go to septic crew. There’s pretty likely a period of time where you’re safe to use your system without power.

In that case all you need is to fill a few buckets (or your tub) with water before a possible power outage. Then you go poop and dump a bunch of water into the toilet and it will flush just like normal.

I absolutely blew my wife’s mind with this tidbit the first time we lost power at our house. Luckily we have a pond so unlimited flush water lol

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IndigoHG t1_j3aa36i wrote

This! You can always fill your tub with water pre-storm, to flush the toilet.

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-_Stove_- t1_j38864s wrote

I would say that your septic pump is the highest priority there, aside from heat. You can always dump 2.5gal of water in a toilet to flush it...as long as it has somewhere to go. There are a number of roadside springs all over Vermont, they can be a lifesaver when the power is out.

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ReadBonny OP t1_j38cfmv wrote

We know about the water in the toilet trick and we usually fill our tub with water before a storm. We also have a stream that runs through our property. Just concerned about our pump tank backing up because it won't be able to empty without power. We will contact the company that pumps our septic and ask what the capacity is when we don't have electricity.

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EscapedAlcatraz t1_j39wxa4 wrote

Typically these systems are designed to have one days worth of capacity remaining even after the high level alarm sounds. This is the alarm that warns the homeowner that the pump isn't operating. You could probably flush toilets as you normally do for 2-3 days without a worry during an outage, even longer if you are skipping showers due to a lack of hot water.

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Real-Pierre-Delecto2 t1_j380j57 wrote

You didn't mention how you heat your hot water? If electric that can be very taxing on a genny 4500 watts or so when on. Other than that I would skip the whole house idea and get a smaller genny 6500 watts ish and have your electrician wire a genny transfer panel that only runs a few circuits like your well, heat, fridge etc. A cheap harbor freight genny is all you really need up here for the occasional outage. Propane will cost you and yes while there is some maintenance advantage you can always find some gasoline 24/7 propane not so much. Gas genny's are pretty reliable just run em for ten mins a months if you can and possibly keep them hooked to a battery tender.

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ReadBonny OP t1_j381bsm wrote

We heat our water with a large Buderus boiler. This also heats our house since we have radiant floors. I am sure it takes a lot of power, so I'm grateful for the wood stove! Thank you for the feedback.

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Real-Pierre-Delecto2 t1_j382gzd wrote

Probably not in reality. Couple hundred for the boiler gun and a few more depending on how many circulators you have in the system. The newer ones use even less power. My newer Taco's use about 44w while the older and most common 007's use about 80w. Either way it's a tiny fraction compared to an electric water heater. But it's a plus to have oil hot water when trying to size a generator for sure. Other things to avoid and really you should not have a need to power them off a genny are things like toasters, microwaves, electric dryers and the worst of all electric stoves/ovens.

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DCLexiLou t1_j3814p6 wrote

It doesn't have to be that expensive if you are prudent with your usage during outages. We have a Bluetti AC-300 at the moment that is not tied in but will be this year with a transfer switch and additional Power Modules. It easily runs our oil furnace and blower motor. The system is expandable up to 12.5kw. We have 3 ecoflo solar panels that can be run in tandem and they are great as an add-on. One big plus for this system is that it can be recharged via your car/truck. Pull the car out of the garage, fire it up, plug it in for a recharge session. A lot easier than adding propane tanks for the few outages you'll have to deal with on average.

Good luck with your setup.

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-_Stove_- t1_j387vk3 wrote

I have a setup with 8x 150aH deep cycle batteries, which I bought used from a neighbor and refurbished ($350). Also 4x G31 batteries which normally run a schoolbus, and a single LifePO4 pack @ 206aH for redundant redundancy. (Note: I design circuitry for a living, so I have a custom control setup to control charging and draw).

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mr_chip_douglas t1_j38bnlo wrote

Not familiar with solar or batteries, but I had a 18kw Generac installed at my house 2 years ago. Whole house, auto transfer switch, 6-8 seconds after the power goes out it comes right back on. SUPER convenient. You wouldn’t know the power was out of you couldn’t hear it running (it isn’t too loud). I piped it myself to cut down on cost, and it was just shy of $9,000 with some extras (first year maintenance, cold start kit, WiFi monitoring). The cost was insane, but when the news was reading potential multi day power outages, the piece of mind it provided was priceless.

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tanbronson t1_j3992so wrote

I've got solar panels, a 18kw battery, and I'm about to buy a generator.

We lost power for 3+ days recently. The battery lasted about 12 hours, and I do need to figure out why, but a propane generator with batteries is (IMHO) what you want, even with solar.

I ran off the batteries for 4-5 hours at a time, and used battery powered lights. My network was on a separate ups, but that was only good for a few extra hours.

I got lucky and was able to charge the battery when the sun came out, but without a generator you're at risk of losing food.

Oh yeah, I have a wood stove and a propane stove, so I wasn't suffering, but if sun hadn't come out, I'd have been SOL...

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Grouchy-Pudding-3522 t1_j3aan4h wrote

We looked at the power wall and went with a 24 kw propane generator. Cost was about $7k plus installation and came with a 10byear warranty. We also purchased a 1000 gal propane tank for $6k and got a deal on fuel at $1.91 per gallon price locked for a year.

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verifiedboomer t1_j384z03 wrote

I have a suitcase sized battery "generator" for short outages, on the order of 12 hours or so. I can run the freezer, fridge, and Internet for about that long before it dies. It weighs about 70-80 pounds and is a beast to haul around. It does not produce the 240 V that I would need to run the well pump, so no one is allowed to flush at the beginning of power failures if we don't have an estimated repair time.

For longer outages, I wheel out a 3500 Watt, 240 V portable gasoline-powered generator. I installed a transfer switch for the well pump only, and use a (now discontinued) APC Power Distribution Unit to split the 240V into a set of 120 V outlets that I can use to recharge the battery, and run the fridge and freezer. This solution used about 5 gallons of gas every 24 hours during the last set of multi-day outages. With this, a wood stove for heat, and a whole bunch of flashlights, we can continue in relative comfort indefinitely, provided we can get out and refill our 5-gallon gas cans.

We have solar, too, and briefly considered a powerwall setup, but we have no place to put it, and it would still end up being useless when the power is out for more than a day or so.

The moral of the story is that our civilization and all its comforts are very brittle. We feel very independent with our setup, but the moment we can't get gasoline, things get medieval in a hurry.

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df33702021 t1_j38ngx5 wrote

Nevermind the batteries. The claims on powerwalls and backup battery systems are often quite exaggerated. Also they need to be heated. LifePo4 batteries cannot be used in freezing temps. You need to keep that in mind. If you use them in freezing temps, they will be destroyed. Solar power is irregular. For example, the last few days would not have produced any meaningful solar power. One Bluetti EP500 that you reference is 5.1 kwh. I use ~10kwh/day which is super low compared to almost anybody else. (Typical house is more like 30-50 kwh/day.) So if you want to power your house for a long length of time, you'll need a bunch of them. And you will always use more power than you say you will.

Do the whole house propane generator with a 500g tank and automatic transfer switch. You 'll be able to do a whole week without power.

edit: I should mention, the batteries should have BMS that disconnects when temps get low, but that's doesn't always happen.

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Real-Pierre-Delecto2 t1_j38seac wrote

> LifePo4 batteries cannot be used in freezing temps.

Yikes so much wrong with this comment in general but this stands out as completely wrong. They do indeed work although you must lower the charge rate and they don't discharge as fast. They even have special low temp versions also powerwalls are installed outside and in unheated garages all over VT so there goes that they also have a liquid cooling/heating system as do many other major brand backup systems. And a 500gal tank for a genny are you nuts a week more like a month and a half at ten gals a day.

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df33702021 t1_j38xqzj wrote

It's not wrong. Typical LifePo4 cannot be used in freezing temps. It causes lithium plating. There are some new lifepo4 batteries that have slightly different chemistries to allow for cold weather down to -4f, but you won't find that in typical off the shelf home power products. If you heat the battery then fine. That's not uncommon and exactly my point. At any rate, who wants to test out their $10k battery and see how it behaves in cold weather.

A 20kw propane generator uses ~1.5 to ~3.0 g/hr depending on load. So say 2/hr that's 2g/hr*24hrs= 48g/day. Do the math for an extended outage. A 500 gal propane tank has 300g usable capacity.

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Loudergood t1_j39mjte wrote

Noone is installing these batteries outdoors.

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df33702021 t1_j39xjhi wrote

Didn’t say they were. I’ve seen them installed in places with marginal heat. Its just something to take into consideration.

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Real-Pierre-Delecto2 t1_j3lwdn0 wrote

They can be discharged below freezing try reading up on the tech at play here. In fact many systems will use the heat created by the discharge to warm the entire bank to the point where it is safe to charge it again. Also your genny math is wacked. No one is gonna be running a 20kw (talk about overkill) genny full tilt for those hours. Other than having a 20kw generator here which is of course overkill you are also wrong on your propane capacity. Capacity is 80% full for a tank so in this case 80% of a 500g tank is 400g.

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df33702021 t1_j3m4hip wrote

In terms of the tank, you are correct that capacity for a full tank is 80%. However, you need to call the propane company to come fill the tank at ~20%, because you don't know their delivery schedule. This is typical regardless of use case. So you have a real usage capacity of less than 80% and more like 60%. BTW, you want a large tank for multiple reasons, not just run capacity.

20kw generators are fairly standard for whole household. Many people have even larger. You are right, they are not going to run them full tilt for 24 hrs straight. That's why I said 2g/hr which is in on the low side of typical 1.5-3.0 g/hr range. You want your generator load to be in the 30-50% range for efficiency and longevity. I fully expect a full 500g tank to last more than a week typically, but we really don't know the use case here. So you have to use the numbers off the data sheet. Otherwise, you are under sizing. At least with the 500g tank you can go an entire week typically and you don't have to worry about it not.

In terms of batteries, you go ahead and use those batteries in zero temps. As I said there are some which can be used down to -4f, but beyond that they can't be used. Those batteries also aren't being widely used for household power. BTW, standard lifepo4 does not make any significant heat being discharged or charged. That's one of the beauties of that chemistry over lead acid. Sounds like you are quoting marketing for EV use. At least you acknowledge that you need to heat the batteries. There's plenty of horror stories where people put lifepo4 in camps, garages, out buildings, etc and heat failed and the batteries were bricked. You can just google it.

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SomeConstructionGuy t1_j38s98g wrote

Sol-ark 15kw plus batteries and solar will do exactly what you want.

But once you start sizing the battery bank for 96hrs of backup with December solar conditions you realize it’s very cost prohibitive. 24hrs can be reasonably accomplished. If you need more than 24hrs it is more cost effective and reliable to shoot for 24hrs of battery and add a small generator that the inverter will call online when batteries run low.

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Stockmom42 t1_j38ucm5 wrote

We have solar and a gas generator. Super grateful for both systems. It really wasn’t that big of a hassle to have the generator installed. We used Taylor rental and they made all the arrangements for the install. Speak to Harveststar if you haven’t already they are awesome with solar and if they don’t know about it they will know who to talk to.

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somedudevt t1_j39rmc6 wrote

Do yourself a favor, look at power consumption of your house. These “electric backups” are normally 100ish ah at 12v or 1200watt total. Your refrigerator uses that in a couple hours. Then what?

If you look at off grid systems, they are 10-20x the capacity of these little portable power packs, and have 1500-5000w solar arrays to replenish them.

At the VERY Cheapest using old school SLA batteries to power a house for a day your looking at $1200 in batteries, some complex wiring, and a weight of 1000lb. Add to that chargers and stuff as batteries do not stay charged they must be maintained it’s just a bad idea.

Get a gas generator, 4 stroke. Get an electrician to install it. Grab 4 or 5 Jerry cans, and call it a day. It will be more reliable, cheaper, and not dependent on the sun to replenish it which generally when the power is out is t reliably uncovered.

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trueg50 t1_j3a5tw3 wrote

Going through this myself. Solar would be great some day with batteries, but it is very expensive and they don't last all that long.

Likely route we are going with is a 10kw PTO generator for my tractor (~$2400) and a GenerLink switch at the power meter. No worries about gasoline, carburetors etc.. just use the same tractor I use all the time. While it is not "instant on" when the power goes out, its very efficient diesel, pretty much maintenance free, and relatively cheap.

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Decweb t1_j3aho62 wrote

I'm guessing you're not going to get more than a day or two out of a battery backup, but of course it depends on your battery capacity. As for recharging those batteries with solar panels, well, it could take a lot of solar panels. Still, worth figuring out if you want the green and self sufficient option.

Me, I have oil heat and a 500 gallon (underground) propane tank hooked up to my generator. It automatically switches on in less than a second most of the time, and I don't know how long I could stretch those 500 gallon of propane, but I'm thinking a couple of months.

Peace of mind, and since it only runs when the power is down, it isn't like it really uses that much propane.

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lavransson t1_j3c639a wrote

Sorry if I'm threadjacking, but I have a tangential question.

I have a 7,500w portable generator that can run gasoline or liquid propane gas (LPG). My house has an external receptacle for a generator that hooks up to the main panel and we have a manual transfer switch to switch off the utility company power and use the generator power. We have an AUX panel that is hooked up to the essential functions: oil burner, well pump, septic system pump, fridge, and a few receptacles in the house.

I also have a 120-lbs LPG tank that I use to power my kitchen range/oven and only that one appliance. We get LPG delivered from a local fuel company (Patterson Fuel) and I am pretty sure they own the tank as it was there when we bought the house years ago and we keep using that same company for LPG deliveries.

We are thinking of switching to an electric kitchen range/oven which would mean we no longer need the LPG. Does anyone know if the fuel company would let us continue to use the LPG tank for our generator? We only lose power once or twice a year at most (so far) so there could be stretches where we don't use any LPG at all. As such, we'd hardly be worth the company having as a customer.

Presumably we'd need to ask Patterson to install an attachment to the existing LPG tank that we could then hook up to our generator.

I'd love to be able to use LPG instead of regular gasoline as this would be more convenient and easier to manage.

Thanks for any tips.

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Professor_Hexx t1_j3chacx wrote

I ended up purchasing an EcoFlow House Kit (Independence 5kwh + smart dual fuel generator) due to the same issues you faced. I will eventually get a solar kit (any solar panels will work with the hub) but right now just the battery + generator is perfect.

Pros:

  • it is a supported package deal so my GF can get help with it in case I get hit by a bus
  • it supports solar (3x1800W arrays), Alternator, AC, and DC inputs
  • the dual fuel generator is 1800W (so small) but will charge the 5kwh of batteries 4 times on a 20lb propane bottle
  • you can use the generator as DC (and when connected this way the system turns the generator on and off as needed) or AC (which you can turn on via pull-cord, button on front, or phone app)
  • I have an iotawatt monitoring system, so I measured my boiler + refrigerator and they use 2.5kwh per day, so (theoretically) if I turn off all the other circuits on battery I can have heat and food (in case the power goes out in the summer) for 2 days before I need to start the generator
  • it has an app for phone as well as a plugged in console (which can be mounted well away from the setup)
  • provides 120v AC and 12v/24v DC in its distribution panel
  • alternative use in an RV or other vehicle
  • expandable to support 240v and has an optional panel to connect to your house main panel to power whole house without wiring (I made a subpanel and powered that with this setup instead)

Cons:

  • pricy, although I did get the package for $2500 off during their xmas sale a few weeks ago
  • specialty cables between hub/battery and specialty connectors on hub for solar and ac/dc out

So far, super happy. Can send pics and more info if anyone likes. This is the kit I bought (without the discount, of course). I was going to get the basic 5kwh kit as I already had a tiny gas generator but due to the sale it was actually cheaper to buy the Independence kit + generator than the kit I actually wanted

Edit: here is a pic of the Grafana dashboard I made for my iotawatt monitor to help determine electricity usage

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Odd_Examination_1387 t1_j3q03rm wrote

I've got the 10kWh system myself. Aiming to get the Dual Fuel Smart Generator in a couple of months! Big spender!

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caesia23 t1_j3dhrnb wrote

Great conversation! One more data point… we’re in Washington county with solar and a powerwall. We made it through 5 days for the Christmas outage on the powerwall because we got ~20 kWh of solar to top it up along the way. Averaged 5 kWh of usage per day during that period to run water a little (well pump, filters, etc.), keep the house at about 55F (oil furnace that uses some electricity, gas fireplace that doesn’t use any), run the fridge, and keep a few lights on.

Couple of learnings… we’ve upgraded appliances and light fixtures and use all LED bulbs, which makes a difference. Your best ROI is reducing your consumption and insulating like crazy. Powerwall app has wonderful data to study your consumption real time. Was key to have a roof rake to clean off the solar panels to get the tiny bit of power from the December sun even on gloomy days. We’ve been wanting to get rid of oil to go electric for heat but that would have tapped out the battery much more quickly, so diversifying your power/heat sources is helpful.

Hope this is helpful! We worked with Green Mountain Solar and unreservedly recommend them. Screw WEC.

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Eremiteees t1_j3l1t50 wrote

Good idea but for the love of God don't go with Bluetti.

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1DollarOr1Million t1_j38fzbj wrote

I know someone that has 2 Tesla powerwalls installed along with solar and he loves it. It’s a really slick system. The walls are about $7500 each I believe but Green Mountain Power has a subsidy plan. Worth looking into.

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NoMidnight5366 t1_j393m3z wrote

One consideration is that when you use propane in small amounts they charge you quite a lot per unit so running the generator can be pretty expensive.

I do like the idea of the battery and solar and you may get rebates there.

Of course as I joked on a previous thread, I spent about 7k on a generator 15 years ago and have since only lost power for about 6 hours since.

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sweintraub t1_j38epfa wrote

Depending what your house uses for power and what car/truck you use, you can often buy a 1-2kw inverter for your 12V and keep the important things going (oil heat, lights, internet, refrigerator, etc.)

You won't be able to use things like electric heat/cooking, dryer, etc but those things can usually wait for power to come back on.

You will need to idle your car while it is on, but efficiency, cost, noise and smell-wise it is far superior to buying a separate unit.

Even better if you have a hybrid or EV.

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