Whole house generator and propane supply

[ncbill]

Solar is not a great option for my house. We have rainwater catchment for our household water (except drinking and cooking) so putting panels on the roof is problematic (not impossible but just a lot of issues to worry about like leaching things into the catchment water.) A separate racking system is possible but that also has concerns and is pretty expensive.

Battery backup instead of generator is something I will look into.

As NW-Bound notes:

"...the all-in-one inverter charger can also charge the battery with AC power from the grid or a generator. What I like about this set up and also the larger $9K setup is you don't need to run the generator 24 hours. You charge up the battery during the day with an inexpensive $500 inverter generator, then shut off the genset to go to sleep. The battery has enough juice to get you through the night easily with a window AC, unless you need to run a central AC at night."

The above is why I recommended the battery-based system I linked.

Generators are more efficient charging a battery pack to run loads versus running the loads directly from a standard (non-inverter) generator.

Because propane is expensive enough here in CONUS...can't imagine what it costs delivered to a remote area of Hawaii!

 

[bjorn2bwild]

As NW-Bound notes:

"...the all-in-one inverter charger can also charge the battery with AC power from the grid or a generator. What I like about this set up and also the larger $9K setup is you don't need to run the generator 24 hours. You charge up the battery during the day with an inexpensive $500 inverter generator, then shut off the genset to go to sleep. The battery has enough juice to get you through the night easily with a window AC, unless you need to run a central AC at night."

The above is why I recommended the battery-based system I linked.

Generators are more efficient charging a battery pack to run loads versus running the loads directly from a standard (non-inverter) generator.

Because propane is expensive enough here in CONUS...can't imagine what it costs delivered to a remote area of Hawaii!

Yes, the battery/inverter/inverter generator set-up is a nice solution on multiple levels.
As a traveler, I am limited to a scaled down, portable version.
During the recent power outage brought on by the remnants of hurricane Hilary, I fired up the trusty Honda 3000is that came with the house and ran the web of extension cords trying to get back to business as usual.
The problem…... after switching to econo-mode, each time the refrigerator tried to start, all sensitive downstream electronics shut down and reset, including the large, newer model GE fridge.
The only option would have been to take the genset off econo-mode, burning more fuel and making more noise than needed – the static load was well under the rated capacity.
Luckily, I travel with 300ah’s of LFP battery power and a 1500w pure sine wave inverter, plus 30A charger.
After isolating the problem load, the generator could be idled down and peace returned to the household.

 

[SecondAttempt]

As NW-Bound notes:

"...the all-in-one inverter charger can also charge the battery with AC power from the grid or a generator. What I like about this set up and also the larger $9K setup is you don't need to run the generator 24 hours. You charge up the battery during the day with an inexpensive $500 inverter generator, then shut off the genset to go to sleep. The battery has enough juice to get you through the night easily with a window AC, unless you need to run a central AC at night."

The above is why I recommended the battery-based system I linked.

Generators are more efficient charging a battery pack to run loads versus running the loads directly from a standard (non-inverter) generator.

Because propane is expensive enough here in CONUS...can't imagine what it costs delivered to a remote area of Hawaii!

Yes, I understand. I think I'm going to need to do some real engineering calculations to figure this out. We don't run any air conditioning or heating units. The only big loads would be oven, stove, hot water heater and dryer. I think we could live without dryer for a considerable period. Ditto with oven and maybe even stove, using grill and camp stove instead. So we could do a considerable amount of load shedding manually and that could make a backup battery/inverter system viable. The longest outage we have had was about 6 days but we have had 2-3 day outages roughly once a year and several hours almost monthly.

I'll need to look into the price of propane here. It is likely higher than the mainland but I don't think it is triple the price while commercial power is. I know that I pay for exchanges about what I paid on the mainland 10 years ago.

 

[Texas Proud]

I am gong to throw this out as an option... have no idea if it is viable or wanted...


So, go with the battery setup as mentioned... that would cover most all power outages...



Next, buy a portable generator that would be able to charge up the batteries if they were running low.. IOW, hook it up and run it for 4 to 8 hours filling the batteries and you have another day or so of power... repeat if needed...


If you want you can get a dual fuel one and buy a 50 to 125 gallon propane tank that you can store in the garage for the generator... that would mean you do not have to worry about having new gas...


Thoughts?

 

[NW-Bound]

Once you go with the setup of inverter+battery+small generator, then solar panels add just a small additional cost, yet give you something everyday even when you don't have an outage.

According to NREL (National Renewable Energy Lab), a 330W PV panel will produce 536 kWh/year (using actual sunlight data), or 1.5 kWh/day on the average in Hawaii. The difference in summer/winter solar production is small in Hawaii due to its latitude.

A modest array of 10 panels will give you 15 kWh/day. This amount of energy would require 3.5 gal of gasoline for a portable 2-kW Honda generator (4.3 kWh/gal).

With electricity cost at $0.42/kWh, that's $6.3/day of electricity cost savings, or $189/month, or $2251/year.

The shipping cost to Hawaii is high, but I can get used panels still good as new for $100 each. If it weren't for the shipping cost, the payback for just the panels is 6 months!

PS. If you have land, a ground-mount solar array can be installed quite cheaply and easily. I would set up the whole thing as an off-grid system, and not tie it to the grid at all. If you do that, you need not ask permission from the utility company.

What I like about my DIY system is that all the components can be updated/added incrementally. I kept adding more panels, more inverters, more batteries as I learned the rope. From the initial 20 panels, I now have 40 panels. From 2 inverters to 4 inverters (2.4 kW each). Battery capacity from 22 kWh to 34 kWh, and to 45 kWh soon.

Still not enough in this 115F heat, and the ACs running 24/7.

 

[RS7-63]

I have a whole house generator that is on Natural Gas. That is nice as I never have to worry about refueling. If I was in your shoes on propane, I would definitely go with a 500 gal tank over the 250. Better to have the extra capacity if you need it.

 

[Skitso999]

I have definitely considered running my old cars on propane. What's the projected cost of that setup

 

[53anddone]

We have a Tesla Powerwall. We can easily cover 48 hours of whole house power and probably double that with just fridge and well pump.

We also have solar which could recharge it if it is sunny.

Where we live a power outage more than 3 days is pretty rare and I like the tesla system. It switches over and we don't even know it except I get a text on my phone.

Its not cheap but there are a lot of incentives particularly if you let the power company use it during peak demand (not outages). That's what we did and they paid for half of it.
I see HE has something:

https://www.hawaiianelectric.com/hawaiian-electric-refines-battery-bonus-incentive-program

 

[meleana]

I am considering installing a whole home generator with a fairly large propane tank. We've had several multiday power outage over the last few years. I could probably go with a portable generator to just handle a few things like refrigerator and freezer but the whole home solution I found is only about 2-3x more than the minimum solution and has an automated transfer switch for a mostly seamless solution. I realize there would be additional costs for installation and pads for the generator and a propane tank. I can do the pads myself and installation I know a licensed electrician who can do for a fee.

I haven't done the calculations yet but I'm thinking a 250-500 gal propane tank, in part because I am in a remote area and propane deliveries might be expensive. So I would want to minimize delivery frequency.

I'd also like the tank to supply some outdoor tiki torches (I'm in Hawaii) and be available to refill my grill tank(s). I know I could hard plumb the grill but its location makes that challenging.

So, a few questions:

Does anyone refill small tanks from a larger tank at home? Is the equipment hard to find? I mostly do exchange now but used to get refills and I think I can handle the process if I have the right equipment.

How much would I expect to pay for a 250 gal or 500 gal tank?

Anyone have experience with a generator with ATS? The brand I am looking at is Generac but there are others I would consider.

I'm mostly choosing propane for safety to avoid storing a couple of hundred gallons of gas to cover an extended outage and having to refill manually often during the outage. Is this a bad choice? I do not want an underground storage tank!

In both our current and previous homes we did not purchase our tanks. We did not want to worry about the condition of the tanks as they aged.

Anyway, our first home was twice the size of our current home. We had two 100 gallon tanks for the generator only. We were told having two tanks was better than having one large tank but I can’t remember why. We used the same company for the oil that heated that home so we were not charged anything for use of the tanks.

Our current home is much smaller and is also heated with propane. We also have 2 100 gallon tanks to heat the house and also for the generator but we don’t lose electric here like we did where we used to live. The propane company does not charge for the tanks.

 

[NoEZmoney]

Other Options / Portable Westinghouse Dual-Fuel Genny

We've had quite a few power outtages that lasted more than a couple days and I got a portable generator to help with this. I didn't want to pony up the $$$$$ for a Generac or similar whole-house unit as that's a lot of money that basically sits idle for 90 to 95% of the time.

Instead I got a Westinghouse W9500 Dual Fuel generator capable of 30/50amp service that provides up to 9,500 (Running) /12,500 (Starting) watts on gasoline or up to 8,500 (Running) / 11,200 (Starting) watts on propane. I've used it a couple times already just to power Fridge / Freeze - fans & lights. I got 10+ hours run time on gas with the 6.5 gallon tank. It will run on propane about 8 or 9 hours depending on load. I haven't gotten it connected to the breaker box yet as I need to get a licensed electrician to install the transfer switch to code.

Now I know guys who've used this same unit to power their central AC, fridge and freezer, some lights and a few small appliances with no issues.

I am confident this will work with mine as well. All said and done, I'll have spent about $2K on everything, including two 30 lb propane tanks, transfer switch, 50 ft 50amp cable, outlet, and install services. Other than wheeling it out on the pavers in the backyard about 40 feet away from house, I'll have an easy to use system. I could even install a small shed cover and leave it in place if the missus doesn't mind.

 

[SecondAttempt]

We have a Tesla Powerwall. We can easily cover 48 hours of whole house power and probably double that with just fridge and well pump.

We also have solar which could recharge it if it is sunny.

Where we live a power outage more than 3 days is pretty rare and I like the tesla system. It switches over and we don't even know it except I get a text on my phone.

Its not cheap but there are a lot of incentives particularly if you let the power company use it during peak demand (not outages). That's what we did and they paid for half of it.
I see HE has something:

https://www.hawaiianelectric.com/hawaiian-electric-refines-battery-bonus-incentive-program

Thanks for the link. Unfortunately that program is only available on Oahu and Maui. And given that everyone is now suing Hawaiian Electric over the Maui fires, I'm not sure what the future of those programs are.

 

[FedRetired50]

have had a Generac since 2004

Installed a 12kw Generac around the end of 2004. What the dealers - and Generac - don't like to talk about is how much they cost to run during long outages. Its nice that they start up on their own while it is pouring outside, and if the outage is a half-hour, that's not a big cost.

At idle my Generac uses 1.5 gallons/hr. More if it is loaded up. If you pay $3/gallon that's a minimum of $108 per day.

I now use a 3 kw inverter generator hooked up to a dedicated panel that runs almost all of my 120 volt loads, and it will run on 3 gallons of gas for 24 hours. At $3.50/gallon that's $10.50 per day. Basically 10% of the cost to run the big guy, and the power output is cleaner.

I only turn on my Generac for an hour or two to run my well pump and water heater for showers. I do leave the Generac on "auto" mode so it can handle those shorter outages, but after 30 minutes I'll walk the smaller generator outside and start it up.

If I had to do it again I would do as others suggest and install a solar + battery offgrid system and use the small generator for bulk battery charging if necessary. All the advantages of the Generac, plus some (less noise, two systems give you redundancy), and none of the downsides. If I had to go without the solar + battery for some reason, I'd keep the 3 kw inverter generator and also get a 7 kw inverter generator that has 240 volts output for the well and water heater. That also gives you redundancy.

 

[catii]

We decided to install a pro-level Thermador gas range when we remodeled our Kaneohe kitchen back in 2014. I originally rented a 100-gallon tank from Hawaii Gas, & were shocked when the bill was $6.32/gallon of propane! So I quickly found two inexpensive tanks of the same size, & had a gas plumber hook them together with a manual transfer switch. Now the gas company just switches out the empty tank, even though it's ours, & charges us $1.67/gallon. Go figure.

We've checked out whole-house generators, & may eventually buy an Onan with ATS. For now, we have two small 2500-watt gasoline generators, which are enough to power our two standalone refrigerators (no freezers) & two standalone freezers. I had an electrician wire the rooms so we can run the generators outside, on a concrete slab. Yes, gasoline does degrade, so besides using a stabilizer, we just pour the 10-gallon storage tanks into one of our gas-guzzling cars.

We have solar hot water, plus 10.1 kWh of solar PV panels on our second floor roof. I'm looking into a short-term solution of the new Enphase IQ8 inverters, which act like a bank of batteries when the sun shines,

Longer-term, when we buy our next car, it will have V2H (vehicle-to-home) capability (https://www.dcbel.energy/blog/2023/01/04/new-year-new-bidirectional-cars-2023-edition/). Several models will power my home for a week! After I use my PV system to charge the car, I can benefit from the large battery in other ways than just on the road. Not quite free power, but close.

I don't know where you are in our islands, but maybe one of these will work for you.

 

[hotwired]

Maine

We live in rural maine, but five or six miles from a small city as well. We have a whole house Kohler generator. We have a electrician that works for us that actually got his license just to install ours, and our research indicated that there are less problems with the Cold war versus the generac overall. It's not like a night and day comparison but overall the Cold war seem to Edge out the generac on reliability. Our tank I think is 500 gallons, and may or may not be the largest legally allowed without some hoops to jump through. I have kind of a pepper mentality and wouldn't mind having 10,000 gallons on site but I know that would be a little ridiculous. I agree with your sentiments about gasoline. Gasoline has a shelf life, and I personally wouldn't consider it or even diesel. As for filling up your own propane tanks, I'll tell you we have a gas stove and we have one of those smaller tanks for it. It's about 4 ft high and 12 in wide, maybe 80 gallons?? I don't know, but we use our gas oven and stove daily and we only have that thing filled once every two years. Unless you grill at least an hour every single day or at least 300 days a year I think it would take you 20 years to pay back whatever extra money you spent running a line to your grill or adding some sort of apparatus to be able to fill your own tanks. We get our tanks filled in town for 18 bucks, and we go through two every summer.

I love our generator, we live in an area that gets probably for power outages a year, I have a battery backup on my computer so if I'm working in my office I literally wouldn't even know we lost power except for my office light going off for 20 seconds! I have our router and modem plugged into the UPS as well so we don't even have a flicker in our internet or Wi-Fi unless it too goes out.

 

[misanman]

I have our router and modem plugged into the UPS as well so we don't even have a flicker in our internet or Wi-Fi unless it too goes out.

I've had our computer/router/modem plugged in a UPS but when the power goes out we have always lost our Comcast/Infinity connection regardless. I don't know why but I'm guessing that they lose power at a local access point.

 

[hotwired]

Yup

I've had our computer/router/modem plugged in a UPS but when the power goes out we have always lost our Comcast/Infinity connection regardless. I don't know why but I'm guessing that they lose power at a local access point.

I was already getting a little long-winded otherwise I would have added that 90% of the time we lose Internet anyway as well, haha!

 

[rmcelwee]

The 5-gal propane tanks have a small vent at the neck that is opened with a screwdriver. Opening the vent allows propane vapor in the tank to escape to make room for the liquid propane to enter the tank.

I'm late to the thread but sending pressurized gas through a small opening tends to build a static charge. I was in the chemical industry for 32 years and this sounds like a good way to build a flame thrower. Just throwing that out there as a safety item. I would bet that the people who fill propane bottles take special precautions when doing this (grounding strap?).

 

[Texas Proud]

We live in rural maine, but five or six miles from a small city as well. We have a whole house Kohler generator. We have a electrician that works for us that actually got his license just to install ours, and our research indicated that there are less problems with the Cold war versus the generac overall. It's not like a night and day comparison but overall the Cold war seem to Edge out the generac on reliability. Our tank I think is 500 gallons, and may or may not be the largest legally allowed without some hoops to jump through. I have kind of a pepper mentality and wouldn't mind having 10,000 gallons on site but I know that would be a little ridiculous. I agree with your sentiments about gasoline. Gasoline has a shelf life, and I personally wouldn't consider it or even diesel. As for filling up your own propane tanks, I'll tell you we have a gas stove and we have one of those smaller tanks for it. It's about 4 ft high and 12 in wide, maybe 80 gallons?? I don't know, but we use our gas oven and stove daily and we only have that thing filled once every two years. Unless you grill at least an hour every single day or at least 300 days a year I think it would take you 20 years to pay back whatever extra money you spent running a line to your grill or adding some sort of apparatus to be able to fill your own tanks. We get our tanks filled in town for 18 bucks, and we go through two every summer.

I love our generator, we live in an area that gets probably for power outages a year, I have a battery backup on my computer so if I'm working in my office I literally wouldn't even know we lost power except for my office light going off for 20 seconds! I have our router and modem plugged into the UPS as well so we don't even have a flicker in our internet or Wi-Fi unless it too goes out.

Do you mean Kohler instead of Cold war?

 

[Texas Proud]

One thing to remember if you plan on buying a whole house generator is how common is it... IOW if it breaks down and you need a part then Generac is probably the best option as it is all over the place... Kohler I believe is 2nd..


I think it was Champions that was quieter than the Kohler but even finding someone who installs and services them is a challenge...

 

[NW-Bound]

Maybe, but if you simply google search Kohler Variable Speed Generator you will get MANY hits. Supposedly mine is variable speed depending on the demand. Sorry, I'm too lazy to go dig up the manual.

Here is a random example:
https://apelectric.com/all-generato...ors/kohler-6vsg-6kw-variable-speed-generator/

Any variable speed generator would have to be an inverter type Those use the generator/alternator to keep a battery charged, and electrical switching inverter converts the battery DC to 50/60 Hz AC (independent of engine speed).

A standard generator must maintain 1800 or 3600 RPM to maintain 60 Hz. Its a direct connection from engine to generator/alternator. Number of poles in the gen/alternator determines the multiple.

-ERD50

I saw the above posts just now.

Very interesting that Kohler now offers generators built specifically to charge batteries. You have to specify the battery voltage: 24V, 36V, or 48V.

Quite pricey at $5,241-5,672 for a 6 kW DC generator. You can do cheaper with an inverter generator putting out AC, then feed this AC power to a battery charger. You can get a generator with remote electric start for $1000, and feed the AC output to the all-in-one inverter/charger units on the market now. Many of these all-in-one units have a low-battery control output that can be wired to trigger the electric start of the generator (a simple relay circuit may be needed).

In theory, the inverter generator+charger setup may not be as fuel efficient as the Kohler generator, but the price difference is huge, plus the inverter generator is independent and can feed your house circuit by itself if the battery+inverter fails, while the Kohler battery-charger generator would be useless.

The fact that Kohler builds and sells something like the above shows that more and more people are doing battery+inverter setup for protection against grid failure. What interesting time ahead!

 

[NW-Bound]

I'm late to the thread but sending pressurized gas through a small opening tends to build a static charge. I was in the chemical industry for 32 years and this sounds like a good way to build a flame thrower. Just throwing that out there as a safety item. I would bet that the people who fill propane bottles take special precautions when doing this (grounding strap?).

I did not know about the above hazard.

Thinking about this, I never see the attendants at the propane filling station do anything special. However, they always open/close the gas bleed port with a screwdriver when the hose is already attached to the 5-gal tank.

Now, if the hose is steel-braided, then perhaps that is how the tank is grounded to the refilling station to prevent static charge build up.

 

[rmcelwee]

I did not know about the above hazard.

Thinking about this, I never see the attendants at the propane filling station do anything special.

I never saw the guys working for me use ground straps either, unless they saw me walking up then they quickly put them on!

 

[FedRetired50]

I did not know about the above hazard.

Thinking about this, I never see the attendants at the propane filling station do anything special. However, they always open/close the gas bleed port with a screwdriver when the hose is already attached to the 5-gal tank.

Now, if the hose is steel-braided, then perhaps that is how the tank is grounded to the refilling station to prevent static charge build up.

It is standard procedure, so nothing to worry about. I believe the assembly is brass to prevent sparks, and I have no doubt the filling nozzle/hose acts as a ground since the rest of the system is definitely grounded.

 

[rmcelwee]

We recently lost power for three days. Then two days later lost it again for 12 hrs. The place we live has very frequent power blips. We are way out in the boonies and will always be the last place to get power restored so we have been discussing buying a Generac. After reading through this thread today I think we are going to stick to our original plan of solar instead. Thanks!

A few random data points in my head, maybe they will help someone:

- We currently run a 10K portable generator that uses 1/2 gallon of gasoline per hour. It is enough to power everything in our temporary home (single wide trailer built in 2022). This includes heat, air, water heater, etc. I do not think we have tried running the washer/dryer but that isn't really a necessity.

- We have two stand up freezers in my workshop (detached metal building with insulation and heat/air). Overnight, with outside temps in the upper 60's, the temps in the freezers jumped from 0 to 12F and 4 to 17F over an eight hour period.

- My generator lost 1/2 qt oil during a two day period.

- I test run my generator with no load on it every 6-8 weeks.

- I have been thinking of using a 48V golf cart as a battery pack. My current cart is 36V and I haven't found a good way to utilize the power it holds.

- Our new home will be ICF (insulated concrete formwork) and purpose built for extremely low electric usage. Hopefully we will never worry about a power outage again. It will have solar and a Tesla wall type battery system.

 

[Texas Proud]

Oh... just want to add info because someone noted how expensive it was to run a large gas generator...


This is with nothing but looking at a bill and a WAG... but we were offline for 22 hours recently and when I looked at my next gas bill I calculate a cost of about $1.20 per hour for the generator...


Not cheap but way less than the over $3 per hour mentioned..