[Fox123]

I am going to replace a generator and I'm looking for feedback on a thought I have had as to improving my home power backup preparedness. I live in eastern Canada, with very cold winters, no natural gas access, and a home heated by ductless heat pumps and a wood burning fireplace.

• Currently I have my well pump, all lights, freezer & fridge, wifi, fireplace fan and certain specific wall outlets on a generator panel that I plug a basic 3500 watt generator into during an outage and manually switch over to. This has actually worked fine, BUT I have been fortunate not to have had a long outage during the winter. This generator would not start for me during a spell of -35C weather we just had, so as a minimum I am going to replace this with a better unit with electric start.
• I want to add the ability to run my hot water tank and at least one of my heat pumps (they are 15000 and 24000 btu units) in the event of a longer winter outage. I am leaning away from installing a whole house automatic system like a Generac that entirely removes the inconvenience of a power outage for the following reasons:

- I don't see them as a solution for a really long power outage because of the expense of running them on propane here. At 2.5 US gallons per hour they would cost about $250 a day.
- I can handle some inconvenience for a few hours or days.
- I don't want the generator and a couple of large propane tanks on my lawn, they would be impossible to hide and wouldn't look great. They just strike me as not viable for a really long outage, and gross overkill for a short outage.
- So my idea is to put the heat pump and water pump on a second generator panel, with a second outside connection. I would get a small generator, probably a dual fuel inverter model, to replace my current one, and I would plug that in for most outages. I would get a larger unit (10,000 watt?) that I would plug into the second connection when in a situation that I needed to power the heat pump or water heater. These generators would be in the garage when not used, would be relatively inexpensive to buy and run, and one would at least partially back-up the other if it didn't work.
What do people think about this? I've not seen it done, so perhaps its not a great idea? Thanks for your feedback.

 

[sledman8002002]

Welcome to the forum Fox123!
Depending on how much juice those heat pumps require, by the sounds of it a larger dual fuel inverter gen in the 9000/7500 range might be all you need to get by.
There is a trick which I'll soon be doing on my own hot water tank. From what I gather/understand it involves adding a 30 amp switch between the fuse panel and the HWT allowing it to heat with only one element when desired. I'm still gathering the info and 'how-to' on this.
If the larger inverter gen does prove to be enough, the 3500 can be kept for a backup to the new unit.

 

[Fox123]

Welcome to the forum Fox123!
Depending on how much juice those heat pumps require, by the sounds of it a larger dual fuel inverter gen in the 9000/7500 range might be all you need to get by.
There is a trick which I'll soon be doing on my own hot water tank. From what I gather/understand it involves adding a 30 amp switch between the fuse panel and the HWT allowing it to heat with only one element when desired. I'm still gathering the info and 'how-to' on this.
If the larger inverter gen does prove to be enough, the 3500 can be kept for a backup to the new unit.

Thanks - I'll check into that water heater idea.

 

[sledman8002002]

Here's a couple of links I've been looking at...

How to Toggle Electric Water Heater Between 120V and 240V?

How to wire electric water heater for both 120V and 240V. Toggle Water Heater between 120V and 240V using DPDT and 3-Way Switches. 120 & 240V Heater Wiring

www.electricaltechnology.org

How to Control a Water Heater using Switches? 1, 2, 3 & 4-Way

Controlling of Water Heater using Single Pole, 2-Way, 3-Way & 4-Way Switches. Control a Water Heater from 2 Places using Crossover or Intermediate Switch

www.electricaltechnology.org

 

[Browse Deweb]

What is your budget? I went with a rack mounted battery backup system as my primary, with my Honda EU7000is as my secondary backup for recharging the batteries. This was not a cheap endeavor, but serves as insurance against prolonged outages since I will be using the batteries 20 hours/day and the generator a few hours/day for recharging. The Honda is also converted to tri-fuel so I can run it on natural gas. I wouldn't recommend running any smaller air cooled engine for days or weeks continuously since they aren't made for that. You'd want a water cooled 1800 RPM generator or a diesel unit designed for continuous duty.

 

[Fox123]

What is your budget? I went with a rack mounted battery backup system as my primary, with my Honda EU7000is as my secondary backup for recharging the batteries. This was not a cheap endeavor, but serves as insurance against prolonged outages since I will be using the batteries 20 hours/day and the generator a few hours/day for recharging. The Honda is also converted to tri-fuel so I can run it on natural gas. I wouldn't recommend running any smaller air cooled engine for days or weeks continuously since they aren't made for that. You'd want a water cooled 1800 RPM generator or a diesel unit designed for continuous duty.

Thanks, that sounds like a great system. It would be a more serious response than my situation justifies, though. Lengthy power outages are very rare for us, but I'm mostly concerned to handle heat if a long one happened during a -30 period. Batteries would probably be pretty short-lived in that scenario, and would sit unused for long periods,

 

[Browse Deweb]

Thanks, that sounds like a great system. It would be a more serious response than my situation justifies, though. Lengthy power outages are very rare for us, but I'm mostly concerned to handle heat if a long one happened during a -30 period. Batteries would probably be pretty short-lived in that scenario, and would sit unused for long periods,

You could get two dual fuel inverter generators that can be paralleled. This would provide redundancy as well as much higher power output when necessary. This guy tested two of the Genmax units and was pretty happy with the results:

I can't speak to their reliability or parts availability, but you can buy two for less than the price of a single Honda EU7000is which is the unit I have.

 

[SpinningGen]

I would just make my own back up generator. You can easily make one with a rebuilt gas or diesel engine and mount the right Jenny to it.

I believe it is Mid Georgia Generator that has all the specs on them, and they have free delivery too. So you could easily get a 30 hp rebuilt diesel and mount a 20 kw Jenny on it and have plenty of power. Get a new or used heating oil tank for high capacity and long run times, and wire in a hertz/voltage/ amps box to your main circuit.

There is no auto start, but hit the starter, throw a few breakers and you are making your own power. My little set up has a 66 day run time for 20 kw when the tank is full.

If you have a tractor, a pto generator is even easier

 

[50ShadesOfDirt]

Most gens don't like starting in real cold temps, so that sounds like possible root cause of problems in your original setup. I couldn't start my gen at near 0F, until I slapped together a temp enclosure and added a temp heat source ... after a bit of time, the gen fired right up, regardless of air temp.

One option to consider is having the gen(s) inside a small heated gen enclosure, attached to your garage or standalone. No moving of gens, etc., cords are inside the garage for plugging, but gen(s) are outside for running. Other threads on this forum, or youtube, discuss these kinds of sheds.

It sounds like you are flexible in what needs powering, and for how long. If this is the case, a "solar generator" (inverter/battery in a box) might be suitable, in addition to the gen(s). Run the gen(s) for powering big loads, for just a few hours per day of outage, and run the solar gen for light loads (lights, recharge, fridge) any other time of the outage. Gens can recharge the solar gen if outage is longer than expected, and typically, the gens can support some loads and recharging, so still not a 24x7 run against your fuel.

Hope this helps ...

 

[Robh]

1) Buy a 'Sense' monitor or something equivalent that will tell you exactly how much power you need for your scenarios.
2) Battery start inverter generator is a great idea. Just wire something up where you can remove the battery and keep it inside your house until needed. Quick connects.
3) As much as we all love propane around here, it won't be your friend in that cold weather. Keep gas handy in the winter, but propane for the summer.

 

[Fox123]

Most gens don't like starting in real cold temps, so that sounds like possible root cause of problems in your original setup. I couldn't start my gen at near 0F, until I slapped together a temp enclosure and added a temp heat source ... after a bit of time, the gen fired right up, regardless of air temp.

One option to consider is having the gen(s) inside a small heated gen enclosure, attached to your garage or standalone. No moving of gens, etc., cords are inside the garage for plugging, but gen(s) are outside for running. Other threads on this forum, or youtube, discuss these kinds of sheds.

It sounds like you are flexible in what needs powering, and for how long. If this is the case, a "solar generator" (inverter/battery in a box) might be suitable, in addition to the gen(s). Run the gen(s) for powering big loads, for just a few hours per day of outage, and run the solar gen for light loads (lights, recharge, fridge) any other time of the outage. Gens can recharge the solar gen if outage is longer than expected, and typically, the gens can support some loads and recharging, so still not a 24x7 run against your fuel.

Hope this helps ...

Thanks. I had read a suggestion (can't remember where) that advised using propane in really cold weather for easier ignition, then switching to gasoline after its warmed up for lower cost - but it sounds like that wasn't right? Also, do you use something like a small propane or kerosene heater in your enclosure?

 

[SpinningGen]

Both points are right in a way…

Propane is better than gas or diesel because it never goes bad no matter how old it gets. It also will fire easier in cold weather as long as it is in a gas state.

what do I mean by that? Isn’t propane always in a gas state?

No.

It has to do with the boiling point of propane. When the temp gets down to -20 or so, the liquid propane in the tank does not boil to a gas state as quickly, so it can have a harder time firing, or it frosts up the regulator.

But solving these issues in diesel or propane is easy. Just go with a bigger propane tank so more liquid propane boils at a rate that the propane engine consumes in cold weather. Or put heaters on your diesel engine so they start when it’s cold. My back up Jenny at work fired two weeks ago when it was -20 below and blowing 40 mph making the wild chill -44 below because it had heaters in the engine.

There are always work around s to issues.

 

[50ShadesOfDirt]

"propane, switching to gas" sounds like a duel-fuel gen scenario, especially for those w/ grid-down & looking at 24-hour runtimes and fuel/cost issues.

Not my scenario, so not much help, other than to say propane has never been an issue in my few cases of 0F or below temps ... propane has never let me down, but I also don't run on small propane tanks for the gen or other propane device, so that matches SG comments above. On this property, we have been on propane and gens for upwards of 10 years, and have made it through 10 colorado winters (which I think equals one of yours).

I do, however, work hard to not run a gen more than 4 hours in 24, and a battery/inverter system is key, as others mention above ... this also solves fuel problems. If you go with solar gen, it can be recharged from small inverter-gen, grid when back up, and be utilized for other functions as well, so it won't sit too idle.

For my temp heater source, it was a small propane heater (mr heater type), and it added just enough heat to a temp enclosure to bring air temp (and gen) up to 20F or thereabouts, from 0F, at which point the gen fired right up. Once started and running, it had no problem staying warm enough to run.

You are on grid, so perhaps an electric/thermostat ceramic heater is feasible, or a portable small propane heater if grid-down for longer periods.

 

[JohnG]

What is your budget? I went with a rack mounted battery backup system as my primary, with my Honda EU7000is as my secondary backup for recharging the batteries. This was not a cheap endeavor, but serves as insurance against prolonged outages since I will be using the batteries 20 hours/day and the generator a few hours/day for recharging. The Honda is also converted to tri-fuel so I can run it on natural gas. I wouldn't recommend running any smaller air cooled engine for days or weeks continuously since they aren't made for that. You'd want a water cooled 1800 RPM generator or a diesel unit designed for continuous duty.

Wow! This sounds like exactly what I'm looking for. What kind of battery backup system are you using? I have an older Honda EU6500is and would like to find a battery backup (used as Primary) that could be charged from the Honda (or from existing Solar, and possibly the utility company grid...when operating). How difficult was installation of the tri-fuel converter? I'd like to switch my Honda to Propane. Thanks in advance.

 

[Browse Deweb]

My system is configured like this:

The batteries, rack and inverter are from Signature Solar. I purchased them when they were running a sale where everything was 10% off and they gave you a free rack with the purchase of 3 or more batteries. Shipping was also flat rate $100 for the sale which came delivered on 3 pallets.

Growatt 12k Inverter:
Growatt 12KW Split Phase Off Grid Inverter | SPF 12000KT DVM-US MPV

48VDC LIfepower4 5kWh Batteries:
EG4-LifePower4 Lithium Battery | 48V 100AH | Server Rack Battery | UL1973

I'm considering getting one of their Chargeverters so I can connect the generator directly to the battery busbars, allowing the Growatt Inverter to power the house while the Honda is charging the batteries. This allows me to use the surge capacity of the inverter for items with big inrush currents like the 4-ton HVAC unit.

The tri-fuel conversion kit for the Honda was purchased from US Carb under part number MSK7000. It was pretty easy to install...you just attach the regulator and run the line through the battery compartment and connect it behind the air filter. You would likely need a different kit since you generator isn't fuel injected. I switched to an iridium spark plug for better ignition and smoother running with natural gas. You do lose a little bit of power, but I never run the generator that hard anyway. My typical power usage is between 1-2kw at any given time.

Keep in mind that battery power now qualifies for the 30% federal tax credit under the Inflation Reduction Act (a misnomer if ever I saw one), so anything you spend on the system is cut by 1/3 when you file your taxes. My $9k battery system purchase became a $6k purchase which is much more palatable. The best part is that I can take the Honda and the inverter/rack system with me when I move.