PowerBoost inspired hybrid house

[fwunder]

Since owning my 2023 7.2kW PowerBoost, we have used it's incredible generator/inverter capability to power critical circuits in our house during multiple grid failures. Critical circuits include, refrigerator/freezers, furnace, security system, well pump and strategic lights and outlets. It has been flawless. The only problem has been grid failure when I am not home with the truck...duh! Soooo...

Of course, I could install a standby generator but that seems soooo 2010's. I have decided to build a battery backup system, with some twists.

System Requirements:

• Easily power the critical circuits currently powered by PowerBoost.
• Enough stored energy ( batteries ) to power critical circuits for three days.
• Expandable energy storage
• Include automatic transfer function <20ms - UPS mode - in grid down.
• Include automatic transfer function to generator source ( PowerBoost ) to recharge batteries and power circuits

Simply put, I am building a home UPS system that will automatically recognize when either grid or PowerBoost is available to recharge batteries and power critical circuits. We rarely have grid failures over three days and with this system the PowerBoost should easily keep us going for weeks

Still in the planning stage, but very close to build stage. It should be fun!

Yes, of course, this offgrid design is most often used in solar or yacht systems, but I think the PowerBoost is the perfect secondary power source.

Here is a drawing of what I have come up with so far. I am NOT an electrician - obviously.

Oh, almost forgot! I did confirm a 30% Clean Energy tax credit for the system that can be carried forward until 2035. Cool!

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[Gros Ventre]

About a year ago I purchased a Generac Emergency Panel. I was dissatisfied with it and so didn't install it. Recently I had to look seriously at replacing my main house breaker panel because I was running out of slots for breakers/circuits. The easier solution was to install the Generac panel as it gave me the needed number of additional slots. Well it's in and operates fine with one exception: when shifting to the F-150 PB generator it trips that off the line. The PB resets once shifted and the truck then carries the load fine except that the truck trips off if the Hotwater heater comes on. Its a 4.4kW heater and I expected the 7.2kW generator to carry it without problems. Apparently the surge when the heater initially comes on is too large. All other big loads are fine: furnace @1.4kW, Well pump at about 1kW, 2 freezers & a refrigerator. Electric clothes Dryer & electric oven are not in the circuit.

 

[fwunder]

Yes, with the system I am building I am not using a "traditional" transfer switch. That function is left to the Victron Quattros which will also allow for "power assist" from two sources like PowerBoost and batteries for extra draw. Of course, it's still important to know what your power requirements are and design accordingly. I use multiple "smart" plugs to measure circuit loads in addition to monitoring generator load on each leg. Looking forward to doing that all from my iPhone.

 

[LN7]

Since owning my 2023 7.2kW PowerBoost, we have used it's incredible generator/inverter capability to power critical circuits in our house during multiple grid failures. Critical circuits include, refrigerator/freezers, furnace, security system, well pump and strategic lights and outlets. It has been flawless. The only problem has been grid failure when I am not home with the truck...duh! Soooo...

Of course, I could install a standby generator but that seems soooo 2010's. I have decided to build a battery backup system, with some twists.

System Requirements:

• Easily power the critical circuits currently powered by PowerBoost.
• Enough stored energy ( batteries ) to power critical circuits for three days.
• Expandable energy storage
• Include automatic transfer function <20ms - UPS mode - in grid down.
• Include automatic transfer function to generator source ( PowerBoost ) to recharge batteries and power circuits

Simply put, I am building a home UPS system that will automatically recognize when either grid or PowerBoost is available to recharge batteries and power critical circuits. We rarely have grid failures over three days and with this system the PowerBoost should easily keep us going for weeks

Still in the planning stage, but very close to build stage. It should be fun!

Yes, of course, this offgrid design is most often used in solar or yacht systems, but I think the PowerBoost is the perfect secondary power source.

Here is a drawing of what I have come up with so far. I am NOT an electrician - obviously.

Oh, almost forgot! I did confirm a 30% Clean Energy tax credit for the system that can be carried forward until 2035. Cool!

Very cool plan! You also get the isolation from the grid of surges and potentially dirty power that can effect electronics - as well as the ability to tie in Solar if you want to do that down the road.

I'm hoping you'll post in this thread during the process - eager to see how it goes!

 

[Gros Ventre]

Loading within a house. I spent some 8-10 days on a generator a few years ago. In general, aside from the big loads (oven, dryer, Hotwater heater) a 4kW Coleman generator worked just fine. Note that it was really about 3 kW from altitude effects on the engine. An important concept with the F-150 is that it is a true 7.2kW generator. Since the engine is so much larger than the generator, there are no altitude reductions in capacity.

 

[JoeWpg]

Some complications here - you are essentially trying to add 2 grid-forming inverters in parallel. Each device (powerboost inverter and your battery energy storage) is used to be the only thing in the grid - they are setup so there is no power demand signal and the power in the inverter is determined by the total loads.

As soon as you add 2 grid-forming inverters, you have to have some smart control which determines the battery power and powerboost power are coordinated. I think you want the battery to charge if the powerboost is connected, and to only discharge the battery if the Powerboost is out and about driving somewhere.

Interesting, but complicated with conventional off-the-shelf controllers.

 

[fwunder]

Some complications here - you are essentially trying to add 2 grid-forming inverters in parallel. Each device (powerboost inverter and your battery energy storage) is used to be the only thing in the grid - they are setup so there is no power demand signal and the power in the inverter is determined by the total loads.

As soon as you add 2 grid-forming inverters, you have to have some smart control which determines the battery power and powerboost power are coordinated. I think you want the battery to charge if the powerboost is connected, and to only discharge the battery if the Powerboost is out and about driving somewhere.

Interesting, but complicated with conventional off-the-shelf controllers.

Actually it is not complicated at all with the Victron Quattros and is quite common witch yachts and other offgrid instalations which often switch between shore power and generator power.

 

[Gros Ventre]

Agree, there needs to be a signal to the battery controller when the PB generator is connected. This needs to signal the battery system to shift to the charging mode. Operating two power sources in parallel is usually handled by having voltage droop charateristics in both machines that are close to the same. Commonly this is about 3% droop no load to full load.

 

[fwunder]

Actually, the Quattro can sense and switch DC or AC1 or AC2 power in. I'm going with split phase Quattros because I need 220. Ground relays are programmable too.

 

[Gros Ventre]

 

[Hullguy]

I’ve never installed anything like this. Curious as to why the AC feeds phases are split between 2 controllers. Is there an interconnection between the 2?. To keep the possibility of one controller failing and single phasing with the other?

 

[Kodiak]

All's that missing is the solar array that can recharge your batteries, or partially, while the sun is out. If you have any clear shot of the southern sky this would be a nice addition to your project. Good luck.

 

[fwunder]

I’ve never installed anything like this. Curious as to why the AC feeds phases are split between 2 controllers. Is there an interconnection between the 2?. To keep the possibility of one controller failing and single phasing with the other?

Each inverter/charger outputs @ 120v. I want 220 @ my sub panel. This might help:

https://www.currentconnected.com/product/victron-48v-quattro-3kva-inverter/

The Victron Quattro 3kVA allows for supplementing generators or grid power by utilizing the battery bank, allowing for a constant flow of power. This inverter comes with 2 independent AC inputs, allowing for multiple AC sources, such as grid power and/or a generator. The Quattro can automatically connect to the active source, meaning there is no need to monitor or manage what sources are being used. In the event of a grid failure or shore/generator power disconnection, the Quattro takes over in less than 20 milliseconds.

The entire system is remote monitored and controlled by the Cerbo GX.

 

[fwunder]

All's that missing is the solar array that can recharge your batteries, or partially, while the sun is out. If you have any clear shot of the southern sky this would be a nice addition to your project. Good luck.

Yes, you are absolutely correct. The sky is the limit ( pardon the pun ). As budget permits I will be adding components - batteries, parallel inverter/chargers and solar. Right now, I will be using my PowerBoost as my secondary. Thanks!

 

[fwunder]

One very cool is the ability to remote start/stop a generator based on SOC of battery bank. What does that remind you of?

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