60kw Generator with battery backup

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JC Boost

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Im a bit stumped here on any extra specific equipment needed for this scenario.

Looking to add a 60kw Kholer to a large residential home with two 200 amp panels. 1 panel has solar/Tesla power walls (3) and gateway and the other panel has solar/ Tesla power wall (2) and another gateway both setup as whole home backup

I would like to add the kholer transfer switches between the Tesla gateway/ats and the home loads. I wasn't sure what else might be needed if one system was still energized by the battery backup and the other panel was off and ready for the generator to take over. Is there even a concern with the generator transfer switches working independently from each other or would I need additional relays? note we are not trying to charge the batteries via generator rather have the generator as an additional backup if the batteries depleted.
 
You will use a pair of RDT transfer switches. Control pair wired in parallel. Either one loses power and the generator will start and power that service.

Be aware the Tesla system turns itself on periodically to check if the solar has come back enough to charge batteries. In that case, the transfer switch may transfer back and shut down the generator for a few minutes, leading to intermittent blackouts.

Of course all these johnny come lately battery systems, Tesla included, could have looked to the past and charged batteries off generators, but they could not be bothered.
 
Make sure the Powerwalls and solar are connected upstream of your transfer switches. They are not necessarily tied into the gateways, they could be in the same panels as the loads.
 
jaggedben said:
Make sure the Powerwalls and solar are connected upstream of your transfer switches. They are not necessarily tied into the gateways, they could be in the same panels as the loads.
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Trying to get parallel generation between a conventional generator and a battery or hybrid battery-solar system can be quite difficult, hence the location of the generator transfer switch downstream of them.
 
JC Boost said:
Im a bit stumped here on any extra specific equipment needed for this scenario.

Looking to add a 60kw Kholer to a large residential home with two 200 amp panels. 1 panel has solar/Tesla power walls (3) and gateway and the other panel has solar/ Tesla power wall (2) and another gateway both setup as whole home backup

I would like to add the kholer transfer switches between the Tesla gateway/ats and the home loads. I wasn't sure what else might be needed if one system was still energized by the battery backup and the other panel was off and ready for the generator to take over. Is there even a concern with the generator transfer switches working independently from each other or would I need additional relays? note we are not trying to charge the batteries via generator rather have the generator as an additional backup if the batteries depleted.
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Thank you for the advice and the expected intermittent blackout possibility. Customer wants to proceed so Im looking forward to the project.
 
Birken Vogt said:
Of course all these johnny come lately battery systems, Tesla included, could have looked to the past and charged batteries off generators, but they could not be bothered.
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Generac has come up with a pretty neat system with the PwrCell packs, an ats, and a dc generator that fires only when the PwrCell needs to be charged.

I haven’t installed one yet, but I want to.
 
Seven-Delta-FortyOne said:
Generac has come up with a pretty neat system with the PwrCell packs, an ats, and a dc generator that fires only when the PwrCell needs to be charged.

I haven’t installed one yet, but I want to.
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I typically stick with Sol-Ark inverter or inverters for hybrid systems (15K) - installing the generator on a two wire start and including a manual bypass.

Franklin Batteries have a generator module kit for the ATS and plays very nicely with generators - Worth looking into. Havent heard great things on the PwrCell system but that doesnt mean much as I havent installed one either. But Sol-Ark is my top choice.

The situation Im in is different as the solar and battery system are already installed and working...adding the 60kw Kholer after the fact.
 
Seven-Delta-FortyOne said:
Generac has come up with a pretty neat system with the PwrCell packs, an ats, and a dc generator that fires only when the PwrCell needs to be charged.

I haven’t installed one yet, but I want to.
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What generator exactly works with their system? I had a request and they said they tried to make one but dropped it before it saw the light of day.

Generac is a generator company. Stick with an inverter company for inverters and batteries. Good ones are, Outback, Schneider/Xantrex, SMA, Sol-Ark, in no particular order. But you really need someone familiar to design and install, it is not a project to take on from scratch, it is its own art. All of the above accept generators and always have.
 
Birken Vogt said:
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Generac is a generator company. Stick with an inverter company for inverters and batteries.
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Generac bought Pika, which was young but a bonafide inverter company. By this argument, you shouldn't use the Schnieder/Xantrex line either. Not that I'm a fan of the Pwrcell product.
 
At this point I’ve had trouble finding an actual Pwr Generator, the DC generator, for sale. I was told at the factory training that I did with Generac this summer that it was forthcoming.
 
No neater than what has been made by Outback, SMA, Xantrex for the last 20-30 years.

Just a rework of a proven design done by people who had apparently never studied what has been working fine for decades.
 
Birken Vogt said:
No neater than what has been made by Outback, SMA, Xantrex for the last 20-30 years.

Just a rework of a proven design done by people who had apparently never studied what has been working fine for decades.
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You don't think a DC generator is a more elegant solution in a DC coupled system with inverter? I think the only reason it hasn't been done is the whole generator industry is nearly 100% focused on providing AC output. Kindof a VHS vs. Betamax situation.
 
Well, I certainly need to up my game on the alternative power options, as I’m perusing that work now, but I must say I didn’t know that anyone made an integrated system with with a DC generator.

The one I’m getting ready to install right now is one I designed myself, with solar panels, an inverter from Xantrax, and batteries. All different brands and all put together by myself.

I will be looking into other integrated systems, and other companies that are manufacturing DC generators. 👍
 
jaggedben said:
You don't think a DC generator is a more elegant solution in a DC coupled system with inverter? I think the only reason it hasn't been done is the whole generator industry is nearly 100% focused on providing AC output. Kindof a VHS vs. Betamax situation.
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You raise a point I have often thought about. It is a mystery to me why we don't see more DC gensets for these applications. While I'm not all that well versed in alternative energy as you are, I often think about these things if I were to build another house. I see so many installs that include solar, storage and genset that, I just say myself, wow, what a poor system design.
 
#1 reason of course is that AC generators will always outsell DC by 100 to 1. So who wants to make one that will only sell a few units.

What few DC generators of various stripes that currently exist are strange and problem prone. Probably because they do not have the install base and warranty claims for the manufacturer to take notice and make improvements. They just will not devote the time.

#2 reason is that, as the old Trace inverters back in the 1990s show and still goes on today, you do not need a DC generator when you already have an inverter. They just run the inverter in reverse as a high power and controllable battery charger. Trace and now Xantrex pioneered it and still does it. Outback is the same way. SMA as well. It is just reversing the power flow through the same components to use a standard genset and not something exotic.

#3 is that it makes even less sense to develop a dedicated DC genset nowadays, since solar and batteries are more powerful than ever before, the genset just runs less and less often.

Those customers that really run their genset a lot are so blasted rich that you are using turbo diesels or V8 propane gensets to meet their demands and there is really never going to be a DC genset made for them, probably only sell 10 units ever.
 
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