The electrical engineer on one of our projects is looking to substitute traditional backup generation with a battery back up system. He requires it to be able to handle a 50 amp load and runtime of about 5-6 hours.

I looked around a little bit on the web and found this system but run time is no where near what he needs.

[Link: tnb.ca]

Anyone know of another system out there that would meet his spec?

TIA

He's the engineer, wouldn't he know what system to spec?

The only way that I know to get that amount of runtime is to build a room full of batteries!

Yeah, He's been looking around and asked if I could reach out to my contacts as well.

With the more common LA batteries that is going to be one heck of a battery bank.

Is this residential?

There may be systems using LiPo or LiFe which would take up less space but I never looked for such a system.

Perhaps something like a battery pack from a Telsa?

Me? I would stick with a ng/propane powered, water cooled gen.

Yes, it is in downtown Toronto and for whatever reason he has talked his client out of traditional methods.

Ask him if he understands the full cost of a system like this. And if he really understands what he's doing.


Even APC's Symmetra LX 16kVA extended runtime system ($18,800) can't come close to the duration of 6 hours under full load (only about 90min). It will do 6 hours under a 3kW load however.
But the bigger cost is replacing batteries ever 5-7 years. On that size Symmetra system, that another $5,000+ at least.

I can find plenty of articles online, talking about what he wants to do. But no actual product for sell and no case studies of it being done (I'm sure the latter is out there). Overall, this looks more like a 'roll-your-own' type custom thing.

Maybe he should stick with a conventional generator. There is a reason why they are so popular compared to...

What about a fuel cell?

I am an electrical engineer that specified and designed computer data centers at one time in my career so I do know a little about the subject. I am now retired and long in the tooth (75) but I designed the electrical system for my house (I was an electrician in college) which has extensive electronics and automation. The house has its own server room which is separately air conditioned from the main house.

The main utility feed is 300 amps split to two 150 amp breaker panels. Each panel has complete surge suppression at the panel. The system ground point is a 1" x 8 foot copper rod at the utility entry point which is well bonded to the metal of the wiring system. Plumbing inside the house is copper but the water supply comes in over PVC. I never wanted to get a severe shock standing in the shower.

The server room has a UPS system which will hold that room for 10 minutes and the theater has one which will hold the theater for 10 minutes. One of the breaker panels (which feeds the the theater and the server room) has a 15KW propane driven backup generator system fed from a 500 gallon propane tank. That system comes on line after 20 seconds of no utility power.

There is space outside for a second Backup generator but I have never gotten around to installing it although the service entrance wiring is set up for it.

What the hell kind of engineer talks a client out of the methods that have been proved successful? If this pinhead wants to experiment and buck the trends, let him do it on his own time, with his own damn money!

I'll be finding that out tomorrow. Stay tuned.

The only solution that remotely comes to mind is an array of Tesla Powerwalls: [Link: teslamotors.com]

Even there, you need lots of them.

Looking at the Tesla Powerwall:
He would need the larger 10kWh model - maximum of 9 linked together. With the maximum 9 installed, it does look like that would just meet his requirements (going by specs given alone). But not everything is detailed, so there might be a catch in there preventing this from working to his specs.
Either way, it's not available yet. And that would cost him $31,500. That doesn't include the cost of the inverter (that can handle that kind of power), power transfer switch, etc... Certainly total would be over $40K+ not including installation.

Additional, replacement batteries come at about 10 years on those lithium (max). So every 10 years, be ready to throw down another $30K+ (or $3K per year operating costs).