Anyone Applied a "Tesla Powerwall" type of battery backup to larger loads?

I have been tasked to supply a location with a backup power supply that can run 240V at 20 amp nominal with 70 amp peak pump loads (120 Seconds max duration) for 24 hours per charge. This is too small for a diesel genset and the residential LNG/LP powered ones are not practical because of the fuel source. They would like to use a Tesla Powerwall or similar but Tesla will not do it because the pumps inductive load would damage the inverter AND they wont touch it without their Solar attached.

I contacted many similar suppliers in the area and once you step outside the residential solar template, they are completely lost.

Anyone done this and can point me in a direction?

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I asked people in my group that are a lot smarter than me (PE EE and MS EE) that do big battery projects and they pointed me to something called "four quadrant inverter"

They also told me to look at Conext Inverters from Schneider Electric.

https://solar.schneider-electric.co...-XC-NA-Grid-Support-Guide-AP-XC-003_REV-I.pdf

A company called Sunverge might be interested in doing small project like this.

Aagh! Schnieder.... I do NOT have good luck with them anywhere else. Drives, UPS, ...
But thank you I will look into it.

I worked on a humongous Dynapower backup battery system that was capable of running 480v at 800amps for nearly 12 hours. That system was its own building on the factory grounds. It was a paper mill. I guess stopping the machinery seriously dorked with the process and that gave them enough time to finish a batch if it just started. I know it was a several million dollar project.

JTCat said:

I know it was a several million dollar project.

Click to expand...

That would certainly be beyond the resources of this project But it would be fun to see that thing discharging.

https://www.rechargenews.com/transi...talled-at-worlds-largest-csp-plant/2-1-768980


https://www.rechargenews.com/transi...st-route-to-24-hour-wind-and-solar/2-1-635666


interesting, thermodynamically ...

Good Lord. That's a lot of power from a thermos bottle of molten metal. I need something
just a bit scaled down from that

TheWaterboy said:

Aagh! Schnieder.... I do NOT have good luck with them anywhere else. Drives, UPS, ...
But thank you I will look into it.

Click to expand...

When you say UPS...do you mean the APC line that Schneider owns?

Yes, their office grade UPS's are pure junk now, I'm hoping the enterprise stuff didn't take a hit too.

I heard of a thing where Siemens can use the S120 servo drives to convert battery power into whatever you need. I think you can basically use whatever for the battery, as long as it's big enough. Special firmware lets the motor module treat the batter as a "motor" and then the infeed module just regens power as needed (or it runs the regular way to charge the battery).



https://support.industry.siemens.com/cs/us/en/view/109751796

TheWaterboy said:

Yes, their office grade UPS's are pure junk now, I'm hoping the enterprise stuff didn't take a hit too.

Click to expand...

Whose UPS do you use now? Been having some issues with APC Smart-UPS failures. I use these in our control panels.

Started using Falcon. Higher Temp rating and more industrial. Which you do pay for.
they have a LiFepo4 option with 10 year battery life but I havent tried those yet.

The problem really is induction motor loads. When started Across-the-Line (DOL), they will needs up to 600% of their rated FLA for a second or two, but even worse, the magnetic inrush is upward of 20x the FLA for a cycle. That rapid increase in current can damage the transistors in an inverter. That's why Tesla is saying no and that's going to be a problem with most UPS systems out there; they never like induction motor loads.

IF however you have VFDs on those induction motors, the starting current and magnetic inrush issues are mitigated by those VFDs. that would likely be OK for ther UPS inverter, but not all VFDs are going to be compatible with the PWM output or square wave output of a UPS. So the solution is often to use a DC battery backup system on the VFDs. There are companies that make those, one of them is Bonitron.
https://www.bonitron.com/complete-systems

But do you mean keeping the pumps running for 24Hrs? That's an ETERNITY for a battery backup system. That is not going to be inexpensive no matter how you cut it.

I do understand the inductive load problem.

A pump runs for about 90 seconds every 15 minutes and will draw maybe 7 amps nominal, the other big load is MOV's drawing 12 amps and one of those those might run once a day. There is very little other load. So it's the inrush that is the biggest problem to be handled and I can probably do that with a RVSS. This is a 240 1ph system. Residential kind of power.