Tesla battery instead of UPS ?

[Dieselboy]

My boss just got 3 x Tesla powerwalls installed in his home. Our office UPS inverter has died. The ups provides us with around 15 minutes of run time which is enough time to trigger automated shutdowns of the equipment. I did systematic and automated shut downs but this highlighted an issue because while it extends the run time to greated than 20 minutes,  the AC units which were cooling the comms room and equipment are now not running because of the power outage.

We're considering Tesla to power the circuit that provides power to the comms room. Has anyone done this yet or considered this?

The concerns are cost and feasability of providing the current draw including the AC.

[Otanx]

We looked at them for our new DC. The cost was pretty excessive. This was a couple years ago, but I just looked at the spec sheet for the new power wall, and it looks like the same issues. The max continuous draw from the powerwall is 5kW with a peek of 7kW. Our racks are build with redundant 208v50A circuits which is 10kW. So for a loaded rack we would need two powerwalls to handle the load. We could probably get away with 1 in most cases, but that then becomes our limit for rack usability. We also had concerns about start time. They say instant fail over, but we were not sure if instant was really instant or not. We didn't test it. At the end of the day we ended up with a normal UPS setup.

Another use case we came up with was to use them as a replacement for a generator. Depending on the run time you want it might work. With a max 5kW draw the powerwall will last for two hours. That would cover most power outages, and gives us time to get COOP running at the other facility. The benefit being the reduced maintenance of having to run a generator, and fuel, etc. We ended up not doing that either, but we never really identified issues with it just a lack of risk acceptance for not doing the normal gen set backup.

-Otanx

[deanwebb]

As long as you don't buy a backup generator with an electric start motor. I've heard stories around those things waaaaaay too many times.

[Dieselboy]

@Otanx - thanks for all the info! I queried about the switchover from mains to Tesla power and apparently it's seamless and immediate now. I was told that the 1st gen was not as fast.

For our broken UPS, APC told me that they are unable to supply a replacement inverter for us. So it means the 8kw ups is ready for the rubbish tip 

As long as you don't buy a backup generator with an electric start motor. I've heard stories around those things waaaaaay too many times.

Simple when you explain it that way but I had not thought about it. I'll ask the boss. He also has a LPG generator 

[deanwebb]

Worst part is that the generator with electric start motor works just fine in testing. It's not until the power's gone that you realize the severe design flaw...

[config t]

Worst part is that the generator with electric start motor works just fine in testing. It's not until the power's gone that you realize the severe design flaw...

Ouch..

This reminds me of a friend of mine who's parents bought a new AC unit for their home when the old unit failed. It wasn't until winter rolled around that they discovered the new unit didn't have a heating coil like the old one.. expensive mistake.

[deanwebb]

Brings back the story of the guys that outsourced their email "to save money over on-prem hosting costs" and then found out on day 1 that they only outsourced the email. Calendar, tasks, and contacts were all optional extras that involved significant upcharges, to where it was now about 30% more costly to outsource.

[Otanx]

@Otanx - thanks for all the info! I queried about the switchover from mains to Tesla power and apparently it's seamless and immediate now. I was told that the 1st gen was not as fast.

That is interesting. I will have to ask my brother how that works. The power wall isn't inline like a normal UPS so by the time it detects the power loss it has already hit your systems as well.

-Otanx

[wintermute000]

Brings back the story of the guys that outsourced their email "to save money over on-prem hosting costs" and then found out on day 1 that they only outsourced the email. Calendar, tasks, and contacts were all optional extras that involved significant upcharges, to where it was now about 30% more costly to outsource.

This is so good, as a consultant it makes me laugh.
"Do you want a DMZ in-scope".
"no"."what about servers X, Y Z, and functions X, Y, Z""oh I guess we'll need it.
<suppresses urge to yell at them to get me someone competent>
Should have done the WITCH procedure and blindly followed, and then bill a million variations later

[Otanx]

After talking to my brother this weekend I found the batteries are in-line with the main power feed. I didn't think it was. So that is how they do the instant on. Just like any other UPS. The power wall is still too small for a rack of gear, but might be OK for a partial rack if you don't have much gear. Also from my brother, Tesla does have the "Tesla Power Pack" which is their commercial offering. It is sized for Utilities so you can scale it for a data center easily. The only problem would be cost.

-Otanx

[deanwebb]

The only problem would be cost.

If a situation clears up when you write a check, it wasn't a problem. It was an expense.

[Dieselboy]

Hey guys Thanks again Otanx for the feedback.

My rack consumes about 4.4kwh max. so I think it could run on one Powerwall. I'd need a 2nd powerwall to run the AC. This is top-of-the-head stuff only.

However we found this: https://lavo.com.au/

It's like the size of a large fridge freezer. It takes water and charges itself up with Hydrogen, releasing O2. During power outage, it oxidises the Hydrogen producing electicity.
Again, the limit is around 5kwh, probably due to the inverter performance. Tesla apparently now have a 7.8kwh inverter over in USA. Australia is the last place to get anything

We've applied for the Lavo and are waiting to hear back. Again, with a lot of red-tape here we don't know how difficult it will be to get approvals. Hopefully the power company accept it like a Powerwall (which is diffcult to get approval anyway) and dont get too hung up on certain things.

[Dieselboy]

Worst part is that the generator with electric start motor works just fine in testing. It's not until the power's gone that you realize the severe design flaw...

I asked him and he says the genny has a 12V battery to start it or something

[dlots]

Don't use Tesla, my understanding is they stop working if they loose communication to the outside world.