Australia's Biggest Tesla Battery Storage System at Moorabool is on FIRE

[ahbushnell]

Of course it's insufficient, given very close spacing (some dozen centimeters gap only). Temperatures inside the burning battery pack are well in excess of 1000 degC, and thermal runaway onset of the adjacent pack is mere 150degC or so, painfully close to ambient temperature. Even if fire is directed upwards, the fire itself radiates enough heat to heat surroundings to 150degC for several meters. I see no other option than significant separation, or less separation coupled with another layer of steel wall, high enough to block the fire rising above the units.

Some fire sprinklers will do the trick. And now maybe they figured out that sprinklers on the outside would be an even better idea.

Or just use a safer, more economical energy storage technology? If it's mostly to run air conditioning, making ice is an order of magnitude or two cheaper than batteries (total system cost, the storage medium is even cheaper than that) and I have never heard of a block of ice catching on fire...

This is for grid stabilization.  I don't think ice will work.

[Berni]

Some fire sprinklers will do the trick. And now maybe they figured out that sprinklers on the outside would be an even better idea.

Or just use a safer, more economical energy storage technology? If it's mostly to run air conditioning, making ice is an order of magnitude or two cheaper than batteries (total system cost, the storage medium is even cheaper than that) and I have never heard of a block of ice catching on fire...

This is for grid stabilization.  I don't think ice will work.

On demand load modulation also does the job of grid stabilization.

The idea is that once you have enough storage to store the heating or cooling energy for one day then you can freely chose when over the 24h that energy will be pulled from the grid. So when load on the grid drops and the standby power generation if forced to throttle back (throwing away the energy as heat rather than letting it trough the turbines) you can instead command 10 000 air conditioners to turn on suddenly gulping megawatts of power and selling it to the residents. This saves money by not throwing away power. Then when there is a sudden rise in demand on the grid you can command the 10 000 air conditioners to turn off and suddenly there are a few extra megawatts of power on the grid within seconds. Then once the plants spool up to catch up you slowly let them turn back on gradually to make up for the time they had to turn off.

This has the same effect as having a giant battery that you command to suck up  megawatts of power when there is too much of it, or tell it to release it megawatts of power when there is need. Pushing extra power to the grid or removing the same amount of load on the grid has the same effect of there being more power available.

Ice stores about 330kJ/kg so about a 100kg block stores about 9kWh and costs a few cents worth of water.
Lithium batteries store about 260 Wh/kg so a 100kg battery pack stores about 26kWh and for a cheep one could get as low as 100$ per kWh so 2600$
So yes ice latent heat is only about 1/3 as energy dense as a lithium battery pack, but it costs many orders of magnitude less. So you might as well go for the cheap option to start with and move to batteries once most air conditioners have already been used up for on site storage. Just like solar roadways only make more sense once we run out of other better places to put solar panels like roofs.

[Kleinstein]

When you compare heat stored in Ice and electricity, one has to take into account the efficiency of the air conditioner. The heat ca. be something like 5 times the electricty consumption, with a low temperature difference possibly even more than 10 fold. Going all the way to making ice needs extra energy when all one really needs is some 20 C for a compftable room.

Yes some heat pumps could be used to control the load and this way reduce the need for electric storage. It is quite effective and already used in large facilities like central cold (frozen goods) storage. Still with small units (e.g. household size may be only 200W) there is quite some control effort.
Still modulated load can not fully replace real storage - someone still needs to provide the little power in a low wind night. Real storage would also act double, as a source and controlled load.

[james_s]

It's too bad it's so difficult to store a really large amount of heat. In the winter my heat pump is pushing heat from outside into my house, in the summer it's going the other way pushing heat from inside to the outside. If I had a massive insulated water tank I could freeze it into a solid block of ice over the winter from heating and then melt it over the summer using it to air conditioning and wind up with hot water by the time winter rolls around. I have not done any calculations but I suspect the amount of water (or whatever) required to store a season worth of heat would be massive though.

A friend of mine said one of his friends once built a ground source heat pump back in the 80s by burying a couple of old condenser coils underground and it created a permafrost.

[Gyro]

Years ago I saw a building project where they were building a massive insulated water tank into the foundations as a thermal buffer - just using its thermal mass, no heat pump involved.

By the time you start involving the latent heat of freezing / melting you have a massive increase in available thermal energy storage. Ideally you'd want to stay close to freezing / melting, otherwise you're just relying on the thermal mass and the temperature change will be much steeper.

[EEVblog]

There is no technical information to support more news, and I'd anticipate no new photos from initial site inspections (unless they are leaked), so all we are left with is 60+ posts here with most trying to vent their opinions and speculate what could have been done better.

Yeah, I don't expect any more news, let alone photos. Tesla or the owner won't be dumb enough to release photos, and the Fire department would probably get in big trouble if they released on-site private property photos.
Might even be the last we ever hear of it, unless as you said, someone leaks something.

[NiHaoMike]

It's too bad it's so difficult to store a really large amount of heat. In the winter my heat pump is pushing heat from outside into my house, in the summer it's going the other way pushing heat from inside to the outside. If I had a massive insulated water tank I could freeze it into a solid block of ice over the winter from heating and then melt it over the summer using it to air conditioning and wind up with hot water by the time winter rolls around. I have not done any calculations but I suspect the amount of water (or whatever) required to store a season worth of heat would be massive though.

It has been done with geothermal heat pumps, get below the water table and you get a thermal connection to a very, very large volume of water.

[trobbins]

It's possible that background info could come out as part of a mitigation description (by Tesla, utility, Oz regulator or other/future project operator PR), or down the track via some site contractor personal who aren't under nda.

[james_s]

Yeah, I don't expect any more news, let alone photos. Tesla or the owner won't be dumb enough to release photos, and the Fire department would probably get in big trouble if they released on-site private property photos.
Might even be the last we ever hear of it, unless as you said, someone leaks something.

I would think a news station could get all the photos they want without setting foot on the property by using a helicopter carrying a stabilized camera with a telephoto lens. The installation is outdoors so unless it's covered by tarps or something it will be visible.

[EEVblog]

Yeah, I don't expect any more news, let alone photos. Tesla or the owner won't be dumb enough to release photos, and the Fire department would probably get in big trouble if they released on-site private property photos.
Might even be the last we ever hear of it, unless as you said, someone leaks something.

I would think a news station could get all the photos they want without setting foot on the property by using a helicopter carrying a stabilized camera with a telephoto lens. The installation is outdoors so unless it's covered by tarps or something it will be visible.

Possible. Also with a drone. I'm not sure anyone will bother though.

[Berni]

True i did forget to take in account that heat pumps move significantly more heat than they consume. But still a block of ice remains very cheep because its just water, all the cost is in the container around it and this is easily expandable. It's not uncommon to have water heaters that hold more than 100kg of water, so the size of such ice storage would not get unpracticaly large just to store one day worth of air conditioning cold.

As for storing heat energy for half a year to cover the summer and winter difference is not easy. This does reach unpracticaly large sizes to store enough of it. Since latent heat can't be used for this, it makes it even worse (Tho molten wax can store heat pretty efficently). If you really wanted to have an advantage in terms of heating/cooling the best solution is to have an underground house. The ground temperature only varies by a few degrees trough the year. Tho in most climates the average ground temperature is too low to be comfortable, but some insulation and the waste heat from all the electrical appliances could bring that up closer to comfortable. But building such a house is expensive and you end up living in a windowless basement so it's not that great of an idea.

Geothermal  is also in most cases too cold to be directly useful, but even the cold groundwater in winter is still a much better source for feeding a heatpump rather than the freezing air outside, can work for air conditioning tho. Unless you end up on top of a hot geothermal spring, those are very useful for heating, but are rather rare.

[ahbushnell]

It's too bad it's so difficult to store a really large amount of heat. In the winter my heat pump is pushing heat from outside into my house, in the summer it's going the other way pushing heat from inside to the outside. If I had a massive insulated water tank I could freeze it into a solid block of ice over the winter from heating and then melt it over the summer using it to air conditioning and wind up with hot water by the time winter rolls around. I have not done any calculations but I suspect the amount of water (or whatever) required to store a season worth of heat would be massive though.

A friend of mine said one of his friends once built a ground source heat pump back in the 80s by burying a couple of old condenser coils underground and it created a permafrost.

https://www.energy.gov/energysaver/heat-and-cool/heat-pump-systems/geothermal-heat-pumps

[TimFox]

Ice:
Improperly designed ice structures can be dangerous:  https://apnews.com/article/arts-and-entertainment-tennessee-905233721dbb5b7692fa99c94e8c4e3b
However, water in its various states has unique physical properties (such as heat capacity) compared against other materials.

[TimFox]

Yeah, I don't expect any more news, let alone photos. Tesla or the owner won't be dumb enough to release photos, and the Fire department would probably get in big trouble if they released on-site private property photos.
Might even be the last we ever hear of it, unless as you said, someone leaks something.

I would think a news station could get all the photos they want without setting foot on the property by using a helicopter carrying a stabilized camera with a telephoto lens. The installation is outdoors so unless it's covered by tarps or something it will be visible.

Possible. Also with a drone. I'm not sure anyone will bother though.

There have been two industrial accidents near Chicago recently that attracted media attention.  Lots of big black smoke, emergency response, and evacuation orders.   There was no shortage of aerial video on local TV stations.

[floobydust]

No news updates, surprising to see a media blackout as if this had occured in a communist country. Dave's 1411 is highly ranked on the search engines. If I lived nearby or downwind I would be upset with the news (lack of) coverage.

I found this days older pic (paywalled Australian News) which showed the fire burning, along with the crane brought in - Tesla's new hot swap technology. Doesn't matter if it's on fire, you can put in a new Megapack before anyone notices...  Actually it likely means they pulled up and ripped out adjacent containers to stop the fire from spreading? If that's the case, then the site is a mess and no pictures of that please.

CFA, Energy Safe Victoria, WorkSafe Victoria, Minister for Energy and Renewables, EPA, Labour Government and Opposition having a conniption 

I would expect the site's planned November operation date to get pushed back, unless they add manpower. TBH I have worked on large scale (AC) power projects like this and it's cookie cutter work unless they make drastic safety changes. It's already too late to increase spacing between units, that would blow up the scope of work so I'm not sure how they'll spin not needing that.

One concern I had is the smoke crossing the HV transmission lines will induce arcing because the spacings are generously for air, not carbon soot etc. Smoke will start arcs between HV lines and typically the breakers will do reclose operations then give up. So it's entirely possible for this incident to have taken out transmission on that line until the smoke moved away.

[EEVblog]

No news updates, surprising to see a media blackout as if this had occured in a communist country.

Nothing nefarious, it's just that no one cares. It's made the headline and that was it.

[chickenHeadKnob]

One concern I had is the smoke crossing the HV transmission lines will induce arcing because the spacings are generously for air, not carbon soot etc. Smoke will start arcs between HV lines and typically the breakers will do reclose operations then give up. So it's entirely possible for this incident to have taken out transmission on that line until the smoke moved away.

Discharge through the air not the biggest problem. I would be worried if the insulators downstream are accumulating soot on their surfaces. My father told of more than one occasion where a bird sitting on an insulator shit down the side and vaporized himself.

[floobydust]

Moorabool Terminal has 500kV (~73m high towers) and 220kV (~56m high towers) transmission lines running through. I know smoke between HV lines induces arcs, I've seen it happen a few times at lower heights/voltages. On second thought in pics the transmission lines are quite far away and high so I don't know what the chances are, but you don't want to take out one of those lines. The 2014 incident where they accidentally grounded the line on one phase was a fun read for the chain of events. Here we had a dumb project manager forget the ground chains were still attached to the lines, switched in 240kV to ground and 1/4 the country noticed those milliseconds.
I haven't seen a single-line for the Tesla Powerwall tie in. It looks like 33kV to 220kV in the yard.

"Every Megapack arrives pre-assembled and pre-tested from Tesla’s Gigafactory – including battery modules, bi-directional inverters, a thermal management system, and AC main breaker and controls. No assembly is required, the Megapack’s AC output is simply connected to the site wiring." 

[james_s]

I remember watching a video where they were starting up a vintage diesel locomotive at a rail museum and the smoke belching out of the stack caused a flash over from the overhead wires used for electric trains.

[sandalcandal]

I *still* reckon making the aisles as narrow as they did and closely clustering the Megapacks in groups of four was penny wise and pound foolish.  They are lucky to have only totally lost two units with casing damage to the units across the aisle from them.

A lot of things will be getting re-engineered for the next installation I bet, I doubt they even considered this a possible failure mode outside a meteor/lightning strike.

First come up with some numbers about the total number of power packs installed versus the number of fires. I'm quite sure they have considered the risk of fire versus the distance between the units.

Yeah, I'm sure a company made by Elon made all the necessary calculations, and left enough time for all the engineers to finish their work with due diligence. And they didn't rush some half finished product that was cobbled together from leftover parts from other companies. Didn't rush, because there was no chance in hell, that the company wasn't profitable so "I dont care how it is we have to ship it, otherwise we run out of investors money". Not a chance. I mean they dont have a track record of this at all.*

*This entire post was sponsored by Sarcasm Inc.

Yeah, over 7 years of development on stationary energy systems for a product launched in 2019 is definitely not enough time for all the necessary calculations, and left enough time for all the engineers to finish their work with due diligence. Plus given it was another 2 years since launch that the system in question was installed there's no way they didn't rush some half finished product that was cobbled together from leftover parts from other companies. And unquestionably they rushed because there was no chance in hell, that the company wasn't profitable because they were already profitable last year and are unquestionably even more profitable this year with over $1B in GAAP net income in the last quarter.*

*This segment was sponsored by Snark Inc.

Sorry is this too fast for you? Maybe we should take a 15 years before releasing a product because nearly a decade is too fast for you? What is this guy smoking?

[EEVblog]

"Every Megapack arrives pre-assembled and pre-tested from Tesla’s Gigafactory – including battery modules, bi-directional inverters, a thermal management system, and AC main breaker and controls. No assembly is required, the Megapack’s AC output is simply connected to the site wiring." 

In that case it seems almost certain the fire will be Tesla's responsibility, unless it's dodgy mains wiring contacts or something? As it appears the fire originated within the megapack cabinet somewhere.

[Grapsus]

It's basically confident IT guys from California building high power stuff from scratch, because disruption. Might take 10-20 years to figure out that you might need walls between the modules in order to limit damage. It will then be called smart-separator or something

[Neilm]

I remember reading in a local paper (very many moons ago) that fire investigators had managed to pinpoint why a "factory" had burnt down. The factory contained a high voltage limulator for simulating lightning strikes. Apparently someone had left a spanner lying around and during testing an upgrade, it had fallen across the capacitor bank.

I don't think there is any point speculating until some form of report is produced.

[TimFox]

Industrial accidents like that happen all the time, but sifting through the wreckage to pinpoint the cause can take a long time.
I was in California a few years ago when a wildfire forced me to evacuate the worksite.
Since the authorities could locate the starting point for the fire, after it was safe they traveled to the power pole in question and found the burned carcass of a large bird that had been electrocuted, set on fire, and fallen to the dry ground whence the fire then started to spread.

[floobydust]

Do we know what battery technology is at this site?
~May 2021 Tesla changed to using lithium-iron phosphate in Megapacks. I wonder if there is new and old out there. Lithium-ion don't have a great safety record, nevermind the lack of fire fighting ability. The shift is supposedly to avoid nickel and cobalt shortages.

The cabinet wiring looked complete, like you need to daisychain power and data connections. During commissioning you check all wiring several times. It wasn't a loose twist-nut.
The hardware is a module kind of a consumer/automotive design glue the thing together and then add more glue, it's not industrial or even utility industry designed. The charge control electronics are in the blob. No sign of disconnects or fuses though.
"An electrical fault sparked the blaze that engulfed a part of the $200m big battery northwest of Geelong last month, the CFA says." Ahhh that's what it was 

These sites will have high line voltages whenever the transformers have light load.
I don't see a voltage reg transformer (tap-changer) anywhere so playing around at the 25MW level, the voltage stress would have been high on the Megapacks during charging. But again, they're supposed to have fuses and firmware to cope.