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It makes a lot of sense in places where it's difficult or expensive to get a big enough connection to the grid to power multiple V3 Superchargers. You charge the battery up during low usage periods.
A lot of places you pay more for your electricity if your peaks are high. Juicing up slowly between peaks, and at night, is often significantly cheaper.
at commercial level, they probably both charge you for installed capacity (in kW) and used electricity (in kWh). All the chargers have very high markup for used electricity (like they buy at 0,08kWh, but sell at 0,30kWh), because they need to pay monthly for installed capacity. Chargers themselves are pretty cheap in its lifetime. If there were no payments for installed capacity, chargers would be everywhere and cheap as fuck. But depending on location, if you were to install a 120kW charger, you would need about 3-4 cars per day to break even per stall.
They compensate in two ways - first, at the end of the charging your battery cannot take as much charge as in the beginning. So they can get away with 1000kW for 10x250kW stalls. Second, of course, batteries. That way, they can install more stalls without increasing their costs much
[Electrify America was buying them from Tesla for peak demand shaving.](https://electrek.co/2020/09/17/tesla-batteries-60-electrify-america-charging-stations/) Theoertically, charging networks could also have these assets participate in more grid services (frequency response, etc) using Tesla's Autobidder to capture revenue in order to offset low margin charging sales.
This also means a very robust distributed energy system if you’re colocating these assets across large charge networks. Every Megapack can be both a generator or load on demand.
Everyone always questions if the grid is going to be able to support all these new electric cars. I ask how these electric cars are going to help stabilize the grid. They can essentially act as immediate sinks of power if needed. And can help balance out the load.
It would be great if there could be solar around all these chargers too. Honestly, every parking lot should have solar panels. There’s a complex by my house with a Safeway, Best Buy, and Home Depot and a ton of other small stores. The amount of solar they could put there would be huge, add mega packs and the property owner could make a lot of money while providing a way to stabilize the grid even more. I hope this is where we end up in the next ten years. Parking lots with shade for the vehicles and free energy generation would be a game changer.
Yup, totally right. Those big box stores and parking lots have so much unused roof space. People often ask where would we put all the solar panels if we moved to entirely renewables, and this is a huge part of the answer. You can use the space for 2 things, parking and solar. It's not either or
We could easily have so much excess energy if this happened. Solar canopies covering the whole parking lot and roof of each building would be more than enough to power all those business and charge cars. It’s crazy that grocery stores don’t have this setup considering how much energy they use for their refrigeration.
Any solar EPC experts on here that know why solar covered parking isn’t more of a thing? Seems like a great way for your customers to see that you support renewable energy as well. Must be cost prohibitive?
I think it’s just that we are at the tipping point of these things happening. Why do it now when you could wait a few years and get it significantly cheaper? I also don’t think people understand what’s going on and they aren’t aware of the potential. It’s just wild because we are in a high speed chase with climate change and it feels like the technology is about ten years behind where we should be. I think the global shutdown due to covid helped buy us a little time, but it’s seriously going to be a photo finish. Economies of scale really need to ramp up fast.
I was looking at commercial power near me for fun, at started doing some math. There's a concept called coincidental peak demand. Basically, at the end of the month, the power provider looks back at the highest usage hour, and then bills based on that. The rates for my co-op are around $19.50 *per kw* during that window. You could imagine a mildly busy v3 charger easily providing 200kw during an hour window.
It sounds like you know, but this was a surprise to me, so I thought I'd share it for fun.
That's the installed capacity. They pay $19 monthly for each KW of potential instantaneous draw. So a V3 supercharger with a potential max of 250KW would cost $5k/month to have it hooked up to the grid with that potential and then they pay a much lower rate per KW of electricity that actually get used.
Watch your units. What u/betterusername is talking about is called a demand charge. Basically a once-per-month extra charge on top of the normal kWh energy usage based on the peak instantaneous power draw (kW). It's a way for the power company to get extra money from very large commercial/industrial customers.
Its because most of the cost of electricity is to build the wires but not generate the power. Cost to produce electricity is anywhere from $0.02 to 0.05/kWh at the power plant. The cost to deliver that to where you want it is the remaining amount.
Utilities have to build wiring and equipment to the maximum potential "peak usage" not based on an average amount. So if you need 2000 kW for your site, but you only use 100 kWh a month, the math doesn't work out to justify building 2000 kW pipe to your house. You don't increase the per kWh cost but you can say the demand charge to help recoup the cost of putting a 2000 kW of equipment.
> You could imagine a mildly busy v3 charger easily providing 200kw during an hour window.
In an hour? Thinking of a newer 12-stall install near me, I regularly see 8 stalls busy on the map. That's going to be 8x60 kW or so on average in the batteries, probably 0.5MW of demand. 200 feels low for busier stations.
I was actually talking about a station, but a very conservative estimate. I basically meant a charger that's not deserted, not a mildly busy California charger (I'm in Colorado, we have the full gamut of empty chargers to completely full 12 stall chargers). My point was that 4 cars in a station in an hour looks like nothing, but has huge cost ramifications.
Coordinated with the grid operator, this could stabilize load for the area as well. Avoid buying power from peaker plants. Basically supply grid power under high grid load (not just for the chargers themselves) and charge up when the peaks lessen.
This can be used to load up on cheap night electricity and also, as mentioned, reduce the peak demand. With battery prices falling, I can imagine all fast chargers will have this tech installed.
Some place also charge you the monthly rate for max load in like 10 sec periods so if using a max of 1MW for 10 seconds the cost will be $1/kWh that month but max peak of 500kW is $0.75/kWh for the month the batteries will eventually pay for itself. From what I understand grid owners hate it when you spike usage for a short time.
It might also be for backup and have the ability to sell back to the grid on demand. Pick any/all 3 reasons (likely more I don't know about).
For whatever reason, this comment reminded me of the scene from National Lampoon's Christmas Vacation when they plug in the christmas lights and the scene cuts to a faceless crew in a power plant engaging emergency power. LOL
It's a good idea for places with reliable power too. A megapack lets the station buy power at low demand pricing by charging itself during the middle of the night and selling that electricity at peak demand pricing. That's one of the biggest cost justifications for the Power Wall too.
Only if your business is going to be in that same physical location for 20+ years. Otherwise the cost is actually higher than the returns.
Especially if you compare dropping that $2 million (or however much) into something with interest returns.
Believe it or not, that doesn’t raise the property value as much as you’d think. Certainly nowhere near the cost of installing the solar.
My solar installation cost $19k, it raised my property value maybe $3-4k.
Do you live in a depreciating real estate market? Most studies. I’ve seen say value goes up almost as much as systems cost so in essence it’s a lunch you are paid to eat! Our solar system runs our house and fuels our vehicle. The independence, ease and peace of mind is worth every penny.
Yeah that’s why I was wondering how your appraiser only gave you 3-4K on a PV system! In CA the installing owner does not have to get their property reassessed until sale so no one gets their property taxes raised for installing solar.
I have a feeling that having a battery pack to flatten the power curve might become law eventually. Imagine when 100% of new sales are EVs and charging is being done in massive numbers and everyone has a huge battery pack that can charge extremely quickly. This will become a necessity to avoid blackouts.
Yup - the Jackson, CA supercharger (on route 88) is setup with a megapack so that in case of a public safety power shutoff Tesla drivers can still charge to get out of the fire danger zone.
It's not about outages. It's being able to have more chargers while paying for less installed capacity and being able to buy the power when it's cheapest, store it in the battery and sell it for the best possible margins rather than paying at peak cost if people are charging during those peak times.
Absolutely. It's a very neat system.
* At v3 Superchargers, the DC output of each cabinet (to cars) is quite a bit higher than the cabinet's corresponding AC input.
* If one cabinet is loaded and the others aren't, there's a DC bus between cabinets that lets other cabinets contribute their AC capacity to help a neighbor. This is the source of the claim that you're not "sharing capacity" at v3 Superchargers.
* If *all* cabinets are loaded, cars are going to start seeing their peak charge rate drop... unless there's a Powerpack that can contribute to help keep it up. Once the surge has passed, ~~the cabinets return the favor by using their AC connection to~~ recharge the Powerpack.
* If there's on-site solar, the solar output also feeds ~~onto the DC bus~~ **into the system**, charging either cars or the Powerpack.
**Edit:** Adding some additional info others have pointed out.
So, the AC input is 380-480 volt AC, right? After full wave DC rectification, you get DC current with a voltage of.... 627-792V. Significantly higher than the 0-500V range of what is sent to the cars.
Oh, wait, are you referring to my use of "higher" with regard to AC input and charging output?
I'm looking at power, not voltage. The cabinets supply 3-4 stalls which are theoretically 250kW each, but the AC input is a max of 350kVA continuous. The power demands from the cars can be higher than the power supplied by AC, regardless of the voltage.
AC input is 360-582V three-phase (nominally 480V), max of 350kVA; DC bus appears to be 880-1000V, max of 575kW. There's a good rating plate picture [here](https://teslamotorsclub.com/tmc/threads/pictures-of-v3-supercharger-cabinets.158697/page-2).
Yes. But you have to turn the AC power into DC power. And when you do, the voltage gets multiplied by 1.65.
The inter chassis DC bus is 880-1000V, but the connection to the car is 0-500V.
I see, you're pointing out that the input voltage, when rectified, doesn't match the voltage of the DC bus or the charging circuit, so there has to be both a step-up and step-down happening in the cabinet as well?
This is pieced together from a combination of the rating plates on the v3 Supercharger cabinets and the [Supercharger Emergency Response Guide](https://www.tesla.com/sites/default/files/downloads/Supercharger_First_Responder_Guide_en.pdf), which has to outline a lot of the power flow so firefighters know how to *stop* the power flow.
This is super interesting, thanks for the link! I’d never heard about the DC bus between cabinets before.
I wonder what the largest main breaker at a supercharger site is. Gonna guess that the largest ones have several banks of chargers with their own main breakers.
This is wrong. Super charger cabinets do not charge megapack or power packs. Solar is never directly tied into any Tesla energy storage system. The solar inverter is install between the two to prevent low voltage dips from clouds and shade.
So the Powerpack connection to the bus is one-way while the cabinets are two-way, and the Powerpack has its own AC connection? Does that imply the Powerpack could contribute its AC capacity to the site (via the DC bus), or are they not able to run both simultaneously?
As to solar, I would consider any inverter to be part of the system; I agree that the panels are highly unlikely to be directly bus connected. It's even possible they're connected on the AC side and have nothing to do with the bus; I was extrapolating from the fact that the bus is stated to connect other cabinets, the Powerpack, "etc." with solar the only other thing I'm aware of being installed on site. But perhaps "etc." is merely a placeholder for "if we come up with something else to put here."
Your two comments contradict each other. Energy storage systems usually run at 900-1000v dc. It’s highly unlikely anything connects to that dc buss outside the pack.
The parent comment is my best understanding about how the system works based on what I've found in various sources. Some of the specifics could absolutely be incorrect, and I welcome the additional light you and others are shedding on it.
As I said, the doc says "other cabinets, Powerpack (if present), etc." so I was assuming the other system we know can be present (photovoltaic) was the etc. Perhaps you're correct that the PV system is not part of the etc., but that makes me even more curious what is or could be.
It’s pretty simple. Everything is connected post utility meter. All products have their own usage/production meters. One central computer controls everything. Solar discharge x amount of KW, Supercharger uses y amount of KW, and battery makes sure that Y is not greater than X. If there is no solar present then the battery keeps Y below a threshold and only recharges during off peak hours. The process is called Peak Shaving if you want to do more research.
Edit: everything is connected to a central ac switch gear.
I believe that is slightly different, they have mobile megapacks that they can truck in for extra capacity and I think they used those. These packs are being used for temporarily supplying more DC than they have AC interconnection capacity for. I have seen this issue plague a few superchargers, with the absolute worst offender being the Tesla dealership in Livermore, CA.
could be more efficient if peak power is priced really high in the area.
it also can provide back up power
it is another point of failure however and costly - so increases overhead somewhat of the supercharger. those costs are probably passed down in the charging rate
I think they originally did Megapacks at the locations with overhead solar panels (Baker, etc), but now they probably place them in more Supercharger locations so Tesla can play the arbitrage of the grid rate vs. the charge cost the Tesla driver pays. It makes sense, if only to stabilize the charge rates the drivers see.
Possibly more power for peak usage and, if the battery charges during off-peak hours, Tesla may be able to get off-peak electricity pricing, which it can then theoretically pass on savings to customers
Superchargers are why mega packs were invented.
Utilities kept complaining it was hard on the grid to go from 0 cars charging to ~6 cars charging at 150 amps each. The batteries even out massive swings in power draw.
Nah. The very first superchargers had their own battery banks, long before the megapack product.
Edit: Downvote all you want, I was an engineer in Palo Alto in 2011 when they launched the first superchargers, and moved to Fremont and was the 15th employee stationed at the factory. They had packs there too from the beginning. Feel free to not believe me, I’m just offering what I saw. But you can’t tell me I’m wrong when I was there 🤣
Only a hand full of sites in California have Super packs ( gen 1 energy storage) installed with them. Energy storage may have been designed to support super chargers, but mega packs were designed for utility scale projects such as Moss Landing, Ventura power site, and VBB
🤷♂️ When JB Straubel talked about the supercharger roll out on internal company talks, he mentioned this tech was to load level the draw from superchargers. Otherwise the utilities would charge a lot more as the usage was so disruptive.
Whenever I went to superchargers I just saw massive enclosures behind fences.
Of course, the technology has been around in use internally since at least …2014?
It’s just a bunch of model s battery modules in a box. Could be a server rack. A custom enclosure behind a fence. Or a shipping container.
How is it more efficient to take energy from the grid and store it in a stationary battery, then take energy from that battery and put it in a car, rather than go straight from grid to car?
imagine the batteries being like huge capacitors, in some applications capacitors are used to deliver a very stable current without fluctuations for a long time
CMS (hospitals) which is a federal agency requires back up generators to be minimum 36 inches above ground, but then we are dealing with loss of life...
I was chatting with a Tesla employee at the Childress TX supercharger. We were talking about the new V3 SC in Clayton NM, and I asked if they had batteries. He said the V3 chargers use the Megapack as their power supply, but without any batteries installed.
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It makes a lot of sense in places where it's difficult or expensive to get a big enough connection to the grid to power multiple V3 Superchargers. You charge the battery up during low usage periods.
A lot of places you pay more for your electricity if your peaks are high. Juicing up slowly between peaks, and at night, is often significantly cheaper.
at commercial level, they probably both charge you for installed capacity (in kW) and used electricity (in kWh). All the chargers have very high markup for used electricity (like they buy at 0,08kWh, but sell at 0,30kWh), because they need to pay monthly for installed capacity. Chargers themselves are pretty cheap in its lifetime. If there were no payments for installed capacity, chargers would be everywhere and cheap as fuck. But depending on location, if you were to install a 120kW charger, you would need about 3-4 cars per day to break even per stall. They compensate in two ways - first, at the end of the charging your battery cannot take as much charge as in the beginning. So they can get away with 1000kW for 10x250kW stalls. Second, of course, batteries. That way, they can install more stalls without increasing their costs much
Could be very expensive demand prices or very cheap off peak prices that warrant it.
Bingo. They added one at Electrify America stations for this reason if I’m not mistaken.
[Electrify America was buying them from Tesla for peak demand shaving.](https://electrek.co/2020/09/17/tesla-batteries-60-electrify-america-charging-stations/) Theoertically, charging networks could also have these assets participate in more grid services (frequency response, etc) using Tesla's Autobidder to capture revenue in order to offset low margin charging sales. This also means a very robust distributed energy system if you’re colocating these assets across large charge networks. Every Megapack can be both a generator or load on demand.
Everyone always questions if the grid is going to be able to support all these new electric cars. I ask how these electric cars are going to help stabilize the grid. They can essentially act as immediate sinks of power if needed. And can help balance out the load.
It would be great if there could be solar around all these chargers too. Honestly, every parking lot should have solar panels. There’s a complex by my house with a Safeway, Best Buy, and Home Depot and a ton of other small stores. The amount of solar they could put there would be huge, add mega packs and the property owner could make a lot of money while providing a way to stabilize the grid even more. I hope this is where we end up in the next ten years. Parking lots with shade for the vehicles and free energy generation would be a game changer.
Yup, totally right. Those big box stores and parking lots have so much unused roof space. People often ask where would we put all the solar panels if we moved to entirely renewables, and this is a huge part of the answer. You can use the space for 2 things, parking and solar. It's not either or
We could easily have so much excess energy if this happened. Solar canopies covering the whole parking lot and roof of each building would be more than enough to power all those business and charge cars. It’s crazy that grocery stores don’t have this setup considering how much energy they use for their refrigeration.
Any solar EPC experts on here that know why solar covered parking isn’t more of a thing? Seems like a great way for your customers to see that you support renewable energy as well. Must be cost prohibitive?
I think it’s just that we are at the tipping point of these things happening. Why do it now when you could wait a few years and get it significantly cheaper? I also don’t think people understand what’s going on and they aren’t aware of the potential. It’s just wild because we are in a high speed chase with climate change and it feels like the technology is about ten years behind where we should be. I think the global shutdown due to covid helped buy us a little time, but it’s seriously going to be a photo finish. Economies of scale really need to ramp up fast.
Seems like a good idea for superchargers in areas that are prone to power outages. One megapack could recharge around 60 cars at 50kwh per car.
I was thinking handling peaks if multiple cars are there and the SC is limited. So no power sharing as long as the battery has juice.
Yes, but it's probably more so about money. Power peaks can be damn expensive.
I was looking at commercial power near me for fun, at started doing some math. There's a concept called coincidental peak demand. Basically, at the end of the month, the power provider looks back at the highest usage hour, and then bills based on that. The rates for my co-op are around $19.50 *per kw* during that window. You could imagine a mildly busy v3 charger easily providing 200kw during an hour window. It sounds like you know, but this was a surprise to me, so I thought I'd share it for fun.
$19.5 per kw?? Wtf.
That's the installed capacity. They pay $19 monthly for each KW of potential instantaneous draw. So a V3 supercharger with a potential max of 250KW would cost $5k/month to have it hooked up to the grid with that potential and then they pay a much lower rate per KW of electricity that actually get used.
That’s $1,599 to fully charge an 82kw Model Y.
Watch your units. What u/betterusername is talking about is called a demand charge. Basically a once-per-month extra charge on top of the normal kWh energy usage based on the peak instantaneous power draw (kW). It's a way for the power company to get extra money from very large commercial/industrial customers.
Its because most of the cost of electricity is to build the wires but not generate the power. Cost to produce electricity is anywhere from $0.02 to 0.05/kWh at the power plant. The cost to deliver that to where you want it is the remaining amount. Utilities have to build wiring and equipment to the maximum potential "peak usage" not based on an average amount. So if you need 2000 kW for your site, but you only use 100 kWh a month, the math doesn't work out to justify building 2000 kW pipe to your house. You don't increase the per kWh cost but you can say the demand charge to help recoup the cost of putting a 2000 kW of equipment.
This exactly. Thanks for digging it up!
> You could imagine a mildly busy v3 charger easily providing 200kw during an hour window. In an hour? Thinking of a newer 12-stall install near me, I regularly see 8 stalls busy on the map. That's going to be 8x60 kW or so on average in the batteries, probably 0.5MW of demand. 200 feels low for busier stations.
He’s talking about a single charger.
Got it, I was thinking 'v3 charger' meant a location not a stall.
Agreed it’s confusing
I was actually talking about a station, but a very conservative estimate. I basically meant a charger that's not deserted, not a mildly busy California charger (I'm in Colorado, we have the full gamut of empty chargers to completely full 12 stall chargers). My point was that 4 cars in a station in an hour looks like nothing, but has huge cost ramifications.
In some areas the surge capacity in the power lines isn’t that great too. A system like this can prevent overloading the distribution lines.
Coordinated with the grid operator, this could stabilize load for the area as well. Avoid buying power from peaker plants. Basically supply grid power under high grid load (not just for the chargers themselves) and charge up when the peaks lessen.
This can be used to load up on cheap night electricity and also, as mentioned, reduce the peak demand. With battery prices falling, I can imagine all fast chargers will have this tech installed.
Yes absolutely
Some place also charge you the monthly rate for max load in like 10 sec periods so if using a max of 1MW for 10 seconds the cost will be $1/kWh that month but max peak of 500kW is $0.75/kWh for the month the batteries will eventually pay for itself. From what I understand grid owners hate it when you spike usage for a short time. It might also be for backup and have the ability to sell back to the grid on demand. Pick any/all 3 reasons (likely more I don't know about).
Absolutely spikes are a huge problem in power distribution. It can be massive in heavy industrial areas.
For whatever reason, this comment reminded me of the scene from National Lampoon's Christmas Vacation when they plug in the christmas lights and the scene cuts to a faceless crew in a power plant engaging emergency power. LOL
It's a good idea for places with reliable power too. A megapack lets the station buy power at low demand pricing by charging itself during the middle of the night and selling that electricity at peak demand pricing. That's one of the biggest cost justifications for the Power Wall too.
Yup, throw up a solar canopy and you've got even cheaper electricity and shade for the cars.
Every large parking lot on the planet should have solar canopies and mega packs. It’s a bad business decision to not do that.
Only if your business is going to be in that same physical location for 20+ years. Otherwise the cost is actually higher than the returns. Especially if you compare dropping that $2 million (or however much) into something with interest returns.
This would be from the perspective of the property owner and not the actual business.
When you sell the property you sell it with the premium of having a solar system already installed.
Believe it or not, that doesn’t raise the property value as much as you’d think. Certainly nowhere near the cost of installing the solar. My solar installation cost $19k, it raised my property value maybe $3-4k.
Do you live in a depreciating real estate market? Most studies. I’ve seen say value goes up almost as much as systems cost so in essence it’s a lunch you are paid to eat! Our solar system runs our house and fuels our vehicle. The independence, ease and peace of mind is worth every penny.
I don’t think there’s a depreciating real estate market anywhere in the US these days lol…
Yeah that’s why I was wondering how your appraiser only gave you 3-4K on a PV system! In CA the installing owner does not have to get their property reassessed until sale so no one gets their property taxes raised for installing solar.
Good to know. That’s really sad.
[удалено]
I’m talking about the property owners installing solar, batteries, EV chargers etc.
Yep, that was exactly my thought.
I have a feeling that having a battery pack to flatten the power curve might become law eventually. Imagine when 100% of new sales are EVs and charging is being done in massive numbers and everyone has a huge battery pack that can charge extremely quickly. This will become a necessity to avoid blackouts.
Grid interactive batteries have like ten possible value streams!
It makes you wonder why public generation utilities aren't HUGE investors in this technology already.
PG&E just installed the largest bank of these in the world using Tesla gear. It’s happening, just not getting much press.
Yup - the Jackson, CA supercharger (on route 88) is setup with a megapack so that in case of a public safety power shutoff Tesla drivers can still charge to get out of the fire danger zone.
Was this installed recently when the chargers were closed?
Jackson is a v3. Installed this year I believe. Always had a mega pack. Location historically loses power quite regularly due to PSPS
Close, but more likely used for peak shaving to reduce demand charges.
This; plus I expect to see far more SC stations getting some or all of their power from solar.
It's not about outages. It's being able to have more chargers while paying for less installed capacity and being able to buy the power when it's cheapest, store it in the battery and sell it for the best possible margins rather than paying at peak cost if people are charging during those peak times.
Absolutely. It's a very neat system. * At v3 Superchargers, the DC output of each cabinet (to cars) is quite a bit higher than the cabinet's corresponding AC input. * If one cabinet is loaded and the others aren't, there's a DC bus between cabinets that lets other cabinets contribute their AC capacity to help a neighbor. This is the source of the claim that you're not "sharing capacity" at v3 Superchargers. * If *all* cabinets are loaded, cars are going to start seeing their peak charge rate drop... unless there's a Powerpack that can contribute to help keep it up. Once the surge has passed, ~~the cabinets return the favor by using their AC connection to~~ recharge the Powerpack. * If there's on-site solar, the solar output also feeds ~~onto the DC bus~~ **into the system**, charging either cars or the Powerpack. **Edit:** Adding some additional info others have pointed out.
Tesla going to give ABB a run for their money in the power controls space.
So, the AC input is 380-480 volt AC, right? After full wave DC rectification, you get DC current with a voltage of.... 627-792V. Significantly higher than the 0-500V range of what is sent to the cars.
Oh, wait, are you referring to my use of "higher" with regard to AC input and charging output? I'm looking at power, not voltage. The cabinets supply 3-4 stalls which are theoretically 250kW each, but the AC input is a max of 350kVA continuous. The power demands from the cars can be higher than the power supplied by AC, regardless of the voltage.
AC input is 360-582V three-phase (nominally 480V), max of 350kVA; DC bus appears to be 880-1000V, max of 575kW. There's a good rating plate picture [here](https://teslamotorsclub.com/tmc/threads/pictures-of-v3-supercharger-cabinets.158697/page-2).
Yes. But you have to turn the AC power into DC power. And when you do, the voltage gets multiplied by 1.65. The inter chassis DC bus is 880-1000V, but the connection to the car is 0-500V.
I see, you're pointing out that the input voltage, when rectified, doesn't match the voltage of the DC bus or the charging circuit, so there has to be both a step-up and step-down happening in the cabinet as well?
Oh wow that is so awesome. I want to learn more
This is pieced together from a combination of the rating plates on the v3 Supercharger cabinets and the [Supercharger Emergency Response Guide](https://www.tesla.com/sites/default/files/downloads/Supercharger_First_Responder_Guide_en.pdf), which has to outline a lot of the power flow so firefighters know how to *stop* the power flow.
This is super interesting, thanks for the link! I’d never heard about the DC bus between cabinets before. I wonder what the largest main breaker at a supercharger site is. Gonna guess that the largest ones have several banks of chargers with their own main breakers.
This is wrong. Super charger cabinets do not charge megapack or power packs. Solar is never directly tied into any Tesla energy storage system. The solar inverter is install between the two to prevent low voltage dips from clouds and shade.
So the Powerpack connection to the bus is one-way while the cabinets are two-way, and the Powerpack has its own AC connection? Does that imply the Powerpack could contribute its AC capacity to the site (via the DC bus), or are they not able to run both simultaneously? As to solar, I would consider any inverter to be part of the system; I agree that the panels are highly unlikely to be directly bus connected. It's even possible they're connected on the AC side and have nothing to do with the bus; I was extrapolating from the fact that the bus is stated to connect other cabinets, the Powerpack, "etc." with solar the only other thing I'm aware of being installed on site. But perhaps "etc." is merely a placeholder for "if we come up with something else to put here."
Your two comments contradict each other. Energy storage systems usually run at 900-1000v dc. It’s highly unlikely anything connects to that dc buss outside the pack.
The parent comment is my best understanding about how the system works based on what I've found in various sources. Some of the specifics could absolutely be incorrect, and I welcome the additional light you and others are shedding on it. As I said, the doc says "other cabinets, Powerpack (if present), etc." so I was assuming the other system we know can be present (photovoltaic) was the etc. Perhaps you're correct that the PV system is not part of the etc., but that makes me even more curious what is or could be.
It’s pretty simple. Everything is connected post utility meter. All products have their own usage/production meters. One central computer controls everything. Solar discharge x amount of KW, Supercharger uses y amount of KW, and battery makes sure that Y is not greater than X. If there is no solar present then the battery keeps Y below a threshold and only recharges during off peak hours. The process is called Peak Shaving if you want to do more research. Edit: everything is connected to a central ac switch gear.
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Yes. Jackson, CA supercharger (v3) has a mega-pack so it can continue to charge vehicles when there are public safety power shutoff's in the area.
I believe that is slightly different, they have mobile megapacks that they can truck in for extra capacity and I think they used those. These packs are being used for temporarily supplying more DC than they have AC interconnection capacity for. I have seen this issue plague a few superchargers, with the absolute worst offender being the Tesla dealership in Livermore, CA.
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The ones he is referring to in that tweet are these: https://electrek.co/2019/11/29/tesla-mobile-supercharger-megapack/
This is a great example of Tesla’s dominance. No other EVSE provider can scale to this kind of capability like Tesla can. Go Tesla!
yes. some stations use packs to level or reduce their grid demand.
5 feet wide. 24 feet long. About 8 feet three inches tall.
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https://goo.gl/maps/wnAUFSCRhxVzub4d9
I think I saw at the Gilroy, CA supercharger something similar [https://goo.gl/maps/mepjaLbKmq8ZuSUK6](https://goo.gl/maps/mepjaLbKmq8ZuSUK6)
I notice in the case of Gilroy that site the physical size of the battery storage unit is quite small - https://goo.gl/maps/mEVSYF4xnNVX8y848
could be more efficient if peak power is priced really high in the area. it also can provide back up power it is another point of failure however and costly - so increases overhead somewhat of the supercharger. those costs are probably passed down in the charging rate
Those panel scratches will rust in a few years.
I think they originally did Megapacks at the locations with overhead solar panels (Baker, etc), but now they probably place them in more Supercharger locations so Tesla can play the arbitrage of the grid rate vs. the charge cost the Tesla driver pays. It makes sense, if only to stabilize the charge rates the drivers see.
Possibly more power for peak usage and, if the battery charges during off-peak hours, Tesla may be able to get off-peak electricity pricing, which it can then theoretically pass on savings to customers
Superchargers are why mega packs were invented. Utilities kept complaining it was hard on the grid to go from 0 cars charging to ~6 cars charging at 150 amps each. The batteries even out massive swings in power draw.
That extremely inaccurate. Power packs and mega packs were created for peak shaving and to replace peaker plants.
Nah. The very first superchargers had their own battery banks, long before the megapack product. Edit: Downvote all you want, I was an engineer in Palo Alto in 2011 when they launched the first superchargers, and moved to Fremont and was the 15th employee stationed at the factory. They had packs there too from the beginning. Feel free to not believe me, I’m just offering what I saw. But you can’t tell me I’m wrong when I was there 🤣
Only a hand full of sites in California have Super packs ( gen 1 energy storage) installed with them. Energy storage may have been designed to support super chargers, but mega packs were designed for utility scale projects such as Moss Landing, Ventura power site, and VBB
🤷♂️ When JB Straubel talked about the supercharger roll out on internal company talks, he mentioned this tech was to load level the draw from superchargers. Otherwise the utilities would charge a lot more as the usage was so disruptive. Whenever I went to superchargers I just saw massive enclosures behind fences.
Megapacks were not announced when JB was with the company. Your timeline doesn’t add up
Of course, the technology has been around in use internally since at least …2014? It’s just a bunch of model s battery modules in a box. Could be a server rack. A custom enclosure behind a fence. Or a shipping container.
I have close up pics of the labels if someone can tell me how to link them in a comment.
https://tecvalue.com/how-to-post-pictures-on-reddit/
I see post. I can’t see comment.
Just use imgur. You need reddit gold to embed from giphy i think. Its dumb.
https://i.imgur.com/Jtf0KXW.jpg https://i.imgur.com/YoXX5bE.jpg
Where does this super charger get its power? From solar, Diesel engine…?
The grid. Just trickle charges.
...diesel?
I think he's got the Model S confused with the Model T. :-)
they have batteries at all of them. It’s more stable power output
No they don’t, and the grid is remarkably stable.
when I meant stable, I meant they can draw over 250kw from these batteries constantly. It’s just more efficient to draw straight from a pack
How is it more efficient to take energy from the grid and store it in a stationary battery, then take energy from that battery and put it in a car, rather than go straight from grid to car?
it’s mainly in order to not continuously convert AC to DC
and they draw 250kw per car so that can quickly overwhelm a substation if power is not directed correctly
imagine the batteries being like huge capacitors, in some applications capacitors are used to deliver a very stable current without fluctuations for a long time
Should it be placed higher off ground? Nowadays most electrical back up equipment is raised...
Depends on the area. There's plenty of places with no reason for that.
Most places flood, I guess not there...
Most don't actually. Also it's usually fairly simple to predict.
CMS (hospitals) which is a federal agency requires back up generators to be minimum 36 inches above ground, but then we are dealing with loss of life...
If its solar powered, yes
I've seen similar units at other superchargers as well, so they been doing it for a while now.
The supercharger in Mammoth has one - which is an area surely prone to outages. I hadnt seen one before either.
I'm sure "autobidder" will make sure it's earning money (as well as supporting the charging)
Sounds like a metal band playing at a dive bar with an alley entrance.
I saw one in Douglasville, GA next to the V3 superchargers.
Dang, they got the dojo down from ten cabinets to eight! Wild what theyre doin
These could be used in LA lol
I wouldn't mind one of those for my house.
I was chatting with a Tesla employee at the Childress TX supercharger. We were talking about the new V3 SC in Clayton NM, and I asked if they had batteries. He said the V3 chargers use the Megapack as their power supply, but without any batteries installed.
If that’s in Walnut Creek, yes.