Tesla Supercharger network

[4sevens.com]

Except it's a lot of complexity to just let you know ahead of time what you would have found out when you got there anyway. The fact is at the point you could make the reservation you'd really have no alternative but to go and wait anyway, so it doesn't really help. Having better queue management once you're there is a different story.

the complexity doesn't have to be apparent to the user/driver - it could all be happening in the background in the software.

Letting them know you're way (through the nice 3g connected touch screen) and it being able to verify that you're on the way automajically secures a charging slot for when you arrive. the user does nothing except use the nav app to indicate a destination - and your car just tells you that you have a confirmed charge slot - and can even calculate how much time you'd need in the slot to fully charge. then you can tell it whether you want a full charge or up to a certain % then it can further calculate the time you'll spend in the charging stall - this info is then used to schedule someone else who is inbound.

I think thats a wonderful want to schedule these superchargers

 

[greencharge]

I think knowing ahead about occupancy, queue length and waiting time would be useful in planning arrival for the user and maintaining flow. To get all this data there needs to be a virtual or physical counter. I am sure Tesla being data driven is on top of it.

 

[gregincal]

the complexity doesn't have to be apparent to the user/driver - it could all be happening in the background in the software.

Letting them know you're way (through the nice 3g connected touch screen) and it being able to verify that you're on the way automajically secures a charging slot for when you arrive. the user does nothing except use the nav app to indicate a destination - and your car just tells you that you have a confirmed charge slot - and can even calculate how much time you'd need in the slot to fully charge. then you can tell it whether you want a full charge or up to a certain % then it can further calculate the time you'll spend in the charging stall - this info is then used to schedule someone else who is inbound.

I think thats a wonderful want to schedule these superchargers

The point it that it does absolutely nothing to get you a charger any faster. All the same people are going to be using the chargers all at the same times they were previously. This just predicts earlier when you will get the slot that you would have gotten all along. The point of reservations is to know to avoid things when you won't be able to go in and go when you can, but with this you are already on the road and committed before you find out.

 

[brianstorms]

New question:

How many of the existing SuperCharger sites actually have solar panels deployed? Elon famously said we'd be driving on sunlight for free forever, but it seems that some (most?) of the SC sites are grid-powered with no PV arrays in sight. Perhaps not installed yet? Or not planned to be? Curious what others know of the solar aspect of the SC rollout and how much of it will ultimately be solar-powered (during the day at least, with unused capacity flowing back into the grid).

 

[bollar]

The point it that it does absolutely nothing to get you a charger any faster. All the same people are going to be using the chargers all at the same times they were previously. This just predicts earlier when you will get the slot that you would have gotten all along. The point of reservations is to know to avoid things when you won't be able to go in and go when you can, but with this you are already on the road and committed before you find out.

I think you're right that 4sevens' idea has practical flaws that aren't as useful as a reservation, but it does have good cool factor. I would find it interesting to have this data available as soon as I enter a Supercharger as my destination, either in the car, or by smartphone -- maybe I could adjust the trip to arrive at a better time.

 

[Citizen-T]

New question:

How many of the existing SuperCharger sites actually have solar panels deployed? Elon famously said we'd be driving on sunlight for free forever, but it seems that some (most?) of the SC sites are grid-powered with no PV arrays in sight. Perhaps not installed yet? Or not planned to be? Curious what others know of the solar aspect of the SC rollout and how much of it will ultimately be solar-powered (during the day at least, with unused capacity flowing back into the grid).

There has been some delay there. Supposedly Tesla didn't have good enough credit and the banks wouldn't approve leasing the panels. Buying them outright would be pricey.

Presumably the situation has improved a good bit there.

Sent from my XT912 using Tapatalk 2

 

[scaesare]

There has been some delay there. Supposedly Tesla didn't have good enough credit and the banks wouldn't approve leasing the panels. Buying them outright would be pricey.

Presumably the situation has improved a good bit there.

Sent from my XT912 using Tapatalk 2

I also believe that the sheer size of an array needed to offset a Super Charger site dictates that they won't necessarily be co-located completely at the SC site itself...

 

[yobigd20]

I also believe that the sheer size of an array needed to offset a Super Charger site dictates that they won't necessarily be co-located completely at the SC site itself...

not necessarily. you can get a decent amount of power. did you know, that if you installed panels across the sahara desert, which is only a fraction of the size of the earth, just a few hours of sun could generate energy to power the whole world for a year? quite amazing if you think about it.... we could really get rid of fossil fuels entirely if the world worked together to install panels throughout the desert.

 

[Rla]

I think you're right that 4sevens' idea has practical flaws that aren't as useful as a reservation, but it does have good cool factor. I would find it interesting to have this data available as soon as I enter a Supercharger as my destination, either in the car, or by smartphone -- maybe I could adjust the trip to arrive at a better time.

JB Straubel has already alluded to creating a much better navigation aid; using and including all the data available about your trip:
* Normal map data (already available)
* Elevation data
* Weather data (temp and wind)
* Supercharger locations (already available)
* Current charge and estimated kWh usage (the data in your car)
* Road speed limits
* Current traffic data

Enhanced trip planning is also on the horizon, with Tesla following the lead of the airline industry, which plans flights with keen attention to weather patterns, headwinds and the amount of fuel needed to get to the destination."We're working on a trip-planning feature that integrates energy and range management with navigation," Straubel said. "We could load altitude databases, weather and wind information into the car, along with details about the roads you are on. There's a long road map of features we want to add."

from Mercurynews

If they were to integrate the usage patterns and real-time (or projected future) use of their SC network along the current route you have set in the car, it could give you a very realistic indication of your trip time, including charging. This could include scheduling rest and food stops, etc. (and charging while being stopped)
* This would ideally call for inductive charging, so you'd just park the car in the right spot, and it would start to charge. But it won't be 'Supercharging' unless that will be the 'under your nose' announcement

Something cool would be to allow real-time communications with your fellow Tesla owners. E.g. say you arrive at a SC location and they are all taken. If you were able to log your 'request to charge' for that location, so that when a car has reached its intended charge level, the owner of the charged car gets notified (via the App, Sms, chat) that there is someone waiting for the charger. They could then confirm that they will come and move the car, or reject. The owner waiting could then receive that communication. This provides transparency... don't you hate just waiting, not knowing what is going on!
So additionally when you 'request to charge' the system could read out the charge level and ETA of the other cars and give you an indication of how long it will take before you can start charging.

 

[bhuwan]

not necessarily. you can get a decent amount of power. did you know, that if you installed panels across the sahara desert, which is only a fraction of the size of the earth, just a few hours of sun could generate energy to power the whole world for a year? quite amazing if you think about it.... we could really get rid of fossil fuels entirely if the world worked together to install panels throughout the desert.

Wow that's fascinating.

 

[JRP3]

You're forgetting one large aspect, storage.

 

[RandyS]

The problem with solar and storage is that if they are going to be used to prevent demand charges at a California Supercharger site (which would amount to about 480kW of load if all 8 bays are occupied for four 120kW superchargers), you would need to provide that solar or storage offset EACH and EVERY time someone used the station throughout the month, otherwise even one unprotected full charge event would incur demand charges for the month. That's a lot of energy to provide (480kW for an hour, etc.) to keep the demand charges off the bill AND the batteries/storage required would also cost a lot of money to install...

Definitely a difficult technical issue in California...

 

[scaesare]

not necessarily. you can get a decent amount of power. did you know, that if you installed panels across the sahara desert, which is only a fraction of the size of the earth, just a few hours of sun could generate energy to power the whole world for a year? quite amazing if you think about it.... we could really get rid of fossil fuels entirely if the world worked together to install panels throughout the desert.

I said "not necessarily", because it depends on the size of the SC site, obviously. If you've got a large area nearby, then you can probably make it work... but some of these sites are a couple of parking spaces, and not much more. Not a lot of surface area if you have a canopy over the top.

Some "back of the envelope" calcs:

Currently you can get 300W panels in a form factor of 3.5' x '5. So to generate the 120 KWh (we know they are going this direction)of energy for a single SC for each hour used:

120,000/300= 400 panels needed.

Each panel is 3.5*5 = 17.5 square feet.

Therefore each charger requires 17.5*400 = 7,000 square feet for each hour of operation.

Assuming 2 chargers at a site is 2 * 7,000 = 14,000 square feet.

If Tesla is assuming 25% charger utilization (6 hours out of 24): 6*14,000 = 84,500

Most solar sites recommend assuming 5 hours of generation time per day on average: 84,500/5 = 16,800 square feet


So just a 2 charger site would require a canopy 170 feet long by 100 feet wide. Even with the fact that each charger stack can serve 2 cars (by splitting the current between the two cars), that's still only 4 parking stalls for a pair of chargers. Not a lot of room for a canopy that size.

Allowing for some error in my assumptions (utilization?), it's still a a pretty good bet many of these sites in a business parking lot are not going to have the space to have the panels co-located there.

Besides... I read somewhere a while back that it was pretty much stated that the solar sites to offset the SC's were planned to be elsewhere on the grid... I just wanted to do the math to see what it would take.

 

[callmesam]

I said "not necessarily", because it depends on the size of the SC site, obviously. If you've got a large area nearby, then you can probably make it work... but some of these sites are a couple of parking spaces, and not much more. Not a lot of surface area if you have a canopy over the top.

Some "back of the envelope" calcs:

Currently you can get 300W panels in a form factor of 3.5' x '5. So to generate the 120 KWh (we know they are going this direction)of energy for a single SC for each hour used:

120,000/300= 400 panels needed.

Each panel is 3.5*5 = 17.5 square feet.

Therefore each charger requires 17.5*400 = 7,000 square feet for each hour of operation.

Assuming 2 chargers at a site is 2 * 7,000 = 14,000 square feet.

If Tesla is assuming 25% charger utilization (6 hours out of 24): 6*14,000 = 84,500

Most solar sites recommend assuming 5 hours of generation time per day on average: 84,500/5 = 16,800 square feet


So just a 2 charger site would require a canopy 170 feet long by 100 feet wide. Even with the fact that each charger stack can serve 2 cars (by splitting the current between the two cars), that's still only 4 parking stalls for a pair of chargers. Not a lot of room for a canopy that size.

Allowing for some error in my assumptions (utilization?), it's still a a pretty good bet many of these sites in a business parking lot are not going to have the space to have the panels co-located there.

Besides... I read somewhere a while back that it was pretty much stated that the solar sites to offset the SC's were planned to be elsewhere on the grid... I just wanted to do the math to see what it would take.

Except that you, like many before you, forget that solar panels get to do TOU. Discharging the panels or battery into the grid during the daytime will net you 4-5X energy usage/charging at night.

 

[scaesare]

Except that you, like many before you, forget that solar panels get to do TOU. Discharging the panels or battery into the grid during the daytime will net you 4-5X energy usage/charging at night.

Not if your goal is to offset power usage, not just cost. And 4-5X might be a bit much...

Now, that having been said, I'm not sure what Elon's stated goal was.

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Not if your goal is to offset power usage, not just cost. And 4-5X might be a bit much...

Now, that having been said, I'm not sure what Elon's stated goal was.

To answer my own question, from the Supercharger unveiling HERE:

• The electricity "used by the Supercharger comes from a solar carport system provided by SolarCity, which results in almost zero marginal energy cost after installation."
• Tesla even says each Supercharger will generate more solar energy than the Tesla vehicles will use, resulting in "a slight net positive transfer of sunlight generated power back to the electricity grid." This point is apparently important enough to repeat: "Supercharger system will always generate more power from sunlight than Model S customers use for driving."

So they plan a net positive generation of overall power via solar... so TOU shouldn't really factor in, unless I'm missing something?

 

[callmesam]

Not if your goal is to offset power usage, not just cost. And 4-5X might be a bit much...

Now, that having been said, I'm not sure what Elon's stated goal was.

- - - Updated - - -



To answer my own question, from the Supercharger unveiling HERE:



So they plan a net positive generation of overall power via solar... so TOU shouldn't really factor in, unless I'm missing something?

"zero marginal energy cost" - this refers to COST not energy USE.

Some Superchargers will not be used as frequently thus resulting in a NETWORK net + of electricity and a TOU for the cost portion. OR they will add a super-large array to a parking lot that will offset 10 other Superchargers.

Then it follows that TOU is EXACTLY how Superchargers "break even".

Elon's tricky, huh?

 

[hans]

not necessarily. you can get a decent amount of power. did you know, that if you installed panels across the sahara desert, which is only a fraction of the size of the earth, just a few hours of sun could generate energy to power the whole world for a year? quite amazing if you think about it.... we could really get rid of fossil fuels entirely if the world worked together to install panels throughout the desert.

This is a nice soundbite but...

- The Sahara Desert is 9,400,000 square kilometres (3,600,000 sq mi) and is not collocated with consumption so this just reinforces the original posters argument that onsite panels are too big to be practical.

- Most proposed desert solar power projects are based on CSP (thermal), not PV panels. The desert is too hot and dusty for PV panels to be efficient and there is not enough water to cool and clean the panels.

I am sure that Tesla will someday cover the Fremont factory roof with a grid-tied PV solar array. Likely one installed and maintained by SolarCity.

- - - Updated - - -

"zero marginal energy cost" - this refers to COST not energy USE.

Some Superchargers will not be used as frequently thus resulting in a NETWORK net + of electricity and a TOU for the cost portion. OR they will add a super-large array to a parking lot that will offset 10 other Superchargers.

Then it follows that TOU is EXACTLY how Superchargers "break even".

Elon's tricky, huh?

Only problem is that most supercharger use is during the day when the rates are higher. TOU helps for slower overnight charging (like at home) but not for quick charging in between cities.

 

[callmesam]

Only problem is that most supercharger use is during the day when the rates are higher. TOU helps for slower overnight charging (like at home) but not for quick charging in between cities.

But each Supercharger can BUY from grid and charge the battery array for $.05/kWh from 11PM - 6AM and then effectively SELL PV on the roof at $.15-.35 at peak time of use. The battery can charge the Tesla drivers and then after COMPLETE discharge can buy from the grid.

 

[scaesare]

"zero marginal energy cost" - this refers to COST not energy USE.

Huh? "Tesla even says each Supercharger will generate more solar energy than the Tesla vehicles will use"

 

[Dave EV]

Most proposed desert solar power projects are based on CSP (thermal), not PV panels. The desert is too hot and dusty for PV panels to be efficient and there is not enough water to cool and clean the panels.

Huh? CSP usually uses much more water than PV since they are essentially steam turbines. They have the exact same dust issues as PV panels do. Many CSP projects in California have switched to PV at least in part because of water supply issues. The biggest benefit of CSP over PV is that adding storage is relatively inexpensive allowing the plant to shift production up to 8 hours.

But each Supercharger can BUY from grid and charge the battery array for $.05/kWh from 11PM - 6AM and then effectively SELL PV on the roof at $.15-.35 at peak time of use. The battery can charge the Tesla drivers and then after COMPLETE discharge can buy from the grid.

But then you would need one full battery for each expected supercharge during peak hours. That would be quite a stack of batteries - you could easily require 30 85-kWh packs worth of storage.

In most of the USA, 1 kW of solar PV will generate 1200-1500 kWh / year or 100-125 kWh / month or 3-4 kWh / day on average. Assume a typical SuperCharge takes 50 kWh, so 1 kW of PV is enough for 2-2.5 SuperCharges / month (we are ignoring demand charges here and just calculating requirements for break-even net generation / usage). Let's say your typical SuperCharger is used 5 times / day - about 250 kWh / day - so for each SuperCharger you need at least 60 kW of PV - that's quite a sizable array if you imagine that your typical roof-top array is somewhere between 3-8 kW. A 62 kW array will take up at least 4,000 sq/ft - or about 40 ft / 100 ft. Now imagine that you have 4-8 SuperChargers per location - that's a lot of solar PV to install!

My numbers are different than scaesare's earlier - he was roughly calculating how much solar PV is required to generate a peak of 120 kW (and it would actually take 130+kW of solar PV to generate 120 kW AC in optimal conditions - no more than an hour or two per day and not in the winter months) - not how much solar PV is required to be net-zero consumption overall.