The Tesla Thread

Skeeter said:
That is what I meant, theoretical throughput. You can't take the 90 second swap time and just extrapolate it.

If you have a Super Charger station with 2 chargers, and a battery swapping station with 2 chargers, at 30 minutes per charge both stations have a maximum throughput of 4 cars per hour.

So to the user it may look like 90 seconds to swap a battery, but thats just because the delay has been pushed lightly further up the chain. Given the complexity and cost of battery swapping, it would be more viable to just put as many Fast/Super Chargers in a station as the electricity feed can supply, rather than go to the effort of setting up a battery swapping station for no overall gain.
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How many petrol stations today have two pumps?

Most have 4/8/16/20 pumps and can deal with hundreds of cars. If battery swapping became common place then you'd have service stations just like today with 8+ stations and a dozen or more batteries being charged at once.

As I mentioned before though, the main issue would be the number of batteries needing to be produced to sustain this sort of infrastructure (ignoring standardization).
 
Jonnycoupe said:
What about if the station has two batteries already in stock charged... Sound like that model might be priced to cover the infrastructure and stock which could make it quite expensive but useful to long distance drivers. Drives more sense to the charge at home mentality.
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Skeeter said:
Home charging hits issues once you start to scale up, just like Super Charging and swapping does.
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Battery swapping is not something that is going to work long term, the infrastructure needed is just prohibitively expensive when you compare it to well all other options including using ICE. Not to mention the costs of all the additional batteries your going to need to maintain etc.

The scale that you would need to make it commercially viable would be huge. Don't forget your not only competing against fast chargers but also just plugging it in at home.

The reason why a fuel retailer can make a profit while only taking a few pence per litre is because during peek times their 8 pumps are constantly in use and everyone needs to visit a filling station at some point and the retailer costs are fairly low, plugging in at home is not an option.
 
Amp34 said:
How many petrol stations today have two pumps?

Most have 4/8/16/20 pumps and can deal with hundreds of cars. If battery swapping became common place then you'd have service stations just like today with 8+ stations and a dozen or more batteries being charged at once.

As I mentioned before though, the main issue would be the number of batteries needing to be produced to sustain this sort of infrastructure (ignoring standardization).
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Could you supply a station without enough power to charge 12+ batteries at a time?

Petrol stations can have more pumps because they store the fuel on site to be transfered into a vehicle. Battery charging stations don't do that, they would need a supply from the grid to sustain multiple chargers. 12+ Super Chargers on the go at once is 1,440kWs. I've no idea how viable it would be to provide that sort of feed to a roadside site like a petrol station?
 
Skeeter said:
Could you supply a station without enough power to charge 12+ batteries at a time?

Petrol stations can have more pumps because they store the fuel on site to be transfered into a vehicle. Battery charging stations don't do that, they would need a supply from the grid to sustain multiple chargers. 12+ Super Chargers on the go at once is 1,440kWs. I've no idea how viable it would be to provide that sort of feed to a roadside site like a petrol station?
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You could install local diesel generators :p
 
Would need to be serious ones.

I just did some real quick googling and calculations. Seems in the UK the total electricity generation capacity is about 105,000MW. Each fancy charger is 12KW. So let's just say that ALL current electricity usage disappears then you could charge 875,000 cars simultaneously.
There are roughly 35 million vehicles licensed for use on the road (in 2013).

Can we see the problem now...
 
Skeeter said:
Could you supply a station without enough power to charge 12+ batteries at a time?

Petrol stations can have more pumps because they store the fuel on site to be transfered into a vehicle. Battery charging stations don't do that, they would need a supply from the grid to sustain multiple chargers. 12+ Super Chargers on the go at once is 1,440kWs. I've no idea how viable it would be to provide that sort of feed to a roadside site like a petrol station?
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Connect it to a local sub station, or in a similar way to many smaller industrial units.

It would mean that you couldn't just plonk one anywhere (but then you can't do that with fuel stations now) but there would be plenty of places to provide that much power, it's not massive in the grand scheme of things. You'd also find it easy to get the higher voltages you need as well - not that 400V is particularly rare outside of domestic premises.
 
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Clarkey said:
Would need to be serious ones.

I just did some real quick googling and calculations. Seems in the UK the total electricity generation capacity is about 105,000MW. Each fancy charger is 12KW. So let's just say that ALL current electricity usage disappears then you could charge 875,000 cars simultaneously.
There are roughly 35 million vehicles licensed for use on the road (in 2013).

Can we see the problem now...
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Its not quite as simple as that, as not everyone is using a Super Charger (they are 120kW btw, not 12kW, although your calculation is correct using 120 so I assume its just a typo). A lot of people will likely be using lower speed chargers like 3kW or 7kW home chargers, or 11/22/50kW fast chargers.

The UK currently only has 114 120kW chargers in the entire country, out of a total of just under 6,000 public charging points.
 
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Amp34 said:
Connect it to a local sub station, or in a similar way to many smaller industrial units.

It would mean that you couldn't just plonk one anywhere (but then you can't do that with fuel stations now) but there would be plenty of places to provide that much power, it's not massive in the grand scheme of things. You'd also find it easy to get the higher voltages you need as well - not that 400V is particularly rare outside of domestic premises.
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There are Super Charger sites in the UK with 8x 120kW chargers, so it may well be possible.

But 12 Super Chargers still caps you at a maximum throughput of 24 cars an hour (at 80% charge too, it takes twice as long to get to 100%).
 
And that is one of the main problems with the battery swap, idea. You'd need a heck of a lot of batteries and chargers for a large fuel station!
 
Skeeter said:
Its not quite as simple as that, as not everyone is using a Super Charger (they are 120kW btw, not 12kW, although your calculation is correct using 120 so I assume its just a typo). A lot of people will likely be using lower speed chargers like 3kW or 7kW home chargers, or 11/22/50kW fast chargers.

The UK currently only has 114 120kW chargers in the entire country, out of a total of just under 6,000 public charging points.
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Ok, so the standard home charger (22 miles per hour of charge) is 7.4kW, enough for 14 million cars. So if we forgo all electricity usage except for cars, there's still only enough power to go around for 40% of the number of cars.
 
Like I said. Fuel and pipes are pretty 'basic' but they can quickly deliver unimaginable amounts of energy.

The future is both ice and EV via PHEV.
 
How often is the average car fuelled up though?

http://www.bbc.co.uk/news/uk-england-28546589

just under 22 miles a day, so the average car would only have to charge for an hour a night, or one night a week. So you'd just need enough power for about 1/7th of the cars on the road each day maximum.

That would work out as charging 5 million a night, and assuming a 7kW home supply that would be around 35,000MW/h which seems far more reasonable. Thats also assuming all cars will be charging at the same time, which they won't. So a peak load of 20,000MW would seem easily feasible. Obviously that would mean more power generation, but not massively so - half a dozen more power plants?

EDIT: Maybe not even that if we were clever (such as automating the recharge to the middle of the night - https://www.gov.uk/government/uploa...Seasonal_variations_in_electricity_demand.pdf

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There's what, 15,000MW spare over night during winter? Loads more in summer (I presume some plants are shut down in summer at the moment?).
 
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Amp34 said:
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If you average it all out EVs would need to charge for 1 hour a day at home on average to do the average daily mileage. With 35m cars thats about 1.5m on charge at once. At 7kW that hits about 10,000MW.

In reality though the cars won't be on charge evenly throughout the day. If you weight to overnight charging your compressing about 3x as many cars on charge at once (spreading over 8 hours not 24). Thats 30,000MW. That would see overnight energy useage during the summer hit the same levels as peak energy usage hits during the winter (take 30,000MW up to 60,000MW).

So without any other changes to energy usage, converting the UKs cars to EVs would see our energy consumption increase between 30% and 50%.

(And thats before you get to the bottom level logistics about how many households can actually use home charging).

Battery EVs also offer no solution at all for aviation or road and rail freight, which account for about half of the oil we use in transport.
 
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Either way the point being is that if done reasonably intelligently then you wouldn't actually need to build much/any more power generating infrastructure - assuming similar mileage, efficiency and cars on the road).
 
That roof, while nerfing the boot opening a bit, is pretty awesome. My GF has the panoramic roof on her Mini and it totally transforms the feel.of the car. Having an almost full glass roof right back to the encompass the rear window will make it feel like being in a convertible without the inconvenience of getting wet and/or cold.

Really hate that screen though. And seeing it perched up there glaring into the drivers face while driving at night makes me hate it more. I get annoyed at small sat nav screens being on when it's dark, that thing is like having a TV on your dash!
 
No blind will mean production is likely to be quite dark tint and poss IR coated. Imagine the solar loading in California!

Interesting to see them brace enough to pursue something we've often looked into. Lack of fabric does reduce the option of closing the blind for 'cosyness'
 
One of the Engineers doing the rides at the launch mentioned it will have a metal, glass or sliding glass roof. I don't know if the rear section will always be glass or not, but I suspect I'll be getting the metal roof if only because I don't really feel like paying for the roof, spend it on Tech Pack instead.
 
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