Tesla Network of Supercharger Stations for the Tesla S Series

September 26, 2012 7:37 PM

"Does Tesla's Supercharger answer the road trip question for EVs?" Tesla announces plans to rollout a network of supercharger stations that will generate more solar power than the Tesla S series cars draw, leading to a net input into the grid. Yahoofinance says "...the first six Supercharger stations, which will allow the Model S to travel long distances with ultra fast charging throughout California, parts of Nevada and Arizona."
posted by BillW (57 comments total)

Ok, hivemind, this has me quite excited. Someone please inform me as to why I should remain skeptical and grounded (this is an earnest request).
posted by sendai sleep master at 7:46 PM on September 26, 2012

"Does Tesla's Supercharger answer the road trip question for EVs?"

From the first article:

The Supercharger stations are designed to work only with Tesla's Model S sedans, which just became available in June.

If you're able to afford a specific baseprice $50K car (and that car will only get you 160 miles per charge, as you'll discover if you scroll that page down), then yes. If you don't have that specific car and you don't plan your routes between charging stations, then no.

If they're going to do this right, they'll take this out of being a proprietary standard and figure out a way to allow any and all EVs to recharge using them. That would be the only way this could possibly be an answer to anything other than one very small demographic's needs.
posted by hippybear at 7:52 PM on September 26, 2012

Oh, I stand corrected. From the Tesla Options and Pricing page I linked above:

Cars equipped with a 60 or 85 kWh battery can take advantage of Tesla's growing network of Supercharger stations.

Raise that baseprice to $60K, please.
posted by hippybear at 7:55 PM on September 26, 2012

If this really works the way they plan it to, this is a game changer. I can't think of a single chain of gas ststions/convenience stores that wouldn't pay tesla to ensure traffic of relatively affluent customers who will be there a minimum of 30 minutes charging.

Once this is in enough places it will be the defacto standard. What standards body designed the gas pump all those years back.
posted by Ad hominem at 7:55 PM on September 26, 2012 [3 favorites]

I'm sure that a more open gas station-like approach is part of the plan, but you can't operate on that scale casually. They are limiting the potential scope of problems to a car they understand intimately and are able to control. This allows you to focus on problems at the system level and worry about integration later.
posted by feloniousmonk at 7:55 PM on September 26, 2012

I'm a skeptical until they can show us the numbers -- e.g. how many customers they expect to serve, the average power required to travel, say, 100 miles, the efficiency of their solar cells. Also, I'm curious about how they expect to store charge -- if there are 3 EVs charging at the same time, that's an incredible amount of energy being drawn at once. Aside from the cloudy-day issue, our power infrastructure will not be able to handle that kind of power draw. They would need to mitigate it with, basically, their own local power station and, I dunno, a compressed hydrogen storage system.

Also, there's no way the station will be run on pure solar. Just not possible -- our current technology cannot produce enough solar energy to power a car without requiring long charging times. It would have to produce enough energy to propel a few 2+ ton cars if they expect multiple customers at once.
posted by spiderskull at 7:56 PM on September 26, 2012

What I mean is that, works with Tesla Supercharger will be a sales point for future EVs.
posted by Ad hominem at 7:56 PM on September 26, 2012

Even "ulta fast charging" means, in this case, at least a half hour - i.e. much longer than many people would like to wait.

There is another company that has, in my opinion, solved this problem much more elegantly, called Better Place. Basically, the concept is that you build EVs with batteries that can be easily swapped out. At a equivalent of a gas station, a robot automatically removes the old battery pack from your car, to be recharged later, and attaches a fresh one in its place. This allows for turn-around times much more like that of a normal gas station, rather than the much longer times of even high-speed recharging.
posted by kickingtheground at 7:58 PM on September 26, 2012 [6 favorites]

More from that page:

The Supercharger is an industrial grade, high speed charger designed to replenish 150 miles of travel in about 30 minutes when applied to the 85 kWh vehicle. [emphasis added]

So, drive for 2.5 hours, at 60mph (slower than most highway speed limits), and then stop for a half-hour, rinse, repeat.

I guess this is a step in the right direction. What I don't understand is, why don't they offer solar panels as an option for the roof? It wouldn't recharge the car entirely while being driven, but if you're looking at anything more than using the car for running errands, surely every little bit helps. (Plus, self charging while sitting unused is always a bonus.)
posted by hippybear at 7:59 PM on September 26, 2012 [1 favorite]

I still don't buy that the vast majority of people take long road trips. Is that really true? Frequently enough that renting a car at $30/day for those infrequent occasions wouldn't work?

I think many people vastly overestimate how much range capability they need in their car. Some people really do drive >160 miles frequently, but I think thats a fairly small number.

The MUCH larger problem for electric cars is having a place to charge them. If you live in a city apartment without a garage (or with apartment-style parking garages) you can't get a charger installed, and its not like sidewalks have plugs yet. You pretty much have to have a house to use an electric car right now, which is unfortunate given how well suited they are for urban areas.
posted by wildcrdj at 8:00 PM on September 26, 2012 [7 favorites]

(And when I say "having a place to charge them" I mean a convenient one. These stations would help with larger trips but no one is going to go way out of their way to charge a car for routine daily driving. Unless most gas stations have chargers -- which is a long way off --, you pretty much need to be able to charge at home or work, and many people have neither option).
posted by wildcrdj at 8:01 PM on September 26, 2012

Actually, back in the days of the EV-1, Phoenix AZ had charging stations installed everywhere. Like, EVERYWHERE. At least in the parts of town I went to (and I worked there as a point-to-point courier, so I was in a LOT of parts of the metroplex every day). Business complexes, shopping centers, I even remember there was some street parking downtown which had EV-1 charging stations.

Still not entirely sure why that program was shredded into tiny metal bits.
posted by hippybear at 8:03 PM on September 26, 2012 [1 favorite]

Kickingtheground, a significant issue with the Better Place mode is that batteries are still quite expensive, and each station would need to maintain a large inventory of batteries for the model to be feasible. That means not only battery inventory costs, but space considerations as well.
posted by oneironaut at 8:10 PM on September 26, 2012

But wait! There's more!

Hours after unveiling plans for a nationwide network of "Superchargers," Tesla Motors (TSLA) on Tuesday quietly cut its revenue forecast for 2012 and admitted that production of its all-electric Model S sedan is "slower than we had earlier anticipated."

Tesla also revealed plans to shore up its balance sheet and raise at least $128 million through the sale of an additional 4.3 million shares of stock, and to make changes to the terms of its $465 million loan from the U.S. Department of Energy.

posted by The World Famous at 8:11 PM on September 26, 2012 [1 favorite]

Hmm. 100kW in 30 minutes. 200kW per hour, so, obviously, 200kW/hrs.

There are 24 hours a day.

This means that each station can charge 48 Tesla S per day at max.

Doing so requires would require 4.8MW of power. Doing this by solar, well, on average, 12 hours a day are dark over the course of the year, so you need to generate 4.8MW in 12 hours, and store 2.8MW for the dark hours.

I suspect that the actual charging rate will be about 2 per day. I'm still wondering how they're storing the power, though -- unless they're actually generating 200kWhr constantly and selling it to the grid when there isn't a car hooked up, but 200kW of solar cells is pretty expensive, both in material and in the land needed for the panels -- and of course, that means you're either drawing that power back if someone recharges at night, or you close when it's dark.

Oh, and to deliver 200kW/hr, which is what they're talking here, you're either pushing over 410A at 480V, or 50A at 4kV. That's going to be one hell of a cable, and one hell of a connector, and I wouldn't trust the average driver with that on a bet.
posted by eriko at 8:14 PM on September 26, 2012

I think charging time is a bit of a red herring. In order to make this system sustainable, you have to solve two problems: power supply and power storage. Focusing on solar in the SW desert gives them an opportunity to figure out how to operate a renewable power supply under ideal conditions. Charging time is going to decrease and it may ultimately turn out that swappable batteries or something else are better, but that doesn't change the necessity to master the operations aspect of generating the power, etc. efficiently enough that it's affordable. Efficiency is why renewables are so important to the mix, because while you could surely do this over the grid, the less you spend there the better for obvious reasons.
posted by feloniousmonk at 8:15 PM on September 26, 2012

Even more interesting is inductive charging Stanford is working on
posted by Ad hominem at 8:15 PM on September 26, 2012

What I don't understand is, why don't they offer solar panels as an option for the roof?

Because with roof panels you might get 300 watts.

The car uses 85,000 watts.
posted by Pogo_Fuzzybutt at 8:18 PM on September 26, 2012 [2 favorites]

Hippybear: Roof mounted solar panels produce in the region of 150 watts. The 60kwh battery lets you drive for about 3 hours (60mph, 180 miles total) - in that 3 hours of driving, you would have generated 0.45kwh from the solar panels - enough to extend your range by maybe 1%.

Spiderskull / Eriko: The talk about their Supercharger stations running on pure solar is "technically" true - they're certainly hooked up to the grid in any case. (they say that the rest of the time they're selling power to the grid). It's pretty safe to assume that when charging the cars, they will draw power directly from the powergrid, and when there's no cars being charged those solar cells feed energy back into the grid, and over time it's a net positive.

Over the last 3 years Tesla Motors has lost over 600 million dollars, most of that funded through federal loans. They still have room to wiggle, but investor (and government) patience and pockets are not infinite. It will be interesting to see where they end up. Fisker is showing them some good competition with a different business model.

Half an hour for a recharge time is fine until you run into a queue. If there's even 1 person ahead of you in the queue you're in for a 1 hour wait. And what if the last guy left his car to charge and went to get a meal and doesn't come out of the restaurant until an hour later? The other scary thing is that you're completely dependant on that one charging station in the middle of nowhere - if one gas station is closed, just head to the next one, and a "low" tank of fuel still gives you about 100km of range. If that one single supercharging station is closed, well tough.

I'm still a believer in efficient petrol and diesel. There are some amazing cars out there for $20k, you could buy a hell of a lot of carbon offsets with the other $40k you would have spent on a Tesla.
posted by xdvesper at 8:19 PM on September 26, 2012 [4 favorites]

I think it's important to note that these stations won't be pure solar. They will draw on the grid as needed (and feed into it if excess energy is generated). They will have a solar component, but they won't be pure solar. In fact, this very careful wording from the third link:

Each solar power system is designed to generate more energy from the sun over the course of a year than is consumed by Tesla vehicles using the Supercharger. This results in a slight net positive transfer of sunlight generated power back to the electricity grid. In addition to lowering the cost of electricity, this addresses a commonly held misunderstanding that charging an electric car simply pushes carbon emissions to the power plant. The Supercharger system will always generate more power from sunlight than Model S customers use for driving.

leads me to believe that what we have here is a grid-powered car charger coupled with a solar EV station which feeds power into the grid constantly during available solar generating hours, while cars draw power from the grid when they charge up.
posted by hippybear at 8:22 PM on September 26, 2012 [1 favorite]

Still not entirely sure why that program was shredded into tiny metal bits.

Because they lost half a billion on the program, then they lost money on every unit and then CARB was defanged meaning they didn't have to sell a bunch of unprofitable EVs to make money on Suburbans.
posted by Talez at 8:24 PM on September 26, 2012 [3 favorites]

I still don't buy that the vast majority of people take long road trips. Is that really true? Frequently enough that renting a car at $30/day for those infrequent occasions wouldn't work?

Buy it! Even if infrequent, the thought of inconvenience and the fear of running out of juice rules out this car for many buyers. By linking SF to LA Tesla addresses this fear with reassurance: "see, you can drive 400 miles safely!"

And since the fear is partly emotional, this is a good way to address it.

(also note: if you drive an 80k car, you probably aren't as down with a Hertz rental as your buddy with the Ford Focus)
posted by zippy at 8:31 PM on September 26, 2012

Inductive charging
Qualcomm Halo
Delphi
witricity
posted by daniel9223 at 8:39 PM on September 26, 2012 [1 favorite]

Also, there's no way the station will be run on pure solar. Just not possible -- our current technology cannot produce enough solar energy to power a car without requiring long charging times. It would have to produce enough energy to propel a few 2+ ton cars if they expect multiple customers at once.

It's entirely possible for the station to produce more power than the cars consume, unless the stations become VERY popular. It won't be "pure" solar, it will be grid tied solar. While a car is charging, the station will be a consumer of energy from the grid. When no cars are charging, the meter runs backwards. The important figure at the end of each month is the kWh produced by the solar system vs. the kWh drawn from the grid. Given a large enough PV array it's quite possible the station will be in the net positive.
posted by thewalrus at 8:40 PM on September 26, 2012 [1 favorite]

I still don't buy that the vast majority of people take long road trips. Is that really true? Frequently enough that renting a car at $30/day for those infrequent occasions wouldn't work?

I think *most* Californians travel between the Bay Area and Southern California at least once in a while. The thing about Tesla owners (or potential owners) though, is very few of them don't have another non-electric comfortable car to use for these long trips. These are people spending $60k+ on early-adopter technology, who own houses (people don't buy electric cars unless they have somewhere to plug them in at home, where they can do renovations to install charging stations) in California. They have second cars.

I'm at least a price bracket down market from there (I recently got a Chevy Volt), and still, my wife has a perfectly good Subaru Outback that we could use for whatever (although the Volt avoids this problem well-enough, anyway).
posted by tylerkaraszewski at 8:41 PM on September 26, 2012 [2 favorites]

Oh, and to deliver 200kW/hr, which is what they're talking here, you're either pushing over 410A at 480V, or 50A at 4kV.

I find it very hard to believe that is practical at all. I'll have to meditate on it I guess. Certainly I don't have any experience with that level of power, so I might just be reacting fearfully, but man that is serious juice.

And even then a half hour wait for 150miles.
posted by Chuckles at 8:46 PM on September 26, 2012

other charging networks:
EV Project
Blink (also Ecotality)
ChargePoint
eVgo (Texas) http://www.evgonetwork.com/find-a-station/

Home charging is still going to be the big percentage.
posted by daniel9223 at 8:47 PM on September 26, 2012

Can someone please enlighten me as to who exactly buys Tesla Roadsters? In my simplistic, stereotyping mind, I can picture the kind of person who buys a Prius. I can also picture the kind of person that buys a Ferrari or a Lamborghini.

I'm having trouble imaging the kind of person that would want a lovechild of both?
posted by cacofonie at 8:52 PM on September 26, 2012

They are saying they charge at 90kW and that it takes 30 minutes to charge a battery. That means the battery capacity is 45k Volt Ampere-Hours. Or, if it is a 100V battery, 450 Ampere-Hours. That means charging at 480V and 200A, not 400A.

Still kind of crazy though...
posted by Chuckles at 8:58 PM on September 26, 2012

Can someone please enlighten me as to who exactly buys Tesla Roadsters? In my simplistic, stereotyping mind, I can picture the kind of person who buys a Prius. I can also picture the kind of person that buys a Ferrari or a Lamborghini.

Silicon Valley engineers who like high-tech and high-performance and who's stock has vested.
posted by tylerkaraszewski at 9:00 PM on September 26, 2012

pushing over 410A at 480V, or 50A at 4kV

IAAEE, so I can probably calculate it, but it's late, and the gist is close enough: I worked with some guys who were seriously into EVs, and who thought very carefully about charging and related issues. And IIRC, the power required to charge 3-4 EVs simultaneously (as you might have at a charging station, the way you see 3-4 cars filling up at the pump now) would strain the limits of a gas-station-sized electrical substation. Not to mention the load on the grid.

So, if EVs really take off, you have to replace gas stations with similarly-sized electrical substations that transform the really high voltage of transmission lines down to the moderately high voltages required to charge EVs reasonably quickly.

They had some ideas for getting around that, but people who build electrical substations are more interested in schemes that require them to build lots of such substations. (As you might imagine, they're not cheap.)
posted by spacewrench at 9:00 PM on September 26, 2012 [1 favorite]

Can someone please enlighten me as to who exactly buys Tesla Roadsters?

People that like fast cars AND like gadgets and feeling futuristic AND have a bunch of money - so, mostly executives at tech companies.
posted by thedaniel at 9:00 PM on September 26, 2012

I'm having trouble imaging the kind of person that would want a lovechild of both?

Seriously? Tech people for a starter. High performance via adanced technology has a LOT of appeal. And electric engines are so much higher-performance than internal combustion (the gap is bigger than between internal combustion engines and steam engines) that even with the battery problem holding them back, it won't take too long before the greatest supercars are electric.
posted by anonymisc at 9:00 PM on September 26, 2012

Half an hour for a recharge time is fine until you run into a queue. If there's even 1 person ahead of you in the queue you're in for a 1 hour wait.

I think any bottleneck in the foreseeable future would be too few charging stations, not getting to one and finding all the power sockets in use and having to wait. I'd be surprised if they dropped the ball and ended up with queues. But then I'm assuming that the stations are a foray into becoming the intrastructure provider of the future. If this is really just a PR stunt (which is kind of how they describe it to their myopic investors), then queues wouldn't surprise me. But Tesla and Musk seem so focused on the complete vehicle experience that I think they'll be in this For Serious.
posted by anonymisc at 9:12 PM on September 26, 2012

They are saying they charge at 90kW and that it takes 30 minutes to charge a battery.

They're saying 30 minutes charge gives 150 miles. That's only a half-charge of the battery. You don't want to quick-charge lithium all the way to full. (Even accounting for "full" not really meaning fully full - EV's trade out some battery capacity to get greater longevity)
posted by anonymisc at 9:17 PM on September 26, 2012

zippy: "(also note: if you drive an 80k car, you probably aren't as down with a Hertz rental as your buddy with the Ford Focus)"

If you drive an 80k car, you can probably afford to rent whatever the hell kind of car you want. They don't only have crappy cars.

On the electrical demands, it's not actually that much. You're getting half a charge in half an hour, so you're charging at 1C. So you're looking at the 85kW of current draw per car, discounting any charging losses, since this is just back of the envelope. 1000A 480V 3 phase service is pretty easy to come by. Lopping off the standard 15% safety factor, you get to use 850A at 480V or 408kW, so you could charge 3 cars at a time with enough left over to run a convenience store, restaurant, or whatever. Or charge a fourth car with the smaller battery.

No substation required, unless you want to charge 100 of them at a time. It's a lot of juice, but it's not much more draw than a small office building.
posted by wierdo at 9:24 PM on September 26, 2012

Roof mounted solar panels produce in the region of 150 watts. The 60kwh battery lets you drive for about 3 hours (60mph, 180 miles total) - in that 3 hours of driving, you would have generated 0.45kwh from the solar panels - enough to extend your range by maybe 1%.

If you park outside, you get 6-12 miles a day free fuel. That's pretty awesome (for me it would mean I would never need to charge or buy fuel), even if it's not going to save you on a road trip.

Adding solar to a car really appeals to me, the stronger argument against is that from a financial perspective, it makes more sense to take those panels out of the roof and use them in a grid-tie system. You lose the ability to park at work on a flat battery and have enough fuel to get home when it's time to go home, but the grid-tie panels will always have ideal facing, and won't be damaged in any accidents, and will continue to earn unaffected by whether the car is parked in the shade or in a garage.
posted by anonymisc at 9:27 PM on September 26, 2012

I think the buyers Tesla is targeting generally keep their cars in the garage. The added weight of the solar panels would probably waste more electricity than they produce over the life of the vehicle.
posted by ryanrs at 9:44 PM on September 26, 2012

it makes more sense to take those panels out of the roof and use them in a grid-tie system

Why not both? Tesla has a well known depleted battery=dead battery problem that the roof panel could avoid.

Why not put solar panels on top of every flat man-made surface, including car roofs?
posted by eye of newt at 10:11 PM on September 26, 2012 [1 favorite]

The added weight of the solar panels would probably waste more electricity than they produce over the life of the vehicle.

Not at all. Solar cells weigh nothing. The weight you feel when you lift a panel is the protective panelling, and the frame. Cars have to carry both of those things anyway, with or without solar cells. (And in a year or two, solar cells are going to weigh 1/6th of that nothing :) The wires and charge circuit board will be the biggest weight, and even that is nothing.

(Furthermore, energy losses due to mass are lower in electric cars than what you're used to, because the energy used to accelerate the mass isn't lost like it is with a combustion engine - it is partially recaptured via regenerative braking, instead of dumped out through the brake pads)

Electric cars are everyday-commuter vehicles (cheap to fuel but shorter range), so even if you have a garage for it, it's going to be spending a lot of time outdoors. (Unless you're Jay Leno and have a car for every day of the month :-))
posted by anonymisc at 10:22 PM on September 26, 2012

Free fill-ups sound a lot more attractive once gas hits $5-8 a gallon - or more. It's a interesting bet on the future, and probably a smart one. We're not finding more easy oil.
posted by Blazecock Pileon at 10:33 PM on September 26, 2012 [1 favorite]

To the hypothetical Tesla drivers of Southern California: You better hope there's no long line up at that Supercharger station in the desert. Because if there is you're going to sit there for 30 minutes+ with no AC...
posted by Kevin Street at 10:40 PM on September 26, 2012

As far as urban EV use goes, there's a startup in Singapore that's trying to tie EVs with car sharing/rentals. Basically you go to one of their stations, swipe your RFID card to use an electric car, and get charged by-the-minute for using it till you return it to some other station. They keep the cars that aren't in use charged, so you're always certain to get a fully charged car. You don't need to pay for the electricity either.

Its still in pilot in just one small part of town, and I've never tried it before, but the idea seems clever, especially if they can get these rental stations distributed all over the city. It doesn't work for people who want their own personal vehicle though, but you don't really need that do you, unless you have specific things you must keep in your car all the time?
posted by destrius at 10:52 PM on September 26, 2012

Pretty sure cafes have AC ;-)
posted by anonymisc at 10:53 PM on September 26, 2012

eriko: Hmm. 100kW in 30 minutes. 200kW per hour, so, obviously, 200kW/hrs.

I know I'm nitpicking, but your units aren't right. Watts are already a rate, so "200kW per hour" doesn't make sense.
posted by vasi at 1:41 AM on September 27, 2012

I know I'm nitpicking, but your units aren't right. Watts are already a rate, so "200kW per hour" doesn't make sense.

Kilowatt-hours are a pretty standard unit of power in utilities. If you use a 10kW appliance for 1 hour, you have used 10kWh of power and your electricity bill will be 10 x [the price of 1 kWh].
posted by EndsOfInvention at 2:09 AM on September 27, 2012

Someone obviously added a 'per' where it shouldn't be. Killowatt Hours are a measurement of energy (one kW for one hour). Kilowatts per hour would be a rate of increase in power.

Also, there's no way the station will be run on pure solar. Just not possible -- our current technology cannot produce enough solar energy to power a car without requiring long charging times. It would have to produce enough energy to propel a few 2+ ton cars if they expect multiple customers at once.

What are you talking about? You can generate as much solar energy as you want, you just use multiple panels. The largest solar installations are in the hundreds of megawatts.
posted by delmoi at 2:54 AM on September 27, 2012 [1 favorite]

To the hypothetical Tesla drivers of Southern California: You better hope there's no long line up at that Supercharger station in the desert. Because if there is you're going to sit there for 30 minutes+ with no AC...

Is there a reason why, as long as there's a place to park at the station, there wouldn't be a power cord waiting? It seems like it wouldn't be particularly difficult to install a whole bunch of those. They wouldn't have to dig a big hole to put in a new tank of explosive liquid, for example. Of course, at some point the Supercharger station could overfill, in which case, someone could build one across the street. That seems to work with gas stations, after all. You have to start somewhere.

Plus there would probably be AC inside the building and they would probably serve cold drinks and ice cream. Fun times at the charging station.
posted by romanb at 3:48 AM on September 27, 2012

Kilowatt-hours are a pretty standard unit of power in utilities...

Yes, but a kilowatt-hour is watts times time, not watts divided by time, which is what other posters seem to be assuming.

If you deliver 100KW for half an hour, that's not "200kW per hour, so, obviously, 200kW/hrs," which doesn't make sense. Use 100KW for half an hour, and you've consumed 50KWH.

Kilowatt-hours are completely goofy, confusing units that almost everyone gets wrong, and no wonder. They are equivalent to measuring distances with "mile per hour hours." I don't know why we don't use joules (and megajoules and gigajoules) instead.
posted by Western Infidels at 6:20 AM on September 27, 2012

Once this is in enough places it will be the defacto standard. What standards body designed the gas pump all those years back.

Gas pumps don't really need a standard. All you need is a hose small enough to fit in the hole in the top of the tank (remember when cars were first getting started gas tanks were discrete things that you could actually see on most cars and they lacked filler pipes). We've got a standard now because of the need for remote filler pipes and because of the unleaded gas lockout but that is a relatively recent invention.

Also, there's no way the station will be run on pure solar. Just not possible -- our current technology cannot produce enough solar energy to power a car without requiring long charging times. It would have to produce enough energy to propel a few 2+ ton cars if they expect multiple customers at once.


The stations are grid tied. IE they are using the grid as storage. Even a 1000A at 480Vs isn't really all that much power. This is very doable and basically standard electrical practice.

Oh, and to deliver 200kW/hr, which is what they're talking here, you're either pushing over 410A at 480V, or 50A at 4kV. That's going to be one hell of a cable, and one hell of a connector, and I wouldn't trust the average driver with that on a bet.

I'm an industrial Electrician. This is a solved problem. We've got welders using 600V 3 phase 50-100A receptacles safely. In fact because of interlocks it's essentially impossible to use them dangerously. The plugs are safer at this level than the dryer plug everyone has in their homes.


It's entirely possible for the station to produce more power than the cars consume, unless the stations become VERY popular. It won't be "pure" solar, it will be grid tied solar. While a car is charging, the station will be a consumer of energy from the grid. When no cars are charging, the meter runs backwards. The important figure at the end of each month is the kWh produced by the solar system vs. the kWh drawn from the grid. Given a large enough PV array it's quite possible the station will be in the net positive.

In fact it would be possible to build stations that are impossible to ever run into the negative. Just design for more solar capacity on an annual basis than you have combined charging capacity. Really Tesla is starting up a power company that happens to have convience outlets for special customers.

This is actaully a very familiar pattern. Back in the 70 and 80s when propane was first taking off the only place oyu could fill your propane vehicle was at propane dealers which were often attached to the offices of refineries. It was weird as hell to have to drive into some industrial park in a car and fill up next to Super B tanker trucks. But eventually you could fill up at at least one gas station in town and usually at least one station at every service station cluster.

To the hypothetical Tesla drivers of Southern California: You better hope there's no long line up at that Supercharger station in the desert. Because if there is you're going to sit there for 30 minutes+ with no AC...

Just couple the charging station with a restuarant (in Nevada add a casino) with valet service. Who the hell is going to want to sit in their car for 30 minutes even if you don't have to wait. Besides that would also solve the "dangerous power cord" problem.

It seems unlikely Telsa hasn't considered these problems. They have the advantage that they won't be swamped with customers; at least intially. Here's hoping the money lasts to allow them to get over the chicken and egg hump of installed network.
posted by Mitheral at 8:14 AM on September 27, 2012 [3 favorites]

You can generate as much solar energy as you want, you just use multiple panels. The largest solar installations are in the hundreds of megawatts.

I was working under the assumption that they are not going to build the equivalent of a solar power plant, which would be prohibitively expensive to build and operate.
posted by spiderskull at 10:22 AM on September 27, 2012

I'm an industrial Electrician. This is a solved problem. We've got welders using 600V 3 phase 50-100A receptacles safely. In fact because of interlocks it's essentially impossible to use them dangerously. The plugs are safer at this level than the dryer plug everyone has in their homes.

Mitheral, can you link a couple of products for us? I'd like to see what it takes.

For example, that charge connector for the car.. I can't really see it pumping more than 100A.
posted by Chuckles at 11:03 AM on September 27, 2012

Here's a couple links. This is a fusable 600V 60A interlocked disconnect. An non fusable 480V 30A. Another non fusible 480V 30A.
With all these you can't unplug the cord (which goes in at the bottom) unless the diconnect or switch is off. The ones we use look like the last one except the plug used is a different shape.

These aren't quite what you want for this application because they assume a connection cord attached to the device (like RV power cords) and you'd want something where the cord is staionary and connects to a socket on the device. Also you'd want to have an interlock on the car that prevented it from being started while charging and some sort of break away switch on the charging station incase the car rolls away, gets pushed away or in some other manner causes the cord to get excessive tension applied to it. Not sure if there is an exsisting product to do that (wouldn't surprise me if there is) but I can think of a couple ways of getting this functionality in a safe for retail manner.

Anyways making a plug to handle 60A at 600V isn't really a problem. One you get out of household voltages things just get larger and more robust the more watts you need them to conduct. This kind of thing might never be self serve but it is certianly possible with trained personel.
posted by Mitheral at 11:53 AM on September 27, 2012

They make road-trip refilling sound like something out of Tomorrowland (sponsored by Monsanto).

Most people who begin a road trip at 9:00 a.m. would normally stop by noon to have lunch, refresh and pick up a coffee or soda for the road, all of which takes about 30 minutes.

What they don't tell you is that road-trip refilling is more like sitting in your car while the tank fills in the hottest/coldest/darkest part of nowhere (while Dueling Banjos plays on the overhead speaker) where you just want it go quickly so you can GTFO. Let alone sitting around for 30 minutes.
posted by pashdown at 6:04 PM on September 27, 2012 [1 favorite]

In totally different Tesla news: With The Oatmeal's help, nonprofit buys property to build a Tesla Museum
posted by homunculus at 10:27 AM on October 7, 2012

Ouch: Romney Calls Tesla a ‘Loser’
posted by homunculus at 10:37 AM on October 7, 2012

Auto Dealers Whine That Tesla Stores Are Illegal
posted by homunculus at 12:50 PM on October 9, 2012