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Tesla hints solar powered electric car charging, through proprietary charging connector

The Tesla Model S/X will have a proprietary charging connector with capabilities well beyond the standard charging connectors used today, but by going it alone could create problems down the road.


At Wednesday's annual shareholders meeting for Tesla Motors, amid talk of Tesla's business roadmap, Elon Musk dropped some strong hints about the Tesla proprietary supercharger, as well as possible integration with solar panels. While there is a battle raging among automakers over the electric car fast charging standards, Tesla has taken a go-it-alone-approach with a proprietary charging connector that's left everyone puzzled, but which Musk promised we'd understand once the full system was revealed later this month.

Because the Model S and Model X are sold with massive battery packs, up to 85 kilowatt-hours in capacity, Tesla had to design in a much higher charge rate than is used on other electric cars. For example most of the charging infrastructure being installed supports a 30 amp charge rate, and the highest charge rate on competing electric cars is 6.6 kilowatts. Recharging an 85 kilowatt-hour battery pack at 6.6 kilowatts would take over 12 hours. Rather than having the Model S labeled as "taking forever to recharge", it was designed with a higher charging rate, supporting a 10 kilowatt or optionally a 20 kilowatt charge rate, corresponding to 31 miles and 62 miles of driving range per hour of charging. Additionally the Model S supports an extremely fast charging rate, that will completely recharge the Model S with a full 300 miles of driving range in an hour. By contrast the CHADEMO standard supported by the Nissan Leaf and Mitsubishi i-MiEV supports only about 120 miles of driving range per hour of fast charging.

Also see Despite Tesla short sellers, Musk promises cash flow positive in 2013 for more the business update section of the meeting.

Musk explained that the Standard (J1772) is not good enough, for the Model S. First, the connectors used for the standard charging system are huge, bulky, and ugly. The Tesla proprietary charging connector is, according to Musk, small, compact and beautiful. Second, as we already noted, the charging infrastructure being installed now doesn't support a high enough charge rate to be useful for the Model S battery pack. While the J1772 standard supports up to a 19.2 kilowatt charging rate, which could have allowed Tesla to use that standard for normal charging, that connector does not support the ultra fast charging rate Tesla desired for the super-charger. Leading to the third point, that Musk said the company could have compromised on using an inadequate connector, that would require a large ugly charging portal, and the ugly, bulky connectors involved. The fast charging cords, whether CHADEMO or the upcoming SAE Combo Plug, are even bulkier than the J1772 cord currently in use. Further, Tesla's design supports a 100 kilowatt charge rate which is way beyond the 50 kilowatt rate supported by either CHADEMO or the SAE Combo Plug.

Instead, the company opted for a small, compact, and beautiful charging port which supports a range of normal and high charging rates.

But does this mean prospective Model S/X owners will be stuck with a car that's incompatible with the charging infrastructure being built? No. First, the on-board chargers are capable of adapting to pretty much any charge current or voltage. Second, Tesla supplies with the Model S and X adapters required to charge from several kinds of power outlets, most importantly the J1772 standard. In short, the Model S and X will be able to use the public charging infrastructure, just at a lesser charge rate than the Tesla-proprietary charging system.

Musk said, "I wish we could adhere to the standard, but unfortunately the standard is not good."

In the Q&A session one shareholder asked about the promise made long ago that the Model S would support a rapid battery swap. Battery swapping capability in the Model S was discussed in the financial documents Tesla filed shortly before the IPO in 2010, but has been quietly dropped from descriptions of the Model S and X. Coincidentally, or not, Project Better Place is headquartered directly across the street from Tesla's headquarters in Palo Alto.

Musk did say the Model S was intentionally architected to support fast battery swapping, in under one minute. He then said "I think we will show you something interesting in that regard," without saying anything more.

Another shareholder asked about the possibility of integrating electricity from solar panels, to charge the Tesla Model S. Musk, being the Chairman of Solar City, a company which installs solar panels under a lease arrangement, is certainly a proponent of solar power. He said "Solar will be the single biggest source of electricity production in the world, certainly by the mid-point of the century, maybe even sooner." But, Elon, what does this mean for using solar panels to charge your Tesla Model S?

He said "there will be some interesting stuff with solar and superchargers, but I don't want to jump the gun on that, that's going to be exciting to see." He went on to say that solar electricity will destroy the notion about electric cars just having a long tail pipe ending at a coal plant. "We have to solve sustainable power generation as well," he said, "and solar is the best way to do that. If we have sustainable power generation, and sustainable power consumption, then we really have solved the problem." He closed this answer by saying that "the supercharger system will help to demonstrate that."

That was a tantalizing bit of hint-dropping, leaving us with not enough to grasp for proper speculation. The Tesla Supercharger system will not be sold to individual customers, but instead will be infrastructure that Tesla, or a partner company, will install at critical locations. In other words, it will be yet another charging network, solely for Tesla's electric cars, existing in parallel with the other fast charging networks being built by 350Green, eVgo, ECOtality, and others. It will have some form of solar power associated with the charging stations, with details yet-to-be-revealed.

One hears in Musk's description of the Tesla-proprietary charging system a seeking-for-perfection that's not willing to compromise beauty for functional utility. In the past the electric car world had competing charging connectors, and it was painful. The Tesla-proprietary charging connector can be seen as a step backwards into a world of incompatible charging ports, or it can be seen as a manufacturer designing a charging port that fits real customer needs. As ugly as they are, at least the J1772, CHADEMO and SAE Combo plugs are functional, work, and are widely deployed. On the other hand, as Musk noted, they would be inadequate for the needs of Model S/X owners.

There's already enough of a battle in fast charging standards between CHADEMO, the SAE, and now the Chinese. Maybe there really is a detante brewing between CHADEMO and the SAE, but Tesla appears steadfast in staying with their perfect proprietary charging connector.


Simon (not verified)    June 9, 2012 - 7:28PM

This is littered with half truths and deliberate attempts to allow misunderstandings to perpetuate. Mode 3, Chademo, Combo plugs etc do not dictate the rate of charge although they may be a limit on it. They are standards, communication protocols, interfaces. The rate of charge is independent(ish) of such things. Elon Musk may claim he will have a 100 KW charger but where exactly will he find sites that have 100KW of spare electricity supply? I could design a 300KW charge connector that would take an 85KWH Model S from empty to full in 17 minutes but where would I find the electricity supply? Come on guys let's stop misleading the folks. If Ford or GM invented Gasoline +++ next week and started to develop their own fuel station network how much chance of success would you give them?
Some things are about competitive advantage and some stuff just has to be shared for the good and more importantly the cost effectiveness of all.
As for Solar. Great stuff, bring it on. But again please don't let us try and con the folks into believing that they are going to trolley up to a charge point and take on board a tank full of Solar juice. Unless we have arrays the size of football fields then Solar is about feeding a charge into the grid or very slow charging. Nothing wrong with that, but let's be honest.

Anonymous (not verified)    June 10, 2012 - 7:37AM

In reply to by Simon (not verified)

Hi Simon,

Firstly, all press conferences are littered with half truths and deliberate attempts to allow misunderstandings to perpetuate. Anyone who has received media training should know that.
Secondly, where would one find electricity? Well... from the grid of course!!!! What kind of a question is that!
Thirdly, you ask "If Ford or GM invented Gasoline +++ next week and started to develop their own fuel station network how much chance of success would you give them?" I would give them no chance, as would you, however, a fuel station network requires production of oil, shipping of oil, delivery of oil and all that jazz. A new charging network would only require charging points and solar production on the grid. While you may not be charging up with solar power at the time, your emissions will be offset when someone else is using your solar power.
Finally, (two points in this by the way) solar will indeed take up football fields of land, there is no doubt about that. However, that land will not be wasted as all plants need is 4 hours of light everyday and as a result, solar panels can... you know what... I give up... can't be bothered... need to sleep

Mr. Clean (not verified)    August 19, 2012 - 9:20PM

In reply to by Anonymous (not verified)

Anonymous who replied to Simon,

Please finish about the solar panel fields and plants!!!

I was really interested to hear what you have to say about it.

And, this may seem like a dumb question, but my philosophy is that the only stupid question is the question that is not asked....

When you refer to "plants" that only need 4 hours of light, were you referring to the solar plants?

You weren't saying that taking up football fields worth of land to make solar work would not be a problem because organic plants (such as grass, tress, flowers, etc.) only need 4 hours of light each day, right?

Just trying to make sure I understand what you're saying.

Anonymous (not verified)    June 10, 2012 - 8:20PM

As to where Musk will install those chargers, as I recall Hilton Hotels has agreed to provide them and, after all, these are only used during trips : that is the reason they have to be fast. With 300 miles of driving range (actually more like 400 around town)
local driving will never exhaust the battery and charging will always be done at home. That's a lot cheaper, anyway. And there don't have to be very many such chargers around the country, either. I disagree that solar will dominate electricity production.
Although solar has become relatively cheap, it is still uncontrollable (there are cloudy days-even weeks, and the sun only shines during the day). Uncontrollable power sources means duplication of capacity (those power plants cannot be shut down, or even destaffed, regardless of how much solar power is available). Duplication means much higher electric rates, almost double. Nuclear is the future energy source for the grid, not solar. Britain, China, India and Russia are going wild building nuclear plants right now. Musk is poorly informed about utility grids and their economics and needs.

Anonymous (not verified)    June 10, 2012 - 9:21PM

Concerning Solar being discontinuous, just keep in mind that energy STORAGE is a big part of the solution. If for instance you were to place a battery pack near the solar Supercharge station then the Solar could trickle charge the battery pack and once you pull your Model S up to the Super Charge Station, your DC fast charging would come directly off the battery pack. This would work day or night regardless on the weather or the need for the sun to shine, the battery pack could also be charged from the Grid. This way the battery pack is always charged and ready to go. Remember Tesla also creates their own battery pack, what is to keep them from having a large battery pack or battery bank, as part of the supercharge station?

This scenario answers his statement as quoted below from this article:

"We have to solve sustainable power generation as well," he said, "and solar is the best way to do that. If we have sustainable power generation, and sustainable power consumption, then we really have solved the problem." He closed this answer by saying that "the supercharger system will help to demonstrate that."

Frankie Rod (not verified)    June 11, 2012 - 6:06AM

My buddy Matt does quality control for Tesla Motors. The engineers give him the cars & he does the tests & if it doesn't pass he sends the info back to the engineers. He was just giving me some insight the other day that this is the cutting edge of technology. Tesla Motors is state of the art futuristic technology.

Karen Shea (not verified)    June 11, 2012 - 6:52AM

What I really want is a car with solar cells on the roof hood and trunk. And solar collector window shades. I drive about 10 miles a week. I don't see why I should need to plug in my car at all in the sunny summer time. This could really flip the demand for parking spaces in the summer if no one wants the shady spot under the tree.

I think in a decade there will be restaurants along the interstates with lots of parking spaces with charging connectors. Just pull of the interstate plug in your car, eat a nice meal and when your done you are both fully charged.

David Herron    June 11, 2012 - 5:28PM

In reply to by Karen Shea (not verified)

Solar cells work best when they're pointing at the correct angle to the sun. Another factoid is that solar cells have a fairly low efficiency in the neighborhood of 10%. Another factoid is that there simply aren't flat spaces on a car of the sort that the Model S is.

Take all that together and it just doesn't make sense to add solar panels to a vehicle. If you want that so badly, get a Fisker Karma which does have solar panels, but the effect is so weak that Fisker says the panels would account for something like 10 miles of driving range a year ..

Solar panels are best located at a fixed installation where they can be positioned for perfect alignment to the sun, for optimal energy collection.

Robert Weekley (not verified)    June 24, 2012 - 11:28AM

As to the comment about Solar Panels on the Vehicle being useless, I step back to my experience with my own electric vehicle now owned for some 5 years, a 1989 Pontiac Firefly - (Geo Metro) A High School Student Built Electric Vehicle Conversion from some 15 years ago (Not the latest technology!) - AKA 'MyElectricFly' and the fact that I do live close to work, and have done detailed data gathering and power recharge monitoring to determine if Solar Panels on My Car would work For Me. While I agree that for most people driving a commute distance of 10 miles or more a day to work - that Solar PV with today's conversion inefficiencies would be useless - that is not my case.

Second - to help you understand why I believe - that for some - like myself - on Car Solar might be the only answer - is that little thing called - Apartment Dwellers - who don't have their own House or Garage! Second - My drive is only about 0.6 miles - 0.9 Kms, and I actually could walk to work, and have done and still do at times! You should know how much Solar Energy Collection Space I have, versus how much the drive to work takes, to even decide if the effort could be of value.

My cars tested and monitored Energy use - driven gently - can be between 67 - 100 Wh/Km of driving, and driven aggressively - can be between 277 - 285 Wh/Km of driving. I work 8 hours a day - or more with overtime. The work Parking lot is 90% unobstructed by tree shade for over 7 of those 8 hours if I am on Day Shift.

I can put not less than 4 Solar Panels on just the roof of my little car, each with 15 watts (for the lowest efficiency solar panels) for a total max of 60 Watts of potential collection. Using the Toronto Annual Average of 5 hours Effective Solar Energy per day x 60 Watts = 300 Watt Hours (just while at work, not counting while driving or back at home). So while I might need to plug in on extended periods of cloudy weather - for most summer days - I will have to drive the car to go shopping or to a movie - to keep from wasting the extra energy available.

If I got good solar panels - I could easily put 80-120 Watts worth of solar collection on the same roof (just costs a bit more to buy), and at the time I bought my 15 watt panels - the same store sold 30 watt panels that were just 70% in size of my 15 Watt panels, but they cost over double more, so I opted for the cheaper panels to test my data.

An other option - is a Solar Trailer. If you designed it for light weight - and good aerodynamics - you almost wouldn't know it was there, and it could give better optimized solar collection options. The Trailer could also incorporate Energy Storage, Expandability, and more, for even greater flexibility!

The point is - We are just beginning to think about how to deal with new energy sources like Optimized use of Solar, (& wind) and Wind Farm Energy Storage has already reached 32 MWh and maybe even larger on a single site location! Reading the magazine - altenerg - I discovered some impressive bits of information I otherwise would not have known. That is the second point - none of us know everything, and each of us can learn new things each day, if we want to actually learn. Also, the best learning comes after the theory, with the hands on experiences!

Imagine - if each solar panel you bought - gave you the choice of integrated Energy Storage for 1 hour, 2 hours, 4 hours, 8 hours, or even 12 hours worth of production from that panel! You could make energy from some panels for day time use, and from other panels for night time use, and from some - even for Grid Frequency Stabilization (The highest priced Electricity is for That Function!)

Also imagine - if your On Grid Home had - besides a Furnace, Air Conditioner, Automatic Dishwasher, Computers, etc. that it had on board energy storage - that you could charge up off-peak, and use to stabilize the demand over the course of the day - Grid demand would start getting flatter: higher at night, using more of the Power Plant's idle capacity, and lower in the day - when you used some of your stored energy for Air Conditioners, and computer uses! Combine that with on home Solar - producing power during the day - when your Air conditioner is running - and you would reduce the demand on your grid loads and on your home energy storage loads - as to available run time for a given storage capacity.

Even Better - decide what are your critical energy needs: Refrigerator for safe food storage, you computer for reading articles like this, or your hair dryer - so you can get to work looking good, and see how much energy they use - by buying a point of use energy monitor for just $20 or so, and then you could determine better - if these items could cost effectively be powered by a large UPS of your own - (Uninteruptable Power Supply)! I use a UQM model - but there is also the Kill-A-Watt Monitor, and others.

From using that Monitor - I discovered that my own Personal Computer, for instance - uses more electricity in 24 hours, than my Electric Car would to charge up from nearly dead! Of course - it is no Leaf, yet alone a Tesla Model S - but maybe you get the point! First you need some detailed data to compare where and how much energy is used to determine it's value!

If Gas Stations by Shell and BP - used their own sister company - Shell Solar, and BP Solar, to put panels on there fueling station canopies, and stored some energy on site, when the grid went down on the North East Years ago, including Toronto, Maybe they could have continued to do business while the lights were out at other gas stations! Just Saying - they pitch their products, but do they even use them, themselves?

On that thought - since Musk is a Solar Proponent - I would like to see - going forward, once they start to reach profitability - that they start to expand solar Installations to their Dealers and to the New Plant Roof!

Anonymous (not verified)    July 24, 2012 - 1:02PM

So this looks like an Apple-type strategy - there will be a parallel world of Tesla-only chargers for the home, Tesla-only for the road; all very "beautiful" but at a much higher price. In the case of Apple this made some sense since Apple was inventing stuff that Microsoft copied - I wonder if it will apply here.
The J1772 standard allows for a max of almost 20kW charge rate; that's about all a typical home can support, so to say that a more beautiful connector is an advantage seems misguided.

Echo Delta (not verified)    August 30, 2012 - 2:27AM

In reply to by Anonymous (not verified)

You can use an adapter that looks like a soda can that takes the J1772 plug on one side (from your charging station found in any wallgreens, a lot of malls, parks, etc) and plugs into the car's 'inlet' in the other.
It was a popular accessory with Roadster users - I think supplied by a 3rd party - but comes standard w the Tesla. You just keep it in the trunk or the frunk for when you need it and you can happily use any J1772 charger you find