Tesla Powerwall, The Specs, Numbers, and Implementation Absolutely Brilliant

[inetdog]

Update on battery chemistry:

http://fortune.com/2015/05/18/tesla-grid-batteries-chemistry/

says

I find the comment on "dirty and expensive" peaker plants poorly informed given that most peaker plants, out here anyway, are gas turbine and relatively clean compared to base load coal plants. They are more expensive though.

[Sunking]

Since when did Fortune Magazine become a technology magazine?

[donald]

Some indication where Tesla is going with batteries can be seen in California's Vehicle-Grid Integration (VGI) planning. Consider the Model S uses an AC induction motor. Consider that the Model S has a large inverter that alters both voltage and frequency to power the motors. This design presumably allows the vehicle battery not only take power from the grid, but to put power to the grid.

Not only that, but the car can probably connect to any grid voltage/frequency in the world with no inverter customization. I don't think Tesla gets too much credit. I think they are probably more clever than even their fans imagine.

http://www.caiso.com/Documents/Vehicle-GridIntegrationRoadmap.pdf

[Sunking]

Some indication where Tesla is going with batteries can be seen in California's Vehicle-Grid Integration (VGI) planning. Consider the Model S uses an AC induction motor. Consider that the Model S has a large inverter that alters both voltage and frequency to power the motors. This design presumably allows the vehicle battery not only take power from the grid, but to put power to the grid.

Not only that, but the car can probably connect to any grid voltage/frequency in the world with no inverter customization. I don't think Tesla gets too much credit. I think they are probably more clever than even their fans imagine.

Clever like a Fox. Musk goes where ever government money and subsidies go. If not for $35K subsidy he receives for every car sold, he would have been bankrupt years ago. Every business he owns is ran on subsidies if not outright government money like Space-X, buying salvaged Russian Rocket Engines.

[Cosmacelf]

Clever like a Fox. Musk goes where ever government money and subsidies go. If not for $35K subsidy he receives for every car sold, he would have been bankrupt years ago. Every business he owns is ran on subsidies if not outright government money like Space-X, buying salvaged Russian Rocket Engines.

SpaceX never bought salvaged Russian rocket engines. Their competitors do. SpaceX engines are their own in house design and built in Los Angeles (Hawthorne).

I would love to see your calcs on $35K subsidy per each Model S sold.

[Cosmacelf]

found this document on SolarEdge's StorEdge solution which seems to be what they are basing their US powerwall solution on.

http://gilleleje-solenergi.dk/downloads/Solar%20Edge/storedge_21_5_14.pdf

It seems to be showing battery optimizers on the second input of the inverter. These optimizers seem to be able to handle different battery sizes and capacities as long as they can chain along up to 350V. It doesn't seem to indicate any grid disconnect device to allow off grid or backup capabilities but that might be done with other equipment.

Cool - thanks for the link. The PowerWall architecture would presumably be different since each PowerWall outputs 350V nominal, so stringing together PowerWalls in series as shown in the SolarEdge StorEdge document you posted doesn't make sense.

Is StorEdge a real product yet?

[ButchDeal]

Cool - thanks for the link. The PowerWall architecture would presumably be different since each PowerWall outputs 350V nominal, so stringing together PowerWalls in series as shown in the SolarEdge StorEdge document you posted doesn't make sense.

Is StorEdge a real product yet?

it is an EU product (don't think it is shipping yet though). it would chain along perfectly fine as the battery optimizers would insure that the bus is putting out a max of 350V that the SolarEdge inverter wants to see regardless of individual battery voltages.

[inetdog]

it is an EU product (don't think it is shipping yet though). it would chain along perfectly fine as the battery optimizers would insure that the bus is putting out a max of 350V that the SolarEdge inverter wants to see regardless of individual battery voltages.

Does the product also fake the presence of some number of SE optimizers to satisfy the two way communications need of the SE inverter? Or is there a mode of the SE inverter that does not try to talk to optimizers?

[tehan]

Does the product also fake the presence of some number of SE optimizers to satisfy the two way communications need of the SE inverter? Or is there a mode of the SE inverter that does not try to talk to optimizers?

I'm fairly sure it actually contains some number of SE optimizers, or at least a bidirectional version of the SE optimizer. In a battery the SE optimizer is playing the role of charge controller as well as ensuring constant voltage to the inverter irrespective of state of charge or number of packs. It's also providing an important safety feature by preventing the pack from putting out high voltage until the inverter tells it too.

[tehan]

Cool - thanks for the link. The PowerWall architecture would presumably be different since each PowerWall outputs 350V nominal, so stringing together PowerWalls in series as shown in the SolarEdge StorEdge document you posted doesn't make sense.

I suspect Powerwall and StorEdge have more or less the same architecture. The series connection works very much like the SE optimizers: the voltage is still 350V regardless of how many you connect (i.e. the packs adjust their output voltage based on string length).

[Sunking]

Cool - thanks for the link. The PowerWall architecture would presumably be different since each PowerWall outputs 350V nominal, so stringing together PowerWalls in series as shown in the SolarEdge StorEdge document you posted doesn't make sense.

You think?

The concept for home use is in parallel with a gizmo that does not exist to make the batteries share load and isolate weaker battery packs. I see a write up on the concept a few weeks ago on a Engineering web site ripping the idea to shreds because it is full of holes and would be incredible expensive to implement. Can it be done yes. Would anybody buy it is the question? There are much less expensive and less complicated ways to get the same job done.

Geez liquid cooling in an off grid or back up system? What are they thinking? No wanother gizmo needed to make it work. Absolutely brilliant. See how deep they can get their hands in your pocket. Rube Goldberg would be tickled pink if he was alive today, and PT Barnum is laughing in his grave wishing he had thought of that.

[tehan]

You think?
I see a write up on the concept a few weeks ago on a Engineering web site ripping the idea to shreds because it is full of holes and would be incredible expensive to implement.

Yeah right. Because who are you going to trust: the company with the $30bn market capitalization and unlimited access to the best of Silicon Valley engineering talent, or the retired blogger sitting in his kitchen tapping away at his Chromebook?

[inetdog]

Yeah right. Because who are you going to trust: the company with the $30bn market capitalization and unlimited access to the best of Silicon Valley engineering talent, or the retired blogger sitting in his kitchen tapping away at his Chromebook?

Actually, that is not a 100% obvious choice, given the nature of Marketing.

[tehan]

Sure, marketing people make unsupportable technical claims all the time. But that's not what was asserted. The claim was that the Tesla/SolarEdge engineers don't know what they are doing. I find that unlikely.

[J.P.M.]

Actually, that is not a 100% obvious choice, given the nature of Marketing.

And the nature of some of what's supposed to pass for engineering.