Supercharger energy economics?

[Ollie Jones]

I've had my model S 90D for a month and a half now, and just took my first couple of Supercharger-powered trips.

I juiced up at the West Springfield MA Supercharger, and then I used the Hookset NH Supercharger. Sweet.

At ~400V x 300A it looks like my initial charge rate was 0.12 megawatts. The cable got warm. Now, if all eight stalls had been full and running at initial rate, that would have been about a megawatt. That is industrial-scale power.

I wonder; can the electric stuff -- the substation -- behind the fence handle all eight stalls at full power? Or, if all eight are occupied, do they cut the amperage to each? Do they count on staggered customer arrivals so they don't have to feed initial-charge power to all eight stalls at once?

What kind of deals has Tesla cut with the grid operators?

What's the utility economics of superchargers? Do they pay for peak load like factories? Do they have a take-or-pay base load rate? Is there any power storage (batteries) behind the fence?

What's the carbon economics? Are they on a brownout / rotating blackout plan to avoid ultra-expensive peaking-generator consumption?

 

[Saghost]

I don't have answers to your big questions, aside from Tesla putting battery packs into some of the more heavily used sites to reduce demand charges (I think they're eventually planning to have batteries and solar roofs on all sites.)

I can tell you your initial assumptions are in error, though - a current generation 8 stall supercharger can only draw around 540 kW. The stalls share stacks of charger modules that convert the power to DC at the needed Voltage and feed the cars (that's why you'll see 1A, 1B, 2A, 2B, etc.) The current stacks are of 12 modules each, capable of 135 kW per stack. So with eight stall/four modules, you have 540 kW at maximum draw.