Archive for April 2nd, 2011

Reviewing a Tesla Charging System

Saturday, April 2nd, 2011

Our good friend, Paul Fulton, who lives only a few blocks away in Los Gatos, bought a Tesla Roadster 2.5 and loves it! 

Paul took Bryan for a quick drive (literally!) a few weeks ago and Bryan was enamored with the acceleration.  The acceleration, 0-60 mph in 3.9 seconds, is similar to the acceleration on California Screamin’ , one of the most exciting roller coasters in the world (and is located in Disneyland, California).  California Screamin’ uses linear induction motors to allow the roller coaster to accelerate from 0 to 57 mph in 4 seconds.

Although we have a deposit on a Nissan LEAF, we can have some fun and dream (fantasize?) about a Tesla.  From an infrastructure perspective, we’d like to have two electric vehicle (EV) charging stations in our garage.  One for the LEAF, and one for a Tesla.  Dream on …

The LEAF charger draws 30 amps and must be on a 40 amp circuit.  The Tesla charger draws 70 amps and must be on an 80 amp circuit.  Since we’re finalizing our electric plans, we need to design the system so we can put in both EV charging stations.

Installing a 70 Amp Charging System

Paul put in a second electric service with a separate meter.  The second service only has the charger for Paul’s Tesla Roadster 2.5.  Paul could put another EV charger on this service at some point.  Having the separate service allows Paul to continue with his home service at the historic rate and, at the same time, have a lower rate to charge his EV.

The separate service with only an EV charging station load qualifies Paul for the E-9B rate, which is 5.6¢/kWh off peak.  Paul will charge his Tesla from midnight to 7:00 am to enjoy this low rate. 

Since Paul just completed installing his charger, Bryan took the opportunity to review it.

There were two significant learnings from Bryan’s visit today:

  1. The Tesla charging station can have a 90 amp breaker (not an 80 amp breaker); and,
  2. Paul recommended that we put in some 110 V receptacles that also have USB charging ports.  These are way cool!  And, yes, our electrical plans just got updated to have the USB charging ports!

Paul had some other ideas but we only had a few minutes.  Oh, a quick search and we found a web site for the receptacles with USB charging ports

Pacific Gas & Electric's E9A and E9B rate structure.

Pacific Gas & Electric's E9A and E9B rate structure.

Two meters for the same house.  The original meter on the left remains on the regular rate while the meter on the right is only for EVs.  It has a maximum rate of $0.056 per kWh.

Two meters for the same house. The original meter on the left remains on the regular rate while the meter on the right is only for EVs. It has a maximum rate of $0.056 per kWh.

The second service is 200 amps, with a single 90 amp breaker that only has the Tesla charging station on it.

The second service is 200 amps, with a single 90 amp breaker that only has the Tesla charging station on it.

The Tesla charging station is surface mounted on the wall of the garage, right by the garage door.  Paul explained that plugging in his Tesla each day was easy and not a chore.  He loves never having to go to a gas station!

The Tesla charging station is surface mounted on the wall of the garage, right by the garage door. Paul explained that plugging in his Tesla each day was easy and not a chore.

Close up of the charging station itself ...

Close up of the charging station itself ...

110 V receptacle with two USB charging ports.

110 V receptacle with two USB charging ports.