Tesla Motors and its customers are famously proud of their environmentally friendly image, but their anti-carbon and anti-oil sentiments are apparently not as absolute as their public statements and vanity license plates might suggest. In the course of investigating Tesla’s Harris Ranch, CA battery swap station, Daily Kanban found that Tesla’s solution to peak demand for grid-powered Superchargers that are also on-site does not involve stationary battery storage or customer battery-swapping at its only swap station. Instead, the company relies upon backup Superchargers powered by diesel generators. Moreover, several Tesla customers were observed charging from the noisy, carbon-emitting backup generator even when the standard Supercharging station had numerous plugs available. This oddly un-green charging option, foisted on customers as a result of Tesla’s lack of desire to make its battery swap capabilities widely available, in turn raises unanswered questions about the environmental claims Tesla has made about its entire charging network.
Harris Ranch, a hotel/restaurant/truckstop destination located about halfway between Los Angeles and San Francisco on Interstate5, was one of six sites where Tesla initially introduced Superchargers in 2012. In April of 2013, the site was upgraded to its current array of six Superchargers. These Superchargers are located directly in front of the Harris Ranch restaurant, near the entrance to the site. On the far side of a sprawling gas station, in a building that once housed a car wash, is the Tesla battery swap station.
When Daily Kanban began observation of the swap station on the morning of Friday, May 22, the first real activity we noted was the delivery of a Supercharger station and a large Collicut backup generator. Over the course of the day, a Tesla employee installed the Superchargers on a plastic pallet at the exit of the battery swap station and hooked them up to the generator. This backup Supercharger setup blocked egress from the swap station, indicating that Tesla had no intention of swapping batteries over the weekend. A notice taped to each of the permanent Superchargers informed Tesla customers that the two additional Superchargers behind the swap station had been installed for “added convenience.”
By midday all standard Superchargers were in use, and as the Supercharger “lunch rush” began to build a line of six Teslas backed up into the Harris Ranch parking lot. Soon a Harris Ranch security guard drove up and told the two Teslas at the front of the line to follow him to the backup Supercharger behind the swap station where they subsequently began charging. Daily Kanban’s observations for the day ended shortly thereafter, and we were not able to fully document the demand peak or the backup Supercharger’s impact on it.
The next day, a smaller Doosan generator had replaced the large Collicut unit and another Tesla employee powered it on at about 9:00 AM. Daily Kanban observed the generator running for a cumulative ten hours over the course of the day, during which time only 8 vehicles actually charged from the attached Superchargers. But unlike the previous day, there was no evidence of Supercharger undersupply on the 23rd. Not once on the 23rd did Daily Kanban observe a lack of plug availability at the standard Supercharger station and at one point both plugs of the backup generator-powered Supercharger were in use at a time when all six standard Superchargers were available.
On the 24th, the same Doosan generator was turned on for just 90 minutes, from 11:45 AM until 1:15 PM and no vehicles were observed charging from it. Again, traffic was much lower and no plug shortage was observed at the standard Supercharger station.
On the 25th it appeared that the mid-day “lunch rush” for Supercharger plugs would not take place, but around 3:00 PM a horde of Teslas descended on Harris Ranch once again, causing lines for Superchargers that ranged from five to seven vehicles. Several Tesla drivers waiting for chargers agreed to speak with Daily Kanban, and most said that they would appreciate the ability to swap batteries rather than wait in line. Though Daily Kanban did not interview their wives and children, their exhausted faces spoke volumes about consumer demand for a more rapid alternative to hour-long waits for Supercharger access.
Tesla’s use of petroleum-fueled generators to power backup Superchargers and its customers willingness to use this carbon-emitting power source may not be completely hypocritical; the standard Harris Ranch Supercharger station does not make use of solar panels, and therefore may be nearly as carbon-intensive as a small gas or diesel generator. But it does point out how far Tesla has to go in order to live up to its initial claims about its Supercharger network...
