Sunday, November 16, 2014

Day 8: The Home Stretch up the Left Coast

From Bakersfield we headed almost due west to Atascadero, a cute little town just inland of the coastal mountain range.  We were still in the valley so the roads were flat, but there was an almost imperceptible increase in elevation.  You probably wouldn’t have noticed it at all in a gas-powered car but the Tesla energy graph made it abundantly clear that we were climbing.*

Having completed the trip**, I can confidently say Atascadero wins the Best SuperCharger Location Award for the #TeslaElectricStartupSuperTrip.  The competition wasn’t even close.  The A-Town SuperCharger is a 5-minute walk from a cute little downtown with a fantastic burger place called Sylvester’s.  Had it been any day other than Sunday, we would have had to decide between Sylvester’s and a number of other tasty places to eat.

LJ at Sylvester's in Atascadero, CA
After lunch, we continued westward until we reached US-1, the iconic coastal road that winds its way along the Pacific.  It was clear that we had reached the Left Coast when I saw this grizzled old man walking his huge orange cat.  I felt a bit bad taking his picture until LJ pointed out that the guy had a huge grin on his face.

Welcome to the Left Coast (San Luis Obispo County, CA)

We took scenic US-1 up the coast, stopping at various viewpoints along the way.  My favorite was the elephant seals colony in San Luis Obispo, only a few miles north of the Hearst Castle.   There were piles of elephant seals snuggling together, with a few of the young ones clearly not wanting to nap.  And there was a random squirrel not too far from this sleeping elephant seal—not exactly two mammals I would expect to see together.  The clouds rolling up from the ocean and over the first range of mountains kept things cool and cloudy for most of the trip up the coast except where the road rose above the clouds. 


The final SuperCharger stop of the trip was at the Gilroy outlets.  Gilroy’s claim to fame is as the “Garlic Capital of the World”.  This was the first location where we saw more than three Teslas—a total of six Telsas (including ours) were parked there when we first started charging around 6:30 pm.  We killed the charging time by doing a bit more shopping for LJ’s new job.  [LJ and I probably shopped more on this trip than we have in our lives together to this point.  It’s a side effect of the Tesla charging locations and the 30-60 minutes we needed to spend at each one.]

Post-charging, we had dinner with Jocelyn (a friend of LJ’s from Cisco) at Los Gatos Brewery, an old haunt for LJ and his Cisco friends from business trips many years back.  About 10 pm we rolled into Menlo Park and unloaded the car at LJ’s new temporary CA home.

The trip may be over, but the super-nerdy science and engineering discussions are not.  I’m working on a final blog post with all sorts of stats and graphs about our trip that I hope to post this week.

*One of the more fascinating things about driving the Tesla is the energy graph.  I’ve shown examples of it in previous blogs, but here’s another one as a reminder.  For any stretch of road, if we aim to keep the speed constant, the energy usage ends up almost directly proportional to the elevation changes.  In that case, the energy graph is essentially a topographical map of where we’ve been.

Tesla energy usage as topographical map.

**For those of you keeping track at home: Day 1 of the trip was Sunday, November 2nd.  Therefore, Day 8 was Sunday, November 9th.  It’s probably not unexpected that it took me longer to complete this blog post since I returned to “normal” life in NC this week.

Day 8 stats:
398.0 miles in 12 hours (with long charging and meal stops) having used 110.9 kWh and 2 SuperChargers:
·         Atascadero, CA
·         Gilroy, CA

Overall trip: 4225.6 miles in 8 days, having used 1455.5kWh at an average energy usage of 344 Wh/mi

Tuesday, November 11, 2014

Routing risk management

The routing of the title is not the network routing that LJ does for a living, but the routing that we needed to complete our cross-country adventure.  As anyone who knows both LJ and me might guess, I’ve been taking a more conservative approach to Tesla energy usage than LJ.  Many of the western SuperCharger-to-SuperCharger legs are laid out such that the first part of the leg is energy-intensive as we climb a mountain and then the second part uses little or no energy or even returns energy to the Tesla.  An extreme example from Colorado is shown below.

To ensure we use our time efficiently while avoiding getting stranded takes two steps: (1) use the evtripplanner calculations and overall elevation change to determine the average energy for the overall segment and (2) constantly monitor the energy usage to keep the segment average energy under that predicted number.  An example energy calculation from the software is shown below.

This screenshot is for the last two days of our trip.  Each of the SuperCharger stops is shown in green (yay for conditional formatting in Excel) and the overnight stop is shown in yellow.  From left to right, the columns are for: segment time, miles per hour, miles to drive, Rated Range miles, average energy in Wh/mi, the elevation gain and the elevation loss.  For each of the green lines, the data is a summary of the lines above it.  

Evtripplanner export with Excel conditional formatting

Taking the last SuperCharger leg of the trip as an example, we needed to use an average of 303 Wh/mi or less to get from Atascadero to Gilroy.  This Gilroy leg was an easy one to manage, as the high energy usage came at the end.  Additionally, for the Atascadero stop, we took a long lunch break, which means we were well above the 187 Rated Range miles that were needed to get us from there to Gilroy.  Had we just put in the 187 Rated Range miles we needed and caught a bad headwind, we would just need to drive more slowly than noted in the spreadsheet.

The most challenging legs for me were the ones where we were intended to use a high average energy rate early in the journey due to huge elevation changes.  On those legs, it was not unheard of for the average energy to stay well above 500 Wh/mi for miles on end or even 600-700 Wh/mi on really steep climbs.  While intellectually I understood that the calculations were quite accurate at sea level and skewed in our favor at high altitude, I still got very uncomfortable with that high of an energy usage.

LJ, on the other hand, was much more willing to follow the numbers.  The loose aviation analogy would be that LJ can handle a Tesla instrument rating and that I would be much more comfortable with VFR (visual flight rating).  [Note to the pilots and aviation nerds out there: I realize that this is not an absolutely correct analogy.]


As we got closer to a destination, the absolute Rated Range value became less important in favor of the relative percentage difference between the Rated Range and the projected range.  If we were traveling at a reasonable 300 Wh/mi with 20 miles to go and 40 miles of Rated Range, we would have to instantaneously more than double the energy usage to be in trouble.  The three most critical variables for energy usage are elevation change, altitude density, and speed.  Elevation change is accurately predicted by evtripplanner and altitude density is dependent on the elevation, so the only user-controllable parameter is the speed.  As long as we don’t double our travel speed—which is difficult when traveling at or near the speed limit—we would not get stranded.

The closest we got to needing a tow truck was back on Day 2, when we rolled into the Angola, IN, SuperCharger with only 5 miles of Rated Range.  A few minutes prior to that, LJ got distracted by a hawk at the edge of the highway and almost missed the exit.  In the Midwest, exits are 5 or 10 miles apart, which means that we would not have made it if we had missed that turn.  Luckily, we caught the exit in time and got to the Angola SuperCharger.

Close to empty


Speaking of luck... we knew we were pushing our luck by doing this #TeslaElectricStartupSuperTrip across the upper part of the US in early November.  It wasn’t until a couple days after arriving in CA on Sunday that we realized how close we had cut it.  Murdo, SD, and other parts Midwest and West caught a typical late fall snowstorm that would have made travel difficult or impossible for us.  The Denver area had snow and low 20s temperatures today.  Given that the Tesla is much less efficient in cold weather, we would have been booking multiple nights in a hotel and I would have been taking last-minute vacation as we spent a few extra days on the trip.

Monday, November 10, 2014

Day 7: Desert Beauty and Vegas, Baby

We left the Nevada border town of Mesquite, NV, and headed into… Arizona, a state that we didn’t realize we would drive through on this trip.  Apparently I-15 cuts through the northeast corner of AZ on its way to southern CA.  That means that we’ll end up driving in 16 states on this trip. 

We took the scenic route of our town to Valley of Fire State Park—given the drought, it’s probably an accurate name.  The drive to the park was across desert land spotted with scrubby brush and the occasional desert flowers, but nothing spectacular.  And then we turned the corner to look into the valley, which makes it easy to see why the park is named what it is.  The unexpected rock formations, with their vibrant red against the vivid blue skies, were well worth the $10 we had to pay for our 15-minute drive-through of the park.  We then followed the northeast side of Lake Mead National Recreation Area, with a glimpse of the lake among rolling hills and mountains.

Valley of Fire State Park, NV

Beehives at Valley of Fire State Park, NV


Coming into the east side of Vegas, we saw a number of cars on the side of the road watching something up in the air.  It was an F16 as shown below.  It wasn’t until later in the afternoon that we realized it was part of the Nellis Air Force Base Open House, aka their yearly airshow.  This was the first bad travel luck of the trip, which is pretty amazing for a 4,000 mile drive across the I-90 route in November.

Here’s what I mean by bad luck: LJ is a total airplane nerd and had even looked up the Thunderbird shows at the beginning of the year to see if he would be anywhere near one of them for a business trip.  Of course, that was months before this startup job and the Tesla Super Trip were even a remote possibility.  The only reason we even realized that there was an airshow is that I saw this smoke loop as we were walking back to get the Tesla at 3:12 pm, three minutes before the Thunderbirds portion of the airshow was scheduled to end.


Anyone who’s been to Vegas may know this, but it’s really two towns (or more).  There’s the bright lights and high-end casinos and hotels whose names many people know, like the Bellagio and the Venetian.  And then there’s old Vegas, the part in the city limits. 

Back in January, Wired magazine ran an article about how Zappos moved its headquarters to Vegas and is buying up defunct property to revitalize it.  Perhaps not surprisingly, the Tesla charger in Vegas is only blocks away from the Downtown Container Park that Hsieh (the Zappos CEO) had built.  It’s a trendy area of small shops and restaurants that would be at home in any gentrifying area and has a 40-foot-tall praying mantis sculpture to increase the quirkiness factor.

This Tesla SuperCharger was unique in a couple ways: it was the first one we’ve seen that was in a parking deck—and it was the first one where we saw any vehicle other than a Tesla parked in the spaces.  Here’s a picture of the clearly-not-a-Tesla that was taking up one of the six spaces.  Luckily there was only one other Tesla there so we had no trouble charging up.

Not a Tesla


After lunch at a BBQ place in the Downtown Container Park, we walked over to The Mob Museum.  In case you’re ever in Vegas with time to kill in the daytime, it was a fantastic place to visit. 

When we got in line to buy tickets, there were surprisingly few people paying with a credit card.  The guy working the ticket window where he could only take credit or debit cards had to keep announcing that he could take the next person in line.  We were both puzzled as to why no one used a card.  Then I remembered that we were in Vegas, about the same time that I saw the guy in front of us in line peel a $20 off the stack of bills that he pulled out of his pocket.


We left Vegas with a completely full charge, which meant that our next stop in Barstow was a short one.  If you recognize this town name, it’s probably from the sign at the other end of I-40 in Wilmington.

On the way out of Vegas, we stopped by the Ivanpah Solar Power Facility.  Over 300,000 mirrors concentrating sunlight to heat up steam and generate electricity.  We were there just as each of the three solar towers turned off.  Edison (the Tesla’s name) did not seem to recognize how much battery juice was being generated right there.

Edison (the Tesla) at the Ivanpah Solar Facility, CA


The final SuperCharger stop of the night was at Tejon Ranch at yet another outlet mall.  While I appreciate the convenience of having the SuperChargers near shopping and restaurants, stopping at this many shopping centers over the course of over a week gets a bit tiring and monotonous.  The stop for the night was in Bakersfield, CA, at a Hampton Inn where we could get a free night on Hilton points. 

Day 7 stats:
478.8 miles in 7 days having used 150.8 kWh and 3 SuperChargers:
·         Las Vegas, NV
·         Barstow, CA
·         Tejon Ranch, CA

Overall trip: 3859.6 miles in 7 days, having used 1344.6 kWh total