It’s something you periodically hear whenever the topics of “electric cars” and “natural disasters” meet: fear. There comes an image of electric cars stranded across the roads, endless impractical lines for charging, while their gasoline-driving compatriots escape to safety. In the aftermath, there’s an image of people in their powerless homes, stranded because their electric car is out of juice, while their neighbors drive around at will with gasoline.

I found this concept curious, as I had heard very good things from EV owners in New York during Sandy. So — as reservation holder for a Tesla Model 3 – this year I’ve been paying close attention to Tesla owners’ experiences during Harvey and Irma, as well as the status of the Supercharger network.

Some background…. this is a Supercharger station:

Supercharger in Sarasota, Florida

In the above, you will see white, freestanding “pedestals”, each of which serves a “stall” (parking place). The pedestals are powered by “chargers” (two pedestals per charger), which are contained in metal “cabinets”, generally in a fenced off area next to the chargers (in this case, the wooden enclosure). 

Tesla is unique among car manufacturers in how they approach charging.  Rather than scattered, low power (~50kW), poorly monitored / maintained DC charging stations located in random locations, Tesla supercharging stations are concentrated (4-20+ stalls), high power (up to 120kW per vehicle), and very well monitored and maintained by Tesla, with locations planned top-down from Tesla. This provides a number of things for users going on road trips:

 * You can trust that when you get to a station, that it will actually work. Even if one charger happens to be out, during that brief period there will always be at least one, and usually several more

 * You can charge quickly. For a typical Tesla vehicle on a V2 Supercharger, the first 50% of your charge takes 20 minutes or less, with the next 30% taking  another 20 minutes or less, and progressively tapering off from there. In general, this means that in the time you stop for a 10 minute stretch-and-bathroom break, you can get ~25% charge, while in a 30 minute meal you can get a ~2/3rds charge. Since you would be parked for the restroom stops / meals / etc either way, you’re also not using up “parking space” just to charge; the space is serving a dual use.

* There are generally things to do at each location, places to eat, etc, as locations are designed for this. They’re also spaced at regular intervals along busy roads, close enough that except in more remote areas, you don’t need to stop at each one:


In addition to being able to use Superchargers, Teslas also can use most high-power charging stations designed for other vehicles, lower power AC chargers, as well as RV / range sockets, dryer sockets, and normal wall sockets.  A map of just high-power chargers alone for Florida:


So, how does this play out in a disaster like a hurricane?  Let’s break it down into different aspects.

1. The evacuation: supply

An evacuation for a disaster like a hurricane is never a fun experience. In the infamous evacuation from Rita, over a hundred people died, two thirds from heat stroke or the effects of heat on preexisting conditions. People kept shutting off their cars to try to conserve fuel (which is always in very short supply), and many ran out of fuel; the stranded cars and medical emergencies made the evacuation even more complicated.

Between Harvey and Irma, the latter created more of an evacuation problem — in part due to the geography of Florida constraining possible evacuation routes, in part due to the long buildup, and in part simply because witnessing the aftermath of Harvey had put many Floridians on edge.  Gas stations were running out of fuel long before Irma arrived.

Evacuees queue for gas. Image: AccuWeather.

Across the whole state, 43% of gas stations remained out of gas even as the hurricane had passed through on Tuesday — an improvement over the day before. Along evacuation routes and in major at-risk metro areas at the peak, the shortages were near universal at times as trucks struggled to get in and meet demand. 

“It's horrible, man,” said Aaron Izquierdo, who waited in a long line of cars at a Shell station in Doral on Friday. “Just yesterday I was in line for two hours to wait for gas, and by the time we got to the pump there was no gas.”

Scott Alderman, who lives in Broward County, was out for a bike ride this morning when he passed a gas station without fuel.

“But a tanker truck was pulling in and, like the Pied Piper, there were 15 or 20 cars following him,” he said.

Alderman has lived through hurricanes before and knows that, once the electricity goes out, it can be days before gas is available again. So he immediately went into action, racing home to tell his wife to fill up her car.

She got to the station within five minutes, he said. But she still had to wait nearly an hour to fill up her tank.

What about for electric vehicle drivers? Before the evacuation, they upped their charge percentages from their daily charge percent to 100%. Tesla gave a free temporary over-the-air upgrade for everyone in the area who had purchased a software-limited range vehicle; their drivers awoke to see that their vehicle had significantly more range than they expected the night before. This nighttime charging occurs when demand on the grid is low, and which would have not had a meaningful impact had 100% of the grid been driving electric.

Beyond this, power demand drops as hurricanes approach due to people leaving their homes and businesses closing, and drops even further after the hurricane hits (due to damage):


Tesla vehicles have EPA ranges of 220 to 335 miles. This reaches up to halfway from Miami to Atlanta on a single charge. For most routes fleeing from a place like Houston, a single charge at home would suffice.

It’s worth noting that the pain of hurricane-induced gas shortages are not confined even to disaster zones.  In the aftermath of Harvey, gas lines and shortage spread to Dallas — partly due to constrained supply and evacuation traffic, but also the fear of being unable to get gasoline. EVs, with their slow, steady nighttime charging, are immune to this problem

A common thought of gasoline vehicle drivers is, “I can always just get some gasoline in gas cans and bring it back to my stranded vehicle.”  But in practice, A) you often can’t just get gas so simply, and B) you can get power from the uncountably many power sockets around you. Not all are equally fast, but the power is always there.

2. The evacuation: the drive

While gas lines were agony for many fleeing the hurricane, how were Supercharger lines?  Well… there weren’t any. Not a single person on the Tesla forums described any wait whatsoever to get a supercharger stall.  E.x.:

I've stopped at the Brandon, Ocala and Lake City Superchargers.Ocala was empty at 12:30 AM. Lake City was 50% full last night at 3 AM but empty at 7:30 AM. Quite a few camping by the Superchargers in Lake City.

Plenty of capacity at the Superchargers if anyone is thinking of getting out.

We left from central florida yesterday, didn't need to stop to charge until we were outside of Florida.

We passed through Kingsland, GA supercharger … which is co-located at a police station!

Empty, no teslas. Friendly cops, and Denny's (not my favorite, but it's the least bad option available IMHO) is about a 5 minute walk.

Then Savannah which is co-located inside an airport parking garage … 2 other Teslas there … Very confusing path of getting parking validated there inside the terminal. (The path to the terminal, if you pull in straight into the Supercharger stall, get out of your car, and walk towards the back of your car and keep on going, eventually you end up in the Terminal … the Information desk is on the first floor directly behind the escalators)

Then August GA which is co-located at a Sheraton (the navigation doesn't make that obvious). One other Tesla.

All-in-all, we didn't wait at any location and were able to charge at full speed as soon as we pulled in.

Good luck to all!

FWIW, a Model S owner posted on FB this morning that while his wife was stuck for over 3 hours trying to get gas for the ICE car, he was happily charging at an almost-empty supercharger.

No wait at the superchargers. I drove past 2 superchargers on day 1 of my haaj. They were 70% full while the wait for fuel (if there was any) was an hour in some places.

Etc. Indeed, part of the issue is that the heavy evacuation traffic may actually have increased their range, rather than decreasing it.  As one can see from playing around with the official Tesla range calculator, range vastly increases from the EPA rating when speeds are reduced; this is generally a much more profound effect than losses from “idling” (which are small, even with the air conditioning running) and start/stop traffic.

There was indeed range anxiety on the trip, but not from EV owners:

Hi all. Missed many posts but wanted to jump in and give my 2 cents. I'm in Miami and just had power restored today since Sunday. I can confidently say you want an EV in a situation like this. 

The 50 car deep lines at gas stations plus uncomfortable moments were you had to yell at for trying to cut in line were not pleasant. Many ICE drivers were experiencing “range anxiety”, sitting in their cars for an hour or two with the engine (and A/C) off and/or pushing the car a few feet at a time towards the gas station. 

3. Those who did not evacuate


Life in the aftermath of a disaster is not fun. My sister was in Houston for both Ike and Harvey. With the trees crashing down around their house during Ike were scary, the misery in such storms is the endless days living in sweltering heat without air conditioning, and being eaten by the rapidly-breeding mosquitos if you ventured outside. The roads are blocked by debris and/or flooded.  And those fuel shortages from before the evacuation? They don’t get any better after storm damage, flooding and blocked roads. Any gas stations that lost power and don’t have backup generators shut down.

EV owners, however, tend to use their vehicles as a “lifeboat”.  A charged Tesla can run its climate control for days on end in “camping mode”. The rear seats fold flat for sleeping.  A large screen is available on the front. The car has its own mobile data service which may remain up if yours goes down, and of course you have a sound system and ports to charge your electronic devices.

I don't have power, but there was less damage here in Daytona Beach. 

Last night I sat in the Tesla with the a/c running listening to ABC news. The cell service has been poor. 

Without power, there will be lots of cranky Floridians about today. It's supposed to be hot today.

I'm still without power, and I'm sleeping in my car as we speak. Too hot in the house…

Estimate for restoral is late Friday night. Thank goodness my gym reopens tomorrow.

We absolutely went for a swim today…but the pool has been without filtration or chlorination via the salt system process for days, so not gonna be so inviting soon. Jim made coffee on the grill yesterday. Thank goodness I chose a resourceful man! The only reason he didn't sleep in here with me was because the generator keeping our fish and fridge alive keeps shutting down randomly, and you can't hear it at all in the Tesla. Another bonus to sleeping in here for me!

I can't say I slept like a baby, but it was better than in the house for sure…until now. Because I drank a LOT of water yesterday….this thing needs a potty and it's perfect.
At least it's early enough no one will see me climbing out ungracefully in my nightgown.

It could be worse, we have no damage to anything but some plants, and even that is minimal. It's amazing how they weathered those winds.

I will say right now that in nearly 4.5 years of Tesla ownership this is the first time I've tried camper mode. It is awesome! Verizon (as well as other carriers) has suspended data charges until the 15th, so I had my phone set up as a hotspot in the charging cradle so I have internet on my tablet.

As noted, getting fuel in the aftermath of a storm can be challenging. Getting electricity is, however, surprisingly simple. Firstly, anyone who has a backup generator (such as a natural gas generator) or an AC coupled solar system can drive to their heart’s content.  But even someone with no power and no generator can almost invariably get power, because virtually never is the power down everywhere, and the car can charge on any power socket. A number of people have been discussing places in their areas that they would go to if they ever had to recharge the car. None had to.

Certainly, if you have a backup fuel supply — in a safe storage tank (rather than sitting around in plastic jugs in your garage), and properly stabilized and replaced on an annual schedule so that it doesn’t go bad — you can let an internal combustion engine idle to provide air conditioning and the like. Beyond the noise, however, this is quite a suboptimal solution. Idling cars for protracted periods is not a good idea for a number of reasons:

  • The coolant temperature runs hotter. Modern cars get most of their cooling air from compression under an air dam as the car drives. A well maintained car shouldn’t “overheat” just from idling, but it will usually run hotter. An poorly maintained car can overheat when idled for protracted periods of time (I have personally experienced this).
  • The combustion temperature is lower. The low temperature exhaust has two effects. The first is that combustion is less complete, so it tends to cause more carbon buildup in the engine and exhaust system. The other is that it doesn’t heat up the catalytic converter as much.
  • Pollution. While a car with a reasonably new / well maintained exhaust system should reach a “sufficient” catalyst temperature to meet emissions regulations even when idling, an older car with a less-than-clean catalyst may not. Higher catalyst temperatures are, regardless, always better when it comes to pollution. Most importantly, however, exhaust from an idling car tends to build up on calm days. In my own experience, the last time I used an idling car as backup (in my driveway, not my garage), my home’s carbon monoxide detectors started going off after several hours.

4. Infrastructure durability: Harvey

Harvey may ultimately go down as the most expensive hurricane disaster in US history. Superchargers in Harvey’s wake were subjected to the same punishing winds, and then terrible floods, that everything else was.

The Channelview Supercharger in Houston, for example? Here’s what happened to the hotel it is attached to:


This La Quinta hosts the Victoria Supercharger:


How much survived?  Amazingly, everything.  The Columbus supercharger was down for a brief period, but came back up.  The Columbus charger was built in a flood zone, so they simply had it elevated:


If you look closely, you’ll notice the water line on the concrete.  Unfortunately, elevating gas stations isn’t such a simple prospect — and this was all too common of an occurrence:


5. Infrastructure durability: Irma

Irma turned out to be one of the worst types of disasters for electric vehicle infrastructure you could set up: a electrical distribution system disaster of historic proportions. On Monday, two thirds of residents in the entire state were without power.  Power restoration estimates in many places have been placed at “weeks, not days”, with the grid requiring a wholesale “rebuild”.  While the wind-and-flooding damage of Harvey scored the Supercharger network an “A”, its response to Irma would be rated a “B-”.

On Monday at 9:30 AM, Tesla reported the following status:

Open: DeFuniak, Tallahassee, St. Augustine, Port Orange, Riviera Beach, Plantation, Fort Myers

Closed: Live Oak, Lake City, Ocala, Pinellas Park, Sarasota, Naples, Fort Drum, Port St. Lucie, Florida City, Marathon

Another report from the afternoon was even worse, with a user’s screen showing Riviera Beach as also being down.  Two sites were of particular concern: the Naples supercharger was only a block from the water, while Marathon was reported to have been entirely submerged by the storm surge.

A pattern slowly started to emerge, however, in that a number of the stations might not have been down at all. One by one, calls to Tesla revealed stations as having been inspected as being operational, while they continued to show as down in peoples’ vehicles; in short, it appears that the loss of communications networks due to the power outage was hindering report. Plugshare reports track the history of the event:

Tuesday, 4:36 AM: First confirmed charge at Ocala.

Tuesday, 6:56 PM: First confirmed charge at Sarasota

Tuesday, 7:22 PM: Pinellas Park, Fort Myers, Naples, Port St. Lucie, Riviera Beach, Florida City confirmed up by Tesla.

Tuesday, 11:28 PM: Live Oak, Lake City confirmed up by Tesla.

Thursday, 4:52 PM: First confirmed charge at Fort Drum

In short, within a day and a half, all but two superchargers had come back up, with one of the remaining coming up two days later. And it’s possible that some of the above never went down at all. The only “loss” appears to be Marathon, where much of the whole island itself is likely a loss. 

One may ask themselves, how exactly is this possible? How is it that in the middle of so much destruction, and particularly in the middle of so much power loss, that the Supercharger network could be this durable?  There’s a couple key factors.

  • Superchargers are small. They’re not very large targets for debris, and they’re easy to elevate to avoid floods. The pedestals are simple sealed devices that simply provide a cord, and are fed by a sealed conduit.
  • Superchargers are extremely high power. A typical Supercharger station may consume about half a megawatt peak, while a large Supercharger station may consume 1 ½ megawatts peak. These power figures are typical of a large office building or small skyscraper — yet they’re generally located in suburbia. In short, they tend to be the biggest consumers around. If the power is down to them, it’s down to everyone in the area. If you want to restore power to anyone in the area, it’s going to come up at the Supercharger first.
  • Tesla recognizes the importance of keeping them up. Which should go without saying, but it’s essential that a provider of EV charging infrastructure treat it as critically essential, rather than just “something we built to convince a bunch of hippies to buy our cars, but not something that we actually care whether it works or not”. To Tesla, Superchargers are not even just a loss-leader: they’re designed to be profitable, starting with the Model 3, so that they can ultimately replace gas stations.

6. The future

While the above all applies to the current situation of low EV penetration, it’s fair to ask how things would have fared if everyone drove an electric vehicle?  In particular:

  • While some urban superchargers are nearing Tesla’s target utilization rate (a gas-station-like 1/3rd occupancy), today most highway superchargers are generally far from that. They’ll be busier in the future, and this could represent bottlenecks during high traffic figures if not designed to compensate for this.
  • Even in a high-adoption-rate scenario, the difference in home charging between a “night before evacuation” scenario vs. “normal overnight charging” is likely to be insignificant to the grid. However, the increase in daytime supercharging for people on-the-road is a meaningful factor to consider.

However, none of these appear to be fundamentally problematic aspects. Even today, an average supercharger station (around 8 stalls) costs a mere $250k to build, a quarter of what an average gas station costs. In the future, they will likely be much cheaper. In short, overbuilding to accomodate evacuation traffic is not a fundamental problem.  

In addition to the reduction in power demand as a hurricane nears (people who leave early, businesses that shut down, etc), a state can readily order power curtailment from industry if there are shortages. Likewise, better interconnects can be built with neighboring states.

Tesla is increasingly moving to superchargers buffered by “Powerpacks”, a convenient size to carry on a semi (and indeed, Tesla is preparing to unveil its first electric semi). Tesla service vehicles with powerpack-buffered Superchargers from the region could converge on locations in need of more Supercharging stations in advance of a potential disaster, and either:

  • Wire directly into the grid with temporary interconnects
  • Use large flatbed-portable generators (hundreds of kilowatts to a few megawatts), such as are used to back up nuclear powerplants.
  • If the goal is to provide supercharging to less populated areas, power could be trucked in on powerpacks, akin to trucking in gasoline and diesel. 20 or more powerpacks could be carried by a single semi, for a total of 4,2 MWh of electricity, providing 15-20 thousand miles of electric vehicle range per delivery.

In general, however, this should not be needed. The simple situation is, electricity is available everywhere — far more available than gasoline. If “almost everyone” is driving electric vehicles, the power distribution and charging infrastructure will be built to meet demand during bad situations, such as evacuation from disasters. The economics for doing so in no way appears to be prohibitive. 

  • September 15, 2017