Using an Electric Vehicle During a Hurricane Evacuation?
Plan Ahead! (Here’s Why)
The Quick Summary
There are not enough charging stations to support the number of electric vehicles (EV’s) on the road during an emergency (e.g., major Cat 5 hurricane) in southeast Florida. Other major metropolitan areas may be the same or worse.
You may wait in line to charge your EV during a large-scale evacuation from SE Florida. Gas drivers will come and go while you wait. Best-case scenario, a 20-minute wait at some chargers. Worst-best-case scenario, a 40-to-60-minute wait at all chargers. Wait times don’t include charging time. Wait times may exceed those shown above at charging stations located closest to the exit route.
None of this applies if you can get where you want to go on a single charge. Keep in mind that charging stations may be crowded on your way home, so plan your return to avoid charging lines. All EV evacuees will leave the state in this analysis.
Leave at least 36 to 48 hours in advance of a hurricane to avoid charging lines (hopefully).
If You Wait to Charge
What will you and the adults/children traveling with you do during the time while waiting to charge? Some locations could have over 70 EV’s (or about 200 people) waiting. Where will they all wait?
Many charging stations are at gas stations with convenience stores. Gas vehicle drivers usually crowd the store during non-emergency times. That crowd adds to the EV crowd during an evacuation.
There is little or no room to sit in the store. The wait will be inconvenient. Restrooms will not be exceptionally clean. Restroom paper items will be exhausted; count on wiping your hands on your clothing unless you bring supplies (e.g., TP, paper towels, snacks). If you’re lucky, a restaurant is a short walk away.
Someone will have to manage the EV line waiting for a charge. An improperly managed charging location could lead to a “mob rules” scene. Other evacuees may use the charging locations as parking stalls (see My Visit…, below). Can you even get to a charger? Or do you limp to lodging (if available) and wait overnight, hopefully with destination charging? Will the hurricane change course and affect your unplanned stopping area?
If You Must Use an EV
If all you have is an EV, leave 36 to 48 hours in advance of a storm. Leave early (say 1 or 2 AM) with reservations at your planned stops. Florida population is now over 22 million, so road conditions will be worse than anything I’ve experienced.
Florida is one of the states with the highest number of charging stations. Conditions may be worse for EV’s in another state. If you live in another state, leave as early as possible and plan your route before leaving.
What Should Change?
These suggestions would better facilitate large-scale population movements.
1) Arrange the EV chargers like gas pumps. This would allow the vehicle to drive up to the charger, charge, and leave without pulling in and then backing up. Lines could easily form at each charger.
2) The chargers need an overhead canopy just like the gas pumps. Currently, there is no shelter for EV’s.
3) EV manufacturers need to make all vehicles so they can use a supercharger to achieve 80% charge in 15 minutes or less.
4) EV users need more charging stations. More in rural areas and double the number of chargers along interstates and other major limited access roadways.
Manufacture EV’s with the charging plug port in the same location on all EV’s made for sale in the United States. Or make the chargers so they can reach any location on an EV.
My Visit to a Local EV Charging Location
Here’s what I saw at about 8 AM on a Wednesday morning in early July.
1) Two “charge point” charging (CP) stations east of the gas station’s store. Both CP stations were blocked by a pickup truck towing a service trailer.
2) 8 superchargers located west of the store. One supercharger in use. 6 superchargers were blocked by a fire truck.
3) It would be very difficult for an orderly line of EV’s to form if all the chargers are in use.
4) A single parking stall provides access to each charger.
5) No stall was labelled as being only for charging use.
Queueing Theory
Queueing theory means that a line will form if the number of EV’s entering the line exceeds the number leaving the line. Simple and almost common sensical.
Let’s apply it to a charging location with 8 superchargers. It takes 15 minutes to charge and let’s say another 5 minutes to enter, attach charger, charge, detach charger, and exit the parking stall at the charger. Total charging time is 20 minutes. This station can charge 24 EV’s per hour (3 cycles per hour x 8 chargers). A line will form if more than 24 vehicles arrive per hour or more than 8 per 20-minute period.
Now let’s look at the entire route, which includes both route 1 and route 2 as shown above (i.e., I-95 and Florida Turnpike). There are 661 total charging stations available. The charging stations are all occupied at the 8th travel hour under the best-case scenario. 191 EV’s will have to wait 20 minutes until a charging station is available, then spend another 20 minutes charging.
However, some EV drivers may decide to wait at charging stations that are close to the main travel route as opposed to driving 20 to 30 minutes away to an open charging station. Charging station line wait times at facilities close to the main route may exceed 20 or 40 minutes with much quicker service at remote locations.
Wait times range from 40 to 60 minutes under the worst-best-case scenario; all chargers will be occupied during peak travel hours (maximum traffic). Crowding at stations near the main route may be even worse.
Remember, charging time is in addition to waiting time.
Background Information
Technical details follow. Results are skewed in favor of EV usage to eliminate bias accusations.
1. Evacuation will take 24 hours.
2. A major hurricane will cross the Florida coast at the Palm Beach/Broward County line.
3. Palm Beach and Broward County will evacuate.
4. 53% of residents will leave (typical of past major storms).
5. There are 6,432 private Tesla’s in Palm Beach and Broward Counties, combined.
6. 3,409 Tesla’s will evacuate. No reliable data for non-Tesla EV’s.
7. Non-Tesla EV’s and commercial/governmental EV’s are not included in the analysis.
8. The best-case scenario uses a uniform evacuation rate.
9. The worst-best-case scenario uses a normal distribution for the evacuation rate.
10. All EV charging stations within 20 or 30 minutes of the main travel routes are included.
11. EV charging stations around the Miami-Dade area are not included.
12. Primary evacuation routes are along I-95 all the way to Georgia (Route 1) or I-95/Turnpike/I-75 to Georgia (Route 2).
13. An EV can leave Florida in six hours (driving time).
14. All EV’s will leave Florida to have the best chance of evading the hurricane.
15. All EV’s will charge at least once prior to leaving Florida.
16. This analysis looks at the whole evacuation route (both I-95 and turnpike, together). Traffic travels in bunches (plug flow) and that fact wasn’t considered.
Final Thoughts
Have an evacuation plan before using an EV to evacuate. Know where charging stations are located or have access to this information. Preselect and reserve overnight stopping points. EV’s should leave at least 36 hours in advance (when possible).
If you want to provide your own analysis, please do and offer it to better inform me and others. I will amend the article if something changes.
Author’s Postscript
I’m listening to Hurricane Idalia coverage as I put the final touches on this article. I’ve evacuated prior to hurricanes many times and stayed in place as well. My experience shows that everything along an evacuation route is strained to the limit via millions traveling over a short period of time.
I think EV drivers are used to charging on demand. I’ve never seen a line at a supercharger location (see below). Hopefully this article helps EV drivers understand what they may face when facilities are strained to near failure.
