I’m building a new home and want to ensure it’s ready for a future EV, even though I don’t plan to buy one until they’re fully driverless. The house won’t have a garage (at least initially), so charging will happen via a receptacle on the front porch. I’m thinking of starting with a 120V/20A outlet but might consider a 240V line for better flexibility.
Here are some things I’m considering:
Charging outdoors in the rain. I assume it’s fine as long as I’m careful when plugging in?
I’d prefer to keep things simple and avoid any specialized installations until I actually buy an EV. However, I want to prepare for the possibility of needing more power down the road.
I’m retired and live about 15 miles from a large suburb where I assume there will be plenty of charging options in the future. I don’t drive much, so home charging will mostly be supplemental.
What’s the best way to prepare for this without going overboard on costs?
You should get a NEMA 14-50R outlet installed. It’s a standard 240V outlet that works with many EV chargers, like the Grizzl-e Classic.
Edit: Go with 240V if you can—it doubles the charging power. A 20A/240V circuit would be fine, but 120V/20A isn’t ideal, especially since most EV portable chargers are limited to 12A on 120V.
If you’re building a new house, I’d recommend running wiring capable of handling 60A/240V to a junction box. Install a NEMA 14-50 outlet for now, and if you need to upgrade later to a hardwired EVSE (which might become standard), it’ll be much easier with the wiring already in place.
Rain won’t be an issue for EV charging, as chargers and cars are designed for outdoor use.
As for driverless cars plugging themselves in, I doubt that will be a thing anytime soon. They’d probably use inductive charging or require human assistance at charging stations.
@chozen
I was thinking more along the lines of driverless cars going to charging lots where attendants handle the plugging in. That way, people wouldn’t have to spend time dealing with it themselves.
After reading the comments, my plan is to run 3-inch conduit from the outer wall to the utility room so it’s easier to add a 240V/50A circuit later. For now, I’ll just install a 120V/20A outlet for general use (like tools). Once I get an EV, I can add the necessary charging setup based on what’s available at that time.
Make sure you run wiring capable of 40A or more to the porch, even if you only install a 120V/20A outlet for now. That way, you’re future-proofed for adding a 240V outlet later.
Also, for your new build, use a 225A load center to leave room for future expansions, like a second EV charger, home battery, or solar system.
Consider installing charging pedestals in the driveway, which could be useful if you decide to have dual EVs in the future.
As for hurricanes, look into using an EV’s battery as a backup power source. With the right setup, you could power essentials like a fridge or microwave during outages.
@jeff
Just to clarify, wire size is based on current, not voltage. For 240V at 20A, you’d use the same wiring as for 120V at 20A. For 240V at 60A, you’d need thicker wires, but it’s the current that dictates that, not the voltage.
@jeff
I know the difference between 120V and 240V. My house is being designed with future needs in mind, like a utility room adjacent to the porch wall for easy upgrades. I’m also considering options for hurricane readiness, like running a generator or potentially using an EV battery for emergency power.