Solar charging an EV takes some pre-planning or costly add-ons

On a recent Internet of Things podcast, we took a voicemail from Jared on our podcast hotline. Jared’s home is equipped with solar panels and he recently purchased a Tesla EV. He’s looking for some smart device that will let him charge his EV directly when his home is producing more energy than it’s using.

I can relate to Jared’s question because I had 41 solar panels on my prior home. I’ve since moved to a home without solar panels but we did purchase a Tesla Model 3 about a year ago. We’re also considering a solar panel install where we now live.

Jared’s house uses Enphase solar products. I know the brand because that’s exactly what I had at my prior residence. And Enphase makes a great product. However, unlike many other solar energy companies, Enphase has taken a traditionally different approach. Instead of having a single inverter to change DC power from solar panels to AC power for home use, Enphase uses a micro-inverter on each solar panel. This helps overall energy production in the case of shade cover on some panels.

That doesn’t mean Jared is completely out of luck; it just means his options are more limited. If he had one single power inverter, for example, he could replace it for one that supports EV charging separately from the other circuits. Of course, that wouldn’t be cheap, even if it was an option for Jared. I have spoken to some industry folks and I’ve heard that Enphase is starting to offer systems with a centralized inverter, mainly because that’s needed for optional battery support.

There are some “smart” EV chargers that support load balancing and solar-only charging. And these should work with Jared’s existing solar power system.

Unfortunately, they too can be pricey. That’s because they’re not just a standard EV charger; they have smarts and connectivity to see the flow of electricity from the panels to the home to the grid. However, they can be far less expensive than upgrading your solar inverter. A reader reached out us after the podcast to point us to the Emporia Electric Vechicle Charger with additional home energy monitoring solution could suffice for $440 in total. Four hundred dollars of that cost is the charger, while the required energy monitoring hardware is just $40. That particular monitoring solution only works with a handful of energy providers, so an alternative energy monitoring option might be needed.

Clean Energy Explained, where the above image comes from, has a list of 10 smart EV chargers to consider. Some of these, however, are well over $2,000, making me wonder if it’s even worth it for Jared. Each has different features and pricing, of course, so for anyone interested in a smart EV charger, I’d start by reviewing this list.

It’s worth noting that Tesla is reportedly introducing a solar charging feature for its EVs. However, that’s not yet official and I fear it may only be for homes with Tesla Solar. Hopefully, that’s not the case because a Tesla-provided solar charging feature would accomplish Jared’s goal.

I did find one other interesting solution: A mobile app, called Charge HQ, that uses your solar panel power data to tell your Tesla when to charge with excess production. It’s available as a free beta, although it only supports a limited number of solar panel power inverter brands for now. However, it works to add “smarts” to nearly any EV charger. The app connects to your Tesla over Wi-Fi or cellular to tell it when to charge based on your panels producing more electricity than you’re using.

To hear Jared’s question in full, as well as our discussion on the topic, tune in to the Internet of Things Podcast below: