EVolution Australia has started selling the wonderful Zappi EVSE in Australia. The Zappi’s claim to fame is that it can be configured to charge your EV only when the sun is shining to leverage the solar panels on your home.
Fully Charged has an excellent overview of how it works.
The theory is that instead of sending the solar power your home isn’t using to the grid for a few cents, place it in your electric car’s battery for use later. I wanted to know what kind of savings there are to be had, so did some rudimentary math:
- I exported 6,345 kWh to the grid the past 12 months @ 11.3c/kWh, earning $717 credit on my power bill.
I’ve driven 26,915km in the past 12 months and the 2018 Nissan LEAF uses roughly 18kWh per 100km – that’s 4,844 kWh of energy used to haul my arse around Victoria.
If charged 100% from the grid @ 18.634c/kWh, that’s $902 spent on electricity.
If 4,844 kWh of the 6,345 kWh exported was placed in the LEAF’s battery instead of sold to grid, I’d miss out on $547 of credit, but I would have saved spending $902 on grid power.
This is an effective saving of $355 by consuming what your solar panels generate instead of selling it to the grid. If that happens every year, for 5 years (assuming grid power pricing stays the same), that’s $1,775 extra your solar panels saved you because you have an EV.
Obivously, this is a crude calculation, the car will not always be home when the sun is shining, so it will be practically impossible for me to charge it only from solar. But based on my driving habits, my car often sits in the garage whilst the sun is shining brightly. I might not be saving the full $355 a year, but seeing as I’ve already sunk money into my solar panels, I may as well extract every last dollar of value out of them and it’s clear that consuming what I generate instead of selling it to the grid is a smart idea.
The Zappi EVSE is $1099, which is only $109 more than EVolution’s standard Cylon 7.6kW wall charger. Over the Zappi’s life span, you’ll certainly recoup that $109 and save more over time. Of course, it can also be set to charge from grid power like any other EVSE. If you’re in the market for an EVSE and have solar panels on your roof, you’d be stupid not to get the Zappi.