I’m sure the question, “how much does it cost to charge an electric vehicle,” is Googled many thousands of times per day. There are rules of thumb and anecdotal answers from a variety of sources. When it comes to validating claims, there is nothing better than hard data.
Fortunately, if you have solar panels with the Enphase Enlighten app and consumption monitoring, you can get a really good idea of how much electricity is used when charging your electric vehicle and for how long it charges.
Take this client’s monitoring system for example:
Since EV charging is very energy-intensive, it is easy to spot when the car is plugged in, especially if you have a high-powered charger. This client has a 40A charger. The app tells us that there was about an 8,000 watt jump in power use at 9:00 pm. That ran consistently until 2:00 am.
To calculate the energy used, multiple power by time. Five hours x 8,000 watts = 40,000 watt-hours, or 40 kilowatt-hours (kWh). Since a kilowatt-hour costs about 12 cents right now in Southwest Florida that’s about $4.80 this client spent to charge their car.
To put this in perspective, let’s say this client has a Tesla Model S with a 100 kWh battery. Obviously it was not fully discharged when they plugged it in. It was probably around 40% depleted at the time, or slightly less to account for efficiency losses in the charging process.
Some clients plug their cars in every night when they come home. Some charge occasionally at irregular intervals. And some just charge when the battery gets low. Either way, the Enphase Enlighten app can help pinpoint how much energy it takes to fill up an EV battery. It takes a little manual effort, but after a while, owners get a feel for how much their car costs them to operate as a percentage of their electricity bill.
One thing is certain – charging an electric vehicle at home is not free. But it’s a lot less than gas at today’s prices! And charging with solar power can drastically offset the impact of having an electric vehicle. Using the Enphase Enlighten app, clients can get a handle on what the EV actually costs to charge. It’s just another benefit of an Enphase based solar energy system and the Enphase app.