Chevy Volt Energy Usage – Charging on 240v vs 110v
One of the questions circulating around about the Chevy Volt and any other electric car out there is how much more efficient it is to charge an electric vehicle on 240v (Level 2 Station Charging Station) vs. a 110v (Level 1 Charging Station). For those wondering why it would make a difference – it is the same reason that long distance transmission lines from power plants are run at tens or hundreds of thousands of volts vs. your regular household outlet at 110 volts – namely that less energy is lost to the resistance in the wire.
Because I have a ChargePoint Network Installed Charger at home and Have used a couple Public ChargePoint Network Stations, I’ve been able to see that at home on a 240 volt circuit, it takes roughly 11.9 KwH to Fully charge my Volt’s depleted battery. (the weather here has been pretty consistent at around 50-60 F, so chances are – no extra energy was used to heat or cool the battery)
Compare this to my 110v charging experience in the public, and you’ll see that the total power usage was 13.5 Kwh. Granted, I only have one data point here, and certainly there is a possibility for measurement error / slight variations to the Volt’s actual charge depletion when it was plugged in (it tries to maintain 30% state of charge, but it will vary) – But the 13% difference is significant enough to state that there are certainly charging efficiencies to be gained by stepping up to higher voltage.
If you are interested in my Chevy Volt charge data, it is available here.
Is the extra efficiency in having a 240v charger worth the cost difference? Probably not. If you are paying say 10 cent per Kwh, you would basically save 1 cent per KwH by having a 240v charger vs a 110v charger.
If you look at my entire charge history in the excel sheet, You’ll notice that I’ve used 544 Kwh since buying the Volt (netting roughly 1760 EV Miles). To offset the cost of installing a charger (lets call it $1,000 though we all know it can be much more) You would need to charge for 100,000 KwH or by my math, drive 330,000 EV Miles.
Of course the real benefit is the ability with 240v to charge quickly and displace more gasoline usage – which I’ve certainly done a lot of.
Read more about my Level 2 Charging Station Installation here for more background on what it takes to install a Level 2 Charger at home