Gregory J. Hassler

DC Fast Charging is cheaper than you think.

Most people assume that AC and DC charging costs are a direct comparison - but they aren't.

When you look at the costs of charging an electric vehicle, most people assume that AC and DC costs are a direct comparison - but they aren't. Here's why. Few in the EV industry talk about this, but DC charging is cheaper than it would appear on the surface. The price you pay per kWh isn't comparable to AC charging for two reasons: For DC fast charging, you pay for the energy (kWh) after the AC->DC conversion process. Any efficiency losses (heat) during the conversion are paid for by the charge point operator (CPO). Basically, with AC charging you are paying for the energy INTO the charger, and with DC charging you pay for the energy OUT OF the charger. Or, think of it as the higher price of DC fast charging is also covering the 'unseen' / unmetered cost of the energy conversion. On top of that, DC fast charging is, well, faster. This means your car isn't 'awake' as long, and isn't running thermal management systems for as long as they may be with AC charging (which could be 6, 8, or 10+ hours of these overhead losses). By comparison, DC fast charging generally only takes 20-40 minutes, so your water pumps, compressors, heaters, fans, etc. are only running for a fraction of the time to move the same total energy. These two gains together add up to an effective gain of 5% - 10%. Think of it as an automatic discount to the 'sticker price' of AC charging. If your DC charging costs $0.50 / kWh, that would be equivalent to an AC charging cost of about $0.53 - $0.54 / kWh. Not a huge difference, but something worth considering. If you're new to EVs or considering the switch, my book Electric Vehicles for the EV Curious covers the full picture at curiousaboutevs.com.