Refuel or charge?

Hello, I’ve been standing near a charging station many times and thought of charging or not. Sometimes I just loaded with the enbw card. I knew it wasn’t economical to load. At IKEA it’s free, but never a column free, because some people are waiting for a column to be released in the car. Now I’ve found a computer online where you can play around with the prices. Does one know how much kWh the e300de needs on 100 kilometers when it’s driven purely electric? Only with diesel I’m on average at 6.4 liters on long distances in a mediocre way (city/country/city).