You forgot to multiply it by the 10 m2. And btw maximum size of the truck is almost 10m long so you could probably squeeze in closer to 20m2. So, you would get

You forgot to multiply it by the 10 m2. And btw maximum size of the truck is almost 10m long so you could probably squeeze in closer to 20m2. So, you would get 20km range from a day of charging. Not earth shattering but better than nothing