Couldn't find where he or how you arrive at those numbers. Anyway it's not solely about energy costs per km but total cost. And here the lower weight of FCPM trucks comes into play. What they discuss at the ceremony:
A truck, including its load, must not weigh more than 40 tons. Let's take two comparable trucks: one with a battery, the other with a fuel cell. It turns out that the fuel cell truck's drive system is four tons lighter. This means its payload capacity is greater. Therefore, up to 20 percent fewer trucks are needed to transport the same goods. Instead of five trucks, there are only four on the road.
In the best case you can save acquisition costs, driver wages and insurance for one truck per every four others. It's going to take a while until you make that up with saved energy costs.
A truck, including its load, must not weigh more than 40 tons. Let's take two comparable trucks: one with a battery, the other with a fuel cell. It turns out that the fuel cell truck's drive system is four tons lighter. This means its payload capacity is greater. Therefore, up to 20 percent fewer trucks are needed to transport the same goods. Instead of five trucks, there are only four on the road.
In the best case you can save acquisition costs, driver wages and insurance for one truck per every four others. It's going to take a while until you make that up with saved energy costs.