I forgot to mention it's a 1.6L.
Also, even if it made 14kW instead of 15kW, I'd have 21kWh of usable electric energy. So 1kW of electric + 14kW if diesel = 21 hours of both. If I need 2kW electric I'd have 10.5 hours until I ran out. If I needed 5kW electric I'd have about 4 hours of driving. Of course there are many variables. I could also slow down and put the diesel in 4th gear and still make road time with less electric use.