colonial weapons

Alan said:
If you can make a man-portable laser with a power generator capable of
multiple firing (rather than a 1-shot chemical reaction) and fit it on a
backpack, making a powerplant that would drive a 100-tonne tank for a
thousand km and fit in a suitcase is Noooo problem.

[Tomb] Not counting of course the fact that said tank is mounting a
laser about 20x as big as the one you are carrying and it mounts a huge
power consumptive ECM suite. Plus let's look at how much energy is
involved in lifting 100 tonnes, holding it suspended, and accelerating
it up and down hills and up to a few hundred kph. I think this statement
of Alan's is a bit "long in the tooth". Unless he'd care to back it with
some math?