Ozop Energy Solutions Inc (OZSC)

[The new economan]

These carts are a huge improvement over the existing units. The new units allow the aircraft to be serviced on battery power, with the generator off. The reduced noise levels vastly improve safety and efficiency - and the new carts are designed to service several types of aircraft instead of just one. The old cart/generators wear out, and need to be serviced/replaced. This is simply the evolution of technology over time - a better mousetrap.
By the way, the cost/expense of this (or any) contract does not concern the military at all. Their funding is nearly limitless.