Here's the deal:
Armoured Fighting Vehicles (AFVs) and Protected Patrol Vehicles (PPVs) are already power-hungry machines with advanced computer systems and communication equipment, but future battlefield vehicles will be equipped with even more electronics, such as situational-awareness technology, sensors and vehicle cooling systems. All of this will place an increasing burden on existing 28V generating systems.
If you'll allow a comparison, it seems like this development is following the form of highway expansion projects. That is, when you build more lanes to reduce traffic congestion, you often get more cars to fill in the extra lanes and end up back at square one. We may soon have vehicles that can squeeze more work out of a gallon of fuel, and it may be that the savings will not be captured as reduced fuel demand, but rather as support for more powerful and more numerous computers, communications devices and sensors.
Food for thought: the energy efficiency KPP could be used in more ways than one in systems acquisition.