Bad design adds weight. Nor do modern engines have a problem properly set up going deep off road. Problem here is just your kind of thinking that it has to be heavy to be rugged.
The same problem in cars, we don't do lightweight, just cut a pound here and there and pats each other on the back about how good they have done when cutting weight 50% just isn't that hard with composites. But it's not what they do.
When I started sailing everone said how dangerous and terrible sailing qualities multihull sailboats were until I sailed a couple and they were great leaving the monohulls in the dust both up and downwind. After that I just ignored a lot of experts and just looked at facts showed me the error of following the crowd when it's wrong.
Jerry, as William alluded to in his post, the cause of the weight is its ruggedness. For a miliatry application this would go way beyond what you would expect for commercial or industrial applications. It's not just off-road. It's WAY off-road and pretty much needs to be built for, or have add-ons for, the most extreme environments imaginable. All of this adds weight.
I had a similar thought when looking at the description and the picture. I like the variable speeds and load following features, as well as the towable off-road ruggedness. It looks like a good candidate for mountain living.
The challenge of any generator system is not just in making it lightweight and efficient, but more in making it durable and reliable. The abuse of being hauled off road must be seen to be understood. And the abuse suffered while "running under fire" is a lot worse than that. IT would be interesting to see another photo of that system package after one mile off-road at 45 MPH.
The sad reality is that, just like race cars, reliability is vital, and a broken generator is not very useful. And unfortunately, most of the time durability equates to more weight.
The question is why it even weighs a ton much less saving 1.5tons!!?
A 150HP alum diesel, a 3ph 100kw alt/ ACProulsion EV motor/ inverter and a 10kwhr, 200kw peak A123 Litium battery pack would weight 1200lbs and use 50% or less fuel using stock componants on am alum or composite skid/casing available 15 yrs ago or more except the batteries .
The first thing that caught my eye in the image attached to the article was the use of modular aluminum extruded structual members. While these are perfect for a prototype, one has to think about how much they contribute to the 1.5 ton weight savings. Would a production generator of this design use aluminum for its support structure (Not just modular elements as shown, but purpose-built structure)?
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.