My original post was not intended to suggest that the MOD would go green, but that petrol/diesel engines might become rare, for example Volvo going pure electric.
So long as the fundamental issues with batteries remain unsolved - energy density, recharge time, weight - the demand for IC engines won't go away. It may well change, and the source of the fuel will likely change to something bio based (while the concept of peak oil has been horribly overblown, the bottom line is that fossil fuel
is a finite resource and eventually we'll run low). But imagine the battery you'd need to drive a huge ship across the Pacific, or a 50 ton long haul truck/lorry coast to coast, or a large airliner halfway around the world?
It'll change - likely in ways none of us foresee - but unless someone can invent a battery with similar weight, energy density, and refuel times (or perhaps a fusion reactor that is the size/weight/cost of a comparable liquid fuel engine), the demand for liquid fuel engines isn't going to go way.