At the moment Elon Musk is creating a factory that will have a large amount of its processes done through automation. On top of this as the roof will be covered in solar panels, alot of that will also be powered by renewable energy.
I can see alot of parallels in the mission of Huel, and that of Elon Musk, put shortly, a sustainable future.
Take all the components of Huel, find a way to produce it all in a single location, through as much automation as possible and with as much of the energy being used coming from renewable sources.
It would almost be like the GigaFactory meets the Eden Project.
On top of this, with drones and self driving vehicles around the corner, even delivering it direct to the customer can have improvements made in the way of CO2 emissions.
If this was done, not only would it greatly improve the carbon footprint, but the production costs would be reduced, thus reducing the cost of huel to the consumer making it accessible to even more people!