Alright, I've fucked around and added Petrusite consumption to naval vessels (I won't bother for ground troops since the amounts involved are minuscule compared to your production and naval consumption). I'm counting Petrusite and Irradiated Petrusite together as it gets really annoying to do them separately. It's still a work in progress, so the values might change as I take onboard people's thoughts and people create increasingly larger ships.
In short, though:
Helghan currently produces 1,000,000 tonnes of Petrusite per year.
Helghan naval vessels consume a flat amount of Petrusite per month which is determined by the formula M/50 where M is the total mass in tonnes of all the Petrusite-using components on the ship. This is then multiplied by 12 to get the yearly consumption per ship.
For example, the Noctis class has 48 arc cannons and 20 Improved PTCs for a combined mass of 57,720 Tonnes of Petrusite equipment. Per month, a single Noctis consumes 57,720/50 (or 1,154.4) Tonnes of Petrusite, and per year, it consumes 1,154.4*12 (or 13,852.8) Tonnes of Petrusite. Your Petrusite use is currently minimal as you've swapped out your Petrusite powerplants for fusion ones. Without that, the standard Hasta would consume 2,640 t/month (31,680 t/year) compared to its current consumption of 0 t/year.
As an aside, I'm considering adding Petrusite powerplants for naval vessels to encourage you to fuck around with creating expensive but incredibly powerful ships.
Edit:
I've updated the Naval sheet on the OOB page to have the latest data. If you spot any errors, let me know and I'll double check them.
Helghast Order of Battle: Doctrine: Super-mobile blitzkrieg doctrine based around deploying divisions via ship-based dropships and cruisers. Navy...
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