[@Lucius Cypher]
[quote]Again, why would his aura not be even distributed if he has a specialized organ made precisely to distribute aura through his body? If his aura isn't evenly distributed through his body, then he couldn't move it in the first place. Aura is effectively his blood, and it's the reason why EMP's are even effective against him since they fry the circuits his aura can flow through. Gren's power source is suppose to be able to allow him to distribute aura throughout his body evenly, both for the purpose of making it function as well as protecting him. The idea that it's not active all the time or unevenly distributed means that he's either turned off, or a part of his body isn't working i.e. is broken.[/quote]

That is a bunch of technojargon to justify your argument there is absolutely no reason why his systems would have to function in that manner. The real problem is that if machines made to manipulate and use aura in such a manner exist for Gren who's machines are all at least several years old then they should exist fairly standardly in the show in a mundane setting. Hunters could use this tech to increase there aura output, hunter weaponry should include these devices to increase how well they can be used as aura conduits, the power companies should be able to use it in their industry. You've made a very clear point of the fact that Gren's tech is old and outdated. Which means it should be fairly widely available if not on the open market then on the underground ones for those with money. Yet there is no evidence of that. It is much more logical to assume he runs off something much more standardized. 

[quote]Plus a clean power source, even an electric one, would require even more advanced tech then simply being powered by aura, which we can at least assume doesn't have any sort of byproduct. Sure he does need biofuel for his thrusters and his extra electronic bits like his built in phone and camera uses electricity, but those could be safely disabled/their power source removed without affecting Gren's ability to function. At worse he looses mobility, communication, and perhaps the ability to make his helmet cover his face at will. Otherwise we'll end up back to that discussion with the fusion core since apparently he's now running off some sort of engine or fuel that is small enough to fit inside his body but has a power output strong enough to power him indefinitely, especially considering the sort of feats of strength and endurance he preforms.[/quote]

Also no reason to assume that a clean renewable energy source would have to be more advanced than their aura manipulation technology which we have seen two examples of in the show both of which have been kept very secret and by all indications are new innovations. 

Atlus has had a certain type of police android that was recently replaced with a newer model early in the show. It is not unreasonable to assume they have been around for years and have just such a power source. A police android that runs out of power during the course of its duties would not be very effective at what it was designed to do.