Virus Batteries

"The speed and relatively cheap cost of manufacturing virus batteries could prove attractive to industry."

I am having trouble getting my head around this one. I just can't believe you could actually use viruses to make a battery and the thought they can actually make a car battery is extraordinary. We live in strange and amazing times. This whole article is fascinating but it completely does my head in. They say the viruses are harmless to humans..but are they? How do you get power out of a virus since they normally get into your system and do it in. These viruses do the opposite. It just challenges my whole notion of a virus. It seems like a fantastic idea though and it is about time we moved on from the industrial era.