Vanadium batteries

[nedskelly]

This is on Facebook, looks interesting, sounds expensive but may be OK in a couple of years
http://www.abc.net.au/news/2016-12-08/v ... ge/8094376

Gary

[bagmaker]

from the link -'Its claimed the batteries have a longer life span than lithium-ion versions and store at least four times the energy."
Compared to size or weight I wonder...

[T1 Terry]

These are just the same old Redox flow batteries first put forward by someone from the NSW uni back in '67..... might even be the same person because it was a female that first came up with the idea.
The whole tale is a load of spin with a ton of facts left out. These cells need to be totally discharged after 4 days use to strip the metal build up from the membrane or the cell becomes non functional. This means a min of 2 units are required for off grid storage as one unit needs to be discharged into the other unit every 4 days so there is still storage capacity available. The full loop efficiency is less than 70%, lithium is 99.9??% Each one of these storage devices is quite large, I've heard of them being compared to the outside unit of a split system air con system but having seen one in the flesh I've never seen an air con unit that big, you really need to see one to appreciate just how big these things are. They require a crane to lift them into place, that heavy, they can not be moved while operational, they take 72 hrs to heat up enough to come on line yet they shut down if they get too hot, forget about summer in a heat wave. They have one set up at the old "depot" in Adelaide to power a computer set up on the upper levels.... you guessed it, the whole affair was off line during the black outs
As far as a longer life than lithium batteries.... what part? There are pumps and electronic circuit boards and exchange membranes and the actual fluid itself, it all needs to be refreshed on a regular basis. It's a bit like the great grandfathers axe, still the original and has had 30 new handles and 5 new heads. As yet no one has actually exhausted an LiFeP04 battery when used as a house power battery so what do they use as a yard stick to determine the actual life of a lithium battery to be able to claim another battery will out last it?