Yep Because I refer to the efficiency to manufacture...

Yep
Because I refer to the efficiency to manufacture electricity.
ie : Mining, processing, shipping, manufacturing logistics , erecting construction , harnessing and storing renewable is extremely inefficient way to produce electricity.
Fossil fuels have already been harnessed processed and stored by nature . Thats about as efficient it can get. ;o) Merely dig it up and burn it....

So is it a good investment to get into battery storage? Well hell yes - Because the Big Corporates are telling us its the way we are going and governments are funding this idology with more of our taxes - so get on board. You cant stop it - so work with it.

Therefore if all this wind and solar is to be the future - it wont work without batteries. LD batteries, large capacity storage batteries is the key.

Yes its a good investment Matt DYOR though ;o)