ah glad i am not the only "hoarder" here then - i have a whole load of useful "stuff " tucked away for future projects
well a slightly different take on this is my system - i started out with rain water harvesting to run the loo ( saves a fortune ) and it went from there
it all started when the water meter got installed - and the biggest use was loo flushing - soooooo - a few rain barrels and a small pump later + finally a use for some gel deep cycle batteries from my mobility scooters that ,whilst no good for driving them , work just fine and hold their charge well in low draw situations ( scoots take a high draw and last about a couple of years of daily use - but "retired batteries " will still give good service - i have a couple of 10 year old ones that are STILL going reasonably strongly )
well it went from there - 3 x 12 w solar panels ( again maplin specials ) - a 6 amp charge controller or 2 and some others for things like reading lamps here and there , and i ended up with the plumbers and electricians nightmare that runs quite a few things here now - ex mobility scooter batteries are regularly "donated" to me , and a lot of times they are fine - given a little TLC

- so far only 2 have been declared U/S and recycled
current amp /hr capacity is approx 1550 in total - + 600 lts of water storage , but hope to upgrade this if i can find a 1000 lt IBC at a good price ( for our long summers

)
trouble is it becomes addictive

- and if one can manage with out wanting to run 'HI draw " stuff - quite do'able too for not a lot - certainly lighting for area and emergency use is possible - as well as small computers etc
one things for sure if you have an "inventive" bent - and are not too worried about the "look " of things - then this is the way to go - start small - and have fun learning as you build up your own system - no doubt a few "experts" will differ with my opinion - but then when have I ever listened to them
if it does what YOU want - then what the heck ?? - works for me