In my experience with off-grid electricity, it seems that energy storage is the most expensive and troublesome part of the whole thing.
The conventional wisdom is that good old lead acid batteries are still the most cost effective solution, and that AGM batteries are nice for a low maintenance solution if you are willing to pay more.
All of that works out pretty well, until I have about 3 or 4 days without sun. Then, I start to see that I need a bigger battery bank. But the batteries I have are already the most expensive part of the system.
I wonder if there is any sort of DIY solution to drive down the cost of energy storage?
I also wonder about other technologies. Dave recently posted this link in another thread for a different battery technology..
Have any of you tried anything like this?