One can buy a 300 amp hour battery for anywhere between $100.00 and $500.00. The discrepancy in quality can be greater but I choose not to think about it beyond $500.00. Makes my head hurt.
You see, I have a 48 volt system and no ‘ordinary’ battery comes with more than 12 volts so I have to marry up four batteries at the very least to get 48 volts. And 12 volt batteries are the lightweights of the battery world. They are the ‘disposables’. If you want ‘hardy and durable’, you drop down in voltage. A 6-volt battery of similar weight to the 12-volt is twice as long lived. And you’d need two of them to replace the 12. Ergo, if you follow the logic, two-volt batteries are the best.
Add deep-cycle to the specs and maybe a few hundred more amp hours and one can easily spend the $500.00 on one battery and have only 1/24 of the batteries you need to fill out a 48 volt system. Do the math – that is $12,000.00 for the right batteries for my system! And I know that one can spend double that quite easily depending on the size of your amp-hour capacity.
For a really good, heavy duty, long lived, guaranteed, 2-volt based system for a house our size at say, 1000 amp hour rating (modest), you can easily spend $20,000.00 not counting HST. That batch of bats would occupy the space of a small bathroom and require proper ventilation and insulation and monthly maintenance (not because they really need monthly maintenance but rather because one feels the need to fuss when one has spent that much money on batteries). They would last maybe twenty years.
I mention all this simply to vent my spleen. I need to get it out, to share, to vent my gases, as it were. You see, the bats are just, maybe, (depending on how committed you get to the amp hours and the quality of the bats in the first place) not even 33% of the cost of the electrical system. After you build the appropriate buildings to house everything, add an appropriately sized diesel genset, the right electrical interfaces (inverter, charge controller, panels, etc.) wire, attachments, solar panels, wind turbines and towers and a simple off-the-grid system can easily top $50,000.00. And all that is before you get to wiring the actual house!
Living off-the-grid is not cheap electrically speaking. Not really. Who woulda thunk it, eh?
But let me reveal the most salient point: it is well worth it. WELL worth it. Would I pay an upfront cost of $50,000 vs a minor urban monthly hydro bill of only $300 to live out here? ABSO-bloody-LUTELY.
Who woulda thunk that!?