Just found
Iron-Edison who sells Nickel Iron Batteries. These are far superior for Solar Applications, but at the time I was buying I couldn't find a supplier. Obviously someone else found the same thing an decided to fill that niche ( Yea Capitalism!) They import the batteries from overseas.
The main downside of Nickel Iron Batteries is the Size and Weight.. Otherwise they can be charged faster than Lead-Acid, they can be safely discharged to a (much) greater amount with no damage, and will basically last forever. There is really no point in the future when you would have to buy new ones
So to give you an idea: I have a 48V set of 800 Amp Hr Hup Solar one Batteries. They may be discharged to 80% 2000 times and will last with monthly watering for 20 years. Normal discharge needs to be no more than 20-30% if they are to last - meaning I have an effective capacity of 170-250 Amp Hrs on a daily basis ( 170amps*48V =8.1 KW-Hrs) and can use 4X that in a pinch, if I am willing to sacrifice battery life to do it. Charging emits H2 gas which must be vented, and I can suffer from sulfation and other problems unique to Lead-Acid batteries. They use 8.6 Square feet of floor space ( 24 inches high) and weigh 2968 Lbs, and cost in the $12K range. (yeah, I know..) (8KW-hr is enough to keep some lights on and run heating fans, freezers and fridges for a day.. with PV Solar, the idea is that the solar handles the Daytime loads, and the batteries are just there to get you through the night.. so 8Kw-hrs is usually more than enough to get you through a night till the sun comes back up and recharges the batts and gives you power for other stuff. Totally off-grid people always do laundry during the day
)
The Equivalent 800 Amp hr Nickel Iron system from Iron Edison would cost $30K. It would use 31.8 sq feet of floor space ( 2 feet high) ( they sell a rack.. to double stack them..) and weigh 5280 lbs. (wow) But because I can safely discharge them 80% without damage and forever, they have an effective daily capacity of 645 amps-- or 30KW-Hrs. Enough to run a house for a day and then some. You probably don't need that unless you want it for Backup purposes - and even then its probably more than you need. (average house will use 15-20Kw-hr a day) So if you size this for 8Kw-Hr of back up and plan to discharge to 80% - you need a 200amp-hr battery- NOT a 800 apm h-r battery. Granted I have the option with the HUP Solar One batteries to run for 4 days that way. But if you sacrifice that, a 200 AmpHR Iron-Nickel battery will work
A 200 Amp Hr Nickel-Nickel battery will run you $8000, use 7.4 feet of floor space (18 inches high) and weigh 920 Lbs. AH. Much better.
However, I suspect that because the batteries are not manufactured inthe United States, they are not eligible for the RE tax credit.
They also seem to offer decent discounts in their
package deals ...
Of particular interest to those here should be the
small generator alternative for $3.3K. Its expandable, has 100 Ah of Nickel-Iron battery storage, and will produce 1kw-hr of power over the day. So 80% of 100 is 80 Amp-hrs*12 v= 960 or just under 1Kw of power.. so the panels are sized to recharge the batteries and not provide a lot else. Its basically a 1000 Watt, fuel-less generator.
For those of you with the small cabin or RV plan..
check out the 12 v package for $6.8K -- 12 V systems MUST be located very close to the Inverter and batteries to prevent significant power loss in the cables. 300 amp-hr capacity Ni-FE battery and 2-2.5 Kw-Hrs of daily production. This can also directly power any 12V systems you already have in the RV... you have 2.8 Kw-Hrs of storage capacity. Again the Array is sized to recharge the system, and not power provide power over that.
But you have a house - check out the
Freedom Package ( their packages are named freedom, independence, patriot.. I notice a pattern.. either they are preppers themselves, or hey did some market research and know who is buying these bigger systems.. but I suspect the former. You only care about the batts lasting forever if if plan to deal with a situation where you can't replace them)
The Freedom Package is a Grid-tie with backup - so you can still keep your connection to the grid, but you will not loose power during an outage ( most people don't understand that grid tie means your power STILL GOES OFF even if the sun is out..) It will produce 8-10Kw hrs a day - what most would need for "emergency" siutations - to keep freezers, fridges and fan running, as well as some lights, and small appliances. Batter is a 300amp-hr at 24 Volts, so about 5.7 Kw-hrs of effective storage capacity. This is the smallest system I would suggest for a Home's backup power and it will set you back about $15K - some portion of which (at least half I would expect) will be Tax Credit deductible. --
For a totally off-grid cabin look at
The Independence Package for $28.5K - this is a full 48 V system ( the type Telcos and other industries use) with 400 ah-hr battery backup.. so 15 Kw-hrs of battery capacity. Enough for a day of backup in most homes with no battery recharging ( the sun don't shine) - and if you use a minumum of power that should keep your fridge, freezer, heater fans and pumps running for 2 days... Its a 4000 Watt array so between 16-20Kw-Hrs a day - enough to run most normal houses. The equivalent Grid-Tie package is
the Patriot Package and runs $31.5K and yes, this is pretty tempting to me. Govt tax break would be at least $8K on it. ROI is bad but not as bad as you might think.. over 20 Years, with the tax break, you are looking at about $100 a month. What is your electric bill now? The system will last more than 20 years.. just not producing as much, and you have power - no matter what - over that entire span.
However I prefer Outback inverters (the Cadillac of the industry) - largely because they offer automatic gas/diesel/propane/nat-gas generator backup and they are a really tried and true product. And oh, lookie, they sell one...
The Outback Ni-Fe package runs $42.5 K and its the closest to what I have installed, bu it uses slightly higher capacity panels ( 24 of them) and the newest Outback inverter. It has a 6000 watt array ( 24-30 KW-Hr ) daily production, and can provide over 8000 Watts of power through the inverter. (my current system can do 6000) - and has a 600 Amp-Hr 48V battery for 23 KW-Hr of battery storage (this is getting really close to being able to provide my 4 days of backup I have with the HUPs discharging them to 80%) But yeah, its $45K by the time you get all of the other materials and have it installed... .. I would probably ask them for a custom package price with a smaller 300 amp battery and maybe only 4000 Watts of panels but maybe not- once youstart running pumps 24x7 for aquaponics, you want that extra power.. .... But yeah, this is the one to get if you have the funds. More than enough power, on or off grid, and it will last a good long time. At least 20 years at full capacity and then diminished capacity as the PV panels age.. As A ROI operation, this still sucks - with tax breaks its still over $150 a month over that 20 Year span. ( but conceivably it will go longer than that..) but still, that is the price of energy independence, and the writing is on the wall - Your electricity charges are going to go up and up during that 20 years.