Have not used them. It looks like most manufacturers now manufacture a line of them, a lot of advertising wank, and claims being made, I have looked at the specs,and do see a advantage over lead acid in stationary aplications where infrequent charging, or not full charging is typical ( key word.. typical) but that's not a homes battery bank typical condition, or I should say not for Alberta or Saskatchewan just no excuse for not having enough panels in these two provinces.
Also that advantage under deficit charging conditions comes with a price.
I see its use more in industrial application, telcom, remote oil lease sites . It will work of course for home application, but I myself will be sticking with simple flooded lead acid, though I am impressed with LiFePo4 composition and the price is falling, I do believe that's going to be more cost effective than lead acid long term (over 20 years)...it may be now I haven't checked prices lately. Even if it is I will still be sticking with lead acid for my main bank, but I likely will add a second small back up bank of LifeP04 in about 2 to 3 years from now, and use this back up bank in place of a generator(or to cut down the use of) for the winter months of Dec and January.
Wallet capacity, and what you use, amphr wise is also a determinant factor in battery selection.
Just wondering what is your daily amphr needs?

I do not yet have to buy, still have a few years, so I also am waiting to see how the chemistries evolve - I have time to research, and I figure there is going to be something excellent, with the push to electrify personal vehicles.

LifePO4 looks good, Tesla's new 2070 cell is getting a lot positive press (80% capacity after ten years complete daily cycling). If the bank account swells enough, NiFe has the longevity I seek, but lacks the charging capacity (unless I go huge). I looked at the price of a Powerwall not long ago, looked like the best deal, based against time, but an acquaintance of mine tried to get one, they coudn't be bothered to respond to his inquiries -shrug-, not sure I can count on them to supply some to me.

As for storage capacity/AH needs, I'm designing for minimal personal consumption, but again, if finances allow, I'll get as much storage capacity as possible. One of my main reasons for a large bank is the ability to take a hard charge. Until I found PbC batteries, a moderately-sized 48V LifePO4 was the only thing capable of taking all of my potential generating capacity (7.3kW). I'm thinking there will be times when I may have one good winter day of sunshine separated by long stretches of cloud, so want to capitalize on it.

I guess my priorities are longevity, (dis)charge capacity, then storage capacity. I'd probably mostly just skim the top in summer, but really, my tendency is to consume everything I make LOL, so I'm sure I'd find other uses for any excess. My bigger concern is winter, fewer & shorter sunny days, greater need for power. I could probably make do with a lead acid bank, but I really really really want something that is going to last. PbC kinda looks like the right compromise between lead-acid and LifePO4.

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I'm thinking there will be times when I may have one good winter day of sunshine separated by long stretches of cloud, so want to capitalize on it.

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Yes you can be certain of it. The technical name for that long stretch of cloud is called "December"

This array at nait has been up since 2012...I keep my eye on it and it roughly matches what I see south of that location.
https://enlighten.enphaseenergy.com/pv/public_systems/EwPs64809/overview

If you go to the calendar at the bottom left and click it it will show you production by day, months and years back on a day by day basis.
From memory I think each array (left and right) is 1500 watts so 3000 total.
You can absolutely beat their production numbers in the real world ( as you would not use angles of 14,18, and 27 (if you care about production), also the right side isn't swept clear of snow in the winter) so consider these numbers to be poor under winter conditions, a real 3000 watt array fixed at 60 degrees or better would beat their numbers but they use this array for gathering data on production at different angles even if they are not the best for our northern location.

This site has a better break down on production by side ( swept/unswept) and by individual panels, Though the data is poorly laid out IMO...
https://data.edmonton.ca/Environmental-Services/City-of-Edmonton-NAIT-Solar-Panel-Reference-System/9dz3-sqyw/data

Just checked and my memory was wrong its 1380 per side for 2760 watt total.

Good data, it'll take a bit to wrap my head around the presentation. I've been trying to rationalize 2D trackers, but I think I will overgenerate with my panels at fixed angles, as it is LOL.

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Man, there are some pretty lean days (City data) around winter solstice LOL. OTOH, that is a poorly optimized panel placement, if one were positioning for maximum power. It looks like the NAIT data is per-panel, which would yield some interesting numbers, but like you suggest, the data is not displayed for general consumption.

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Well I have been giving this some thought as the day will come when I need new batteries. So I have been looking harder at these, and as best I can tell, yes carbon as added changes batteries characteristics, but too the degree of their claims, lets just say I am yet to be impressed.
I looked over the old standard t105 series as its characteristics are so well known and due to the volume made often the best value dollar wise.
This is the data sheet http://www.windandsun.co.uk/media/172100/Trojan-T105-datasheet.pdf on this sheet what you want to look at is the graph of TYPICAL CYCLE LIFE IN A STATIONARY APPLICATION at the bottom of the page.

Note the T105 at 20% discharge will give you a lifecycle of 3000. I am going to use 25% discharge here just because that's How I recommend people size there system, for 25% daily discharge of capacity of their bank, and on that battery it comes in bang on 2500 cycles so that works out to 2500/365 = 6.85 years. I will just round up to say 7 years

The T105 RE with "Carbon Technology" http://www.trojanbattery.com/pdf/datasheets/T105RE_TrojanRE_Data_Sheets.pdf
looks to be 3300 cycles on the graph to a daily discharge of 25%. So that's 3300/365= 9.0 even years.

In the real world you can beat both those time frames, but its another topic. At first glance that looks good, two batteries, same size case and the Smart carbon one, used the same way as the first, clearly has two more years of life in it. I believe them that it does, I do not question this. I question the marketing of their "smart carbon technology" as the reason. I admit it sounds like a break through, a researching/manufacturing achievement...right?
Maybe more like a marketing/sales achievement if you ask me.......
What I discern from the data sheet is that that the regular T105 comes in at 62 pounds and the T105 RE "smart carbon" comes in at 67 pounds. Was it the addition of "Smart carbon technology' or the extra thick plates containing 5 pounds more lead that led to the longer battery life?? I bet you can charge a whole lot more for "Smart Carbon" TM, than extra lead. Just my thoughts, they have battery lines above the T105 series with thicker plates and the better performance that thicker plates provide, that's a market that is already developed. I could be all wrong of course. So far it looks like I will be staying with regular FLA batteries (t105 clones) and just to give you a idea on the cost effectiveness off them, The quote I got on replacement (3 month ago) was 155 dollars each x14 so that's 2170.00 and I expect 8 good years+ one ok year( maybe squeak out 2 ok years), out of them so going just with 8 years ( at 6 now) that's just 271.00 dollars a year, using up to 5kwhrs a day from my batteries, (Unlimited after the batts are charged and the sun is out) I weld, grid, run Air compressors, chop saws, electric chain saws you name it, house lit so bright Stevie Wonder could see in it, .....if you visited you would be unable to tell my house from any other.
Whatever technology comes out I wont be looking at it unless It can beat the performance (costwise) I am already getting. Tell me what price did you get on one of these carbon batteries, tell me the price and model (so I can look up the amp hrs) and I will crunch the data to see what it will cost me per year to use them....

In my looking at these new type batteries and by that I mean the addition of carbon, ...and why?..Pro tip here....., always ask Why?,And then ask it again, (unless your a scientologist, I haven't offended them yet have I ??) as proper lead acid construction has been around and its characteristics known for over 100 years, I kept thinking why?, and beyond just marketing and more money....
The trail lead to me to a newer international testing standard for RE batteries, IEC 61427, It turns out that PSOC (Partial state of charge) is now a major component of the testing of RE batteries, and the addition of carbon helps under PSOC and under the elevated testing conditions of 40 degrees C, (which is BS).In other words this "carbon" addition is really just to meet better contrived specs. Once manufactures did what they could to get better ratings regarding this contrived spec, thier marketing department took over to see if it could be turned into a value added feature to flog!! Extra lead and carbon helped meet this spec, weather this is something you wish to pay for is your business, as for myself I am happy at paying about 22 dollars a month for power( or less) with 100+ old lead acid technology.YMMV

I know little about solar heat and electrical storage. There is a push here in Nova Scotia towards solar power. It all seams a little mind boggling...

How large of a system is reasonable for a 1800 sq ft home? I assume batteries are stored inside the home to keep them warm. Is there maintenance involved and how large of a bank is required? I assume that the solar power is tied into the main panel in the same way as the generator.

Is this usually done in stages to supplement the grid. I know some start by just having their water heater done by solar. What do you guys recommend surrounding type/make/size of batteries/panels?

Hey Peppercorn, youv'e really delved into it! I have to admit, my focus has waned since originally posting this, I've barely kept up on emerging chemistries. My recollection was that the C-rate on PbC, both in & out, was much higher than FLAs. One of the facets that appealed to me was a bank's ability to take a hard charge quickly.

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I know little about solar heat and electrical storage. There is a push here in Nova Scotia towards solar power. It all seams a little mind boggling...

How large of a system is reasonable for a 1800 sq ft home? I assume batteries are stored inside the home to keep them warm. Is there maintenance involved and how large of a bank is required? I assume that the solar power is tied into the main panel in the same way as the generator.

Is this usually done in stages to supplement the grid. I know some start by just having their water heater done by solar. What do you guys recommend surrounding type/make/size of batteries/panels?

Cant really comment on the push in Nova Scotia, I assume its like in Alberta where it is grid tie that's being encouraged/pushed, that's a different animal and I cant really say more on it other than its not for me, I like having no connection to them at all.
Size of your house has nothing to do with it, its largely based on your consumption measured in kwhrs, and that may or may not mean what you are using right now, but rather what you can bring it down to and still live the way you wish.
For example in alberta I have read the average daily consumption is 20 000 watthrs or as expressed on your bill 20 kwhrs (a day) that would take a bank of batteries (using them the way I do to 25 % discharge) of 80 kwatts My bank is 20kwatts giving me 5 usable, so you would need a bank 4 times as large, or nearly 9000.00 dollars in t105s, but because the usage is so great you really cant/shouldn't use t105s you need much heavier plate construction for this higher demand, so this will now bump you up into a much more expensive class of batteries , I would ball park a figure of maybe just your battery costs going to 15 Thousand, maybe more, could be 20 000.
the good news is as you should see is that costs rise exponentialy with consumption but the reverse is just as true if you reduce your demand.
Reducing your power demand is key to getting everything into the reasonable cost range. The list you can do is long but for brievity I will just mention a couple....electric stove, I cant be exact, because questions of cooking for how many people, and frequency of oven use determine actual use in each house hold, but in my experience changing from electric stove to a gas stove will save roughly 6kwhrs a day or more, Switch from a electric hot water tank, to on demand propane, and again this is determined by how many people using hot water but I will guess on the conservative side for two people and say a 5Kwhrs a day savings. Then changing the way you heat, a forced air furnace with a typical blower motor of 1/4 or 1/3rd hp in the winter could be consuming around 3.5 kwhrs a day (gessing 30%DutyCycle) there is ways to change that, not for now though as I have to get to bed...my point is change just these three thing and you can knock 14.5kwhrs off your power demands easy. 20-14.5= 5.5kwhrs a day this now puts you as a prime candidate to go off grid. Got to get to bed.

So I recommend not panel or batteries at this time but reducing usage first, and that may mean new appliances. Some new 18 cuft fridges are now at 320kwhrs a year ( .877 kwatthrs per day), I just seen a new 10 cubic ft chest freezer at Pevey mart that uses 220kwhrs a year (.6kwhrs a day)
These are very, very good figures.1.477kwhrs a day would cover a full size fridge and large 10 cuft freezer.
Once people get serious about reducing power usage they find lots of ways to reduce and it does not have to come at the expense of comfort.

Thank you for your thoughts Peppercorn. Your approach seems practical, It requires a rethink on the way I've come to use electricity in my daily life. Great information!

Wayne, as luck would have it this add came on kijiji today and damn if it isn't just what I said would be needed to run a typical home in Alberta (80kw battery bank) (that hasn't engaged in power management) thought you might find it interesting
https://www.kijiji.ca/v-home-outdoor-other/red-deer/portable-solar-generator-battery-storage-seacan/1336519005?enableSearchNavigationFlag=true

Its all self contained complete with a back up diesel generator, a split phase inverter...nothing to go into your home its all in the 20 foot container, the power cable would just be hooked to your yard pole or at the service entrance to your house.
Of note in the picture and video, I believe only half the battery bank is uncovered, I think it extends under the plywood so in reality the actual bank is twice as large as can be seen, and I don't believe those are lead acid, rather AGMs, so even more dollars than my first guess. I suspect AGMs because the unit is portable and they don't want to risk acid spillage that could occur from lead acid batteries being moved about., but the cost must be nose bleed high. They don't have a retail price in this add, but I cant imagine it less than 60,000, I am feeling around in the dark, it could be a lot more, I just don't know for sure.

I can tell you this, the cost of just the batteries make the way I suggest starting with a few new appliances look down right cheap but this is for someone who doesn't want to do that I guess, some people in Alberta have a lot of money sloshing around and I bet they don't have a problem selling these.