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Small Cabin Forum / Off-Grid Living / Off Grid Solar at $0.16/kWh
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electrodacus
Member
# Posted: 25 Mar 2015 16:43
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Hi All,
This is my first time for me on this forum.
I think I got your attention with that title
That 16 cent/kWh is a bit misleading because that is the amortisation cost for all the equipment but not for installation.
I moved offgrid about two years ago and I was searching for solutions to power my house.
Solar PV was an easy choice but battery was extremely expensive (I'm not referring to initial cost but at amortisation cost).
My house (also build that one) is small you can even call that a small cabin is 65sqm (700sqft).
It is also energy efficient so I only need an average of 80kWh/month.
So if I'm to take how much energy I will use over 25 years (the normal life of PV panels) then
80kWh x 12month x 5 years = 24000kWh

Now le me give you the total cost of my installation.
PV panels 3x 240W each is about $200 total $600
PV support made of 2x4 just $35
Wires and DC breakers about $100
*Solar BMS (SBMS4080) $179
2400W inverter $500 (only use this about 1h/day most things work directly from 24V DC)
Battery is a 8 cell LiFePO4 from GBS so 24V at 100Ah and the cost for this was $1200 about 3 years ago.
I will make a capacity test for the battery soon but if my expectations are right and I only have 5% capacity loss or less after 2 years of full time Off Grid use then I will need just another battery after 12 years to have 25 years life.

So total initial investment is
( $600 PV + $35 support + $100 wires + $179 Solar BMS + $500 inverter + $1200 LiFePO4 battery ) = $2614
But in order for this to last 25 years I need another battery and a PV support since is made of wood so another $1200+$35 in about 12 years.

So total expense over 25 years $2614 + $1235 = $3849

Now $3849 / 24000kWh = $0.16/kWh

Here is a 7 day energy production and consumption graph for my house at the beginning of February this year
7 day energy graph

SE Ohio
Member
# Posted: 25 Mar 2015 17:08 - Edited by: SE Ohio
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Nice setup. Where r u?

pizzadude
Member
# Posted: 25 Mar 2015 17:14
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Ah! Great 1st post!
I am prepping my "cabin" for a similar set up. Just purchased (3) 230w 24v panels for $570, yesterday actually.. Have my 3000w inverter, fused @250adc, with a 2000w backup I purchased for $100 months ago... I just couldn't resist. And I got my twin Honda ei2000s for even more power💪
It's nice to join up with like minded folks here. Sharing ideas, gaining knowledge. It's all good here bro.
Welcome
Cheers!

Nirky
Member
# Posted: 25 Mar 2015 17:33
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Hope you reach your Kickstarter goal. If you haven't chosen your LCD supplier, check out my former company: https://www.crystalfontz.com/
They can get virtually any kind of LCD display and modify it in virtually any way you require.

electrodacus
Member
# Posted: 25 Mar 2015 17:38
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I'm in Canada Saskatchewan is cold here but sunny.
Using mostly DC is an important saving.
In my case that 2400W inverter is a TripLite PV2400FC quite efficient under large load about 90 to 92% but when there is nothing connected on the AC is still using 30W a bit over 1A from the 24V battery
So 30W x 24h x 30 day is 21.6kWh just to have the inverter ON all the time.
In my case since I use it just when I needed mostly for electric cooking about 1h/day in average I only use 0.9kWh per month for the losses do to inverter + the inverter will last much longer and not need replacement.
Those 20kWh difference in my case is 25% of the total 80kWh so a realy significant number since that is just loss nothing useful except for some heat maybe
Same sort of savings I get from using a LiFePO4 that is well over 95% efficient vs about 70% for Lead Acid but that is harder to see offgrid since you will anyway have unused solar PV energy.
My battery is usually charged before afternoon in most days.
If you look at the graph there is quite a bit of unused energy because battery is limited and once it is full the rest is mostly unused.
Is quite well to see in day 6 when we when shopping so more than half the day PV solar was wasted since battery was charged and we where not at home to do some electric cooking or something like that to use the energy.
Here is a photo of the house that I build and battery
OffGrid house

electrodacus
Member
# Posted: 25 Mar 2015 17:47
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Quoting: Nirky
Hope you reach your Kickstarter goal. If you haven't chosen your LCD supplier, check out my former company: https://www.crystalfontz.com/
They can get virtually any kind of LCD display and modify it in virtually any way you require.


Thanks. I already have an LCD selected is 2.2" and 320x240 resolution.
On the last Solar BMS I used a monochrome 84x48 resolution screen and I barely managed to display all the informations on that.
The LCD need to be also quite flat to fit in my application the one that I use is 2.4mm and it also need to be serial SPI in my case since I do not have that many pins available on the microcotroller for a parallel interface.
But thanks for the link. It seems they have quite a selection of LCD's I will take a look to see if I can find something better.

Nirky
Member
# Posted: 25 Mar 2015 18:06
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No problem. They have a very active tech forum in which tech answers all related questions.

groingo
Member
# Posted: 26 Mar 2015 10:39 - Edited by: groingo
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Just checked out Eletrodacus's website http://electrodacus.com
lots of interesting information to be sure and we can never have enough of information.

creeky
Member
# Posted: 26 Mar 2015 13:29
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hi electrodacus. i have followed your build for some years now. since you started your home build.

your solar controller / bms for lithium. I am looking at 4 700 amp winston cells for my off grid home. i use about 2.5-4 kw daily depending on how much sun I get (1.5 when it's really dark cloud).

My record is 6 kw. and I plan to break that this year.

I use only 120v ac. I have a TBS inverter that has very low idle draw. And the electric fridge, microwave etc appliances are much cheaper in ac than dc.

So my question is how your bms works. how are you balancing your cells?

thanks. and welcome. I am very happy to see your lithium set up.

electrodacus
Member
# Posted: 26 Mar 2015 14:48
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Quoting: groingo
Just checked out Eletrodacus's website http://electrodacus.com
lots of interesting information to be sure and we can never have enough of information.


Thanks. I'm glad you found the information useful. You can check my youtube videos there are quite a bit more info there about OffGrid energy.
I will also be happy to answer any questions regarding OffGrid energy.

electrodacus
Member
# Posted: 26 Mar 2015 15:13
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Quoting: creeky
hi electrodacus. i have followed your build for some years now. since you started your home build.

your solar controller / bms for lithium. I am looking at 4 700 amp winston cells for my off grid home. i use about 2.5-4 kw daily depending on how much sun I get (1.5 when it's really dark cloud).

My record is 6 kw. and I plan to break that this year.

I use only 120v ac. I have a TBS inverter that has very low idle draw. And the electric fridge, microwave etc appliances are much cheaper in ac than dc.


You can see more details on my website about recommended PV size and battery based on consumption based on extrapolations from my own data.

I have 3x 240W PV panels a 24V 100Ah battery so 2.5kWh and my daily use when is sunny is around 2 to 4kWh but when is cloudy fro more days that drops just to essentials so 0.8kWh so I an have about 4 to 5 days of backup.
Out of that 0.8kWh 0.3kWh is the worse case I get from PV even in the darkest snowy day and difference of 0.5kWh I use from battery.
It seems you want to have a 12V installation with 700Ah battery that is 8.4kWh.
Not sure how sunny is at your location and how large is your PV array but based on 1.5kWh minimum even a 400Ah battery may be sufficient extrapolating from my data.
With LiFePO4 is good to keep the battery as small as possible.
If you are thinking about the Solar BMS then for 12V you will need to have matched PV panels so 32 or 36 cells PV panels only. The more common 60 cells and 72 cells only work with 24V battery.
There is no DC-DC converter for MPPT in solar BMS since I consider that obsolete technology if you are interested about the cost of energy. I have a video I think is the last one on my channel explaining this and some other obsolete technologies related to the low price of PV panels.
Here is a link to that video URL

Quoting: creeky

So my question is how your bms works. how are you balancing your cells?
thanks. and welcome. I am very happy to see your lithium set up.


The cell balancing is different from most other BMS on the market all things related to battery management are done by the ISL94203 chip from Intersil (you can take a look at they spec if curious).
Most BMS available on the market wait until the end of charge to start balancing the cells with relatively high current for sort period and each cell balance monitor is individual from the others so it only knows the cell that is connected to and start draining that cell when it gets to 3.5 or 3.6V
The Solar BMS will monitor all cells and as soon as a cell is higher than a user programmable threshold than others the cell starts to be discharged with a small current.
So even when the battery is at 40% SOC if the cells are unbalanced they will be balanced so there is a lot of balance time a few hours a day thus even very large cells 1000Ah can be kept in balance easily.
There is also an option to do cell balancing during discharging but that is realy not necessary.
Cells should be balanced at initial install (usually is purchased new they are balanced from factory) and the solar BMS will keep them in balance indefinitely.
This was a simplification the balance circuit is quite complex in the ISL94203 and there are tone of settings but the default that I will have there will work great.

Best regards,
Dacian.

creeky
Member
# Posted: 26 Mar 2015 18:40 - Edited by: creeky
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i have 2 1kw arrays. The panels are big 48v (57 voc). I can program my mppt ts-60s for lithium easily enough. (they have a new firmware upgrade. it is even easier to do custom programs now. the firmware upgrade knocked out my old settings. It took about 5 minutes to put my custom settings for my crown batteries back in).

my lead acid battery pack is now going into year 5. it was much better this winter as I kept it above 0C. But it's definitely a PITA. You lose so much capacity in the winter.

It's interesting to see you using nearly as much power as I do with a (in 12v) 200 amp hr set up. Nice.

How deep do you discharge your GBS batteries? Do you have a generator supplement?

I will take your advice and think about a 400 amp hr setup. I'm looking for a bit more power. kind of like 2 foot itis in boating. every boater wants a boat that is just 2 feet longer... thx.

PS-had a look at that ISL94203 chip from Intersil. Looks good. Good luck with your project.

electrodacus
Member
# Posted: 26 Mar 2015 19:19
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Quoting: creeky

i have 2 1kw arrays. The panels are big 48v (57 voc). I can program my mppt ts-60s for lithium easily enough. (they have a new firmware upgrade. it is even easier to do custom programs now. the firmware upgrade knocked out my old settings. It took about 5 minutes to put my custom settings for my crown batteries back in).


What sort of panels are those ? They are not standard 60 cells or 72 cells.
Must be custom panels. In any case is they are realy 57Voc it will not work with the Solar BMS.
That lithium setting on the TS60 is useless unless you have a separate BMS that monitors each cell and is able to send a signal to the TS60 to stop the charging when any cell gets above 3.55 or 3.6V


Quoting: creeky

my lead acid battery pack is now going into year 5. it was much better this winter as I kept it above 0C. But it's definitely a PITA. You lose so much capacity in the winter.


With Lithium batteries you will always need to be above 0C during charging.
But I have my LiFePO4 pack inside the house at comfortable temperature since they do not need any venting as Lead Acid.
It will be impossible for me in this cold climate to keep Lead Acid above freezing since it needs that external venting and outside temperatures are usually getting in the -30 to -40C.

Quoting: creeky

It's interesting to see you using nearly as much power as I do with a (in 12v) 200 amp hr set up. Nice.

How deep do you discharge your GBS batteries? Do you have a generator supplement?


I do not have a generator. There is good sun here even in winter. As I mentioned before I can have 4 days with absolutely no sun in winter but usually in one of the days I get a hour of sun or is less thick clouds so I had even 7 to 9 days of bad whether with no problem but there was a total of 3 to 4h of sun during those 9 days or a partially cloudy day
I discharge the battery as deep as it needs. Normal sunny days is about 30 to 40% DOD but if you look at the graph there are days where I use more than the entire capacity of the battery from the battery in the sense that battery gets charged and discharged a few times the same day to 30 or 40% DOD
When there are a few days without sun it can get down to 10% SOC (90% DOD) but there is no problem for LiFePO4 they actually like to be partially charged than fully charged they do not have any problem with sulfation like Lead Acid if not fully charged.

creeky
Member
# Posted: 27 Mar 2015 09:40
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ya. my panels are too much for you controller/bms. I plan to add a separate bms. Or buy a complete unit.

balqon has complete storage solutions.

and REC from Slovenia has a fairly inexpensive BMS

I'd be interested in your opinion of their solution.

In winter I have to heat my batteries. I originally built my camp for 3 season use. The batteries are in a separate building. I have insulated them (about r40 now) so they self heat to some degree. when it's -30 I put a propane radiant heater on them. PITA. I am thinking if I was to use LifePO4 I could insulate, close up and add a small electric heater.

I am always gobsmacked when I see the dod people run on their lithium batteries. 90% dod. A far cry from the 20% I try to keep to.

groingo
Member
# Posted: 27 Mar 2015 10:24
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In your video I saw you originally were using PWM controllers, in a nutshell what is your performance difference between your BMS controller and the PWM?

electrodacus
Member
# Posted: 27 Mar 2015 14:06
Reply 


I used those PWM controllers since I had no other option but they do not have a BMS and I needed to check manually cells everyday and take care they are not over charged or over-discharged.
I also had no idea how much battery capacity I had left.
I needed to power down the solar PV panel when battery was charged to not degrade the battery.
LiFePO4 do not like PWM and constant voltage charging.
So I was working as a BMS at that time not that much fun.

electrodacus
Member
# Posted: 27 Mar 2015 14:40
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Quoting: creeky
I'd be interested in your opinion of their solution.

I just seen this seems to be new.
But that is just a BMS in order to get to the same level as Solar BMS you will need to add a lot of other peripherals.
They do not provide enough information I do not see an installation diagram or pinout.
You will need a current shunt not sure what type it accepts but it can only measure the battery current not the PV current also. It also dose not have his own controller and display so it can not calculate the battery SOC extremely important since you can not know the SOC on LiFePO4 without energy county type SOC. The charge discharge voltage on LiFePO4 is almost flat. The battery can be 20% SOC or 80% SOC and you will have no idea. SOC is extremely important in offgrid.
Solar BMS is an all in one charger and BMS with all you need no external relays (they will not last long), current shunt and SOC monitor calculators.
If you add all that it will be more complicated more expensive and offer less information.
The Solar BMS is the only single device I know of that has everything integrated.
So all you need is the Solar BMS, Battery, PV panels and some DC breakers for secondary protection and manual disconnect capabilities.
You can not have the BMS separate from charger as all the others try to do (those are good for EV but not of Solar).

Quoting: creeky
In winter I have to heat my batteries. I originally built my camp for 3 season use. The batteries are in a separate building. I have insulated them (about r40 now) so they self heat to some degree. when it's -30 I put a propane radiant heater on them. PITA. I am thinking if I was to use LifePO4 I could insulate, close up and add a small electric heater.


You have Lead Acid now ? and you have that thermally isolated ?
LiFePO4 will not self heat since they are way more efficient may be even 99% in low discharge rate.
And if you charged them below freezing they will degrade irreversible by an effect called Lithium plating.
Solar BMS has external temp sensor input and can be programed not to do charging if temp below a specified value.
Discharging in colder temperature is not a problem but the capacity at lower temperature will be smaller (not quite as small as with Lead Acid) but still smaller.
I have my batteries inside the house I think that is the best place to have them.

Quoting: creeky
I am always gobsmacked when I see the dod people run on their lithium batteries. 90% dod. A far cry from the 20% I try to keep to.


LiFePO4 likes to be partially discharged and hates to be full charged sort of the opposite way the Lead Acid prefers.
LiFePO4 also has so many deep discharge cycles than you can discharged them to 70% DOD every day and you still have over 20 years of use.
Winston for example spec is >7000 cycles at 70% DOD
If you use a Lead Acid charger and charge LiFePO4 to 100% including the constant current phase and float then you reduce the life of LiFePO4 in quite a significant way. They hate to stay fully charged same for other lithium batteries.
As an example the most common Lithium battery that you have in laptops and cellphones LiCoO2 is normally charged at 4.2V CC and CV to get the max capacity possible that is more important in portable applications than battery life.
So at 4.2V CC- CV charging you have 100% SOC but just about 500 cycles life.
If you drop the voltage with 100mV you double the cycle life.
The best gain is at about 3.9V where you have just 65% of the original capacity but battery lasts 8x more (4000cycles in this example).
This 3.9V with LiCoO2 was used mostly in military energy storage applications that is why there are 3.9V protection circuits that people use now with LiFePO4 on those inexpensive and simple BMS but 3.9V for LiFePO4 is wrong and will damage the cells much faster than if used just at 3.6V ideal for this chemistry.

You still did not mentioned what sort of PV panels do you have are they DIY with 94 cells or so ?

groingo
Member
# Posted: 27 Mar 2015 15:20
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Creeky,

As far a battery heating goes as long as your battery shed is insulated well you can do as I did, pipe in the heat from the house to your battery shed, in my case I just use a retired power supply fan from a computer, draws 2 watts at 110 and keeps the batteries comfortable.

electrodacus
Member
# Posted: 27 Mar 2015 15:50
Reply 


Quoting: groingo
Creeky,

As far a battery heating goes as long as your battery shed is insulated well you can do as I did, pipe in the heat from the house to your battery shed, in my case I just use a retired power supply fan from a computer, draws 2 watts at 110 and keeps the batteries comfortable.


A Lead Acid needs external venting so is almost impossible to keep warm (you need more energy to keep it warm than you use from the battery)

With LiFePO4 is not a problem since no venting is required you can completely isolate the battery and use a low power electric blanket inside to keep the temperature at a set point.

I'm in to energy efficiency and with Lead Acid in my climate the energy needed to keep that warm and also do venting will have been much larger than what I will have used from the battery so electric heating will have been impossible.
And using heat from the house is also a bad idea in my case since is still energy and I'm not willing to use more energy to heat the battery than I get from it.
My house will be heated with electricity for PV panels so heating a vented battery will make no sense.
Having the battery inside the house with no need for venting requires no energy and battery is at the exact temperature it likes to be the most same as humans prefer

groingo
Member
# Posted: 27 Mar 2015 17:53
Reply 


Quoting: electrodacus
A Lead Acid needs external venting so is almost impossible to keep warm (you need more energy to keep it warm than you use from the battery)

With LiFePO4 is not a problem since no venting is required you can completely isolate the battery and use a low power electric blanket inside to keep the temperature at a set point.

I'm in to energy efficiency and with Lead Acid in my climate the energy needed to keep that warm and also do venting will have been much larger than what I will have used from the battery so electric heating will have been impossible.
And using heat from the house is also a bad idea in my case since is still energy and I'm not willing to use more energy to heat the battery than I get from it.
My house will be heated with electricity for PV panels so heating a vented battery will make no sense.
Having the battery inside the house with no need for venting requires no energy and battery is at the exact temperature it likes to be the most same as humans prefer


That may be true where you are but in the Pacific Northwest where winters are a bit milder is has performed very well, this past winter my batteries never went below 61 degrees and have performed very well, keep in mind my total energy use over 24 hours on the worst days was under 180 watts.

creeky
Member
# Posted: 27 Mar 2015 19:05
Reply 


sadly my batteries are in the solar shed 200 ft from any heated room. I will say that this winter I tightly wrapped my batteries in 3" of polyiso inside the R25 insulated shed and the heat they create charging and discharging keeps them between 6 and 10C. I also close the vent unless equalizing. Until we hit that -20 to -30 time; then it's out with the heater for a couple hours every other day. It's been over a month since I needed supplemental heat.

e.d. that's why I like the lithiums. as you say. i can wrap them in 6 or 8" of polyiso insulation and use an electric blanket. I've been looking for one of the old kind. the new ones use digital controllers and (i've been told) pulse on at a high amp and off. the old ones are analogue and draw a low amperage steadily. I'll run it off the genny if need be.

on thing about ontario. it's not actually that cold during the "bad" heavy cloud season. the coldest weather actually sees quite bright sunny days. so that should help.

finally: the best derate info I've found is 7% on the lfp. 25 to 0* (*could have been colder) C. that was from a source in australia. a far cry from 50% for lead acid.

noted: If I could put my batteries in a heated/vented location near my living space, as I heat partially with wood (free), the cost would be quite low.

electrodacus
Member
# Posted: 27 Mar 2015 21:11
Reply 


Quoting: groingo
That may be true where you are but in the Pacific Northwest where winters are a bit milder is has performed very well, this past winter my batteries never went below 61 degrees and have performed very well, keep in mind my total energy use over 24 hours on the worst days was under 180 watts.


180 watt is power so was that the minimum continues load?
That will be about 4.3kWh. Or is that 180Wh?
Anyway if winters are milder is not such a big problem to keep any battery above freezing.

Quoting: creeky
sadly my batteries are in the solar shed 200 ft from any heated room. I will say that this winter I tightly wrapped my batteries in 3" of polyiso inside the R25 insulated shed and the heat they create charging and discharging keeps them between 6 and 10C. I also close the vent unless equalizing. Until we hit that -20 to -30 time; then it's out with the heater for a couple hours every other day. It's been over a month since I needed supplemental heat.


LiFePO4 will generate almost no heat since they have much higher efficiency so you can not base you heating on batteries getting warm.
On Lead Acid at just 20% SOC efficiency can be as bad as 50% so half the energy will be heat and Hydrogen generation.

Quoting: creeky
on thing about ontario. it's not actually that cold during the "bad" heavy cloud season. the coldest weather actually sees quite bright sunny days. so that should help.


Yes that is true here in Saskatchewan also usually the coldest days are sunny.
That will work great for my Solar PV heating for the house.

Quoting: creeky
finally: the best derate info I've found is 7% on the lfp. 25 to 0* (*could have been colder) C. that was from a source in australia. a far cry from 50% for lead acid.


Yes derate is not as bad on LiFePO4 but if you charge them at any current when below zero you will damage them.
The damage will not be instant but you will be degrade the battery capacity every time you charge them below zero and in not reversible.

Quoting: creeky
noted: If I could put my batteries in a heated/vented location near my living space, as I heat partially with wood (free), the cost would be quite low.


No source of energy is free
I actually chose PV heating over, propane, diesel and wood/pellets because is the least expensive.
Even if you can get the wood for free you need to add in account the investment in wood stove and replacement every few years. On pellets the stove is quite significant cost and it will not last long.
Currently I use propane as temporary and that is about 5 to 8x more expensive than solar PV heating.

creeky
Member
# Posted: 28 Mar 2015 08:32
Reply 


A wood stove will rarely need replacing. The stove I'm using is 34 years old. But. I live in an area with plentiful trees. This is one reason my solar shed is 200 feet from my cabin and my arrays are 100 feet apart. To find sunny spots. Southern Sask. isn't quite so well treed.

I'm just starting on my solar heating. I built in some passive. I have a solar hot water heater ready to install. And hope to get to a screen style solar air heater (builditsolar) this year.

I hear you on the cost of propane. We had a cold winter and my propane costs were almost double my expected use.

How are you planning to use PV for heat. Directing the energy directly to resistance heaters? And for overnight some sort of "mass" storage?

electrodacus
Member
# Posted: 28 Mar 2015 13:18
Reply 


Quoting: creeky
How are you planning to use PV for heat. Directing the energy directly to resistance heaters? And for overnight some sort of "mass" storage?


Yes directly with resistive heaters embedded in concrete under the ceramic tiles closely spaced loops about 4cm apart.
There will be about 30 loops probably and a what I call Digital MPPT that I need to design and build and that will connect more or less of this loops so that I get the max power point.
The concrete slab is completely isolated and large about 14 cubic meters and at 10C delta can store 100kWh that is quite significant 10% of my monthly needs.
Now I heat the same concrete slab with hot water from the propane heater and I can have even a few days in winter without any heating with just a few degrees drop in temperature.

creeky
Member
# Posted: 28 Mar 2015 14:18
Reply 


everybody loves a good do it yourself story and you've certainly done your bit.

congrats. look forward to seeing your build.

groingo
Member
# Posted: 28 Mar 2015 23:05
Reply 


Quoting: electrodacus
Now I heat the same concrete slab with hot water from the propane heater and I can have even a few days in winter without any heating with just a few degrees drop in temperature.


Saw you setup in you video, you built the place right and spotted the tubing you laid before the concrete for the in floor heating, question...you mentioned you were using water in your system and wondered if it worked as well as ethylene glycol for heat retention and freeze resistance

MtnDon
Member
# Posted: 28 Mar 2015 23:24
Reply 


Quoting: groingo
ethylene glycol


Don't use that; it is toxic. Use propylene glycol; non toxic in case of a leak or spill. It is the law for good reason.

electrodacus
Member
# Posted: 28 Mar 2015 23:40
Reply 


Quoting: groingo
Saw you setup in you video, you built the place right and spotted the tubing you laid before the concrete for the in floor heating, question...you mentioned you were using water in your system and wondered if it worked as well as ethylene glycol for heat retention and freeze resistance


I use water and there is no risk of freezing unless I leave the house unheated at all in winter for probably over 2 weeks.
The temperature drop is around 1C to 2C in 24h with no heating at all depending on how cold it is outside.
I will probably just use the electric heating anyway once that is done.

groingo
Member
# Posted: 29 Mar 2015 01:14
Reply 


Quoting: MtnDon
Don't use that; it is toxic. Use propylene glycol; non toxic in case of a leak or spill. It is the law for good reason.


What law? They are both in everything from anti freeze to wood sealers.

Steve_S
Member
# Posted: 29 Mar 2015 08:53 - Edited by: Steve_S
Reply 


Very interesting thread... Checked out Electrodacus website & some videos. Considering that our build is about to resume (as soon as weather permits here in Ontario) it's getting time to revisit the Solar Solutions which I got quotes for last fall. BUT then I see this...

Electrodacus, I'm not Solar Power versed like Creeky or Groingo - suppose you could call me a noobie (eeks), so bear with me.

We determined last year that I need to setup for 1200-1500 watts panel capacity, likely using this basic config:
* 4x Canadian Solar CS6X-305P.
* Outback Flex-60 or 80 (have no need for 240v power)
* 8 Surrette S-550 Lead Acid Batteries setup for 48v
* 2000w Inverter / 3000w max. PURE SINE.

So how would I determine a comparable system using the LiFePO4 batteries ?

Getting info from some vendors / manufacturers is harder than pulling hen's teeth, "if" they answer questions at all. Gave up asking Balqon as I wanted more info on their ESS-24V, 4 kwhr which comes close in dollar value to what I would have to pay for 8 Surrette S-550's with the big difference being 24v VS 48v bank. Creeky aimed me at Balqon

Thanks in advance
Steve

EDIT---
We will be powering our 16x20 full-time cabin which will have an propane cook stove, wood stove, Energy Star fridge (312kWh / yr) and our water pump which will likely be a Grundfos SQ-5, Soft Start 115v 2 wire unit.

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