Installing a 48v 5KVA Inverter/CC solar system
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Greenwize
Registered Users Posts: 25 ✭✭
Greetings, I’ve ended up on this forum several times during my search for answers.
Previous months I went financially a bit over my head and bought a used Solar Array setup, I ended out buying parts I probably won’t need in the end.
10 micro inverters that accompanied the 10 240W solar panels I bought.
Since I wanted it to be a off-grid system, these became “useless”, when I once again bought a mppt 24V 100A charge controller along with a 1000w UPS, after some pondering time I returned the UPS and instead bought what I thought was a 5000w UPS,
turns out it was a 48v 5KvA Inverter/charge controller.
Oh well, it was brand new, had a manual with guide lines.
First I had to get a proper battery bank above atleast 200Ah according to the manual.
I bought 4 x 230Ah Vision AGM Batteries.
The manual the says I need a DC circuit breaker of atleast 50A between the Panels and Inverter. (Another 50A AC Circuit Breaker if it inevetibly have to be connected to the main grid)
By direct translation & using google search shopping which kinda sucks, I now sit here with a 63A PV Array Isolator...
apparently the complete opposite of what I needed? 😄
After all this eagerness I’m running low on budget, and to make the whole ordeal possibly worse, I can’t connect it to the grid of my apartment as I’m currently renting.
”Talking like this cause I want to buy the whole property in the future”😅🤙
If anyones willing to guide me the slightest, I will be so grateful!
Best Regards
Mike
Previous months I went financially a bit over my head and bought a used Solar Array setup, I ended out buying parts I probably won’t need in the end.
10 micro inverters that accompanied the 10 240W solar panels I bought.
Since I wanted it to be a off-grid system, these became “useless”, when I once again bought a mppt 24V 100A charge controller along with a 1000w UPS, after some pondering time I returned the UPS and instead bought what I thought was a 5000w UPS,
turns out it was a 48v 5KvA Inverter/charge controller.
Oh well, it was brand new, had a manual with guide lines.
First I had to get a proper battery bank above atleast 200Ah according to the manual.
I bought 4 x 230Ah Vision AGM Batteries.
The manual the says I need a DC circuit breaker of atleast 50A between the Panels and Inverter. (Another 50A AC Circuit Breaker if it inevetibly have to be connected to the main grid)
By direct translation & using google search shopping which kinda sucks, I now sit here with a 63A PV Array Isolator...
apparently the complete opposite of what I needed? 😄
After all this eagerness I’m running low on budget, and to make the whole ordeal possibly worse, I can’t connect it to the grid of my apartment as I’m currently renting.
”Talking like this cause I want to buy the whole property in the future”😅🤙
If anyones willing to guide me the slightest, I will be so grateful!
Best Regards
Mike
Comments
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Welcome to the forum Mike!
My first suggestion is to stop buying anything until you have a fully worked out paper/back of the evenvelope design. In my humble opinion, is that solar power systems should be a "balanced" design. It is so easy to go out buy xyz on sale, and then down the road, somebody has a killer deal on batteries, etc. And then when you try to fit everything together, you find out that it is like you have a jigsaw puzzle with pieces from unrelated puzzels mixed in.
And, as you also find out, your present living conditions can limit what you can do with solar power. Living in an apartment, renting a home, living in an area with lots of trees, tall buildings, and/or a location that does not have much sun--Also really impacts your options and costs.
We have a set of "rule of thumbs" which helps get to a "reasonable system" configuration. And you can modify components and tilt them to better fit your needs, price point, etc.
First--In general solar power is not a place to make "investments" with your hard earned savings. Solar rarely provides a positive return on investment (grid tied solar + a utility billing plan with substantial subsidies from utility/utility customers/the state--And like anything political, politics can change and affect any "investments" that where made based on "how things were". Personally, I tell family and friends to have, at least, six months living expenses in the bank before you start spending on other "things".
Next, the batteries you have purchased do have a limited life... SLA/AGM typically have a useful life for 5-7 years (guess). And they do need to be recharged every so often to keep them from "sulfating" (the soft fluffy lead sulfides will transform into hard black crystals. This permanently reduces the battery capacity... And, roughly, if they are below 75% state of charge, the sulfation happens quicker (a "dead" lead acid battery can have significant sulfation in days, if not hours). So--You need to recharge your battery every 1-6 months (AGM batteries stored at room temperature, once every ~6 months. Flooded Cell Lead Acid and batteries stored hot, you need to recharge them every month). So--Get a volt meter and measure the resting voltage, and get a good quality charger that has an SLA/AGM battery mode.
Next post, I will go through some math to estimate what your system could look like...
-BillNear San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset -
Thank you very much!
Hehe, yea I never planned it to go this way, the seller was selling it as a whole setup, but since I needed it to be off grid, thats where it went hay wire, he just said some jiberish about connecting a parralel of the miceo onverters onto the grid, but I would never do that as it can/will overload the whole wiring of the house, especially not without going around the hpfi.
anyways, I got a few pictures of the equipment, I believe that would be a start, I’m just really wondering if I can avoid hooking this 5KVA inverter onto the grid, and just run it off grid, eventually with a generator hooked up to keep the batteries charged aswell.
And then there was this new device which I hoped would be the last, but it was mistakingly a Isolator not a circuit breaker.
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I cannot tell you much about the inverter/charger. The DC wiring looks to be reasonable (keep it short from the battery to the battery bank).
In general, a very large AC inverter with a smallish battery bank--If you are running a saw for a minute or so at a time (building a home), it can work (in less than 2 hours, a 5 kWatt inverter can drain a 48 volt @ 230 AH battery bank in 2 hours or less... However, if you are just looking at off grid power, say you want 5 hours of energy at night, for two nights, and 50% maximum planned battery discharge (for longer battery life), that is 20 hour discharge rate (on average). If you run a refrigerator, it may take around 100 Watts, running 50% of the time, or roughly (100 Watts * 0.50 duty cycle * 24 hours per day= ) 1,200 WH per day... A "smallish inverter" typically around 1,200-1,500 Watts, and a large enough battery bank to run the small loads x 24 hours per day for a couple days.
Anyway... Some numbers. Conservative, as would typically be used on a small off grid home or near full time cabin (vs summer/sunny weekend place).
Your battery bank, if we assume 2 days storage (no sun, between backup generator runs), 50% max discharge, the average daily load support would be:- 48 volts * 230 AH * 0.85 AC inverter eff * 1/2 days storage * 0.50 max discharge = 2,346 WH per day
In any case, energy usage is a highly personal set of choices--And these are just starting suggestions. Measuring your loads and conservation are the first starting points for going off grid.
Next, sizing the solar array. Two sets of calculations. One is sizing the array based on the battery bank rate of charge. 5% can work for weekend/summer system, and 10%-13%+ works well for full time off grid:- 58 volts charging * 230 AH * 1/0.77 solar panel + controller deratings * 0.05 rate of charge = 866 Watt minimum array
- 58 volts charging * 230 AH * 1/0.77 solar panel + controller deratings * 0.010 rate of charge = 1,732 Watt array nominal
- 58 volts charging * 230 AH * 1/0.77 solar panel + controller deratings * 0.13 rate of charge = 2,252 Watt array "typical" cost effective maximum
http://www.solarelectricityhandbook.com/solar-irradiance.htmlCopenhagen
Measured in kWh/m2/day onto a solar panel set at a 34° angle from vertical:
Average Solar Insolation figures
(For best year-round performance)
Being farther away from the equator, not a lot of sun during the winter. You can tilt the array closer to vertical in winter for a bit better harvest, and better shedding of snow (if an issue in your area). Or setup a tracker to optimize harvest during winter. Lastly, if you only are there March through September, we can use 3.25 Hours of sun per day as our "break even" array sizing (may need to use a genset during poor weather, etc. at times):Jan Feb Mar Apr May Jun 1.27
2.07
3.25
4.25
4.92
4.76
Jul Aug Sep Oct Nov Dec 4.67
4.50
3.60
2.44
1.45
1.27
- 2,346 WH per day (based on battery bank sizing) * 0.52 off grid AC system efficiency * 1/3.25 hours of sun per day = 1,388 Watt array "March" break even
You have 2,400 Watts of solar panels, so that is a very nice size array for this battery bank... And an example of "dead of winter" and March energy harvest from a fixed (snow free) array would (roughly) be:- 2,400 Watt array * 0.52 off grid system eff * 1.27 hours of sun (dead winter) = 1,585 WH per average day "winter"
- 2,400 Watt array * 0.52 off grid system eff * 3.25 hours of sun (dead winter) = 4,056 WH per average March day
If you have trees/mountains/etc. that block your sun, that is always an issue. Solar electric panels need to be shade free to harvest solar energy... Even a few bare branches can easily kill 50% (up to 100%) of your solar array harvest (while shaded).
So--Not a bad mix of components (solar panels and battery bank).
For the AC inverter--Need to know more about it (you can post a link here to the inverter-charger and manual).
Just to give you an idea of what an evening on solar power might look like energy wise:- 2,346 WH per day * 1/5 hours per night = 469 Watt "average" load
- 40 Watts * 24 hours per day = 960 WH per day
- 960 WH Tare loss per day / 2,346 WH battery energy per day = 0.41 = 41% of daily energy budget
In any case, you need to read more about your inverter before you buy more hardware/build out your system.
Your thoughts?
-BillNear San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset -
Thank you for such a quick and detailed description! I’m willing to sell and get rid of that inverter & get a properly sized setup.
I have about 400watt running approx 16h a day, which is my highest load and most important equipment to keep running.
The reson why I bought the 5KvA was because I thought the setup would be able to run my 800w psu computer aswell which eats a couple hundred Watt/h. By eventually upgrading with a small 500w wind turbine for the future
I’m very new to this so you just taugh me alot with your calculations
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After getting warned on a resale site DBA.dk where the person send me a link about the first Charge controller I bought by the same guy, being a cheap chinese copy, which doesn’t support MPPT &100A as matching its description. - https://m.youtube.com/watch?v=MPoeFc762yQ
As mentioned I thought about selling the AC Inverter, as I don’t trust this 48v 5KVA is legit, as it could be a fraud aswell.
But the shop I accidentally bought that Isolator from had a inverter which have almost the same identical look and costs exactly same, yet smaller- https://www.vivaenergi.dk/solcelle-webshop/220V_hybrid_(Batterilager)/1400-Hybrid-Power-1024-inverter-48V
Talked with a guy at VivaEnergi, I told them my future orders will be genuinly bought through them when a solution have been found -
So to get this running smoothly, i would need a proper sized Inverter. (well first of all the money for it, haha)
Maybe there is a way to test this badass lives up to its expectations?
-If needed & i get one that can fit around 6 PV’s at 240w = 1440W minimum, yet if possible, a little room to upgrade with a small wind turbine or maybe the rest & even a couple more newer & bigger panels.
So it would be somewhat more than 2400W.
So the consumption from the AC Inverter would suddenly be a droplet, or am I completely wrong? 😃
Then I should have all the necessary parts already to finally get it running 😃
I have 10 of these micro inverters:
And the big 5KVA AC Inverter:
Was trying to find a link of the manual so I won’t have to plaster a bunch of pictures of it, hehe
But its a chinese no-namer 😅 -
Just to clarify a bit... Yes, it is possible to use GT micro inverters and connect them to (some types) of Grid Tied Inverters. The GT inverter will set your line voltage and frequency (230 VAC @ 50 Hz?). And the GT inverter will add current to the GT Inverter "micro grid" if the loads are greater than the GT inverter output, and the OG inverter will absorb excess current/energy if the loads are less than the GT output. As long as the GT output is less than the rating of the OG inverter.
The extra AC micro-grid energy is used to recharge the Battery Bank. Depending on the OG inverter design and configuration, the OG inverter will either (or both) start deviating from 50 Hz by +/- 1.0 Hz -- Which would cause the GT inverter to shut down for ~5 minutes before trying to restart (voltage and frequency have to be "good" for at least 5 minutes).
There are newer versions that use the +/- Hz to notify the GT inverters to "throttle" their output power (i.e., +/- 0.0 Hz, 100% output). To +/- 1.0 Hz is 0% output (made up numbers, I do not know the details).
Anyway, unless you are trying for a micro off grid power system (multiple homes/points of usage), OR trying for a hybrid GT/OG inverter system, this is not the "first hardware setup" I would suggest trying. You have to have "compatible" OG (and ideally GT) inverters mated together for optimum operation. Wrong stuff--You can end up overcharging and ruining your battery bank (or worse).
Anyway, a little background. In engineering, it is hard to say something is "impossible" or too expensive. All it takes is for somebody somewhere to design and make a device to prove you wrong.
BEFORE PURCHASE ANYTHING (or depose of anything), finish the paper design first. There are lots of parts that have to "fly together in formation"... You have to match the array to the charge controller (MPPT or PWM) to the Battery bank (12/24/48 volts). There are some configurations that (depending on hardware) cannot "work together" -- Or you have limitations like only groups of 2-4 solar arrays in series to match the Vpanel input of the solar charge controller, and battery bank (too few panels in series, too low of array voltage to charge the battery bank. Too many panels in series, you can exceed the Vpanel max input voltage). There are lots of ways to not do things right.
And there are lots of options out there... Panel A + Controller A work well together, or Panel A + Panel B work with Controller B, etc.
I suggest you go through a couple paper designs to see how everything fits together... From that point, you will know enough to be dangerous.
You have to have some starting point... Ideally, that is your loads you want to support, your location, and season(s) you want to run from solar. The next point is the rough sizing of the system (battery bank, solar array). At that point, you can start picking solar panels, charge controller, battery bank, AC inverter, etc... And then try to "hook them all together" on paper (check specifications, pricing, etc.).
If you don't have that stake in ground (I used your present battery bank as that "stake" here and defined the system around that using the solar panels you already own). You pretty much have to decide what you Need, and how much you want to spend. Solar is not cheap, and "oversizing your system" can be a waste of money. Undersizing a system so that it cannot support your loads--Also a waste of money...
-BillNear San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset -
I added a picture of those micro inverters for the details, haven’t planned to use them, they matched the panels but have all been put for sale
Except for the 5KVA, I’m just puzzled, perhaps i should go for a smaller Inverter as you also mentioned its quite overlill & eats alot of power on its own.
The seller told me to put panels in 3 strings to that Inverter.
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I wont sell the panels, batteries or the big inverter for now, no worries, hehe 😃
As it is, I can use all 10 PV’s on the garage in the yard, I got permission from the owner, If I just stick to the part I’m renting, but I imagine going for a 6 panel setup to be deployed faced south on my big balcony instead (Don’t like the idea growing on me about her lawfully saying thats hers when/if I decide to move etc)
Maybe upgrade with 290w PV’s in the future & of course a 500w wind turbine as mentioned before 😂 ..
I could finance a final Inverter or necessary part, but what size, as you pin-pointed, I must be sure what numbers I’m looking at, I would say 1440w-1740w from 6 Panels depending wattage size/model.
With a 500w turbine I’m looking at 1940-2240w
A 2.5 or 3 kilowatt Inverter would seemingly be a better sufficient choice.
The battery bank was bought & calculated to run the 400w equipment for about 2 days without sun, somewhat disregarding seasons, exactly as you even described.
I only bought this overkill 5KVA cause I thought it would be far better future proof for upgrades as you can tell, didn’t think it would be that costly on its own
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Lets say I decide to install this badass supported with a generator, and just upgrade on it as time goes by, with wind turbine, better set of panels, whatever can be sucessfully engineered to generate some power in a usefull way you say it can drain the current battery bank on its own within 2hours, isn’t that quite alot more than just 40Watt an hour?
I calculated my 400w device to run on the bank for quite some time. I think it was 230Ah * 48Volts = 11.040w % 400w= 27.6Hours.. I must be completely off. Haha 😃
Noticed VivaEnergi had a 24v - 2.4KW “Identical” inverter and even 24v & 48v 4KW hybrid inverters identical to the one I probably have:
https://www.vivaenergi.dk/solcelle-webshop/220V_hybrid_(Batterilager)/1662-HybrdiPower1024-24
Does it extend the battery bank & what are the odds that I don’t already have the same 48V 4KW 5KVA similar edition?
They are/could just be branding their name on it, if thats the case, I already got a 63A PV Isolator & all i need is lore or less that dc circuit breaker as can be seen here on their finished layout:
https://www.vivaenergi.dk/solcelle-webshop/220V_hybrid_(Batterilager)/1621-HybridPower1024-48
Along with a generator I suppose what I already have should be sufficient to supply the mentioned load on the bad days.
but the 48v & 2hours drainage you clarified worries me.
If it can extend my current battery bank by using a identical 24V Inverter I sure would go that way 🤔😃
Thank you so much so far Bill, I apologise for the amount of post but I really appreciate your efford due to the situation, I play around alot with crypto and I sure will be showing my appreciation when things have settled ! -
Please don't make any decisions based on what I suggest... I try to "do the math" and ask the questions--And you need to decide what is important for you.
I guess that the "inverter" you have is really an "inverter/AC charger/MPPT(?) solar battery charger". There are a lot of those out there, and combining the three different pieces of equipment into one can make things easier... It can also make things more difficult (3-in-1 systems, if one fails, the whole unit needs to be repaired or replaced--And it can be difficult to isolate faults).
Regarding mounting... These days, it canu. I am 1/2 a world away and really cannot make these decisions for you.
cost more money to mount the array (including framework), than the solar panels cost. And if you do this right (withstand wind and snow loading, properly mount and waterproof the mounts to the garage roof/etc., and in the USA, when you mount "stuff" permanently to the rented/leased structure (in terms of shops, air compressors, lights, etc.) now belong to the owner of the property (if they want to keep the stuff). And when you move, what happens to the racking/holes in the roof, etc. (you repair, call a roofer, etc.).
About wind turbines... I am not a big fan of small wind. Personally, I don't believe that the 1) perform as advertised, 2) can require a fair amount of maintenance and equipment--such as a crane, if not a tilt tower), and 3) really only work well in an area that is "miserably" windy (trees "flagging with wind direction") and the turbine is high enough above trees/obstructions to be in non-turbulent air (typically 10 meter minimum tower, and at least 3-10 meters above nearby upwind trees/buildings/etc.). If you want a turbine, I would suggest design and build your system with solar panels (and backup genset as needed) first--Then add a turbine down the road you want to try (turbines are usually the "cheap part", towers, concrete, wiring, etc. tend to be the majority of the costs--And don't mount to roof/side of building).
Small electrical loads that run for long periods of time can be "worse" that large loads for short periods of time... For example:- 1,500 Watt Microwave * 1/10th of an hour (6 minutes) = 150 Watt*Hours per usage
- 120 Watt refrigerator * 0.50 duty cycle * 24 hours per day = 1,440 WH per day
- 400 Watts * 16 hours per day = 6,400 WH per day (assuming your desktop computer?)
- 30 Watts * 16 hours per day = 480 WH per day
- 48 volts * 230 AH * 0.85 AC inverter eff = 9,384 WH of stored energy in the bank
But--As I am trying to say here--You need to look at your energy needs as a whole. If you only need 5 kWatts for 15-30 minutes a day--Then that system will work for you...
However, if you need 400 Watts @ 16 hours a day, then that 6,400 WH per day usage out of an (optimally charged and running) battery bank with a capacity of 9,384 WH total--that is about the best you can expect---And you have to recharge back to >90% SoC the next day (i.e., 100% capacity - 10% (full is >90% SoC) - 20% (battery aged capacity before replacement) - 20% maximum discharge (discharging below ~20% state of charge, you run the risk of "killing" one or more "weak" cells). Or, gives you about 50-60% daily usable capacity at the end of the bank's life (engineering Worst Case specifications... Could you pull 80% of capacity out of the bank--Yes when new, less yes as the bank ages, if it gets cold less capacity, less than full charge in winter, etc.).
Also, lead acid batteries take upwards of 6-10 hours of charging per day when deeply discharged (up north, your sun is probably not above the horizon for 4-6 hours per day--of useful sun).
Looking at the inverter/AC/Solar charge specifications:
https://www.vivaenergi.dk/solcelle-webshop/220V_hybrid_(Batterilager)/1400-Hybrid-Power-1024-inverter-48V
The 2.4 kWatt version (assuming everything works as spec'ed) may not be a bad unit to try (local to you for service and support?). Notice that there are a wide variation in some of the specifications... (hopefully, cut and paste posts here correctly):TECHNICAL DATA
Hybrid Power 1024-48V
(No. 1400)Hybrid Power 1024-24V
(No. 1634)Hybrid Power 1024II-24V
(No. 1826)HybridPower 1040
(No. 1401)HybridPower 1040II
(No. 1827)Inverter power (220V) / (Peak) 2400W (4800W) 2400W (4800W) 2400W (4800W) 4000W (8000W) 4000W (8000W) battery voltage 48V (42-60V) 24V (21-31V) 0V / 24V (21-32V) 48V (42-60V) 0V / 48V (42-63V) Can run without battery No No Yes No Yes Number of panels (270-300Wp / 31V)
1 string:
2 strings:
3 strings:
4 strings:
5 strings:1x 2
2x 2
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-1x 1-3
2x 1-3
3x 1-3
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-1x 4-11
2x 4-10
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-1x 3
2x 3
3x 3
4x 3
5x 31x 4-11
2x 4-10
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-Recommended max. panel effect (Wp) 1100Wp 2000Wp 5000Wp 3750Wp 5000Wp Max panel input (watts / amps) 900W / 18A 1500W / 60A 4000W / 18A 3000W / 60A 4000W / 18A Panel MPPT voltage range 60 - 88V DC 30 - 115V DC 120 - 450V DC 60 - 115V DC 120 - 450V DC Max. panel voltage (Voc unloaded) 102V DC 145V DC 500V DC 145V DC 500V DC Max. bat. charging from 230V
10, 15A 20, 30A 2, 10, 20, 30, 40, 50, 60A 2, 10, 20, 30, 40, 50, 60A 2, 10, 20, 30, 40, 50, 60A Max. bat. charging from panels 10, 20A 20, 30, 40, 50, 60A 10, 20, 30, 40, 50, 60, 70 & 80A 10, 20, 30, 40, 50, 60A 10, 20, 30, 40, 50, 60, 70 & 80A Max. total bat. Charging
(Panels + 230V)20A 60A 80A 120A 80A Max. efficiency charger / inverter 98% / 93% 98% / 93% 98% / 93% 98% / 93% 98% / 93% External generator start signal Yes Yes No Yes No Power consumption in standby mode 2W 2W 2W 2W 2W Power consumption at idle 12W 12W 35W 15W 35W Operating temperature 0 - 55 ° C 0 - 55 ° C -10 - 55 ° C 0 - 55 ° C -10 - 55 ° C Size (Depth, Width, Height in mm) 100 x 272 x 355 140 x 295 x 479 100 x 300 x 440 140 x 295 x 468 100 x 300 x 440 Weight 7.4 Kg 11.5 Kg 9 Kg 11 Kg 10 Kg Notice that some of the models have 2watt / 12watt (search mode/tare load) specs, and another has 2w / 35w loading. And different amount of solar panel support (the 3rd column has a higher Vmp-array operating voltages)... You (or the person configuring this system for you), need to really understand and follow the input requirements for the solar charge controller (section of the AC inverter charger block).
At worst, you can use the smaller inverter/charger unit, and get a separate solar charge controller to support more panels for winter/heavier loads (you can put several charge controllers on one battery bank without much issue).
24 or 48 volts is not as important as finding the right hardware for your system. Yes, 48 volts works better for larger (Watts) systems (lower Amperage wiring)... But look a the hardware and specifications (and options you want, etc.).
You need to look at your 400 Watt loads... That is a lot for an off grid power system. If this is a weekend system--Then a small/fuel efficient genset for a few weeks a year. If you are full time off grid (like 9 months or more), then solar may be worth the costs.
-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset -
Alright, I see Bill & don’t worry I wont, I’m quite ambivalent as you’d probably noticed by now, gotta have some certainty before I jump into action
If I supply the “current” setup with a generator, i guess it would be sufficient.
Yeah the 400w is a little high and its a LED light for indoor gardening.
I think I will go about setting this inverter up to the batteries and get it running with the panels, I was told 3 strings, and my balcony can fit about 6, so for now i can hit 1440W, not sure if thats in anyway sufficient or workable as a temporary solution, it would just be a relief to see it running atleast, until theres a potential buyer on it😃
If thats not the case.
Then I’ll probably have to buy the one I linked through that company & yes they are somewhat local 😃 -
I forgot that is was 400 Watts for greenhouse lighting... And, the math says no (hours of sun, size of array, 400 watt load * 16 hours per day).
What is the cost of electricity for you? In most areas, off grid solar power is >> than the cost of utility power (you already have power at your present place--Need Green House LED here or elsewhere?).
Simplest thing to do is add up the cost for hardware+batteries, and replacing batteries once every 5 years, and electronics once every 10 years, divided by the amount of power you will generate over the (10-20) years. And with solar, you pretty much are Pre-Paying your power bill for the first 5-10 years...
Vs cost for utilty power.
Vs cost for genset power (again, the cost of fuel/kWH per tankful)... In the US, for a small gasoline powered system, something like $0.50 to $1.00 per kWH--lots of pricing variables for fuel+genset (you probably want to include the cost of a genset/genset overall every so often too... Growing season * hours of power per day--How many hours per year to run a genset)... In times past, many "growers" used gensets for their lighting (to avoid power bills, "grow" in the middle of nowhere).
From an engineering point of view, don't fall in love with solutions. Do some cost analysis and figure out what works best for you. Off grid solar--Just is not usually a cheap option. And if you are looking for Winter tomatoes with solar in Denmark, there just is not a lot of sun.
-BillNear San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset -
I like the thought of wind/turbine energy especially after closer readings on nikola tesla’s experiments & his pneumatic turbines, as well as the mechanical oscillator, at some point I envision it could be played around to work in unity, possibly making a diy device eventually from scrap & everyday parts that can be modified & are easily available.
If this medium act as a spring in a mechanical oscillation it should potentially self amplify & resonate like a frictionles swing.
Not sure if thats exactly the right way to describe it, but hopefully it made some sense atleast😅
However thats quite off the topic I apologize, but I still think its ery interesting, which is also why I would love to have room for further future upgrades/experiments, but you’re right & I will focus on the PV’s to keep the calculations managable 😃 -
Haha, Its a big efford just to make red tomatoes at home in the dead of winter then I agree
There are so many spices that are freshly unavailable, I just hope the quarentine will lift off before its completely disastrous, but some restaurants are wildly in love with fresh Saffron, for now its more like a hobby, a little costly but I have my interest with electricity and mechanical devices aswell 😃
I’m actually not sure what the price of electricity is exactly, but it does get quite expensive for me every quarter & they just increased the kw/h price quite some recently asweel
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Just as the cost of oil/fuel has "tanked"... Funny how that happens. Price of oil goes up, electricity/gasoline goes up. Price of oil plummets, the price of electricity and gasoline stay high or go up...
Another thing to look up... I am not sure, but research I did a few years ago (similar question posted then), check how much light (and what spectrum) you need for the specific plants you are raising... In some cases, to set flowers, etc., did not need "full sun", but just a (relatively) small amount of light in a specific spectrum to get the plant to proceed with its "normal/forced" growing cycle.
-BillNear San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset -
Hello, I'm back after some time to reconfigure my setup.
Shortly had those 4 x 230Ah Vision Batteries for a few weeks before sending them back.
I decided not to trust the 5kva Inverter I bought at first.
Instead I went with expensive brand new 3kw 24v Hybrid Inverter(Remote display & Bluetooth) - https://www.vivaenergi.dk/solcelle-webshop/220V_hybrid_(Batterilager)/2045-Hybrid-Power-1030-inverter-24V
Along with a decreased battery bank, 1 battery to start out 24v 100Ah HybridPower LiFePo4 Battery. - https://www.vivaenergi.dk/solcelle-webshop/LiFePO4_batteri/2017-24V-100ah-lithium-bt
And decided to limit my use onto fewer smaller loads to begin with, will be upgrading the battery bank as soon as possible to sustain the amount of energy the array will be producing.
I skipped the garage plans, water came down the ceiling.
But I can actually fit all 10 Panels on the balcony, but 6-8 or 9 PV’s would be optimal, the Inverter can max take up to 3 strings
However, the Inverter Manual informs how it can be hooked up to charge from the grid / AC Input, however the shops website where I bought it, they clearly state these CANNOT be grid connected, now I'm fairly confused & wonder why, after watching a couple videos with people setting up these hybrid, they just use a simple extension cable for the AC input & Output, the input could be fitted right into a wall socket etc.
These are the Panels I have:
Hope you''re enjoying the summer!
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Okay, so I figured what size of cable I would need.
But regarding stringing the arrays together.
The inverter can take 115v
Mc4 cables max 25A
My panels are rated at 29.6v & 8.11A each = 240W
The Inverter manual is recommending 3 strings series, but its determined by using 270-300w Pv’s as reference. Mine are quite smaller.
So I’ve been thinking:
Wouldn’t I be able to both series & parallel connect 4 panels together in a string to reach & only push a total of 59.2v & 16.22A
So I’m not exceeding the limit of the Inverters 115v& MC4 cables 25A, or am I completely incorrect, would I have to consider the Maximum Series Fuse Rating: 15 ?
my limited rusty knowledge makes me doubt 😃
If thats possible, then I could eventually reach a total of 12 Panels divided onto 3 strings 🧐😊
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The working voltage of the panel (Vmp--voltage maximum power), is a fixed (sort of) voltage that depends on the number of cells in series in the solar panel (30 volts Vmp ~ 60 series connected cells).
The "variable value" is the Imp (current maximum power). That is based on the surface area of each cell (larger surface area, more current). So when you have Pmp=Vmp*Imp, your smaller panels have the "same" Vmp, but smaller Imp.
The 115 VDC max input... 4*30 volts = 120 Vmp-array--Too High. 3*30 volts = 90 volts Vmp-array, which is within the spec'ed value of the controller (you have to read the controller requirements very closely, they can be confusing, and sometimes even wrong).
So, in your case, the 3x panels in series hits the proper working voltage. And you connect as many as you need in parallel to hit the input current/power requirements. As an example, for a derated 3 kWatt input (solar panels have less than rated output on hot/sunny days) (I don't know what the inverter/charger input is, assuming 3,000 Watt array):- 3,000 Watts * 1/0.77 panel+controller derating * 1/(3 panels series * 29.6 volts Vmp per panel) = 43.9 Amps Imp-array typical maximum
- 43.9 Amps Imp-array / 8.11 amps per series string = 5.41 ~ 5 parralled strings (5strings * 3 series panels = 15 total)
Of course, you can use fewer parallel strings... Your choice.
You need to look at the specifications for each "black box" in your system... The 24 volt LiFePO4 102 AH battery has a 100 Amp @ 3 second max discharge Which is about (24 volts * 100 amps= ) 2,400 Watts surge--And would suggest a maximum inverter of ~1/2 that size (inverters can typically surge 2x rated Watts) or ~1,200 Watts max (before battery shuts down/gets damaged).
On the charging side, looks like 25 amps @ 29.0 volts (max voltage). Don't see any other spec. (my Danish is not useful)... So, the typical largest suggested solar array (unless the charge controller has output charging current limiter--Which many MPPT controllers can do), your suggested maximum wattage array would be:- 25 amps * 29.0 volts * 1/0.77 panel+controller derating = 942 Watt array maximum
- 942 Watt array / 240 Watt panels = 3.92 panels or ~ 4 panels total
Again, you have to check the detailed specifications of everything. The 2s*2p looks OK, and if the charge controller can limit maximum charging current--Then you could go larger (more harvest in mornings/evening, and during winter).
Details matter--I hope I am not being too confusing... I am making lots of guesses here.
-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset -
I think I understand most of it
The first part gave me some better insight.
By connecting 1 string @ 2 series + 2 parallel, I can maintain the voltage below 115v while still not going above 25 amps per String etc MC4 cables won't be overloaded.
In Series 2 * 29.6v = 59.2 volt & in Parallel 2 * 8.11 = 16.22 amps (of course only if the MPPT will handle it)
59.2 volt * 16.22 amps = 960 watt
But If I connect it that way into a combiner box, won't the final MC4 cables exceed its 25A Limit?
With 2 strings each around: 16.22 amps * 2 = 32.44 amps
If thats possible, I can finally make use of them, stringed like that with fuses in a combiner box, I won't have to make several cambles for several 1x2panel strings, just to make use of all 10,& that way it would fit perfectly as a 2 series * 2 parallel panels on a 2 string setup, (4 panels * 2 strings ) a total of 8, where I guess my limit would be 12 panels on the max 3 strings as the Inverter Manual recommends. But lets say your calculation is correct, & I can increase the strings to a total of 5, wouldn't I even be able to increase the total amount of panels to 20? Since mine are slightly less powerfull on the amps due to the smaller lmp
Warning! Danish Language!Tekniske data
HybridPower 1024-48V
(Nr. 1400)HybridPower 1024-24V
(Nr. 1634)HybridPower 1030-24V
(Nr. 2045)HybridPower 1040
(Nr. 1401)HybridPower 1040II
(Nr. 1827)Inverter effekt (220V) / (Peak) 2400W (4800W) 2400W (4800W) 3000W (6000W) 4000W (8000W) 4000W (8000W) Batterispænding 48V (42-60V) 24V (21-31V) 24V (21-32V) 48V (42-60V) 0V / 48V (42-63V) Kan køre uden batteri Nej Nej Nej Nej Ja Antal paneler (270-300Wp / 31V)
1 streng:
2 strenge:
3 strenge:
4 strenge:
5 strenge:1x 2
2x 2
-
-
-1x 1-3
2x 1-3
3x 1-3
-
-1x 1-3
2x 1-3
3x 1-3
-
-1x 3
2x 3
3x 3
4x 3
5x 31x 4-11
2x 4-10
-
-
-Anbefalet max. paneleffekt (Wp) 1100Wp 2000Wp 2000Wp 3750Wp 5000Wp Max panel input (Watt / Ampere) 900W / 18A 1500W / 60A 1500W / 60A 3000W / 60A 4000W / 18A Panel MPPT spændingsområde 60 - 88V DC 30 - 115V DC 30 - 115V DC 60 - 115V DC 120 - 450V DC Max. panelspænding (Voc ubelastet) 102V DC 145V DC 145 DC 145V DC 500V DC Max. bat. opladning fra 230V
10, 15A 20, 30A 20-60A i 10A trin 2, 10, 20, 30, 40, 50, 60A 2, 10, 20, 30, 40, 50, 60A Max. bat. opladning fra paneler 10, 20A 20, 30, 40, 50, 60A 20-120A i 10A trin 10, 20, 30, 40, 50, 60A 10, 20, 30, 40, 50, 60, 70 & 80A Max. total bat. opladning
(Paneler + 230V)20A 60A 120A 120A 80A Max. effektivitet lader / inverter 98% / 93% 98% / 93% 98% / 93% 98% / 93% 98% / 93% Startsignal til ekstern generator Ja Ja Ja Ja Nej Aftageligt display for fjernkontrol Nej Nej Ja Nej Nej Bluetooth og smartphone APP Nej Nej Ja, Android Nej Nej Strømforbrug i standby mode 2W 2W 2W 2W 2W Strømforbrug i tomgang 12W 12W 12W 15W 35W Arbejdstemperatur 0 - 55° C 0 - 55° C 0 - 55° C 0 - 55° C -10 - 55° C Størrelse (Dybde, Bredde, Højde i mm) 100 x 272 x 355 140 x 295 x 479 140 x 303 x 525 140 x 295 x 468 100 x 300 x 440 Vægt 7,4 Kg 11,5 Kg 13 Kg 11 Kg 10 Kg
To clarify from the previous post, I wont connect the complete setup/all the strings at once, until I have atleast an extra battery, then I'll simply connect more as I get the desired battery bank size up to support the amount of panels.
And of course nothing will be assembled until all the calculations and metering for wires etc have been done & is ready
Silly question, but how would I figure out if the build in Charge Controllers - MPPT of the Hybrid Inverter is capable & got the option to Limit The Maximum Charging Current? I believe it should be a great quality, because I brought that previous unknown branded 48v 5kva Inverter with me for VivaEnergi to look at it, I was told the company tested many before deciding on the HybridPower choice for their productline, and many look the same, but ensured me the one I already had was legit atleast
Wouldn't the option to Limit The Maximum Charging Current be written in details about the mppt somewhere, or maybe there's another way to figure that out?
Hehe, I'm sorry I didn't translate and calculate it more detailed to begin with, I just needed & tried to explain it as basic as possibly since I'm still quite limited at whats important to look at, quite already knew I most possibly had been missing a few important details Sorry Bill! .But Thanks so far!
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Just for the heck of it... Google Translate:
Technical data
Hybrid Power 1024-48V
(No. 1400)Hybrid Power 1024-24V
(No. 1634)Hybrid Power 1030-24V
(No. 2045)HybridPower 1040
(No. 1401)HybridPower 1040II
(No. 1827)Inverter power (220V) / (Peak) 2400W (4800W) 2400W (4800W) 3000W (6000W) 4000W (8000W) 4000W (8000W) battery voltage 48V (42-60V) 24V (21-31V) 24V (21-32V) 48V (42-60V) 0V / 48V (42-63V) Can run without battery No No No No Yes Number of panels (270-300Wp / 31V)
1 string:
2 strings:
3 strings:
4 strings:
5 strings:1x 2
2x 2
-
-
-1x 1-3
2x 1-3
3x 1-3
-
-1x 1-3
2x 1-3
3x 1-3
-
-1x 3
2x 3
3x 3
4x 3
5x 31x 4-11
2x 4-10
-
-
-Recommended max. panel effect (Wp) 1100Wp 2000Wp 2000Wp 3750Wp 5000Wp Max panel input (watts / amps) 900W / 18A 1500W / 60A 1500W / 60A 3000W / 60A 4000W / 18A Panel MPPT voltage range 60 - 88V DC 30 - 115V DC 30 - 115V DC 60 - 115V DC 120 - 450V DC Max. panel voltage (Voc unloaded) 102V DC 145V DC 145 DC 145V DC 500V DC Max. bat. charging from 230V
10, 15A 20, 30A 20-60A in 10A steps 2, 10, 20, 30, 40, 50, 60A 2, 10, 20, 30, 40, 50, 60A Max. bat. charging from panels 10, 20A 20, 30, 40, 50, 60A 20-120A in 10A steps 10, 20, 30, 40, 50, 60A 10, 20, 30, 40, 50, 60, 70 & 80A Max. total bat. Charging
(Panels + 230V)20A 60A 120A 120A 80A Max. efficiency charger / inverter 98% / 93% 98% / 93% 98% / 93% 98% / 93% 98% / 93% External generator start signal Yes Yes Yes Yes No Detachable display for remote control No No Yes No No Bluetooth and smartphone APP No No Yes, Android No No Power consumption in standby mode 2W 2W 2W 2W 2W Power consumption at idle 12W 12W 12W 15W 35W Operating temperature 0 - 55 ° C 0 - 55 ° C 0 - 55 ° C 0 - 55 ° C -10 - 55 ° C Size (Depth, Width, Height in mm) 100 x 272 x 355 140 x 295 x 479 140 x 303 x 525 140 x 295 x 468 100 x 300 x 440 Weight 7.4 Kg 11.5 Kg 13 Kg 11 Kg 10 Kg
No problem GreenWize. We all start at the point of "we don't know what we don't know" point with new projects...
Trying to keep things in some sort of order... I call the battery the "heart" of your system. You size it according to your power needs, and then size the charging around it (and your loads/inverter/etc.) to "keep the battery happy".
So--You first need to find the maximum battery charging current. Let's say it is 30 Amps for the moment. Looking at your 3kW 24 volt inverter/charger, we see that its charging output can be set between 20-60 amps in 10 amp increments. So, that gives you good control over the battery charging current independent of solar array size.
One question that comes up, is the current limit based on the solar charger section' output, or the "true current" to the battery bank. For example, if you have 30 amp charging current, and a 20 amp load (@24 VDC into the inverter block), does the charge controller limit to 30 amps out - 20 amp load = 10 amps charging battery? Or does the Charger Block limit 30 amps to the battery, +20 amps charging, so the "charging block" outputs 50 amps at that moment in time.
Limiting battery charging current has been a desire for many folks... They want large solar array to both charge the battery bank, and run the daytime DC loads. There is only one (US) MPPT solar charger that I know of that can do this easily... That is the Midnite MPPT family of charge controllers. They have a battery shunt that measures current into and out of the battery bank... So the controller can limit 30 amps to battery charging, and still supply 20 amps (or whatever) to the DC Bus loads during the day.
You have to be careful here with charging (and discharging) current for your LiFePO4 battery bank... It has internal sensing/controls, so if you over current (or over/under voltage) you may trip the battery protection BMS (battery management system). And your system will go "dark"/"strange" and try to figure out why.
For another question, if you set the Solar to 30 amps limit, and the 230 VAC to 30 Amp limit, does that mean the battery can get 60 amps charging current if both Sun is up, and AC voltage is available? Perhaps the Generator control can be set to turn of genset/AC voltage when battery voltage/charging current is "high enough" (want to protect battery from too much current charging).
Now we at least have some basic assumptions and better specifications for the hybrid AC Inverter/MPPT charger...
With MPPT charge controllers, there are several limitations. One is the minimum Vpanel-input value. In your inverter/charger, it says 30 VDC. In practice, for a 24 volt battery, you typically want a minimum of 1.3x your battery charging voltage for "full" MPPT function (29.0 VDC charging * 1.3 = ) ~38 volts minimum (really even higher for "hot panels" with depressed Vmp-panel)... So, 2x 30 volt Vmp panels = ~60 VDC--That should be great.
Next, looking at the inverter/charger again, there is a limit of 60 amps (I think). So:- 60 VDC Vmp-array series (2x series) * 60 Amps = 3,600 Watts max Vpanel input rating (>1,500 or 2,000 ?? Watt spec)
- 2,000 Watts ?? * 0.77 panel+controller derate * 1/29.0 VDC Charging = 53 Amps
- 2,000 Watt ?? Max panel / 240 Watt panels = 8.33 ~ 8 panels max (2s x 4p)
And wiring from array to charge controller/battery bank. The +/- wires from the combiner box/array need to carry the total current of the array (heavier wires for more current). Also, it depends on the distance from solar array to battery bank... 10 meters or less, the voltage drop of the wiring is usually not a big issue. 30 meters or more, then you need higher voltage array (i.e., 3s panels, vs 2s panels)--(Power=Voltage*Current)--The higher the working voltage, the lower the working current, and the smaller AWG wiring needed (save costs on copper).
I want to stop here--Because you have to give us more information (distance from Array to charge controller), and the number of panels you want (4, 6, or 8 as an example). Once we have a design choice hear, we can continue on. Trying to keep doing stuff step by se
Also, let me know if you are following this OK... It sounds like your English is probably better than mine (my only language--Google Translate works great, even doing legal stuff in Chinese--for the most part). But it is easy to get lost. Please ask questions if I am not clear.
There are a lot of black boxes/functions here. Need to make sure not to trip over any of them.
-BillNear San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset -
I have indeed learned alot and thrown many questions into the air to solve this by now, it really is great, Its been over 12 years since I skipped studying to become a Electrician, so it feels great dusting off & teaching new & rather advanced stuff like this
I will try to shine some light onto those black boxes!
There is approx 16.4feet - 5m from the Array to my Hybrid Inverter/Charge Controller, I'm going with 8 panels but since the battery bank is rather small at this point, I can easily settle for 6 to start out with Those batteries costed me a fortune, & I will most probably solder my own for the future, have been looking at Lithium Titanium Oxide to enjoy their long life cycle, 60.000 something, can be bought as 18650 cells, 2.4 volts 1500mAh, half the size of LiFePo4 but I can live with that!
BtwI won't mind to reconfigure the Combiner Box the day I upgrade, rather the opposite
If lets say the combiner and wiring would be (2s x 4p = 8), Wouldn't the parallel reach 32.44 amps, overloading the MC4 cable, or am I still misunderstanding something here, will the fuses in the combiner prevent that?
I sure follow you most of the part, just trying to make sure I get your point at the questions marks "2,000 Watt??".. Still thinking, but I can continue to re-read your messages and re-write my own reply several times until I put the puzzle together, hehe
Agreed, I use google translate every once in a while when searching for specific items, terms in another country, I will, sure will Bill
Yes, no reason to be tripping, don't wan't no explosions, damaged equipment & fireworks outside
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I have 2 x these cables and loose mc4 connectors the first guy who kinda got me into this mess sold me.
They might come in handy, also the reason why I’d prefer to go 2 x 4 panels 😃 Cheaper in wiring 😂
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Those MC4 4-1 combiners... They are a cheap and quick way around using a Combiner Box. But, as you have asked, does not look right (safe).... The MC4 2-1 combiners are usually OK. The larger number combiners, not usually a good fit (no fuses, too much combined current in output single cable).
https://www.solar-electric.com/mnpv6.html (example of a combiner box, fuses/breakers extra)
The typical solar panel has something like 12 AWG or 10 AWG wiring--Which using a typical NEC minimum requirement is a maximum of 20 or 25 Amps per wire. You have up to 4x8.11amps Imp = 32.44 Amps total. Which would use > 10 AWG to meet code requirements (North American NEC, your codes are different and use Metric sizes, I assume). Just for reference, for every 3 AWG increase in diameter (i.e., from 12 awg to 9 awg) is a 2x increase in square inches of cross section and roughly 2x current capacity.
So, your first choice--Do you bring the solar array wiring from the array into the house/battery shed, then to the combiner. Or do you put the combiner box at the array, combine (15 amp fuse/breaker per string), and bring the (I guess, 4p*8.11a=32.44 amps on a pair of +/- cables to the charge controller Vpanel input? Either is fine--Your choice. And you have a choice of using heavy cable for the combined run (for your 4p planned), or use lighter cable for 2p run today--And replace later when needed.
Make sure to use outdoor rated / UV rated wiring (if exposed to sun/rain/etc.) (sun will degrade insulation).
Say you use 4p or 32.44 Amps. In the US, our AWG current/breaker/fuse ratings should usually be derated by 1.25 (or 1/0.80) for continuous current flow. So, for the 32.44 Amp Imp-array circuit:- 32.44 Amps * 1.25 NEC derating = 40.5 Amps
https://lugsdirect.com/WireCurrentAmpacitiesNEC-Table-301-16.htm
And you can use 10 AWG cable (with higher temperature rated insulation) or 8 AWG for pretty much any other type wiring.
There is always looking at voltage drop too... Your run is short. But for longer runs, it can become a big issue (voltage drop for long wire runs, lots of voltage/energy loss). Running some simple/quick calculations. Assume 17 feet one way run (some calculators use round trip distance--Just check the details), 32.44 Amps, 60 Volts Vmp-array, and 10 vs 8 AWG wire runs (in the US, the smaller AWG wires are usually only available in "even" gauges... No 11 or 9 AWG is available).
https://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=3.277&voltage=60&phase=dc&noofconductor=1&distance=17&distanceunit=feet&eres=32.44&x=65&y=17
10 AWG
Voltage drop: 1.10
Voltage drop percentage: 1.84%
Voltage at the end: 58.9
https://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=2.061&voltage=60&phase=dc&noofconductor=1&distance=17&distanceunit=feet&eres=32.44&x=73&y=19
8 AWG
Voltage drop: 0.69
Voltage drop percentage: 1.15%
Voltage at the end: 59.31
We usually aim for ~3% to 1% voltage drop... Going less than 1% is not usually worth the cost of copper wiring.
Regarding the 2000 Watt ??... From the specs:
Max panel input (watts / amps) 1500 Watts / 60 Amps
Recommended max. panel effect (Wp) 2000 Wp
Not sure what the different "numbers" mean... I am guessing that the controller is rated for 60 Amps maximum at any wattage/array configuration. Watts/Amps=Volts (1500W/60A=25V)--Not sure what 25V means here (way too low of Vmp-array voltage for proper solar charging--Usually zero charging at 25 volt array input)...
Specifications are not always correct--And seem to be less correct these days (short time to market, documents thrown over cube walls from engineering to technical publications department).
The above calculations are reasonably conservative... In the USA/North America, the current rating of wiring is much more complex in detail--Ambient Temperatures, Conduit size, Conduit fill factor, Insulation type, etc.).
I guess you will be using Euro Spec'ed cables and equipment. So, you will have to "translate" into your local available hardware and requirements.
Some warnings with Lithium batteries. LiFePO4 chemistry is about one of the safest Li Ion chemistries out there... Generally they do not overheat/catch fire if "abused" (and with integrated BMS, less chance of that).
However, a couple of things to watch for. Li Ion chemistries do not like to run near freezing or below... And generally should never be charged below ~0C. Some BMS will turn the battery off--Others may not. For a cold climate, the Li Ion batteries need to be kept "warm".
Lead Acid batteries can work well below freezing (-18C to -40C is usually OK if Lead Acid batteries are kept charged. AGM batteries can "freeze" and not be damaged--But cannot be charged when frozen. The electrolyte specific gravity falls as the Lead Acid batteries discharge, so their freezing temperatures rise).
Li Ion batteries can release Hydrofluoric Acid if they catch fire. HF Acid is a very dangerous poison. And if it gets into your home/cabin, it can require the affected areas to be torn down and hauled to a toxic waste dump. I am not trying to tell you not to use LiFePO4 batteries, but you need to be aware of the issues. Will LiFePO4 batteries release HF Acid--I do not know--There are many different chemistries, and it is not clear (to me) which may have the HF issues.
Random battery MSDS (material data safety sheet) for LiFePO4 battery:
https://www.batteryspace.com/prod-specs/MSDS_LiFePO4.pdfSpecific hazards:Generally a good idea to have a separate battery/equipments--But in cold climates, the question of heating the area >5-10C can be an issue.
If the electrolyte contacts with water, it may generate detrimental hydrogen fluoride.
Since the leaked electrolyte is inflammable liquid, do not bring close to fire.
-BillNear San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset -
I see, so from the combiner box and to the charge controller its no longer a limited MC4, but can now withstand currents depending on the Gauge size cable I choose to use, while the fuses make sure that nothing gets overloaded if a panel decides to fail on the circuitry
The recommended sized wire would probably be 10 Gauge, my old teacher mentioned the other day, that we normally use 1½ kvadrat cables, trying to convert that into either mm, mm2, awg & gauge
However VivaEnergi said, either 4 or 6 Kvadrat cable, but the same guy said the inverter could only handle 3x3 strings, while I'm not sure if he understood the fact my panels were 240 watt with a lower lmp than the reference from the manual (270-280 watt)
Since they most probably have higher amps, I could easily understand why they might have be connected that way, 3x3.
By connecting the way I've drawn, (not sure if you noticed my added beautiful paint example of the 2s & 2p string ) I guessed it would comply with the limits, opposite if it really was either 270-300 watt panels, their amperage would in 2s & 2p string, exceed the limits, again just taking a guess why he would be wrong suggesting me to only connect 3 when these are weaker on the amperage end than what he maybe had in mind, hehe, maybe he heard me crystal clear & for the sake of safety wouldn't suggest otherwise.
Just to be sure I understand you completely, when I write 2 strings x 2s & 2p, is that the same as your 2 x 4p?
My drawing might even be wrong with the way I describe it
That makes more sense now, I can see why your also confused too regarding that part.
About the Batteries, I already have a small wooden shed on the other side of the wall where theres a previous hole from a old Sattelite TV. (Keeping that shed will take up some space & maybe limit the amount of panels, but not completely sure yet, will figure out later today)
They used a old tube, which I will probably rip out, drill the hole a little bigger, throw a tube into another tube, and use the surrounding open are to get some ventilation moving out that way since my apartment is like a sauna, due to the amount of windows & my lucky southern ocean view position, basicly year round, the sun doesn't have to shine much, I'm also sandwiched between two other tenants.
With a termostat controller & its sensor outside, connected to the fan, I believe that won't be an issue, but I plan to have the inverter on the other side of the wall, here in my living room, I can add some pictures if you'd like & don't mind this centuries biggest cluttery mess
EDIT: I am such a joke, now I mentioned the mess, I just walked to the kitchen to grab a drink, & what do I notice laying on the LiFePo4 Battery crate, a complete danish manual for setting everything up, kvadrat is simply mm2, the awful danish language
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Yes, while reading this manual, I'm now certain that he didn't hear me when I said 240 watt, he thought I meant their references or similar.
"Recommended PV cabeldimensions:"
Model 1030: 4mm2 (15-18A)
Model 1050: 6mm2 (30-60A)
These are the exact same details/numbers he adviced me when I asked about string & cabel size yesterday
I'll continue
"Control of voltage from the panels"
Before connecting & turning on the inverter, you have to meter the current from the panels, which should be:
HybridPower 1030 MPPT: 30-115V (Max 145V)
HybridPower 1050 MPPT: 60-115V (Max 145V)
At voltages above the max level, NEVER plug in. The inverter will then burn off.
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google translating: (The words Arbejdsspænding, Spændingsniveauet & tomgangspændings translation is a bit confusing)
You'll see it as, Working voltage, Voltage level, Idle Voltage).
Panel Interconnection
The following examples apply to panels with approx. 30v Vmp (working voltage) (typically 270-310W).
If you have panels with a different working current, then you have to calculate the voltage level yourself. Remember to take into account changes in panel voltage due to heat and cold. As a rule of thumb, the working voltage + 15% and -15% must be within the MPPT range. Also remember to take into account the idle voltage (Voc).
HybridPower 1030 & 30V Panels
On HybridPower 1030 you can connect up to 2000wp panels as follows:- 1,2 or 3 panels in 1 string
- 1,2 or 3 panels in 2 strings
- 1 or 2 panels in 3 strings
Then theres several pictures as an example
But this is just perfect, & I suppose this confirms my believe that it is indeed possible for me to accomplish this 8 panel setup as the final result
-
Pictures are great...
I see you have already some answers since I started writing this reply--But I will leave as is.
Regarding wire AWG conversion, I am guessing that Kvadrat (Danish for "square'?) is sq mm:
https://www.engineeringtoolbox.com/awg-wire-gauge-d_731.htmlAmerican Wire Gauge
(#AWG)Diameter
(inches)Diameter
(mm)Cross Sectional Area
(mm2)0000 (4/0) 0.460 11.7 107 000 (3/0) 0.410 10.4 85.0 00 (2/0) 0.365 9.27 67.4 0 (1/0) 0.325 8.25 53.5 1 0.289 7.35 42.4 2 0.258 6.54 33.6 3 0.229 5.83 26.7 4 0.204 5.19 21.1 5 0.182 4.62 16.8 6 0.162 4.11 13.3 7 0.144 3.67 10.6 8 0.129 3.26 8.36 9 0.114 2.91 6.63 10 0.102 2.59 5.26 11 0.0907 2.30 4.17 12 0.0808 2.05 3.31 13 0.0720 1.83 2.63 14 0.0641 1.63 2.08
10 AWG = 5.26 mm^2.
1.5 mm^2 is way too small for 32.44a (or 40.5a derated).
However, if you look at a marine specification for wiring 14 SAE (AWG is American Wire Gauge, SAE is Society of American Engineers--Note that SAE is slightly smaller than same gauge number in AWG).
https://www.westmarine.com/WestAdvisor/Marine-Wire-Size-And-Ampacity
14 cable SAE is rated for 35 Amps maximum in boats. 14 AWG is rated for 15 Amps in NEC (technically 20 Amps, but for some reason I could never find, 14/12/10 AWG have all been derated by 5 amps in the NEC tables over what the "math" said should be the current rating).
I worked on a small apartment building that used 14 AWG wire on an electric water heaters that was drawing something like 19.x amps (vs 15 amps NEC rating) in metal conduit... Built in 1955 or so, and wiring looked fine (no sign of overheating). I did replace the 14 AWG wiring with 10 AWG and a 30 amp breaker a few years ago--Just because I felt better (other issues, the 20 amp breaker was tripping after 60 years, and I needed to install a larger breaker to make it reliable as the replacement breakers would trip too).
Anyway, as I said, NEC is much more conservative vs Marine ratings...
You are correct... He does not understand the differences between your 240 Watt panels vs the ~300 Watt ones in the specifications/manual. I don't see any reason to be concerned with 4x parallel strings of the smaller panels.
Regarding wire diameter (or mm^2), you can run into issues where the wire binding points in the inverter might not take the larger diameter cable. You might have to connect a smaller pig tail for a short run to the connection points. Or you can trim a couple strands off the cable to fit the hole/binding area (frowned upon by code--But it is your system and decision).
Looking to make things fire resistant... Using sheet rock (gypsum wall board) or concrete backer board (concrete boards used in wet areas) for wall/floor or similar material vs all raw wood if there is a small electrical fire to prevent/reduce chance of fire spread.
-BillNear San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset -
I sure did, hehe, that paper pamplet gave a great amount of info.
Edit: Kvadrat must be mm(2), a danish online shop selling csbled categorizes it as 6mm2, looks to be a thick decent cable. Between 9 & 10 Gauge.
I see, so would I actually be able to use those 4 to 1 MC4 + & - cables I got?
I thought about making use of some starlite to plaster the interior so it wouldn’t get in contact or be able to get around, burning the wood, it is a super efficient thermal deflector, a flattened thin dough of it can resist a gas burners torch pointed directly towards your hand, & it will be unharmed, even for an extended amount of time, hoping that would be secure enough & its cheap to make 😃
https://youtu.be/aqR4_UoBIzY
The inverter indoor will be mounted on a fire resistant wooden surface
haha, so much have changed in this day & age, but I would probably had done the same & switch the 14AWG 😅
I’m missing out on alot I’m certain, eyes are getting swollen, my own personal batteries are shutting down, going into sleep mode to recharge 😅 but will follow up on your post, atleast its now somewhat clear which cable size range to go with 😃👍 -
It is close to send 32 amps down 10 AWG cable... Still missing the fuse/breaker per string (should be used when you have 3 or more parallel string connections in an array). You can get MC4 fuse holders (and preloaded with XX amp fuses). Hopefully these Amazon links works for you (find same/similar product that can get shipped to you for more reasonable pricing than from USA):
https://www.amazon.com/mc4-fuse-holder/s?k=mc4+fuse+holder
https://www.amazon.com/Odyssey-15A-Solar-Holder-Waterproof/dp/B00VAQHLVY (including 15 amp fuses)
Yes, the 4-1 MC 4 combiner would work, and probably is "safe enough" for your usage. And running 32.xx amps (rare peak current on cool/clear day around solar noon) on 10 AWG cable and 30 amp rated connector is not going to end the world.
The MC-4 fuse holders are not cheap, but cheaper than a typical combiner box... Your voltage drop on the 10 AWG cable with ~32 amps is not bad.
Just keep an eye on everything (no melting insulation, etc.). It is always the trade off between conservative design and running on the edge/cost effective design. You are not over the edge on anything.
Good night,
-BillNear San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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