Office solar setup - checking up numbers and loads of Qns as usual

Nila

Load:
Morning : (10AM - 5PM )
25 computers at atleast 110Watt each.. of which 20 will be definitely ON all the time and 5 randomly used.
some lights should be like 10W * 20 so 200Watts there .
a laser printer

Evening (5-7PM ):
30 computers at same wattage 110W.
200watts of lightings may be couple more for the night..

Night : (7PM - 2AM)
6 Computers at same wattage and
fewer lights , about 10 of them

Everything is switched off between 2AM to 10AM in morning.

Grid availability and usage :
Grid will be switched off for 6 hours in 2 ( 3 hour blocks ) between morning to evening and another 2 hours between evening to night .
Power will be available on and off every day but there are some so-called scheduled maintenence where you get a complete down time 9-5 !!

Panel specs from my vendor:
Watts: 230
VMP : 29.61
VOC : 37.08
IMP : 7.77
ISC: 8.25

Inverter: Xantrex XW 6048.
2x CC: Xantrex MPPT 150 / 60
Battery bank : 600AH at 48V ( 4 years warrenty ) 200AH / 12V batteries 4 in series/ 3 strings.

Generator : 20KW existing diesel generator which I would like to turn it off for goodness.

Weather averages are between 24c-40c ..
Even record temperatures will not go below +12C - +48C so we do not need to worry about those extreme VOC's

Solar PV Array :
I believe I can have 3 panels in series for 150VOC CC safely.
and CC Specsheet tells me I can have 5 parallel strings.

so 3 in series and 5 parallel strings which means 15*230 = 3450
( 3540/58 = 59.48 approx theoritical max amps ) and CC Is rated for 60 A so I believe that is the max this CC can take with my panels.

Now If i add another CC , I can easily add another 3500watts of panels .

Is there a better idea? here. and are my numbers correct?


Expectations :

Trying to run all the computers and lighting with this PV modules all the morning 10-5 AM or at-least for most part of it , and use Grid charging only if battery goes below lets say 70%.
So I can maximize the bleeding energy..

Trying to reduce the Generator usage which sucks 20$ worth of fuel every day from us.


Questions:
how much panels do we need to be able to efficiently keep batteries charged and also to have enough PV output to power the computers,etc directly during mornings?

Xantrex 6048 has grid export facility.. Actually we cannot sell back to grid here so is there any other use of that function?

Is Xantrex 6048 worth the 3x spending over a local brand inverter? especially for our usage pattern?
When going with xantrex we think we need to buy the Control panel/distribution panel together too so that raises costs a bit.

Regarding Charge controller.. I wanted to go with midNite but xantrex has local availability and much better pricing.
MidNite Sales people seem to be too busy for us and I am not feeling good using them at the moment.

If i plan to have like 4.5KW of panels for now and add 2.5KW later on.. is it okay to split it across 2 Charge controllers and scale it that way?

Battery bank, I sized it actually keeping in the mind that we need it only as a backup/morning time buffer and not like something we absolutely depend on.
We can actually just use generator to charge whenever battery goes below 50%.

We can get the Govt rebates/other advantages only if we go with the 230/ or lower watt panels and not with the higher/cheaper panels.
will this Panel spec I posted work right with my cc/bank?.


Sorry for lot of questions at once.. I am going to bank tomorrow to like sort of talk with them and arrange loans,etc I wanted to be sure I'm doing this right.

BB/Coot, I know you have been helping me a lot with the initial planning of this system. I am very thankful for you guys.

And you tell me If/when I can move out of the Beginners corner ?


Again - please feel free to yell at me if i do not make sense anywhere or over expecting stuff.

Cariboocoot

Re: Office solar setup - checking up numbers and loads of Qns as usual

One thing I can think of to start off: any chance you can switch out those 25 computers using 110 Watts each for 25 laptops that will use like 35? We're talking 75 Watts * 25 = 1875 Watts less, which is 13 kW hours per day right there. Might be worth it to spend the money on new computers rather than on the power system.

Otherwise for that one time period you've got 25 * 110 = 2750 Watts * 7 hours = 19,250 Watt hours just for computers. 200 Watts in lighting over that time adds another 1400 Watt hours.
Switch to the laptops and it's more like 25 * 35 = 875 watts * 7 hours = 6,125 watt hours. In most (but not all) cases the laptop can do anything a desktop can.

At one point in the day you will have 30 of these computers running (3300 Watts) plus lighting and printers (routers? Internet modem(s)?) so the 6 kW inverter is probably a good idea at that level.

I'm being dogged here; have to go right now. But you see how much can be saved if the loads can be reduced. The intermittent grid makes sizing the battery bank a lot of guess work. We'll try to figure something out.

Nila

Re: Office solar setup - checking up numbers and loads of Qns as usual

Hi Coot,

Regarding the laptops -- they cost very high on repairs and desktop is very cheap.
We are some sort of web dev/software developers so using laptop for like 9 hours is very very hard and desktop is very convenient.

Also note that most computers do not take 110.. just some of them and I can bring them to like 70 or 50W if i remove the individual UPS connected to each PC and use better PSU's

Each UPS takes like 20W , so u can consider each PC to take about 90W not 110W and I am sure with some optimizations I can bring it down to like 75W.

It is possible we may add staffs in future so i wanted to give myself some room to work with for the future


Routers// modems yes but they are negligible compared to the size of the load. Printer we use it very very rarely.

Please help me size my bank correctly.. I would be happy to down size it like to 400AH haha as it saves lot of costs.

Cariboocoot wrote: »

One thing I can think of to start off: any chance you can switch out those 25 computers using 110 Watts each for 25 laptops that will use like 35? We're talking 75 Watts * 25 = 1875 Watts less, which is 13 kW hours per day right there. Might be worth it to spend the money on new computers rather than on the power system.

Otherwise for that one time period you've got 25 * 110 = 2750 Watts * 7 hours = 19,250 Watt hours just for computers. 200 Watts in lighting over that time adds another 1400 Watt hours.
Switch to the laptops and it's more like 25 * 35 = 875 watts * 7 hours = 6,125 watt hours. In most (but not all) cases the laptop can do anything a desktop can.

At one point in the day you will have 30 of these computers running (3300 Watts) plus lighting and printers (routers? Internet modem(s)?) so the 6 kW inverter is probably a good idea at that level.

I'm being dogged here; have to go right now. But you see how much can be saved if the loads can be reduced. The intermittent grid makes sizing the battery bank a lot of guess work. We'll try to figure something out.

Cariboocoot

Re: Office solar setup - checking up numbers and loads of Qns as usual

I here you about the desktops. We've had both, and when a laptop fails it's a write-off; not worth the repair effort. The desktops ... well I've got some very old HD's that just keep migrating from one to the next in case we still need the data. Hurrah for the day when we don't! Around here laptops are cheap, which may not be the case everywhere too. But for our work the laptops suffice and were a great improvement for saving power at the cabin. Desktop would use as much as 190 Watts at times; laptop maximum 35. My netbook (which suffices for my work) uses 12.

So if the loads can't be reduced further than you need the 6kW inverter capacity, or more if you're going to expand. When everything is on at once, there's your number. Aside from the XW you could use stacked Magnums or an Outback Radian. Better part of $4,000 US no matter what, and that's not necessarily the price where you are either. Try to look up Victron inverters; might be better/cheaper where you are.

Now as for that battery bank ...
First thing you have to work with is the total loads in Watt hours. This is huge as we already know. Second thing to consider is how long you'd actually have to depend on them to supply the power. This is the big question mark as your utility supply is erratic.

It seems you can count on it being off for 3 hours straight. But how long between 'outages'? Will there be enough time inbetween to recharge partially or fully? Big question mark again. Over-all you've got 8 hours off time per day. But sometimes that will be all in one block, right? So I'd suggest trying for a battery bank that can supply full power for 8 hours. Your biggest draw is around 4kW and if you multiply that out by 8 hours you get a whopping 32 kW hours.

On 48 Volts that's 667 Amp hours.

How are you fixed for obtaining forklift batteries? Is it possible? If so, you can start "cutting corners" on the numbers there as they can take 80% DOD so the battery bank needs only be around 1,000 Amp hours. This makes it easier to recharge too.

Let's see if we can get the battery bank size fixed before we try to guess at PV & controllers.

NorthGuy

Re: Office solar setup - checking up numbers and loads of Qns as usual

paimpozhil wrote: »

We are some sort of web dev/software developers so using laptop for like 9 hours is very very hard and desktop is very convenient.

At one point I used laptop as my main computer. I had a huge monitor, keyboard and mouse connected to it and it felt more like desktop. I needed this mostly for travel. If I need to, I just disconnect laptop and go. It was really simple connection called "docking station" - you slide laptop in and everything works.

The huge plus of this system was that it didn't need UPS. If there was a power outage, laptop simply used its batteries, so I had a very small UPS for monitor only. I didn't do that to decrease consumption, but it happened to be very energy efficient. Laptop - 20W. Monitor was a huge drag, but now there are some energy efficient one. One workplace will consume no more than 40W. But if you let laptops take care of themselves this is only 20W for monitor that you need during outage.

Whatever you overspend on laptops, will pay back because you need much less batteries and solar panels.

Nila

Re: Office solar setup - checking up numbers and loads of Qns as usual

Hey Coot,

A typical desktop costs around 300-400$ here for us.
Same config on the laptop would be atleast 600$.

I will talk with my partner to see if he likes this idea

When a keyboard fails its like 6$ on PC, on laptop it is like 25$ .. screens 25$ vs 75$.
Also I know for sure guys here will not treat things carefully and they like to abuse the devices haha.

So Rugged Desktops is much better deal for us on long run.

Desktops depreciate slower as you can keep adding ram and upgrade CPU .. and later change mobo ,etc and keep things running swapping parts is easy .
Laptop cannot be upgraded easily.. it has its limits.

Me and my partner and all our management staffs do use Laptops. atleast 5 of our employees do use laptops instead of desktops and keep in mind that I quote the loads bit higher than what it is now because I know for certain we will scale a bit in near future



Battery Bank:

Yeah I can count on it for being off 3 hours straight.. time between outages will be like 2 hours usually but its not written on the stone..
I can use generator anyway for any outage more than that .

I would say lets have a system that can do backup for like 4 hours max, anything more than that we should be backing up on the generator .
that's about 16KWH and , I think i need 666AMPs at 48v.

Realistically I believe our loads MUST be only about 3kw or bit lesser but lets not consider it for now .

Industrial forklift batteries are like 10x or even 20x costlier than LA batteries. i am trying to go with LA which has 4 year warrenty.

I think just 3 strings of 200AH / 12V will give me 600AH which I think is enough for this setup.. do you agree?

Cariboocoot wrote: »

I here you about the desktops. We've had both, and when a laptop fails it's a write-off; not worth the repair effort. The desktops ... well I've got some very old HD's that just keep migrating from one to the next in case we still need the data. Hurrah for the day when we don't! Around here laptops are cheap, which may not be the case everywhere too. But for our work the laptops suffice and were a great improvement for saving power at the cabin. Desktop would use as much as 190 Watts at times; laptop maximum 35. My netbook (which suffices for my work) uses 12.

So if the loads can't be reduced further than you need the 6kW inverter capacity, or more if you're going to expand. When everything is on at once, there's your number. Aside from the XW you could use stacked Magnums or an Outback Radian. Better part of $4,000 US no matter what, and that's not necessarily the price where you are either. Try to look up Victron inverters; might be better/cheaper where you are.

Now as for that battery bank ...
First thing you have to work with is the total loads in Watt hours. This is huge as we already know. Second thing to consider is how long you'd actually have to depend on them to supply the power. This is the big question mark as your utility supply is erratic.

It seems you can count on it being off for 3 hours straight. But how long between 'outages'? Will there be enough time inbetween to recharge partially or fully? Big question mark again. Over-all you've got 8 hours off time per day. But sometimes that will be all in one block, right? So I'd suggest trying for a battery bank that can supply full power for 8 hours. Your biggest draw is around 4kW and if you multiply that out by 8 hours you get a whopping 32 kW hours.

On 48 Volts that's 667 Amp hours.

How are you fixed for obtaining forklift batteries? Is it possible? If so, you can start "cutting corners" on the numbers there as they can take 80% DOD so the battery bank needs only be around 1,000 Amp hours. This makes it easier to recharge too.

Let's see if we can get the battery bank size fixed before we try to guess at PV & controllers.

Nila

Re: Office solar setup - checking up numbers and loads of Qns as usual

Hi NorthGuy,

I completely agree with you from this point, Whatever we spend on laptop will come back on savings from less panels/batteries.

I believe you don't even need that UPS if you are ready to work with smaller screen until power comes back.

However like i replied to coot, This is not really going to work for my staffs,,

This suggestion would definitely work for me though , I am using laptops at office already.

Having a large Dell 17" will not require me any mouse keyboard or monitor lol.. it is a DESKTOP

Everything is cool until i open it on the cheap flight with limited spacing ).. the guy next to me will be freaking out.

NorthGuy wrote: »

At one point I used laptop as my main computer. I had a huge monitor, keyboard and mouse connected to it and it felt more like desktop. I needed this mostly for travel. If I need to, I just disconnect laptop and go. It was really simple connection called "docking station" - you slide laptop in and everything works.

The huge plus of this system was that it didn't need UPS. If there was a power outage, laptop simply used its batteries, so I had a very small UPS for monitor only. I didn't do that to decrease consumption, but it happened to be very energy efficient. Laptop - 20W. Monitor was a huge drag, but now there are some energy efficient one. One workplace will consume no more than 40W. But if you let laptops take care of themselves this is only 20W for monitor that you need during outage.

Whatever you overspend on laptops, will pay back because you need much less batteries and solar panels.

Cariboocoot

Re: Office solar setup - checking up numbers and loads of Qns as usual

paimpozhil wrote: »

I think just 3 strings of 200AH / 12V will give me 600AH which I think is enough for this setup.. do you agree?

Well if we cut the 'down time' to 4 hours instead of 8 then yes it dials in around 667 Amp hours at 48 Volts.

Being able to count on the generator will ease things too, but I'd advise building in at least the ability to add some more capacity right away if need be. Once the system is running you'll find out within a year whether or not you have enough battery capacity and in that time adding on some more is still possible. or you could simply go with four strings (about the most you'd ever want to put in parallel) right from the start.

So that would be initially three strings of four 12 Volt 200 Amp hour batteries for a total of twelve, with the space, wiring, and circuit protection installed to add an additional string if needed. That's 600 Amp hours capable of expansion to 800. This would give you a maximum 14.4 kW hours DC (slightly less on AC due to inverter consumption and conversion loss). The four strings would give you about 19.2 kW hours DC, which is looking like the original figure. Hey! Maybe we're doing this right?

Some extra running power may be available during daylight hours from the panels once the batteries are full. So let's talk PV array.

Normally the rule-of-thumb in this case would be to shoot for 5% peak current, as you have generator and grid available that will do most of the charging and you have plenty of daylight. Working against you is that you have plenty of heat, so the panel Voltage will be a tad low.

If we go for the larger battery bank: 5% of 800 is 40 Amps. At 48 Volts that's 1920 Watts. Normally that would get 'up sized' to 2493 Watts. The panels you were looking at were 230 Watt with a Vmp of 29. You would need three in series to get the Vmp up high enough to charge a 48 Volt system (needs to be >70 Volts, 3 * 29 = 87 which leaves room for V-drop from heating panels). Three such strings would be 2070 Watts, which would work for the 600 Amps hours (about 33 Amps) but for all four battery strings you'd want to up it to four strings (12 panels) for 2760 Watts and about 44 Amps peak current (5.5% max rate).

The good news is that can be handled by one 60 Amp MPPT controller.

How's it looking so far?

Nila

Re: Office solar setup - checking up numbers and loads of Qns as usual

This is looking very good for me

12 batteries for now.. 4 after a year if needed

20KWH DC is absolutely very good but I may not need that much for now to begin with so lets be fixed on 12 batteries... 3 strings for now.


So for panels : are you sure 2760 Watts is enough? and Please note originally I wanted to be utilize the PV power on the morning maximally.

Batteries are expensive but panels are not.. I am happy to do a 4200-4400 range array if you think it is helpful.. or atleast do the maximum 1 CC can take.

You please tell me how to do that.

Cariboocoot wrote: »

Well if we cut the 'down time' to 4 hours instead of 8 then yes it dials in around 667 Amp hours at 48 Volts.

Being able to count on the generator will ease things too, but I'd advise building in at least the ability to add some more capacity right away if need be. Once the system is running you'll find out within a year whether or not you have enough battery capacity and in that time adding on some more is still possible. or you could simply go with four strings (about the most you'd ever want to put in parallel) right from the start.

So that would be initially three strings of four 12 Volt 200 Amp hour batteries for a total of twelve, with the space, wiring, and circuit protection installed to add an additional string if needed. That's 600 Amp hours capable of expansion to 800. This would give you a maximum 14.4 kW hours DC (slightly less on AC due to inverter consumption and conversion loss). The four strings would give you about 19.2 kW hours DC, which is looking like the original figure. Hey! Maybe we're doing this right?

Some extra running power may be available during daylight hours from the panels once the batteries are full. So let's talk PV array.

Normally the rule-of-thumb in this case would be to shoot for 5% peak current, as you have generator and grid available that will do most of the charging and you have plenty of daylight. Working against you is that you have plenty of heat, so the panel Voltage will be a tad low.

If we go for the larger battery bank: 5% of 800 is 40 Amps. At 48 Volts that's 1920 Watts. Normally that would get 'up sized' to 2493 Watts. The panels you were looking at were 230 Watt with a Vmp of 29. You would need three in series to get the Vmp up high enough to charge a 48 Volt system (needs to be >70 Volts, 3 * 29 = 87 which leaves room for V-drop from heating panels). Three such strings would be 2070 Watts, which would work for the 600 Amps hours (about 33 Amps) but for all four battery strings you'd want to up it to four strings (12 panels) for 2760 Watts and about 44 Amps peak current (5.5% max rate).

The good news is that can be handled by one 60 Amp MPPT controller.

How's it looking so far?

Cariboocoot

Re: Office solar setup - checking up numbers and loads of Qns as usual

Usually the 'target' for a 600 Amp hour bank would be 60 Amps peak current (10%). That would work out something like this:
60 Amps * 48 Volts = 2880 Watts / 0.77 (typical efficiency) = 3740 Watts.
Using your spec'd 230 Watt panels it would be approximately 16 of them for 3680 Watts and probably configured at four strings of four in series.

Something else to consider would be buying a MidNite Classic which is capable of 80 Amps (10% of the larger battery bank) and using their string calculator to set up an array with your panels. It would probably be 21 or so (4830 Watts) or seven parallel strings of three.

Keep in mind these numbers are "possible" not "absolute".

Nila

Re: Office solar setup - checking up numbers and loads of Qns as usual

4 in series is not possible with 150VOC CC. will 5 strings of 3 per series do the job?

Xantrex's 80AMP is like very costly ,, more than 2 of the 60AMP controllers price here.

I guess it makes more sense to buy two 60AMP controllers instead of one 80A because I can scale/support more array later on if needed upto like 7KW.. but on 80A i would hit dead end on 4.8KW

Considering the fact that we are looking for bit of excess power in the morning to be able to use the sun directly lol.. is it okay to go with 6 parallel strings?
MidNite sizing tool says even 5 or 6 parallel strings of 3 is fine with Classic 150.. Is that okay?

If the panels provide more ampere than a charge controller would support the rest will be wasted or will it damage the controller?

Cariboocoot wrote: »

Usually the 'target' for a 600 Amp hour bank would be 60 Amps peak current (10%). That would work out something like this:
60 Amps * 48 Volts = 2880 Watts / 0.77 (typical efficiency) = 3740 Watts.
Using your spec'd 230 Watt panels it would be approximately 16 of them for 3680 Watts and probably configured at four strings of four in series.

Something else to consider would be buying a MidNite Classic which is capable of 80 Amps (10% of the larger battery bank) and using their string calculator to set up an array with your panels. It would probably be 21 or so (4830 Watts) or seven parallel strings of three.

Keep in mind these numbers are "possible" not "absolute".

Cariboocoot

Re: Office solar setup - checking up numbers and loads of Qns as usual

Don't get fixated on one model.

MidNite Classic comes in three (four actually) 'sizes': 150 Volt maximum input, 200 Volt maximum input, 250 Volt maximum input. http://www.solar-electric.com/misocl.html (don't forget the lite and mngp full flavors.:D, niel)
All have the HyperVoc function which allows the input Voltage to go to their rated V-in + nominal system Voltage for accepting Voc. In a hot climate very high panel Voltage isn't going to happen.

However, the maximum output current rating goes down as the input Voltage rating goes up. You have to balance them. I suspect that in your climate the 150 actually would work with 4 in series even though the Voc would exceed 150.

If you are planning for a lot of future expansion, go with the '60 Amps worth of panels' (six strings of 3) and one Classic 150. That would be maximum under normal circumstances and keeping the array Vmp closer to system Voltage improves the controller efficiency a bit.

These are the best controllers going at the moment, and they parallel well for future expansion.

Excess current (within reason) is simply 'clipped' (ignored; not passed) it won't damage the controller.

inetdog

Re: Office solar setup - checking up numbers and loads of Qns as usual

Cariboocoot wrote: »

All have the HyperVoc function which allows the input Voltage to go to their rated V-in + nominal system Voltage for accepting Voc. In a hot climate very high panel Voltage isn't going to happen.

However, the maximum output current rating goes down as the input Voltage rating goes up. You have to balance them. I suspect that in your climate the 150 actually would work with 4 in series even though the Voc would exceed 150.

My understanding, although I do not have a Classic, based on the literature and comments from Midnight staff on forums, is that the Classic will not actually turn on and produce output when the panel Voc goes above the nominal limit. But it will not damage the controller as long as the voltage stays below Vin +Vbatt.
The fact that Vmp is below the Vin limit will still not allow the Classic to turn on when Voc is above Vin.

Which brings up an interesting question: If the Classic is sitting with the panel voltage between Vin-max and Vin-max + Vbatt, and the battery is disconnected or gets its voltage pulled very low, will that same input voltage now damage the unit?

niel

Re: Office solar setup - checking up numbers and loads of Qns as usual

the classic will not pass current when in hyper voc, but they do have models that are rated for higher voltages that can take it out of the hyper voc range of the lower voltage classic and allow production at a higher voltage. the tradeoff is less current handling capability as you go higher in voltage with each successive model above the 150. their pv sizing tool is very good at showing the possibilities not only with differing combos of pvs, but it will show what each model of classic can do with that particular pv arrangement you've selected. keep in mind that the farther apart the input and output voltages are that are applied to the classic, the worse the efficiency will be too.

now if you are close to the 150v limit with your pvs on a cl150 you may want to consider a cl200 as edge of cloud or cold temps can push it into the hyper voc range for awhile. the hyper voc only is a buffer that prevents damages from occurring on the classic, but will not be productive for power operating in that range. of course if the voltage comes close to the top end of the hyper voc voltage range that you are running risk of damaging the classic.

inetdog

Re: Office solar setup - checking up numbers and loads of Qns as usual

Cariboocoot wrote: »

It seems you can count on it being off for 3 hours straight. But how long between 'outages'? Will there be enough time inbetween to recharge partially or fully?

If the reasons for the blackout periods is generation capacity, and if everybody gets the same, charging batteries from grid to carry through grid outages will just increase the load and cause a longer blackout period. Plus costing everyone because of the energy losses in the charge/discharge process.

It will work fine for awhile if you are the first one to do it.
By contrast, any power you get from solar to charge batteries, with the excess going to reduce your usage, benefits both you and all other users.

Nila

Re: Office solar setup - checking up numbers and loads of Qns as usual

You are right. If everyone has an inverter its going to just increase the blackouts.
Almost every home that has bit of income will run an inverter for the lighting/fan loads.. as the blackouts are so common.

To be honest I do not care about the govt/grid, They couldn't even produce/plan enough powers for big cities here.

I want to be able to take most of the Sun's energy
and if I have to get the backup energy from the grid, I do not mind when its available because that lets me use less battery.

I m investing tons of money on this crap just because of the grid failures, so I do not care about the load i am increasing or decreasing or whatever.

inetdog wrote: »

If the reasons for the blackout periods is generation capacity, and if everybody gets the same, charging batteries from grid to carry through grid outages will just increase the load and cause a longer blackout period. Plus costing everyone because of the energy losses in the charge/discharge process.

It will work fine for awhile if you are the first one to do it.
By contrast, any power you get from solar to charge batteries, with the excess going to reduce your usage, benefits both you and all other users.

Cariboocoot

Re: Office solar setup - checking up numbers and loads of Qns as usual

You'd be surprised how fast Voc can drop to an "acceptable" level for a Classic to function from.
Although the bright boys are still working on further improvements (the elusive "Voc clamp") which we in the Great White North could really make use of. It's so much fun to try and plan a system when you know the array Voc can hit 1.3X rating in Winter.

Nila

Re: Office solar setup - checking up numbers and loads of Qns as usual

Ive used the Midnite's sizing tool

For my panel spec at 3x6 and 4x5 setups.

It seems to be better with the 3x6 strings.. tool slightly warns with 4 modules.

Attachment not found.
Attachment not found.

We do not have to worry about those cold times lol..
I do not even own a different set of dress for seasons /boots or anything.. The climate here doesn't vary too much it always hot apart from few days of year when it rains.