Solar Panel, Inverter and Large UPS's - Offgrid system help pls

[inetdog]

Hello fastfwd,

The image hosting site that you have chosen, postimg.org, is throwing random ads onto the full page views of your images. Ads I can tolerate, but some of the ads they are using are misleading at best and malicious at worst. Please try to find a different hosting site, as we may be forced to delete all of your image links. Still deliberating that.

inetdog, Moderator.

[solar pete]

Yep, I think if I were in your shoes I would take the 5 best panels and see if you can get some more exactly the same, (you generally need at least 6 panels to get minimum voltage on a string).....you may find that a wholesaler around the place might have a few more and do the grid tied, it will be easier and cheaper than trying to incorporate those batteries as they just are no good for daily cycling What was the brand of the panel again, I can ask the boys if we have any in the warehouse, cheers

[fastfwd]

Well I dont know,... what old mate fastfwd is paying sounds like .26 cents AU, over here in little old Adelaide I pay between .26 cents to .40 cents, thats cause our moron gumbyment sold our electricty network (that was already bought and paid for from tax payer dollars) to a Singapore billionaire and agreed to make up new laws for him guaranteeing he make at least 10% a year on his money, HOW THE HELL DOES THAT WORK, ok rant over, go solar

pete you being from Aus also and having a similar system to what i have in perth. You think im better of just using as much of that solar gear as i can and get a qualified solar installer to install it as a normal solar solution attached to the grid like any other house in aus? I think 1.5KW systems here are around $1500-2200 AUD installed. I believe 1 of the 6 panels i have that is smashed needs replacing but the rest have been tested working perfectly. The inverter that i have is a 2800Watt (3000watt DC). Being that i only have 5 x 255watt panels that are working fine i have roughly 1250watts total of panels atm. I could use all of that equiptment...buy another 5 panels on top and have a 2.5kw system for half the price?

you think this might be a much better idea?

[solar pete]

Well I dont know,... what old mate fastfwd is paying sounds like .26 cents AU, over here in little old Adelaide I pay between .26 cents to .40 cents, thats cause our moron gumbyment sold our electricty network (that was already bought and paid for from tax payer dollars) to a Singapore billionaire and agreed to make up new laws for him guaranteeing he make at least 10% a year on his money, HOW THE HELL DOES THAT WORK, ok rant over, go solar

[Living Large]

That 26-cents is Down Under Dollars, Convert that to USD is 19-cents. LOL

Oh, I didn't see that. I found a 4 year old link that compares costs between numerous countries in US $, and from what I found I assumed the $.26 was USD. Yes, at 0.19, LOL.

[Sunking]

Do the math. I do not think you can come close to beating the POCO, even at $.26/kwh. And what is the cost of parenting this beast? Immeasurable.

That 26-cents is Down Under Dollars, Convert that to USD is 19-cents. LOL

[Living Large]

lets say i ditch the idea of using my UPS's as battery banks as it does seem a little difficult for what i will get out of it. Going forward with my 6 x 255watt panels(1500watt total) providing they work (having them tested today). What would i need for an offgrid system to be equal to the amount of power my solar setup will generate? Example: batteries, charge controller etc. Looking to run a minimum of 4.2kWh/day to a maximum of how much the 1500watt solar panels and battery bank can take.

I'm happy to spend a bit of money providing its going to save equal to the same ammount or more over a few years. Here in Aus the price of power is ludicris at roughly 26c per unit.

Your question appears to be, can an off-grid system be built and maintained for less than 365*4.2*0.26 = $400 a year? Your panels wear out after 20 or 25 years, inverter, CC etc 10 years. Batteries? Let's say 4 years though the varies a lot. Will you need a backup (generator) for topping off and cloudy weather?

Do the math. I do not think you can come close to beating the POCO, even at $.26/kwh. And what is the cost of parenting this beast? Immeasurable.

[Sunking]

lets say i ditch the idea of using my UPS's as battery banks as it does seem a little difficult for what i will get out of it. Going forward with my 6 x 255watt panels(1500watt total) providing they work (having them tested today). What would i need for an offgrid system to be equal to the amount of power my solar setup will generate? Example: batteries, charge controller etc. Looking to run a minimum of 4.2kWh/day to a maximum of how much the 1500watt solar panels and battery bank can take.

I'm happy to spend a bit of money providing its going to save equal to the same ammount or more over a few years. Here in Aus the price of power is ludicris at roughly 26c per unit.

Simple there is no possible way you can get 4.2 Kwh/day usable with 1500 panels in your location. Only way to get to 4.2 Kwh per day with only 3.25 Sun Hours is if you use 2000 watts of panels. running a 24 volt battery @ 875 AH, with a 80 amp MPPT controller.

[Sunking]

Just doing some more digging...

found this site on the forum http://pvwatts.nrel.gov/pvwatts.php - a 1.5kw solar system such as the one i have acquired supports a maximum of 7.8kWh max in summer and a 3.9kWh minimum in winter at my address. I have 175watts of usage i want to power off grid which adds up to 4.2kWh per day.

So really i am on the money with the solar setup i have for the power i want to support, i just need storage that can support the same. Where can i look for a solution for this and what coin am i looking at spending to provide such a solution? at 26c a unit in Australia the cost comes to roughly $700 in savings per year. Will the batteries for this cost more than $700. If it can pay itself off in one year that would be ideal.

You have done so many things wrong, it is hard to decide where to start.

So let's start on Pay Back. It is impossible to ever acheive payback on an Off-Grid System. Anything you take off-grid will cost you 4 to 6 times more than buying it from the POCO the rest of your life. So if you are considering doing this to save money, then you are delusional. Never going to happen

Second blunder down under you made is sizing your battery to be fully discharged every day. If you do that, your batteries will be dead in less than a year. Minimum battery size for a system to be cycled daily is 5 times the capacity you use in a day which gives you 3 days of clouds to CYA and to maximize battery cycle life. Emergency system size is 2 days. So you have estimated $700 is delusional, more like $3500 to get the most bang for your buck. If you buy a top of the line battery, only discharge 20% per day, you might get 5 years out them before needing replaced. However that takes a lot of Tender Loving Care to get 5 years. At 4.2 Kwh per day requires a 12 volt 1750 AH weighing in around 1300 pounds and costing around $4000 for a 5 year battery

Lastly no place on earth gets 12 Sun Hours. When you looked at PV watts, you inputted garbage and got garbage out. Efficiency assumption in PV watts is 80% for a Grid Tied System. You did not change that to 66% if using a MPPT controller, or 50% if you use PWM Controller. So everything you got from PV Watts is garbage because you input garbage. In a off-grid solar system you have to use the worse case month of the year. You cannot use average or peak. If you use say Average, you go dark in short months. So adjusting and accounting for your eror in winter you receive 3.25 Sun Hours in winter. I have no clue where you came up with 12 Sun Hours, but that is Horse Feathers and Fairy Tales. So at best your 1500 watt solar panel can only generate [1500 watts x 3.25 hours] x .66 efficieny factor = 3.2 Kwh of usable energy per day. Good news is with only 3.2 Kwh only requires a 12 volt 1330 AH, 1000 pound, $3200 battery. If you could get a full 5 years out of your 1st of batteries (impossible for a newb) battery coast alone and nothing else will cost you $0.542 per Kwh USD or $0.75 per Kwh Australia Dollars. So your 26c Australian just went down under the tubes. YOU WILL BE PAYING 3 times as much for power vs buying it jus tin battery cost alone.

[fastfwd]

Just doing some more digging...

found this site on the forum http://pvwatts.nrel.gov/pvwatts.php - a 1.5kw solar system such as the one i have acquired supports a maximum of 7.8kWh max in summer and a 3.9kWh minimum in winter at my address. I have 175watts of usage i want to power off grid which adds up to 4.2kWh per day.

So really i am on the money with the solar setup i have for the power i want to support, i just need storage that can support the same. Where can i look for a solution for this and what coin am i looking at spending to provide such a solution? at 26c a unit in Australia the cost comes to roughly $700 in savings per year. Will the batteries for this cost more than $700. If it can pay itself off in one year that would be ideal.

[fastfwd]

NO, those AGM batteries are NOT meant for daily cycling. Notice the "HR" designation. That's the "high-rate" discharge version, even worse than the general purpose models for cycling.

Essentially, these are the wrong batteries, similar to an SLI, or automotive starter battery, which is the wrong type to use with a solar setup.

But could you? Yes, or course - but you'll only get about 300 cycles, if you are lucky, from them for daily cycling to 50% DOD, and that is if they are indeed in nearly perfect shape.

Adding to that, is the problem that nobody recommends a large bank made up of small cells in a large series/parallel arrangement for capacity. At least not here. Back in the 90's, maybe the EV guys would have to do this (and they did so primarily with Genesis 18ah agm's). YOURS are even smaller at only 5.5ah capacity each.

The biggest problem is that you will learn basically nothing from this setup if you are interested in solar, aside from doing a one-off benchtop hack for an inappropriate UPS bank.

Still, they are free, so if you want to fool around, then pick only TWO of the best ones at most to parallel for a 12v system. That would be about an 11ah rating. Recycle the rest.

Now, with two of them in parallel, use no more than a 60W panel and a small pwm charge controller. These batteries are rated at a current no larger then .3C, so 11ah * .3 = 3.3A. A 60 watt panel (60w / 18v = 3.3a) is a perfect fit.

What to do with it now? Attach a mobile 5v USB adapter and charge tablets and cellphones. Or a small 12v dc/ac inverter, and run an LED (40w equivalent that actually pulls about .7W) bulb in a nearby tablelamp. Since only half the battery's power is usable for any sort of cycle life, that means you'd be able to run that LED bulb for about 7.5 hours before needing to recharge. And don't expect more than a year's life out of these faux-starter batteries.

So, there is some stuff you can goof on, but most of it is trash for our purposes. If you must press on, grab a Tecmate-Optimate 3, or model 6 charger to cull the best from the pack.

Great information thankyou,

lets say i ditch the idea of using my UPS's as battery banks as it does seem a little difficult for what i will get out of it. Going forward with my 6 x 255watt panels(1500watt total) providing they work (having them tested today). What would i need for an offgrid system to be equal to the amount of power my solar setup will generate? Example: batteries, charge controller etc. Looking to run a minimum of 4.2kWh/day to a maximum of how much the 1500watt solar panels and battery bank can take.

I'm happy to spend a bit of money providing its going to save equal to the same ammount or more over a few years. Here in Aus the price of power is ludicris at roughly 26c per unit.

[PNjunction]

NO, those AGM batteries are NOT meant for daily cycling. Notice the "HR" designation. That's the "high-rate" discharge version, even worse than the general purpose models for cycling.

Essentially, these are the wrong batteries, similar to an SLI, or automotive starter battery, which is the wrong type to use with a solar setup.

But could you? Yes, or course - but you'll only get about 300 cycles, if you are lucky, from them for daily cycling to 50% DOD, and that is if they are indeed in nearly perfect shape.

Adding to that, is the problem that nobody recommends a large bank made up of small cells in a large series/parallel arrangement for capacity. At least not here. Back in the 90's, maybe the EV guys would have to do this (and they did so primarily with Genesis 18ah agm's). YOURS are even smaller at only 5.5ah capacity each.

The biggest problem is that you will learn basically nothing from this setup if you are interested in solar, aside from doing a one-off benchtop hack for an inappropriate UPS bank.

Still, they are free, so if you want to fool around, then pick only TWO of the best ones at most to parallel for a 12v system. That would be about an 11ah rating. Recycle the rest.

Now, with two of them in parallel, use no more than a 60W panel and a small pwm charge controller. These batteries are rated at a current no larger then .3C, so 11ah * .3 = 3.3A. A 60 watt panel (60w / 18v = 3.3a) is a perfect fit.

What to do with it now? Attach a mobile 5v USB adapter and charge tablets and cellphones. Or a small 12v dc/ac inverter, and run an LED (40w equivalent that actually pulls about .7W) bulb in a nearby tablelamp. Since only half the battery's power is usable for any sort of cycle life, that means you'd be able to run that LED bulb for about 7.5 hours before needing to recharge. And don't expect more than a year's life out of these faux-starter batteries.

So, there is some stuff you can goof on, but most of it is trash for our purposes. If you must press on, grab a Tecmate-Optimate 3, or model 6 charger to cull the best from the pack.

[fastfwd]

Before i find out if these batteries would be fine for cycling daily. Just doing some research on draw requirements and what these UPS's will hold.

So the 175watts of power draw to hold up my fridge, small switch rack and server at home which i have calculated with my power monitor for 12 hours.

http://powerquality.eaton.com/UPS/se.../byLoad_01.asp - using this online eaton calculator i put in 175 watts and maximum time allowed and it recommended the MX2200 series with 3 x EXB battery modules which is what i have already. Its the smaller of the 2 sets of UPS's i have. This says it will keep alive 175 watts of draw for 12.5 hours. These UPS's have a max draw of 1900 Watts and my Solar panels have a max of 1500 Watts. I cant find information on this but from memory they take 3-6 hours to charge once they have depleted. I think 1500Watt of solar charge through a 12 hour day should be enough to charge them.

now just to find out if someone can take a look at these batteries to see if i can cycle them daily.

[fastfwd]

It would be interesting to get the proper specs for the batteries, we have several resident battery experts who might chime in. Sounds like you should be able to do something with them, I am no techy so I wont be much good to you with this project. It could be that those batteries are still worth a bit of $$

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These are the batteries. There is 2 banks of 15 in each EXB which makes 30 batteries per EXB and i believe the UPS models have 20. So at a minimum there's 110 of these batteries per UPS stack...if i run the two UPS stacks with the connector to both UPS's there is a minimum of 220 of these batteries for the 2 x MX4000 series UPS's.

The battery says 12V, 22WPC/15min./1.30VPC/25C

Website for the battery - http://www.bb-battery.com/productpages/HR/HR5.5-12.pdf

here are some more images of me pulling apart the UPS.



Here is the pictures/details on the solar panels and the Inverter:




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[solar pete]

Thanks for the info Pete, very helpful.

I have 6 panels so its 1500WATT. You may be correct the UPS's are 3600WATT max per UPS totaling 7200WATT if you add them up but that is usage on stored power not actual power needed to charge them.

I agree its probably going to be useless as UPS's batteries are made to hold charge and not cycle daily. What i could do is pull one of the batteries out as they are easily accessible. The last time i checked they were Phillips or Panasonic made. I will check the actual details on the batteries themselves. If they are suitable i might be able to pull all the batteries out and daisy change them to a charge controller or something.

Really just trying to use what i can for free for the time being. These UPS's themselves were 30-40k AUD each including battery banks and there's 4 of them and plus the solar stuff there's over 150k worth of equipment as new value. I have seen some people online do some stuff like this i just need some direction where to start.

It would be interesting to get the proper specs for the batteries, we have several resident battery experts who might chime in. Sounds like you should be able to do something with them, I am no techy so I wont be much good to you with this project. It could be that those batteries are still worth a bit of $$