Help with specs for my proposed RE system

tonygcan
tonygcan Solar Expert Posts: 91 ✭✭✭✭
in General Solar Power Topics #1
Hello,

I am finalizing the equipments specs for my proposed RE system. I would like to get your opinions on my equipment selection and other tips that I may need to know. Any help will be greatly appreciated.

Following is my list of equipment that I am shortlisting:

4 units Surrette 12CS-11PS 357 Amp Hour 12 Volt Deep Cycle Battery
8 units Kyocera KD225GX-LPB 225 watt polycrystalline solar panel

I'd like your suggestions for the CC. I am looking at 2 models.

1. Morningstar TS-MPPT-60 TriStar 60 Amp MPPT Solar Charge Controller
or the
2. Xantrex XW MPPT 60 Amp Solar Charge Controller

I still don't have specs for an inverter. I live in the Philippines and we work with 220 volts over here. I haven't been able to find a 48 volt DC to 220 volts AC in the WIND SUN store. I also still need to find out if they can ship to Manila, Philippines.

Would appreciate any advise on the inverter for my requirements.

Thanks for any input.
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Comments

  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    #2
    Re: Help with specs for my proposed RE system

    Hi,

    I assume you've already done the calculations to determine how much capacity you need in the batteries and how much solar you need so will leave that subject alone.

    8 of those panels are mismatched for a 48V bank, because you'd need at least 60V to EQ the batteries, so would need at least 3 panels in series. You can't put 4 in series, because then the Voc is higher than what the charge controller can accept. So best bet would be to go for 9 panels in a configuration of 3 strings of 3.
    Or
    Go with a higher capacity 24V battery bank instead of the 48V, then you can just use 4 strings of 2 panels in series. It's preferable to go for all the batteries in series instead of putting some in parallel.

    As far as the batteries are concerned, have you investigated forklift batteries instead of the Rolls? I ask, because when I did the research over here (Spain), forklift batts came out considerably cheaper than the Rolls for the same capacity and similar cycle life. It will certainly cost you less on transport. There are a few caveats with forklift batts:
    - They self-discharge slightly faster
    - They may need more frequent topping up since there isn't a lot of space above the plates.
    - They may need more frequent EQ charges, but given the amount of PV you want to install, you won't have a problem doing EQ from the PV array.

    As for the CC, the Morningstar unit is more efficient than the Xantrex if there are large voltage differences between the array voltage and battery voltage. If you go with 3 panels in series you'd be using about 90Vmp from the panels so quite a difference to the 57.6V you need to charge at.
    The morningstar also has a built in web server and ethernet connection for easy monitoring and a modular display system. As you can see, I prefer the morningstar :)

    As for inverters, you could try the Victron energy Phoenix (inverter only) or Multiplus (inverter + charger) which appear to do 220V at 60Hz, site: http://www.victronenergy.com/
    Their reseller in the philippines is: http://www.norwegianmarine.com.ph/
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #3
    Re: Help with specs for my proposed RE system
    tonygcan wrote: »
    I still don't have specs for an inverter. I live in the Philippines and we work with 220 volts over here. I haven't been able to find a 48 volt DC to 220 volts AC in the WIND SUN store. I also still need to find out if they can ship to Manila, Philippines.

    Would appreciate any advise on the inverter for my requirements.

    Thanks for any input.

    XW6048 gives 240 VAC output.

    get 9 PV's for 37A output @ 54V knock 20% off for aim & heat, and it's down to 30 amps. That would keep 4 batteries in series, happy.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #4
    Re: Help with specs for my proposed RE system

    I suspect that the "220 VAC" spec is a hold-over from the days when we used to call the two line Voltages "110 & 220". Most likely any electrical device you have runs fine on 240 VAC. Either the Xantrex or the Magnum inverters (as well as others) should work fine.
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  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #5
    Re: Help with specs for my proposed RE system

    Thank you Stephen, Mike and Cariboocoot,
    Sorry about that, I assumed that the PC panel was a 12 volt with Voc at 29.8 volts. If Vmp is 29.8 volts wouldn't that mean that 2 in series would be enough to go into a 48 volt battery setup?

    At any rate, you're correct. maybe a 24 volt system would give me more options in terms of equipment choices.

    Battery physical size and weight, freight cost are of concern to me but we don't have quality batteries available in the Philippines. We have a local manufacturer that brings out 12 volt batteries with 100Ah and 200 Ah C20 ratings but I'm not sure how durable their batteries are. I do have 4 of their 100Ah batteries hooked up to 4 - 60 watt Sharp pv panels but I've only had them for one month. Indian made Su-kam batteries are also available here. I will check out what's available.

    Thank you for the CC suggestion. If I may could I find out which one you would choose between the Morning Star or the Apollo Solar T80?

    Thank you also for the inverter suggestions. I will check out the model and also check with the local supplier.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #6
    Re: Help with specs for my proposed RE system

    From a few years ago, our host:
    Windsun wrote: »
    Just a heads up - we no longer carry the Apollo stuff for the simple reason that far too much was coming back on warranty.

    The MorningStar products seem to be a very good choice--But they can be expensive when you start adding on the options (such as digital display, external displays, Computer communication adapters, etc.).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #7
    Re: Help with specs for my proposed RE system

    On a 48 Volt system you'd normally have two "24 Volt" panels in series. They have a Vmp of around 35, so the expected Vmp for a 48 Volt system would be in the neighbourhood of 70. Charge Voltage would generally be about 57 +/-, so two panels with Vmp of 29.8 adds up to only 59.6 Volts. With the losses normally expected in the system (wiring, charge controller) that wouldn't be enough to do a proper charge, much less equalization.

    Those four batteries configured for 24 Volt would be 714 Amp hour. In my opinion you'd need a 2200 Watt array, and you'd be running a 60 Amp controller at its peak from time to time, possibly daily (depending on your charge needs). In the Philipines you probably will have a significant production losses from hot panels. You might want to consider the Outback FM80 or one of the new Midnight Classic units, and a somewhat larger array.

    Or maybe we should go back to the #1 question: what are your loads? Generally you pick and inverter and size the battery bank on that info, then set up the array & controller to meet the needs of the batteries.
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  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    #8
    Re: Help with specs for my proposed RE system
    tonygcan wrote: »
    Battery physical size and weight, freight cost are of concern to me but we don't have quality batteries available in the Philippines.

    That's why I suggested forklift batts, because that's a completely different market (with different prices) to renewable energy. If there are electric forklifts, then there must be battery suppliers.
    Hawker-enersys are a global batt manufacturer with offices in the philippines, contact details here: http://www.enersys-hawker.com/contact/contact.asp?lang=sk&ID=69
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  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #9
    Re: Help with specs for my proposed RE system

    Based on what I have learned I made the following calculations:

    500 watts at 7 hours a day = 3,500 watt hours
    allowance for cloudy days 2.5 days
    Total number of watts 8,750 watt hours
    Depth of Discharge 60%
    Alloted watt hours 14,584
    Correction Factor at 70F 1.04
    Total Watt hours 15,167
    System voltage 48volts
    Battery amp hours 316Ah

    at 24 volts it would be 631Ah

    Are my calculations correct or am I missing out on something?

    My system is off-grid with the provision to charge the batteries from the power company. We don't have provisions here to be grid tied.

    So morning star or Outback CCs it is. Thanks for the tip on the Apollo CC.

    Enersys is based in Singapore but they must be the Asia-Pacific office in-charge of the Philippines. I will inquire from them.
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  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    #10
    Re: Help with specs for my proposed RE system

    Your calcs look good. Only minor adjustment I would make is that your constant draw of 500W is about 20A on a 24V battery. So on a 631Ah battery, if the 20A was constant you'd draw it down in 31 hours, which means that when you select the battery it would be better to get one rated at 631Ah at C20, not C100.

    If you're not familiar with the "C" values for stating battery capacity this explains it nicely: http://www.windsun.com/Batteries/Battery_FAQ.htm#Amp-Hour Capacity
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  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #11
    Re: Help with specs for my proposed RE system

    Thanks for the link. Lots of good info!
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #12
    Re: Help with specs for my proposed RE system

    I don't know about your local insolation average, nor your local weather, but I would guess that 7 hours of good sun, on average per day over the course of the year is too optimistic.

    Tony
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #13
    Re: Help with specs for my proposed RE system

    There would appear to be some problems with your calculations. Is that 3500 Watts expected production or expected use? This isn't clear. As Tony said, you probably can't count on 7 hours of "equivalent good sun" per day. Unless you use a tracker, even long daylight hours don't add up to large solar harvest as the panels mostly aren't in good alignment with the sun. Also, 60% Depth Of Discharge is a no-no; you don't want to take batteries below 50%.

    Working backwards from your proposed battery bank (631 Amp hours @ 24 Volts) you get:
    Approx 300 Amp hours @ 24 Volts = 7.2 kW hours maximum @ 50% DOD
    63 Amps * 28.4 Volts charging = 1512 Watts, less derating 77% = 2 kW array (about 7.5 kW hours 'harvest' per day based on 5 hours equivalent good sun).

    In AC terms the 2 kW array would yield approximately 5 kW hours per day.

    The big question is: since you have grid, why solar? Is the grid unreliable?
    tonygcan wrote: »
    Based on what I have learned I made the following calculations:

    500 watts at 7 hours a day = 3,500 watt hours
    allowance for cloudy days 2.5 days
    Total number of watts 8,750 watt hours
    Depth of Discharge 60%
    Alloted watt hours 14,584
    Correction Factor at 70F 1.04
    Total Watt hours 15,167
    System voltage 48volts
    Battery amp hours 316Ah

    at 24 volts it would be 631Ah

    Are my calculations correct or am I missing out on something?

    My system is off-grid with the provision to charge the batteries from the power company. We don't have provisions here to be grid tied.

    So morning star or Outback CCs it is. Thanks for the tip on the Apollo CC.

    Enersys is based in Singapore but they must be the Asia-Pacific office in-charge of the Philippines. I will inquire from them.
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  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #14
    Re: Help with specs for my proposed RE system

    Hi again, sorry for not clarifying. 3,500 watts is usage. That's how much I plan to allot to my renewable energy source.

    I live in the city and we do have electricity available. Its just that we are planning a home renovation this summer and rather than purchasing a silent type generator which would cost about USD 9,000.00 I would rather spend the money installing an RE system which I could utilize everyday and still rely on when we do experience power outages.

    The generator would be a sleeping investment. From experience, since it hardly gets used, when you do need it during a blackout it will likely not be running well.

    I know that I won't be able to power as much with the RE system as compared to a generator but I will be able to power the essentials.
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  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #15
    Re: Help with specs for my proposed RE system

    New Equipment Specs 24 volt system

    4 units Surrette 6CS-17PS 6-Volt 546 Amp-Hour Deep Cycle Solar Battery in series to achieve 24 volts
    9 units Kyocera KD225GX-LPB 225 watt polycrystalline solar panel in 3 strings of 3 panels each.
    1 unit Morningstar TriStar 60 amp MPPT solar charge controller
    1 unit Xantrex XW4024-120/240-60 4000 Watt Hybrid Inverter-Charger (I didn't realize this was this expensive) :cry:

    Question - Does the XW4024 act as a charge controller and inverter in one or does it work separately as an inverter separate from the CC (which in this case would be the Morningstar)?
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  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    #16
    Re: Help with specs for my proposed RE system

    The XW acts as a mains charger + inverter, i.e. you can plug the grid and/or a generator into it to keep the batteries topped up. It is independent of the charge controller you use.

    But since you have the grid available and the batteries are just for backup, do you really need 2.5 days on them?

    I don't know how you're charged for electricity in the Philippines, but in some countries the rate depends on the peak power of the service, i.e. you pay more for a 16A service than a 5A one. If you had a 4kW XW with batteries, you could then opt for a much smaller service, e.g. 5A and save on that because you'll have the full 4kW + 5A available through the XW.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #17
    Re: Help with specs for my proposed RE system

    The XW is a family... There is the XW Hybrid AC inverter and an XW Solar Charge Controller.

    The XW Hybrid Inverter performs both Grid Tied (ability to feed DC Battery Power back into the AC Power Grid) and also operate as an Off-Grid Inverter is the AC Main Power is down.

    The XW Hybrid Inverter can also connect to a 240 VAC 50/60 Hz generator and recharge the DC Battery Bank.

    There are actually even more functions that it can perform (like using battery power to assist the AC generator)--It is a very interesting and complex piece of gear.

    The XW Solar Charge Controller is pretty comparable with most standard MPPT type Solar Charge Controllers. It takes solar PV array energy and pumps it into a battery bank and controls the proper DC charging of the battery bank (voltage and current).

    In a simple way for your use, you can look at the XW Hybrid inverter like a Large UPS (uninterrutable power supply) and the XW MPPT Charge Controller is just a solar charger for the UPS battery bank.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #18
    Re: Help with specs for my proposed RE system

    Thanks guys. That means I'll need both the morning star CC and the Xantrex inverter. You're right, i won't need the 2.5 days allowance. What I intend to do is tune my RE system to run more and more of my power requirements until I achieve pretty much what the system can power on its own.

    Is my list of selected equipment okay? I'd also like to ask for your suggestions what other accessories I will need like system monitors and the like.

    I'll be in the States this April and plan to order from wind & sun and have the items trucked to my forwarder in LA for shipping to Manila. It would be nice to include other equipment that may prove necessary for a good setup.

    Thanks
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  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    #19
    Re: Help with specs for my proposed RE system

    You may also need the System Control Panel to set certain values in the XW inverter. You can program the basics without it, but there are some things that you can't adjust without it.
    http://www.schneider-electric.com/sites/corporate/en/products-services/renewable-energies/products-offer/range-presentation.page?c_filepath=/templatedata/Offer_Presentation/3_Range_Datasheet/data/en/shared/renewable_energies/xantrex_xw.xml

    Since you're decided on the XW, there may be some advantages to using the XW MPPT charger IF they both talk to each other. E.g. you set the EQ settings in one place and then both of them work together to perform the charge. I've got a feeling, that they don't really work together, but it would be good if someone familiar with the system could comment.
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  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #20
    Re: Help with specs for my proposed RE system

    Thanks Stephen. That's a good argument for taking on the XW CC.

    ALSO, I was re-reading the earlier posts and it seems I made a mistake with my final list. Since I will be using a 24 volt system then instead of the 9 PV panels I required I would need 8 PV panels, 4 sets of parallel PV panels with a set of 2 panels connected in series.
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  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    #21
    Re: Help with specs for my proposed RE system

    You can use those panels in a 3 x 3 configuration or a 4 x 2 configuration with either MPPT controller (they both accept a Voc of 150V). But a 4 x 2 will be a bit more efficient because the voltage difference between panels and batteries is not that much.
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #22
    Re: Help with specs for my proposed RE system
    tonygcan wrote: »
    Thanks guys. That means I'll need both the morning star CC and the Xantrex inverter. ..

    I'm using MS 60 MPPT and xw6048, and they play well together.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #23
    Re: Help with specs for my proposed RE system

    For day to day monitoring of your battery bank state of charge... I would highly recommend a Battery Monitor (or one from Victron had good reviews here too). A battery monitor allows non-technical folks to simply read "percent of charge" right from the battery monitor display rather than having to measure Specific Gravity or Rest Voltage of the battery bank. Also, a few have alarm contacts that you can program to alarm at 50% state of charge (or whatever numbers you choose). The meters are not perfect--but they can make battery management a lot easier.

    Taking care of your battery bank is critical for their long life.

    You might consider ordering from a Vendor that can configure and test your system electronics (I believe our host NAWS has this service and they do ship overseas).

    Being far from parts depots and technical support can have its own fun (as I am sure you know well).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #24
    Re: Help with specs for my proposed RE system

    Thanks. I will work with the 4x2 configuration. AM I correct to conclude that parallel connections with batteries is not recommended but parallel PV panels is okay?

    Good to know that the MS MPPT and the XW inverterwork well together.

    And I definitely wil install a battery monitor. Will research now.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #25
    Re: Help with specs for my proposed RE system
    tonygcan wrote: »
    Thanks. I will work with the 4x2 configuration. AM I correct to conclude that parallel connections with batteries is not recommended but parallel PV panels is okay?
    Solar panels are, for the most part, Current Mode devices--they output their current based on available solar energy and not based on small changes in output voltage... Therefore, when you place several solar panels strings in parallel, the output their available current (or balancing, current sharing issues).

    With Batteries, if you place two batteries in parallel, small voltage changes can make big changes in current sharing in parallel strings. Voltage drop in wiring, differences in battery temperatures, failing/older cells, etc. all can affect how well batteries "share" current.

    While many folks have paralleled larger numbers of parallel battery strings, my own personal recommendation is to limit it to around 3 strings in parallel maximum. More than that, you have lots of cell electrolyte levels to check (lots of flooded cell battery caps), and you should monitor the voltage/current at various points in your battery bank to catch any early life failing cells before the can cause further damage to the string/bank (shorted cells/open cells/etc.).

    Each battery parallel battery string connection should have its own fuse/circuit breaker to help reduce the chance of fire. Large lead acid batteries have a scary amount of current available in a dead short (1,000's to 10,000's of amps). Fusing each string can limit damage/dangers of short circuits melting interconnect wiring, etc...

    Also, I would suggest that you get an inexpensive (or expensive) Clamp type DC current meter (this one or this private labeled version) are "good enough" to diagnose most DC battery wiring/current sharing issues. Clamp meters are easy and very safe to use. Takes a bit of understanding to use them properly and interpret the readings correctly. (AC current clamp meters are less expensive and more accurate but will not measure DC currents).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #26
    Re: Help with specs for my proposed RE system

    I did get a clamp meter but I could only find an AC one. Thanks for the link I'll purchase one when I get to the states.
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #27
    Re: Help with specs for my proposed RE system

    The Sears Clamp on DC ammeter ~ $60 is a great value.

    Tony
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #28
    Re: Help with specs for my proposed RE system
    icarus wrote: »
    The Sears Clamp on DC ammeter ~ $60 is a great value.

    Tony

    I just ordered one myself :cool:
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    #29
    Re: Help with specs for my proposed RE system

    Bought myself a DC clamp meter from Sears yesterday. There were 2 models. one for $60 and the other for $99. Bought the more expensive one.

    Sears was the only store open in San Rafael, CA on Easter Sunday.:D
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