Update on a PV System in Haiti

KeithWHareKeithWHare Solar Expert Posts: 140 ✭✭✭
In April 2010, I helped install a PV system at a clinic about 10 miles east of Port-au-Prince Haiti. The clinic is operated by an Ohio based organization called Healing Art Missions (www.healingartmissions.org).

For more details about the system, see the thread http://forum.solar-electric.com/showthread.php?9127-Off-Grid-system-in-Haiti

Because of under-watering and over-watering (I'll do a bit more training this week), the batteries have deteriorated and badly needed to be replaced. The battery bank is three strings in parallel. Each string has four 6-volt, 225 Amp Hour Trojan T105 batteries. When I arrived last Saturday, there were four really bad batteries (voltages of 5 or less) distributed across the three strings as well as a lot of corrosion on the terminals. The system was working during the day time when there was sunlight, but the inverter was shutting down when the state-of-charge dropped below 99%.

One of the people I work with on Healing Art Missions had arrive the week before I did and had purchased 12 new Trojan T105 batteries, so we removed the old batteries, cleaned up the connectors, and installed the new batteries. The connectors are corroded enough that I want to replace all of them. Hopefully, I will have the new cables this evening.

This is one of the worst of the cables:

Attachment not found.

The end with the red tape had originally been on the positive terminal.

Here are several of the old batteries. I don't think the sides bulged when they were new.

Attachment not found.

With the new batteries the system is back to working very well. Yesterday, we pumped a couple of hundred gallons of water and ran a clinic all morning. Because of the extra power use in the morning, the batteries didn't fully recharge until early afternoon.

When I install the new cables, I have Vaseline but not dielectric grease. Is smearing the battery connections with Vaseline a reasonable choice?

Keith

Comments

  • KeithWHareKeithWHare Solar Expert Posts: 140 ✭✭✭
    Re: Update on a PV System in Haiti

    And, before anyone asks, I have not tested the specific gravity of any of the batteries, old or new. I thought there was a hydrometer here someplace, but I haven't found it.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Update on a PV System in Haiti

    Always a problem when someone else is looking after a system. It gets worse if several someones are. Demonstrates yet again our axiom about how easy it is to kill a set of brand new batteries.

    Yes you can use Vaseline to help keep out the oxygen and acid.
  • mike95490mike95490 Solar Expert Posts: 9,361 ✭✭✭✭✭
    Re: Update on a PV System in Haiti

    3 parallel strings = not as good as fewer parallel strings. If you have to stick with that size battery, look into
    converting to a 48V system, and just manage 2 parallel strings.

    or possibly a forklift battery ?

    or what about AGM, gets rid of the vent caps and water/acid mess. co$t is higher, but may last longer
    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 ,

  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Update on a PV System in Haiti

    in the case of many people handling the maintenance then i would lean agm batteries as it would take the watering aspect out of the equation. you have to be sure battery settings are correct and to make all of them aware voltages can't be allowed to go high on these batteries. maybe make 1 person to be in charge of controller settings so you know who to hang for these more expensive batteries if they go bad.

    another thing to keep in mind is the salt air corrodes too. might be better to replace the entire cables as the corrosion has wicked up under the insulation and is eating away at the wire. as was said too if possible go with as few parallel battery banks as possible and if you can't go higher in voltage on the inverter to allow that then try to get the largest capacity batteries you can to use to minimize the number of paralleled banks.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Update on a PV System in Haiti

    I'll second what Neil said, pitch those cables in the garbage and have some proper cables made with Adhesive lined heat shrink on them. I'd also re-think the way you have the batteries cubed together, there should be at least 1"- 2" for space between them to dissipate the heat, especially in that location. It's always the details that get into the way of success.
  • newlnewl Solar Expert Posts: 53 ✭✭✭✭
    Re: Update on a PV System in Haiti

    Good advise re AGM and/or single person maintaining for future reference, though OP said that replacements were already purchased and are in use.
  • KeithWHareKeithWHare Solar Expert Posts: 140 ✭✭✭
    Re: Update on a PV System in Haiti

    To respond to several comments...

    We are far enough in from the coast that salt water is not seem to be a particular issue. At this location in the Cul-de-sac, much of the weather seems to come from the east.

    A bit more space between the batteries is a good idea, but won't happen without building a new battery-rack.

    The original design was based on the inverter and batteries we were able to get in Port-au-Prince in the months after the 2010 earthquake. Moving to a 48 volt system would require a new inverter and a new e-panel. I'd like to do that, but it is not practical in the near term.

    The battery cables are now replaced. They do not have heat shrink. I didn't think of that in advance and so didn't bring heat shrink tube with me. I haven't see it here. I have smeared the connectors with Vaseline.

    I need to do a bit more training for the person who is now maintaining the batteries, but the battery maintenance has been more consistent with the current person.

    Nobody is tweaking the settings on the charge controller or the inverter.

    It's currently 10:15 AM local time and the Outback charge controller has output 2.3 KWH from the 1560 watts of solar panels.

    Keith
  • KeithWHareKeithWHare Solar Expert Posts: 140 ✭✭✭
    Re: Update on a PV System in Haiti

    I washed the panels this morning. This photo is when I was half finished.

    Attachment not found.

    And, before you spend too much time commenting on the shading, this was a bit before 7:00 AM. The panels are in clear sun by 8:00 AM. At noon, the panels are generating 1300 watts out of a theoretical 1560 watts (12 * 130).

    I don't have good enough data to tell if cleaning the panels improved the output.

    Keith
  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Update on a PV System in Haiti

    83%, not bad seeing as they are almost flat on the ground from that photo...8)
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Update on a PV System in Haiti
    westbranch wrote: »
    83%, not bad seeing as they are almost flat on the ground from that photo...8)

    Which is not such a problem in Haiti as it would be in, say, Williams Lake. :D
  • northernernortherner Solar Expert Posts: 492 ✭✭✭✭✭✭
    Re: Update on a PV System in Haiti
    KeithWHare wrote: »
    The battery cables are now replaced. They do not have heat shrink. I didn't think of that in advance and so didn't bring heat shrink tube with me. I haven't see it here. I have smeared the connectors with Vaseline.

    You could also wrap the cable ends with electrical tape if you have that? This is what I used for my cables.
  • KeithWHareKeithWHare Solar Expert Posts: 140 ✭✭✭
    Re: Update on a PV System in Haiti
    westbranch wrote: »
    83%, not bad seeing as they are almost flat on the ground from that photo...8)

    The panels are at an angle of about 18 degrees, which is about right for 18 degrees north latitude. For a while in June & July, the sun is north of this site.

    There is no risk of snow gathering on these panels.

    Last Friday, the Outback FM60 recorded 8.2 KWH of power generated, which included recharging the batteries, pumping about 300 gallons of water, and running a clinic for about 50 patients plus about 25 eye exams and several cholera patients. I spent a fair amount of time just watching the system work, because there wasn't anything else I needed to do.

    With the new batteries, the system is back to working as expected. Now if we can get five years out of the new set...

    When we installed this system in April, 2010, the alternative was a generator. At that point, gas was $7 to $8 a gallon when it was available. There is now a power line closer, but it is intermittent and expensive. So even with this battery replacement, I'm estimating that the system has already paid for itself.

    Keith
  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Update on a PV System in Haiti

    Man, does time fly, I remember your original post almost like it was last week.

    Looks like it is a well balanced system.

    Good luck with battery set #2

    ADD: Keith have you got a MN Battery Condition Monitor down there?
    http://www.midnitesolar.com/productPhoto.php?product_ID=444&productCatName=Battery%20Accessories&productCat_ID=39&sortOrder=2&act=pc
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • CDN_VTCDN_VT Solar Expert Posts: 492 ✭✭✭
    Re: Update on a PV System in Haiti
    westbranch wrote: »
    Man, does time fly, I remember your original post almost like it was last week.
    I also remember reading the first postings, where did that time go ?

    KeithWHare wrote: »
    I washed the panels this morning. This photo is when I was half finished.

    Attachment not found.

    And, before you spend too much time commenting on the shading, this was a bit before 7:00 AM. The panels are in clear sun by 8:00 AM. At noon, the panels are generating 1300 watts out of a theoretical 1560 watts (12 * 130).

    I don't have good enough data to tell if cleaning the panels improved the output.

    Keith
    Keith you do a great job on Panel cleaning . I did mine and it did improve the starting time. I also waxed mine for ease of just hosing the "dust" (pollen /ash / stuff off) .

    VT
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