Announcement

Collapse
No announcement yet.

Help in design first basic system - powering 12 volt landscape lighting, etc

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Help in design first basic system - powering 12 volt landscape lighting, etc

    Hello all,

    I have been toying around with a solar project. I have a good background in building and electronics, but new to solar.

    I'd like to have a good quality system to run my outdoor landscape lighting (all 12 volt, some incandescent/some led). I am currently gathering the total amps drawn, but don't expect it'll be large.

    I'd like to get a system that can grow as my needs grow, but will never be a big system.

    I am thinking of starting with a single 100w panel, (about $120 on amazon) and want a good controller and other needed items, which won't be useless if i add a few more panels next year. I'd also like a good, solid battery, which had plenty of headroom to not drain every night, and can take more batteries/growth going forward. I have been looking at options and wanted to get a list of suggested components from the experts here, keeping in mind i don't want to under build or quickly outgrow. My budget is ~$500, but can be more for the right components/setup.

    I have plenty of sun and a great location for storing batteries/controller within about 20 feet from panel(s).

    Any and all input would be appreciated!

  • #2
    Originally posted by leosantamana View Post
    Hello all,

    I have been toying around with a solar project. I have a good background in building and electronics, but new to solar.

    I'd like to have a good quality system to run my outdoor landscape lighting (all 12 volt, some incandescent/some led). I am currently gathering the total amps drawn, but don't expect it'll be large.

    I'd like to get a system that can grow as my needs grow, but will never be a big system.

    I am thinking of starting with a single 100w panel, (about $120 on amazon) and want a good controller and other needed items, which won't be useless if i add a few more panels next year. I'd also like a good, solid battery, which had plenty of headroom to not drain every night, and can take more batteries/growth going forward. I have been looking at options and wanted to get a list of suggested components from the experts here, keeping in mind i don't want to under build or quickly outgrow. My budget is ~$500, but can be more for the right components/setup.

    I have plenty of sun and a great location for storing batteries/controller within about 20 feet from panel(s).

    Any and all input would be appreciated!
    from several similar stories around here this route (building solar in 'phases') is the most expensive possible but somehow ppl are taking it again and again. Up to the point I want to suggest other members to sell each other their equipment from the 'lesser' phases to save everybody good chunk of cash.

    It is more efficient to come up with main design parameters based on your needs and build your system based on that without 'iterations'. Solar is not very flexible in terms of extensions and you can easily end up throwing away equipment from your previous 'phase'. Solar is expensive even when done right from the go and doing it more than once solidly moves it to hobby category and not some financially feasible project.

    I'd upgrade your bulbs to LED, looked at consumption level after that point and most likely would drop solar as idea .

    Comment


    • #3
      max2k , I totally get where you are coming from. However, I am not looking at this as a ROI (Return on Investment), rather I see this as a hobby activity. I see some controllers can handle more than others, and, to your point, would rather buy with the future in mind vs. tossing components as i build onwards.

      With that said, what would the suggestion be for a complete system, with only 400 watts (4 panels), in regards to ancillary components (battery(ies), controller, etc). at say <1200$?

      Comment


      • #4
        It is true that easy growth in solar is only in the panels, and even then you have to pretty much stay with the same type within the same string. I think solar landscape lighting is a fantastic way to dip your toes in the pool.

        The key will be your battery, which doesn't 'grow' well at all, and you will have at least two types to pick from, an AGM and a FLA, each of which come in several flavors, so you might want to read up on pros and cons comparisons between the two. This (battery) will be your biggest decision, so read up, and go figure out those loads.

        Comment


        • #5
          Originally posted by leosantamana View Post
          max2k , I totally get where you are coming from. However, I am not looking at this as a ROI (Return on Investment), rather I see this as a hobby activity. I see some controllers can handle more than others, and, to your point, would rather buy with the future in mind vs. tossing components as i build onwards.

          With that said, what would the suggestion be for a complete system, with only 400 watts (4 panels), in regards to ancillary components (battery(ies), controller, etc). at say <1200$?
          would you consider using grid tie solar panels which typically consist of 60 cells and output around 38V with 6-8A? These are commodity due to widespread roof top installations and you could probably get couple as leftovers from Craigslist or alike at very good price as it is hard to sell only 2 panels. Two such panels would give you 500W easily and would probably run at $150/ea or even less as roof top arrays tend to use 300+ W panels nowadays. Just FYI I paid $530 for 2 brand new LG305 couple months ago as part of bigger package purchase for roof top array. Those produce 610W together. If I didn't want 'looks' or the relatively 'latest' panels the panel's price would go down drastically.

          In general, you should start design from your loads, not sources ensuring it will make sense at the end. Let's say you determined that to be Enightly in Watt-hours. Another parameter - how many nights you want your system to be autonomous in case there's no sun to charge the batteries. If you can live with your garden lights off this would drastically reduce battery capacity requirements. Deep cycle FLA batteries can tolerate 50% discharge so their capacity would be Ebat = Enightly x 2 with 0 autonomous days. Battery capacity Cbat in Ah depends on your system voltage: Cbat = Ebat / 12V. Then you'd determine required panel output multiplying it by 1.2 to account for charging/discharging inefficiencies and dividing by # of hours sun is shining at your location: Ppanels = Enightly x 1.2 / 4 Then you'd have an idea how much total panel power in watts you need at the minimum. As you can see not much can be determined without knowing your load requirements.

          One more thing- if you can move up to 24V for your 'system' voltage it would allow you to reduce current required by each load in half (with the same power) and consequently- reduce your wiring power losses 4 times or use thinner wires with the same losses. For lightning this could be accomplished by connecting 2 12V bulbs/LEDs in series and then connecting such pairs to the common 24V 'bus'.
          Last edited by max2k; 09-06-2017, 08:26 PM.

          Comment


          • #6
            interesting idea... i just searched CL and found this:
            SUNIVA OPTIMUS 280 watt Monocrystalline Solar Panel
            Characteristics
            Manufacturer: Suniva
            ModelOPT280B-210 5BB 40mm BLM
            Rated Power Output [W]280
            Length [mm (in)]1652 mm (65.04 in)
            Width [mm (in)]982 mm (38.66 in)
            Depth [mm (in)]40 mm (1.57 in)
            Weight [kg (lb)]17.9 kg (39.5 lbs)


            Series Fuse Rating [A]15
            Maximum Reverse Current [A]16
            Cell TechnologySi Monocrystalline (c-Si) 38.8volts
            Solar Cell's Country of OriginUSA (Yes, made in the USA)
            Number of Cells (Pieces)60
            Number of Bypass Diodes3
            Frame ColorBlack
            Junction BoxNEMA IP67 rated; 3 internal bypass diodes

            $200 each, he has 3. He lists them as "used in good condition" Is this a good deal?

            Newbie question, does the controller or ??? step down voltage to 12 volt (for battery)?

            Comment


            • #7
              Originally posted by leosantamana View Post
              interesting idea... i just searched CL and found this:
              SUNIVA OPTIMUS 280 watt Monocrystalline Solar Panel
              Characteristics
              Manufacturer: Suniva
              ModelOPT280B-210 5BB 40mm BLM
              Rated Power Output [W]280
              Length [mm (in)]1652 mm (65.04 in)
              Width [mm (in)]982 mm (38.66 in)
              Depth [mm (in)]40 mm (1.57 in)
              Weight [kg (lb)]17.9 kg (39.5 lbs)


              Series Fuse Rating [A]15
              Maximum Reverse Current [A]16
              Cell TechnologySi Monocrystalline (c-Si) 38.8volts
              Solar Cell's Country of OriginUSA (Yes, made in the USA)
              Number of Cells (Pieces)60
              Number of Bypass Diodes3
              Frame ColorBlack
              Junction BoxNEMA IP67 rated; 3 internal bypass diodes

              $200 each, he has 3. He lists them as "used in good condition" Is this a good deal?

              Newbie question, does the controller or ??? step down voltage to 12 volt (for battery)?
              no, that is more like retail price for brand new panels. If mods won't mind here's just for reference a page of solar equipment distributor offering multiple panels: https://tandem-solar-systems.com/buy-solar-products/. They all brand new and ready to be shipped in any qty.

              here's another 280W mono brand new panel: http://webosolar.com/store/en/grid-t...CABEgKsGPD_BwE

              When someone has limited leftovers or not the latest/greatest I'd say they need to sell it at least 30% off those prices so keep looking.

              Charge Controller sits between panels and the battery and makes sure it doesn't get overcharged. MPPT type is preferred and refers to the PV inputs of CC. MPPT extracts more energy from the panels compare to cheaper PWM CCs. Some of them might provide 'Load' terminals ensuring your load will be turned off to prevent battery over- discharge too. Many CCs have multiple other settings allowing you to accommodate batteries with total voltage up to 48V. I have no practical experience with them so you might get better response after you give us your load requirements.

              Comment


              • #8
                Originally posted by max2k View Post

                from several similar stories around here this route (building solar in 'phases') is the most expensive possible but somehow ppl are taking it again and again. Up to the point I want to suggest other members to sell each other their equipment from the 'lesser' phases to save everybody good chunk of cash.

                It is more efficient to come up with main design parameters based on your needs and build your system based on that without 'iterations'. Solar is not very flexible in terms of extensions and you can easily end up throwing away equipment from your previous 'phase'. Solar is expensive even when done right from the go and doing it more than once solidly moves it to hobby category and not some financially feasible project.

                I'd upgrade your bulbs to LED, looked at consumption level after that point and most likely would drop solar as idea .
                Very good point. I now have 2 55AH 12V sla deep cycle batteries 2 months old, a 300W 24V inverter True sine, and a 20A MPPT I don't need. All just a couple months old.
                600W, 40A MPPT, 230AH FLA,24V Samlex 1500W

                Comment


                • #9
                  We recently installed a PV system this summer. But long before that, I experimented with building a solar powered landscape lighting system. I started out with a single 30W panel, a salvaged 12V car battery and a cheap $15 PWM controller. After an upgrade or two, I finally settled on the following components. Storage is provided by two Costco/Interstate 6V golf cart batteries (~$85 each) connected in series. The system is now powered by two 30W Instapark SP Mono-crystalline panels (~$80 each) connected in series. Everything is controlled by a Tracer 2210RN MPPT charge controller (~$110, old model) which switches on the lights 10-min after dusk and turns them off 5-6 hours later. I converted all the landscape fixtures to LED (7x 4W MR16 and 7x 1.44W G4 bulbs). The total wattage demand is probably under 50W including the IP camera aimed at the controller to monitor the battery voltage so the system is probably a bit of an overkill (especially for my consistently sunny locale). To keep everything dry, the batteries, controller and camera are housed in a resin outdoor patio/deck storage chest. The controller will automatically shutdown the lights to protect the batteries if they get below a minimum state of charge. Even with the extended rainy period last winter here in SoCal, it ran without a single shutdown.



                  I realize that the system doesn't make much economic sense, but it was a fun hobby project. So far, it's been operating for over 4-years without much maintenance other than topping off the batteries with distilled water every 3 months or so and maybe giving them an "equalizing" charge once a year (if that). When the batteries finally die of old age, I'll probably re-connect the lights to AC power since the whole house is now PV installed. It'll be hard to justify the cost of replacing the batteries, given the very low power consumption of the lights since converting them to LED. It was nice having the only house on the block with outdoor lighting still running during the brief power outage we had a year or so ago. Maybe then, I'll just connect the landscape light power supply to the spare mini 125VA network UPS that I have lying around to enjoy the same effect.

                  Comment


                  • #10
                    Originally posted by Woodworkerii
                    I realize that the system doesn't make much economic sense, but it was a fun hobby project.
                    Sounds like a fun deal. Just out of curiosity, approximately how many light fixtures and how much load wire?

                    Comment


                    • #11
                      Originally posted by AzRoute66 View Post
                      Sounds like a fun deal. Just out of curiosity, approximately how many light fixtures and how much load wire?
                      14 Fixtures. 7 x 4W and 7 x 1.4W on 2 strings of 14/2 low voltage landscape lighting cable--about 80' of cable total.

                      Comment


                      • #12
                        Thanks. I ask only because the wife has the backyard looking like a cross between a FEMA command post and a helipad. At least she goes with the cheap stand-alone solar, so I have not had to wire the backyard - yet. As often as she moves them I think I'll be excused from that chore for a long time.

                        Comment

                        Working...
                        X