Announcement

Collapse
No announcement yet.

can you help with a shopping list for a solar generator?

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

  • can you help with a shopping list for a solar generator?

    hi,
    I have need of a solar generator,I am giving my self a headache with this simple project,I have studied all the wiring...easy enough,but how many watts for the solar panel,what size inverter,battery?
    I need this to charge up two laptops in the evenings( one 13 mac book air+one hp 17inch),plus 2 smart phones (galaxy s3's) and use a small hand held cd player.
    occasionally I will turn on the petrol generator usually at night and would like to boost up the battery if it needs it.
    The unit will be stationary on a varandah,I dont want to unplug anything when boosting with the AC POWER supply,just plug the solar gen into the mains (the generator powers the house,when its on) and charge without disconnecting the panels.
    I would also like some indication how much charge is in the battery.

  • #2
    What you are actually going to build is an off grid solar system with the capability of charging with a generator.
    So to start you need to determine two things.
    Daily use in Watt hours. (Best way is with a Kill a watt meter with each item plugged in for a few days to determine how much each uses each day.
    Second is insolation or sunhours during the worst months of the year you will be there (rainy season) Go here http://www.gaisma.com/en/dir/gm-country.html and find the city closest to where the house is.
    Rich
    WWW.solarsaves.net

    NABCEP certified Technical Sales Professional

    http://www.solarpaneltalk.com/showth...Battery-Design

    http://www.calculator.net/voltage-drop-calculator.html (Voltage drop Calculator among others)

    www.gaisma.com

    Comment


    • #3
      Originally posted by Naptown View Post
      What you are actually going to build is an off grid solar system with the capability of charging with a generator.
      So to start you need to determine two things.
      Daily use in Watt hours. (Best way is with a Kill a watt meter with each item plugged in for a few days to determine how much each uses each day.
      Second is insolation or sunhours during the worst months of the year you will be there (rainy season) Go here http://www.gaisma.com/en/dir/gm-country.html and find the city closest to where the house is.
      thank you,I will get back with the info,It's BRUFUT by the way.

      Comment


      • #4
        Originally posted by gambiasurfgirl View Post
        thank you,I will get back with the info,It's BRUFUT by the way.
        Remember this
        Insolation is 4.98 KWM2 per day in the worst month. actually very good for solar.
        So the calculation would be
        Load (undetermined at this point) x 1.5 (Assuming a MPPT charge controller If using a PWM controller figure load x 2) / 4.98 (hours of insolation)
        Battery size is Load (in Watt hours) x 5 /voltage for 2 day autonomy without having to run the generator.
        So in the example above with a load of say 1000 Watt hours a day it would take using a Mppt charge controller
        Battery size 1000x5= 5000 watt hours = @48V = 100AH @24V =200 AH @12v = 400 AH
        Solar panels would take with MPPT and I strongly suggest you go this way
        1000 x 1.5 =1500/ 4.98 = 300 watts of panels.
        We will talk battery type later on in the conversation.
        Last edited by Naptown; 01-21-2013, 07:09 PM.
        Rich
        WWW.solarsaves.net

        NABCEP certified Technical Sales Professional

        http://www.solarpaneltalk.com/showth...Battery-Design

        http://www.calculator.net/voltage-drop-calculator.html (Voltage drop Calculator among others)

        www.gaisma.com

        Comment


        • #5
          Originally posted by Naptown View Post
          Load (undetermined at this point) x 1.5 (Assuming a MPPT charge controller If using a PWM controller figure load x 2) / 4.98 (hours of insolation)
          I'm trying to wrap my mind around your formula.

          You used 1000 watt hours for your example because the load was unknown.

          Is the below true?

          If I used 3320 watt hours per day x 1.5 for MMPT / 4.98 = 1000

          Would 3320 watt hours be the correct load to get the 1000 watt hours you used for the rest of your example? I'm trying to solve for x since it was unknown so I can apply the same formula to other setups but I need to make sure I understand your example by filling in the blank.

          I know my particular insolation is different as well as load, etc. but if I understand your example I can plug in my own particular variables to see if my setup is correct or needs adjusting.

          I guess I'm not sure if the 1000 watt hours came BEFORE or AFTER you multiplied by 1.5 and divided by 4.98.

          Thanks for the clarification.

          Comment


          • #6
            Originally posted by johngalt View Post
            I'm trying to wrap my mind around your formula.
            Try reading this. It will help.
            MSEE, PE

            Comment


            • #7
              Originally posted by Sunking View Post
              Try reading this. It will help.
              Thanks - The extra details helps it all come together.

              Comment


              • #8
                2 laptops and 2 smartphones,oh and a cd player

                trying to keep up with the usage has been really hard,sometimes the batteries are low,sometimes we are using the phones heavily,its not as simple as how many hours a day the tv is on....
                can we keep the suggestion of 1000w ???
                so this means i need :
                solar panels of 300w
                charge controller 20a? (300w/24v =12.5amp)
                battery 200ah (on 24v)
                well since this is not going to be as small as i imagined,perhaps I should be looking at starting with something this size and just upgrade every so often by adding panels and batteries...is such a thing possible? and if so I would probably want the biggest charge controller and inverter i can afford at the outset.

                Comment


                • #9
                  Originally posted by gambiasurfgirl View Post
                  adding panels and batteries...is such a thing possible?
                  You do not add batteries, you replace them with larger ones.
                  MSEE, PE

                  Comment


                  • #10
                    why

                    Originally posted by Sunking View Post
                    You do not add batteries, you replace them with larger ones.
                    why do you not buy more?
                    I do not know how to calculate at all.
                    so if I were to get say 2kw panels, and buy 4 of 'New 500W Car Power Inverter 12V DC to 220V AC' and put these in parallel to get 2 kw needed for the panels,
                    then how much battery is needed? should it be one battery or can they be put in series or parallel?

                    and what else should one buy? blocking diodes?

                    Comment


                    • #11
                      Originally posted by rainworm View Post
                      ....and what else should one buy? blocking diodes?
                      Self-crimping connectors
                      Electron Grease
                      Wire Harness Smoke

                      but seriously, the charge controller performs the blocking diode function, so you don't need them if you have a charge controller.
                      spreadsheet based voltage drop calculator:
                      http://www.solar-guppy.com/download/...calculator.zip
                      http://www.solarpaneltalk.com/showth...oss-calculator

                      http://www.mike-burgess.org/PVinfo_2.html

                      solar: http://tinyurl.com/LMR-Solar
                      gen: http://tinyurl.com/LMR-Lister ,
                      battery lugs http://tinyurl.com/LMR-BigLug
                      Setting up batteries http://tinyurl.com/LMR-NiFe

                      gear :
                      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

                      Comment


                      • #12
                        smoke

                        Yes you would think I have that
                        The supplier of these low low cost inverters told me it cannot be tied together to make bigger W.
                        I wonder if he is right? 20 of these would give better sinuswave as all on different timing I would think but I do know nothing.
                        He gave this:
                        Input Voltage: DC 10-15V/20-25V
                        Output Voltage:AC 220V, 230V, 240V (100V, 110V, 120V)
                        Power : 100w
                        Efficiency Up To: 90%
                        Unload Current: ≤0.25A
                        Output frequency: 501Hz
                        Fuse: changeable
                        Undervoltage alarm: 8V-9V
                        Overvoltage shutoff: 14.5-15V
                        Plug type: Universal Socket

                        Working temperature:From -20 to 50 .
                        Protection: Over-load,Over-voltage,Low-voltage,Short-circuit,Over-temperature

                        I also wonder if the photo of the girl using a laptop on this device is real? Can you use a laptop safely on a NOT-pure wave unit or modified wave unit?

                        Comment


                        • #13
                          sinuswave?
                          [SIGPIC][/SIGPIC]

                          Comment


                          • #14
                            Originally posted by russ View Post
                            sinuswave?
                            hahahahaha!! ... ya know... I started reading this site for the technical info but now read just as much for the entertainment value. Rainworm has proved very entertaining.

                            Comment


                            • #15
                              chinese

                              yes, it is Chinese version of explenation, not clear to who. I learn technical Chinese very well. Hope helping you. Thank.

                              Comment

                              Working...
                              X