help ! portable solar generator

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System
System Posts: 2,511 admin
in Solar Product Reviews & Opinions #1
I want to buy a portable solar generator and I don't know what are the specifications that I should keep in mind before buying. could u please list out the specifications of such product because I've serfed some companies websites but I couldn't understand thier specifications because it is mentioned as abbreviations ?
the last question I want to ask about is : What is the minimum electricity power (in Ampere) that a portable solar power generator can store?.
Hoping to hear from you soon !.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #2
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    Re: help ! portable solar generator

    Welcome to the forum.

    You're going to need to read a lot and learn a lot before you can sort through all the data that's thrown at people when they're looking to buy anything connected with solar. For instance, there's no such thing as a "solar generator" other than a sun.

    Here's the basic FAQ section: http://forum.solar-electric.com/forumdisplay.php?f=14
    It includes this glossary of terms: http://forum.solar-electric.com/showthread.php?t=6136
    And this long thread full of interesting facts and links for beginners: http://forum.solar-electric.com/showthread.php?t=5556

    The first thing you must do is define what you're trying to do! Are you looking for emergency back-up power? If so, generators are usually a much more practical solution. If your looking for "quiet power" for camping or off-grid living, that's another case.

    Most of those all-in-one solar panel/battery/inverter units are rather meager when it comes to power. And that is another important thing for any application: how much power do you need? Under that heading comes: do you need 120 VAC or DC only (and at what Voltage)? Then there's the issue of what kind and amount of loads you want to supply, and for how long.

    No, it isn't simple and there's no way to make it simple. But you can understand it! :D
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,447 admin
    #3
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    Re: help ! portable solar generator

    A solar generator is really a big lead acid battery that supplies energy to your DC loads or a small AC inverter to power your AC loads.

    And then slap a solar array + charge controller on to keep up with your daily power usage.

    Here is some information on designing and picking components:
    BB. wrote: »
    Add this link to our Solar Beginner Post:

    Emergency Power

    Basically a very long thread that starts from the beginning with a few vague requirements through design and assembly for a "portable" solar RE off-grid power box.

    And here is another example by Mike90045 called the Solar Monolith:

    attachment.php?attachmentid=384&stc=1&thumb=1&d=1234752636

    attachment.php?attachmentid=385&stc=1&thumb=1&d=1234752653

    Update pictures/information here.

    A "solar generator" is not the same as a gasoline generator...

    A gallon of fuel (or ~4 liters) will supply around 5kWH (5,000 Watt*Hours) with a fairly efficient generator and matching load.

    A Car sized storage battery will supply ~500 Watt*Hours (reliably) before it needs to be recharged. Yes, 1/10th the energy in a gallon (4 liters) of gasoline/petrol.

    And for most areas, a sunny non-winter day will require around 250 watts of solar panel (minimum) to recharge that battery in one day.

    Don't buy any hardware/solar components until you have defined your loads/power needs, and have done a paper design (batteries, inverter, solar charger, AC charger, solar panels, backup genset, etc.)first.

    There are lots of tradeoffs to be made and it is much easier and cheaper if you don't have some parts already.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #4
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    Re: help ! portable solar generator

    let's get something straight for you here. batteries store electricity and pvs can generate electricity from the sun. there isn't a minimum that either can come in.

    i suspect what you want to know is the minimum you'd need for a pv and battery system (termed as off grid), but you'd have to tell us what it is you intend to run with it and for how long so we get a good idea of the kilowatt hours you'd need. if this is to be inverted to 120vac then the loads can be monitored with a killawatt meter that our host carries to get a better idea of what you would need.

    many use abbreviations like i used pv. that means photovoltaic panel and would be more in layman's terms your solar panel. some terms and abbreviations can be seen here,
    http://forum.solar-electric.com/showthread.php?t=6136
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  • System2
    System2 Posts: 6,290 admin
    #5
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    Re: help ! portable solar generator

    Capacity 300W
    System voltage 12VDC
    Best output power everyday 426WH
    * For the Inverter
    • Output wave Pure sine wave
    • Output voltage AC110V/220V
    • Output frequency 50HZ/60HZ
    • Output current 1.09A(220V) / 2.18A(110V)
    • Precision of output voltage ±3%
    • Precision of output frequency ±0.1%
    • False output wave of AC <3%
    • Overload ability 120%,30 seconds
    • work efficiency >85%
    * For Solar panel :
    • Pmax 100W
    • Vmp 17.5V
    • Imp 5.8A
    * For Battery :
    • Capacity 12V120AH
    • For Package data:
    • Size (mm*mm*mm) Weight (kg)
    • Power box 595*305*575 51.80
    • Solar panel 823*1265*40 11.80
    • Solar panel bracket 1550*60*60 22.00
    • 20’ container load 350pcs
    • 40’ container load 800pcs
    Thank u so much for your replay. I got a useful information. At least I understand the main components of the solar power generator along with their tasks. If you don't mind : Do the above specifications include the whole specifications of portable and home solar generators ?. secondly, Do these specifications fit with my needs If I have a desktop computer, printer, scanner, about 3 lamps, and Tv ? . finally, regardless of the devices that I have, What is the maximum electricity power (in Ampere) that the battery can store for both portable and home-based solar generators?. I'm so sorry to bother you !.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,447 admin
    #6
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    Re: help ! portable solar generator

    That would power your 300 watts of load for less than 2 hours per day... And generate around $0.05 USD worth of electricity.

    If you are in the middle of no-where, and need a little bit of electric power (laptop computer with DC adapter, a couple LED lights, and a small printer, plus a radio)--It appears it would work.

    But, I would worry that the battery will not last very long unless you monitor its state of charge pretty closely (volt meter, amp meter, or battery monitor).

    This will (most likely) not save you very much money unless you are already running on a genset any time you need electricity.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • spanel
    spanel Solar Expert Posts: 36 ✭✭
    #7
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    Re: help ! portable solar generator
    Thank u so much for your replay. I got a useful information. At least I understand the main components of the solar power generator along with their tasks. If you don't mind : Do the above specifications include the whole specifications of portable and home solar generators ?. secondly, Do these specifications fit with my needs If I have a desktop computer, printer, scanner, about 3 lamps, and Tv ? . finally, regardless of the devices that I have, What is the maximum electricity power (in Ampere) that the battery can store for both portable and home-based solar generators?. I'm so sorry to bother you !.

    You'll need to get a watt meter to see how much power each of those are using... my guess..

    The computer 150-300watts by itself
    printer/scanner.. who knows.. could be ~100 to as much as 1000+ if its a laser printer
    3 lamps.. hopefully 13watt cfls
    tv.. hopefully a small lcd or better yet led.. but again could be well over 100 watts for a larger tv or a CRT.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #8
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    Re: help ! portable solar generator

    A simple analysis of that system:

    1). A 300 Watt inverter means it will not run any load or combination of loads that exceeds 300 Watts at any given time.

    2). A 120 Amp hour 12 Volt battery will at best supply 720 Watt hours, not including loss due to inverter efficiency which probably no better than 90%. At most figure 650 Watt hours. Like Bill said: full load for about two hours.

    3). A 100 Watt panel might harvest 250 Watt hours on a good day (Icarus' formula: Watts * hours of good sun / 2). It would barely make the recommended 5% minimum charge current for that battery. This is a typical "not enough panel" situation. The claim of 426 Watt hours is a figment of someone's imagination, or they expect you to manually re-aim the panel every ten minutes.

    spanel is 100% correct: desktop computers are murder on power. We switched from the full-size creature to a laptop and saved 100+ Watts while doing the same work. Plug all those things you listed in together and it will exceed the inverter's capacity. You could run the computer for about 4 hours if you're lucky.

    My advice is to spend $30 on a Kill-A-Watt meter, get some real Watt hour numbers for what you want to run, and design from there. Much better results from determining how much power you need and figuring out how to supply it than from buying some ready-made set-up and then discovering it's inadequate for your needs.
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