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Solar Power Generator

Discussion in 'Off Grid Living' started by ColtCarbine, Feb 17, 2012.

  1. ColtCarbine

    ColtCarbine Monkey+++ Founding Member

    Quigley_Sharps likes this.
  2. ColtCarbine

    ColtCarbine Monkey+++ Founding Member

    Pruned from another thread

  3. TnAndy

    TnAndy Senior Member Founding Member

    Good rule of thumb is if it advertised as a "solar generator", it's an over priced, underpowered pile of crap. Everything Bruce said and more......
  4. ColtCarbine

    ColtCarbine Monkey+++ Founding Member

  5. ColtCarbine

    ColtCarbine Monkey+++ Founding Member

    How to Build a Portable Solar Power Generator and The Basics of Solar Power

    Copyright © 2005 by Robert Wayne Atkins, P.E.
    All Rights Reserved.

    On a camping trip it is nice to have some of the luxuries we enjoy at home. For example, your children may still want to play their hand-held electronic games, such as a Game Boy. Or you may occasionally want to use your laptop computer, either to play a game, or to watch a DVD movie. If you have a cell phone, then you may need to recharge its battery. Therefore, a portable solar generator would be a nice item to have on a camping trip. However, for this to be a viable option, you would need to drive to your campsite in your car or truck, because the size and weight of a solar generator exceeds what you can carry in a backpack.

    Although a regular generator will produce more power than a solar generator, a regular generator requires a continuous source of fuel, which may not be readily available at your campsite. And the noise of a regular generator may not be appropriate at most public campgrounds. On the other hand, a solar generator is able to produce small amounts of power whenever the sun is shining and it is virtually silent. Therefore, a solar generator is a more practical item on a camping trip than a conventional gas-operated generator.

    Before we look at how to build a simple homemade solar generator, we need to review the basic principles of solar power.

    The Basics of Solar Power
    Solar Panels:
    A solar panel converts the sun’s energy into Direct Current, or DC electricity. Solar panels come in a variety of different sizes and shapes. For the purpose of this discussion we will classify them as either small or large. The solar panel in the picture on the right is a large panel which is rated at 64-watts per hour and its dimensions are approximately 18" wide, 44" long, and 1½" thick. It weighs approximately 22 pounds.

    Small solar panels produce very low DC voltages, such as 1.5 volts for flashlight batteries. Small solar panels are not appropriate for a portable solar generator. (Note: If you are only interested in recharging flashlight size batteries, then please click on this link: http://www.grandpappy.info/wcharger.htm.)

    Large solar panels produce 12-volts DC, which is the same as automobile or boat batteries. Larger solar panels are designed and rated for a certain number of peak watts, such as 60W, or 75W, or 100W. If you had a 100-watt solar panel, you could keep a 100-watt light bulb burning for the length of time the sun was shining directly on the solar panel at a 90 degree angle. Since you probably wouldn't want to use the light bulb during the day, you would need a method to store that energy for future use. (Note: In my opinion, it might be better to purchase two smaller 60-watt panels instead of one large 100-watt panel. If one of the 60-watt panels were to become damaged then it could be disconnected, and the other panel could still provide some power.)

    Batteries: There are many different types and sizes of batteries. They can be used to store the power from a solar panel so that power can be used at some future time. If you are considering the purchase of a 12-volt solar panel, then you should consider the purchase of 12-volt deep-cycle marine or golf cart batteries, so you can store the power from your solar panel(s). Deep-cycle marine and golf cart batteries are of the same appoximate size, appearance, and weight as the 12-volt battery in your car. However, the battery in your car is designed for short periods of high energy output. A deep-cycle battery is designed for long periods of continuous power output. The battery will be the HEAVIEST component in your solar system.

    ysoinver. Inverters: An inverter changes the DC power from a battery into Alternating Current, or AC electricity, which is what we use in our homes. Although the inverter may be attached to a 12-volt battery, it will produce 110-volt electricity which is powerful enough to KILL you. Therefore, you must use the same degree of caution with an inverter that you would for any household appliance. Most inverters have standard three prong electrical outlets for standard household appliances to plug into. Inverters are rated for the number of continuous watts they can produce, such as 100-watts, or 1000-watts. They also specify peak watts, but the peak watts is for a very SHORT moment of time, and therefore you should rely on the rating for continuous watt output. When choosing an inverter, you should first determine what equipment you need to operate. Then purchase an inverter that will produce that number of watts. For example, if you want to operate a 700-watt microwave for 90 seconds, then you would need at least an 800-watt inverter, to provide a small safety margin. The inverter in the picture on the right is a 1200-watt inverter and its dimensions are approximately 10" wide, 13" long, and 3" high. It weighs approximately 10 pounds. The components on the front panel from left to right are: on/off switch, volt meter, watt meter, and two 110-volt outlets.

    Most inexpensive inverters produce low quality AC electricity. For example, if you plug a TV set into an inverter, you will normally see wavy lines on the TV screen, which are the result of the low quality power. On a TV set it is possible to reduce the wavy line effect by plugging a 25-foot extension cord into the inverter. Then coil the extension cord into a small stack of circles (about 12-inch diameters), one on top of the other, on the floor. Then plug the TV into the opposite end of the extension cord. You should see a noticeable reduction in the wavy line effect on the TV screen.

    Before you invest a lot of money in a solar system, you should research the costs and benefits very carefully. There are a variety of other components that need to be included in a larger self-maintaining solar system. The power question does not have an easy answer. There are so many variables that there is no one right answer that would be suitable for the needs of all families. Most companies that sell solar equipment have trained professionals that can answer all your questions and help you select exactly what you need for the application you have in mind.

    How to Build a Homemade Portable Solar Generator
    Now let's look at how to assemble the above components into a simple portable solar generator that could be used on a camping trip.

    A portable solar generator consists of the following items:

    One (or more) 12-volt solar panels,
    One (or more) 12-volt deep-cycle batteries (such as marine or golf cart batteries),
    One (or more) 12-volt cigarette lighter adapters,
    One inverter.

    In the wiring diagram illustration below I have shown one solar panel and one deep-cycle battery in order to illustrate how to build a basic solar generator.

    <center> ysogen-1. </center>
    When considering the purchase of an inverter, I would recommend either a 1,000 or 1,200-watt inverter (continuous power output). If you wish to purchase a larger inverter then I suggest no more than 2,000-watts. This recommendation applies to a portable solar generator that will be used to supply power to a wide variety of potential applications. If you purchase an inverter that is less than 1,000-watts then you will be limiting the number of potential applications for your solar generator. Also, the larger inverters are usually of higher quality and they have a few more features, such as a meter that shows how much power is remaining in your 12-volt batteries, and how much power you are using at the present time. These are really nice meters to have built into your inverter. If your inverter does NOT have these built-in meters, then you will need to purchase a separate DC voltmeter to monitor the charge in your 12-volt batteries.

    ysoadapt. In addition to the inverter, you should also install a 12-volt cigarette lighter adapter on your solar generator system. This will allow you to recharge any battery-operated item that has a cigarette lighter adapter, such as a cell phone, or a Game Boy, or a laptop computer. You can purchase these adapters at most electronic stores, including Radio Shack. Radio Shack normally has a one-hole adapter and a three-hole adapter. I recommend the three-hole adapter if you will only be recharging simple items like a cell phone or a Game Boy. The adapter on the right weighs approximately 7 ounces and it measures 3" wide by 4" long by 1" high. If you are going to be recharging batteries that require a higher level of power then you should consider purchasing several single-hole adapters to minimize overheating of the adapter wiring.

    The simple solar generator illustrated in the above wiring diagram can be used to recharge your laptop computer battery, the battery in your child's Game Boy, and any rechargeable flashlight batteries you might have (if you also have a 110-volt battery recharger for your rechargeable batteries). The solar generator should NOT be used to operate heating (or cooling) appliances because they will drain the power from your batteries very quickly. In other words, no hair dryers or electric heaters or air-conditioners. However, you can operate small fans (either a 12-volt fan plugged into the cigarette lighter adapter, or a 110-volt fan plugged into the inverter.)

    ysocontr. The optional solar controller is recommended to prevent damage to the 12-volt battery, primarily through overcharging. The solar controller in the picture on the right has dimensions of approximately 4½" wide, 6" long, and 2" high. It weighs approximately 13 ounces.

    If you do NOT have a solar controller, then you should disconnect the battery from the solar panel at night. You should also disconnect the battery if you are not going to be present to periodically monitor the charge going into the battery. And you should cover the solar panel with a blanket to prevent it from producing power.

    If you decide to omit the optional solar controller then you will need to purchase a DC voltmeter and periodically check the charge in your 12-volt battery to verify that you are NOT overcharging the battery during daylight hours. The DC voltmeter in the picture on the left has dimensions of approximately 2½" wide, 4" long, and 1" high. (Note: You will NOT need this additional DC voltmeter if you have a solar controller, or if you have an inverter with a built-in voltmeter.)

    The wiring-diagram illustration of a portable solar generator can be modified based on your individual requirements. You can add additional solar panels and/or additional 12-volt batteries to your system if you wish. The wiring diagram illustration below shows three solar panels and three 12-volt batteries. If you wish to use two panels or batteries, just remove the one in the center. If you wish to use four or more panels or batteries, just add them to the center.

    You do NOT need to have exactly the same number of solar panels as 12-volt deep cycle batteries.

    Since it does rain occasionally, it is usually better to have more 12-volt batteries than solar panels. This gives you the ability to store power for use during bad weather.

    If you decide to build your own solar generator, then you should utilize the talents of the solar professionals at the company where you purchase your solar panels. You can ask them specific questions about the size of the solar panels in relation to the number of 12-volt deep-cycle batteries you will require. They will also be able to recommend the appropriate solar controller for the type of system you decide to build.

    Normally, one of the major cost of the 12-volt deep-cycle batteries is the shipping cost. Therefore it is usually wise to find a battery dealer near your home to purchase your batteries. This not only minimizes your cost, but it also simplifies warranty and return issues if your deep-cycle battery does not perform as expected. One source of those batteries is your local WalMart or Sam's Club.
    Falcon15 likes this.
  6. ColtCarbine

    ColtCarbine Monkey+++ Founding Member


    I finally sat down and did a very basic wiring diagram of what a very basic solar generator would look like. Size your wires, battery, panel, regulator, inverter and fuses appropriately and safely. If in doubt, consult an electrician. Heck, consult an electrician anyway to be safe. This will help you understand what I was talking about in Episode 26 – About Solar Generators.

    The diagram is in PDF format – click here to download it. What you’ll see in the center of the drawing are terminal blocks, and fuse blocks. The vertical solid black lines are jumpers between the terminal blocks.
    If you have any questions, please join the forum and ask them there, so we can all benefit.

    The real point of this diagram is to show you that making something like this doesn’t have to be overly complicated. You can do it! Just make sure you read up on electrical safety and codes or have an electrician friend guide you.

    Just think, if you can do this then you have the basics of what it takes to build a larger solar electricity plant, or an array for your home.
  7. ColtCarbine

    ColtCarbine Monkey+++ Founding Member

    Solar Panel System: Getting FREE power from the sun

    Solar Panel Energy System Tutorials, Design Tools, and an Interactive Solar Simulator. DIY Solar panel system help for achieving energy independence. FreeSunPower.com provides free beginner and advanced tutorials for setting up a solar power system for producing free electricity from the sun. Our tutorials cover Solar Panels, Charge Controllers, Power Inverters, Storage Batteries, AC Generators, Wires & Cables, Meters & Monitors, and more. Complete system wiring diagram examples plus interactive online design tools are also featured with a point and click interface. NOT plain worksheets. No math required! And, don't miss our new Solar Energy Electric Power Simulator where you can test drive a Solar Energy System.

    FREE Solar Panels will make you energy independent ! Learn how to become energy independent with our Free Tutorials and solar power system Design Tools that show you how easy it is to setup your own solar energy system and be free from the standard utility company power grid which is prone to black outs, brown outs, and rising prices. Find out how easy and fun it is to achieve energy independence, throw away your electric bills, and become your own utility company ! Even if you don't need an independent system, you can still use free Solar Energy from the sun to reduce your electric bills and even SELL power back to the utility company using a Grid Tie power inverter. Frequently Asked Questions Frequently asked questions about Solar Panels, Charge Controllers, Power Inverters, Storage Batteries, AC Generators, and Wires & Cables. Stop here for quick answers if you want to skip the tutorials. Who can use Solar Power? A Solar Power energy system can be used by anyone to supply all their electrical needs, provide back-up power, or even just as a supplement to the normal electrical grid connection to a utility company. It is ideal for remote locations where power is unavailable or too expensive to hook-up to.

    Solar Panels
    Solar Panels make FREE electricity from the sun, have no moving parts to fail, and last over 25 years. They can be mounted on fixed, adjustable, or tracking type mounting systems. Getting power from the sun's energy is not only Free, but it's Fun to setup a solar energy system and be your own utility company!

    Charge Controllers A Charge Controller is necessary to protect the batteries from over charging and supply them with the proper amount of energy to promote long battery life. The popular 3 stage charging cycle of PWM charge controllers is fully explained and shown visually on a multi-color chart. Also covered are the newer MPPT (maximum power point tracking) controllers.

    Power Inverters
    Power Inverters are available in 3 basic designs. The pros & cons of all 3 are explained so you can decide which one is right for you. The power inverter converts your storage battery power into the 120 volts AC that runs your appliances. It is the heart of your solar energy system. Unless you only run 12 volt DC appliances you will need a power inverter to supply your AC.

    By using a Grid Tie power inverter, you can even sell your extra electricity back to the power company!

    Storage Batteries Without Storage Batteries to store energy you would only have power when the sun was shining or the generator was running. Here we discuss 4 major categories of batteries for solar power systems. The batteries in your system are very important. The care & feeding section of this tutorial is a must read to ensure long battery life and good performance.

    AC Generators
    Even the largest Solar Energy System would not have enough power for many consecutive days of no sun. The AC Generator tutorial will tell you what size generator you'll need and the best techniques to use when charging your batteries and/or supplying power to extra large appliances.

    Wires & Cables To prevent dangerous overheating or inefficient transfer of power, the wires and cables in a solar power system must be correctly sized. This tutorial provides a convenient chart to determine wire size based on solar panel power output and the distance between the solar panels and the batteries. For safety and good performance of your solar power system you will have to use the appropriate size wires when connecting the components of your system.

    Meters & Monitors
    This tutorial explains the importance of monitoring your solar energy system. With the included voltage chart, you can easily determine the basic level of charge on your batteries using just a simple voltmeter. Taking proper care of your batteries will ensure good system performance.

    Power Requirements
    This tutorial is a little more advanced, but explains more about voltage, current, power, and Ohm's Law. Find out about the relationship between AC amps and DC amps. The importance of energy conservation for a solar power system is also covered.

    Battery Wiring Diagrams
    Learn how to use series and parallel wiring techniques to obtain exactly the power and voltage you want using 2, 4, 6, or 12 volt batteries. Series wiring, parallel wiring and using series/parallel combinations show you how to build your battery bank into any configuration you need using simple pictorial diagrams.

    Example Wiring Diagrams for 2KW, 4KW, & 8KW solar energy systems.
    These Example System Diagrams will show how to connect the components of a solar energy system. 2 KW, 4 KW, and 8 KW systems are shown and include the solar panels, combiner boxes, charge controller(s), power inverter(s), battery bank, shunt & meter circuits, AC breaker panel, and AC generator wiring.

    Solar Radiation : Sunshine across the United States
    This tutorial shows a color coded map of the United States that displays the daily average hours of solar radiation (sunshine). This information will assist you in calculating the number of solar panels you will need for your solar power system. Also included in this tutorial is a short explanation of Watts, WattHours, and AmpHours and how they are used.

    Putting it all together
    Take a look at a simple animation of all these components working together. This will give you an overview of the minimum equipment needed for a solar alternative energy system.

    Easy 5 Step Guide: Where to start
    Sound pretty interesting but don't know where to start? You can get just the basic information that you'll need with our easy 5 step guide. If you're feeling a little overwhelmed, then this guide is for you.





    Falcon15, Sapper John and Guit_fishN like this.
  8. BTPost

    BTPost Old Fart Snow Monkey Moderator

    All the above is very good information.... This is a fair tutorial on small simple Solar PV Systems. If one is looking to eventually build at Larger System, from such a Beginner System, as described here, then there are a few design changes that should be considered, BEFORE one spends any money.

    Choice of Charge Controller is one place, where care in design spec, can make a difference in which Units should be Spec'd in...

    Choice of Battery Buss Voltage, which is determined by the choice of AC Inverter/Charger Input Voltage, is a MAJOR DESIGN Point that must be taken very seriously, when looking to expand any simple system to larger system.

    Choice of Batteries, from which to build a Battery Bank, is also a Major Design Point. Car Batteries will work for small systems, but will NOT have the AmpHour Capacity for Intermediate, or Large systems. Batteries last about 6-10 years in this type of Use. One needs to understand what is out there, and available, to fit into the system NOW, yet also being able to be reconfigured into a Larger Bank, if one plans of growing the system over time, while not having to start over completely from scratch, at each jump in system size. Buying right, the first time, often save money, in the long run, but not having to scrap components, because they NOW, do not meet the larger System Requirements, that come along later.

    ..... YMMV.....
    Ganado likes this.
  9. rsbhunter

    rsbhunter Monkey+

    Planning for expansion

    BTPost, excellent post....Just started getting componets for my solar system, bought a 6 pole combiner box, with the system having 5 strings of 2 panels in series......only leaves me enough for adding another 2 panels.....should have bought the box that has 12 poles....could have grown system to a point beyond what i should EVER need....I'm learning fast, that in this realm, it's not what you have to start with, it's what might be needed in the future.....it's ok to have more than you need and not use it, than to need what you don't have....rsbhunter
    BTPost and Nadja like this.
  10. ColtCarbine

    ColtCarbine Monkey+++ Founding Member

    I posted the above information for just that a tutorial, as that is one of the places I got my information, as nobody around here seems to want to share any information and throw a person a bone. I have no intention of building one like the tutorial, thought it was a start at least on what components I would need and how it is wired, I wasn't going to build the exact thing.

    What about this mentioned post what do I need different?

    Falcon15 likes this.
  11. BTPost

    BTPost Old Fart Snow Monkey Moderator

    These are good enough for a small system, and for short outages in a medium sized system, but for a larger system you should be looking at at L16HDs at a minimum. Just my Opinion.... YMMV....
  12. TnAndy

    TnAndy Senior Member Founding Member

    Uh, not really.

    Your panels are 35ish volt open circuit (Voc)...wiring in strings of 2 gives you 70ish Voc.

    Wiring in strings of 3 gives you 106ish Voc, well within the limits of 150v max of the charge controller, even when you de-rate back some to allow for max cold conditions.

    SO, if you decide to expand, you simply buy ENOUGH panels to reconfigure then in strings of 3, meaning a 6 circuit box would now handle 18 panels, not 12.

    Yet ANOTHER reason to select system voltage of 48.....for if you go with 24, that FM80 charge controller would then be the limiting factor, allowing you only 2400w of PV, instead of the 4800w you can use on a 48v system.

    18 x 230 = 4140w

    Continue on your journey, Grasshopper....you have much to learn yet. ;)

    And, if you REALLY want to learn the "nuts and bolts" of this subject, buy this book:

    Amazon.com: photovoltaics

    (If you get it from Amazon, go thru the Amazon link here at SM so the board gets a few cents back to help support the board)

    This is a VERY good, if technical, textbook on solar and installing it. Takes you thru chapter by chapter, with quiz at the end of each to see if you're "getting it". I highly recommend the book if you REALLY want to learn solar.....along with actually reading it.....ahahahahaaa
    BTPost likes this.
  13. arleigh

    arleigh Goophy monkey

    DSCN4150.JPG I recommend having a switch panel ,and meters, so that all components can be tested at random.
    These are 3 position 20 amp switches ,down is on line, center is off line and up is test.
    I have gotten faulty solar panels and was able to repair them (faulty diode).
    especially being able to test batteries is critical ,it only takes one to draw the bank down like a load.
    Gafarmboy likes this.
  14. shamenlong70

    shamenlong70 Neophyte Monkey

    Hi guys I'm total newb when it comes to this stuff so please forgive me if I make a stupid comment , ok so recently I have inherited an array of diffrent size invertors And two twelve volt deep cycle batteries one is 110 am oh and the other 90amph I would like to run a small workshop on solar energy ect the biggest invertor is 2000watts 4000 variable my total power consumption for tools ect lighting heating and music is 4000watts but apart from heating lights music 200watts continuos use the rest would be variable depending on what tool I was using at the time what would you guys recommend I understand I would need a solar control unit
    Here is also a list of tool wattage
    Shop vac 2000 watts
    Stereo. 35 watts
    Lights. 120 watts
    Scroll saw 90 watts
    Sander 300 watts
    Lathe. 375 watts
    Pillar drill 350 watts
    Phone charger 5 watts
    Hot plate 1500 watts
    Any advice ect would be most apreciated
  15. arleigh

    arleigh Goophy monkey

    A great deal depends on how much you plan on running at the same time.
    Most of my lights are now LED which use about nothing compared to florescent or incandescent and they are 12 volt so no AC power needed there.
    Lights usually are the worst consumers because it is a steady drain.
    You might find a battery powered radio/sterio , that uses 12 volts as well . that should save you a lot too.
    A cigarette lighter receiver can work the same as your car for charging the phone.
    2000 watts on a shop vac is an awful lot of power, that's almost 20 AMPS .
    THE HOT PLATE is pulling more amperage than a small microwave oven, unless you need the hot plate for other then cooking food,
    I'd reassess it's importance.
    It is unlikely that you'd be running more then one tool at a time, so the 2000 watt inverter might be acceptable,but it has been my experience that ratings don't always match real life, so use with caution.
    Over time the batteries will diminish in reserve so how the work new will change as time goes on That's why I have meters in the system.
  16. chimo

    chimo the few, the proud, the jarhead monkey crowd Site Supporter+

    Considering how many devices are powered/charged via USB, make sure you get one of these puppies:


    Last edited: Apr 25, 2016
    kellory likes this.
  17. BTPost

    BTPost Old Fart Snow Monkey Moderator

    For my money, I would not get one of those, but rather a Powered Hub that has an External 12Vdc Wallwart.... I just bought a USB 3.0 Seven Port Hub that also sports three High Current Charging Ports... Up to 60 Watts... For quick charging iPads & iPhones, and such...
    Ganado likes this.
  18. chimo

    chimo the few, the proud, the jarhead monkey crowd Site Supporter+

    That would be an optimal solution, I posted the quick, cheap and dirty. ;)
  19. arleigh

    arleigh Goophy monkey

    I'm a little cautious about hub chargers I've lost good electronics that way. at least don't go cheap. considder your investment.
  20. oil pan 4

    oil pan 4 Monkey+

    Solar charge controllers are not optional. If you do not use a solar charge controller you will likely fry the battery and damage or ruin any electronic equipment connected to the battery.
    A typical so called "12 volt solar panel" can normally produce voltages as high as 18 to 22 volts.
    Plus with a proper MPPT solar charge controller you can charge 12 or 24 volt battery systems off panels that produce up to 100 volts DC.
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