Small DIY Solar Systems are Easy to Make

small solar system

A small solar system designed to power lights and possibly your refrigerator for an emergency is easy to build.  It is something that you can do yourself without a lot of training.

If you have read this post, you know how to figure out how many panels and batteries you need. You can use either new or used solar panels.

What you need for a DIY Solar System.

  • Solar panels — make sure they are matching panels, same size same manufacturer. You can mix some panels but it takes a bit of expertise to get this right.
  • Controller — make sure the controller you get will handle the voltage put out by your panels and it needs to protect your batteries by keeping them from being overcharged. Not all controllers do this.
  • Inverter — your inverter needs to be big enough to handle the draw you intend to place on it.
  • Storage batteries — get good quality deep cycle batteries.
  • Miscellaneous wiring — make sure the wiring will handle the current draw.

Now that you have all the parts, it is fairly simple to put it together, assuming you have some minimal electrical skills.

How to build your DIY Solar System.

small solar panel
Here you can see the wiring on a solar wagon. This shows the batteries and the inverter.

Once you have your panels, determine where you want to place them.  They need good sun exposure for as many hours as possible.  One option that I have seen is to build a solar wagon, An Easy to Make Solar Wagon.  You can build a unit that is portable and you can move to make the best use of the sun.  A wagon can carry enough panels to supply lights and run a refrigerator.

See also  Chainsaw Maintenance

With a small solar system, it is best to connect the panels in series.  This means you attach the positive leads to the negative leads.  Two 12-volt panels will produce 24 volts.  So for each panel, you add your voltage increases.  This is different from a large system where you may have strings of panels in series and the strings then connected in parallel.

Next, attach the leads from the solar panels to the controller.  Then run your wires from the solar panels to the batteries.  The batteries should be wired in parallel.  Your jumpers between the batteries and to the inverter should be out of 2 AWG cable for up to 100 amps.  For 200 amps you should use 3/0 copper.

small solar system
This shows the panels connected in series, the controller and the batteries
small solar system
This is how you wire your batteries in parallel

The inverter should be connected to the batteries.  In mine, I would put a box with at least two 15-amp breakers between the inverter and the appliances.  This is not mandatory but is a good safety feature. There are several ways to build these small solar systems, some are more complicated than others.  This page introduces the solar-powered gear that I am most familiar with and can recommend. This one is about as simple as you can make.

How many Solar Panels do I need?

It depends, to run a refrigerator you need about 120 volts to run it and that’s about 10 Solar Panels. If you have 10 solar panels you won’t have to worry about not having enough because 10 Solar Panels is enough for any household appliance. Have fun.

Updated July, 2020

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11 thoughts on “Small DIY Solar Systems are Easy to Make”

  1. Not sure I learned anything useful here. This type of information – generic at best – is available in high school texts. How about some specific information? Panel angles, current, panel combiners, panel orientation …

    1. Did you read the blog before this on how many panels and batteries you need? There are so many variables that it is hard to give real solid advice with out specific information about what type and size of system you are building.
      If you have any questions I will try and answer them.

      1. Hi Howard,

        Do you think you will be showing the solar wagon at the preparedness fair this year? I’m a bit interested since this looks fairly easy to build, maintain, and relocate, but it would be great to see it up close.


    1. It will be in Auburn, California on April 12, I will be posting details in the next couple of days on the blog

  2. If I read this right it sounds like you are running 24 volt power from the panels to the controller but 12 volts into the batteries. Is that right? Does the controller just convert it from 24 to 12v? Then you run wires directly from the battery to the inverter, or does it run back through the controller to the inverter to the load? Does there have to be a ground anywhere in this system?

  3. nice web page .

    we need a help
    we have a freedge and use about 840 watts/day
    and we need to Run FOR 24 HOURS using sun panels
    please need help to designs a off the grid system to run my appliance .

  4. Hello I looking for advise on making a small solar system. I plan on starting off with three 50 watt solar panels. Im not sure what amp solar controller I need and what the max power inverter I can use? Also how many batteries I need to store power.

  5. while you can get controller for small panels its not much more cost to get at least 10 amp which will work for for 200 watt
    and get 12 and 24 check you tube for reviews some cheap are ok some not pwm for low cost cheep mppt are not any better larger system good mppt

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