I've decided I want to build my own portable solar generator to use for power outages, camping trips, and emergency preparedness. Building your own solar generator is actually pretty straightforward if you follow the right steps. In this guide, I'll walk through everything you need to know to build your own portable solar power station for under $200.
Selecting the Battery
The battery is the heart of any solar generator, so it's important to pick the right one. For a portable unit, I recommend using a deep cycle lead acid battery. These are designed to provide steady power over long periods, unlike car batteries which are made to provide quick bursts.
Some key factors to consider when selecting the battery:
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Amp hour (Ah) rating - This determines how long the battery can provide power before needing recharged. For a portable unit, choose a battery with 50-100 Ah.
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Physical size and weight - Look for a compact and lightweight battery so your generator is easy to transport. A 20-30 lb battery with carrying handles works well.
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12V voltage - Most solar charge controllers and inverters run on 12V, so stick with a 12V battery.
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Budget - You can find suitable batteries for $60-100 if you shop around. Don't sacrifice too much quality just to save money.
For my portable generator, I'm going with a 100 Ah sealed lead acid battery that weighs 27 lbs. The ideal balance of capacity and portability for under $100.
Getting the Charge Controller
Since lead acid batteries can be damaged by overcharging, you need a charge controller to manage the power from the solar panel going into the battery. The charge controller protects the battery by stopping the flow of current when it's fully charged.
Here are the key factors for the charge controller:
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12V rating - Match the voltage of your battery.
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10+ amps current - Can handle the wattage of your solar panel.
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PWM or MPPT - PWM is fine for small systems. MPPT is more efficient but pricier.
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Display screen - Shows you battery level, charging status, voltage, etc. Very handy.
I'm going with a 20A PWM charge controller with an LCD display for about $40. Does the job without breaking the budget.
Choosing the Solar Panel
The solar panel captures sunlight and converts it into electricity to recharge the battery. To choose the right solar panel, consider:
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Wattage - 50-80W is a good range for portable systems. Provides enough power without getting too big.
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Voltage - Again, stick with 12V panels to match your battery and charge controller.
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Portability - Lightweight panels in the 10-20 lb range with a carrying case are best for portability.
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Budget panels - You can find 50W panels for around $60 if you look. Avoid really cheap panels that are poor quality.
For this build, I'm using a 50 watt rigid panel with an aluminum frame that folds up nicely into a carrying case. Got it for a good price at just over $80.
Getting Power from the Battery
Now that you have the battery and solar panel covered, you need a way to draw usable AC power from the 12V DC battery. This is where the power inverter comes in.
Here are the key factors for selecting the inverter:
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300-500W - Gives enough power for small devices and appliances.
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Pure sine wave - Important if you'll be running electronics or certain appliances. Avoid cheap square wave inverters.
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12V input - Matches voltage from the battery.
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Outlets - Standard AC outlets to plug devices into. At least two outlets is ideal.
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Under $100 - You can get a good 300W pure sine wave inverter for around $80-90. Don't skimp here.
I'm going with a 400W pure sine wave inverter for $95. Gives me two AC outlets to run a variety of devices.
Putting It All Together
Now it's time to hook up all the components and get your solar generator working!
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Connect the charge controller to the battery using 12V cable.
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Connect the solar panel to the charge controller, which manages the power going to the battery.
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Connect the inverter to the battery using more 12V cable. This draws power from the battery and converts it to AC power.
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Make sure all connections are secure and corrosion-free.
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Add a fuse between the battery and inverter for safety.
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Install your AC outlets into the enclosure and wire them to the inverter.
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Place the battery and electronics inside the enclosure, secured neatly.
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Get a power strip to plug devices into your solar generator.
With all the components connected properly, you'll have a fully functional off-grid solar generator! Just set the panel in the sun to charge up the battery.
Choosing an Enclosure
The final step is selecting some type of enclosure to mount the components in. This can be a small tool box, plastic storage container, or special solar generator case. I found a tough plastic toolbox that fits everything perfectly for around $40.
Some key tips for the enclosure:
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Sturdy and durable to protect components. Plastic works well.
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Good ventilation to prevent overheating. Drill vent holes if needed.
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Mounting points to secure parts in place neatly.
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Portability with handles. The lighter the better for transport.
And that covers the complete process of assembling your own portable solar power station on a budget! With proper part selection and installation, you can build an effective solar generator for emergency power for under $200.