Going off the grid while camping can be liberating, allowing you to connect with nature without the distractions of modern technology and the comforts of home. However, you may still want access to some basic necessities like power for lights, phones, laptops, and small appliances while camping. That's where a portable solar power generator comes in handy.
A portable solar generator consists of solar panels, a power inverter, batteries for energy storage, and the housing or casing to hold it all together. With a properly sized and designed solar generator, you can keep your essential devices powered up even when miles away from the nearest electrical outlet.
Determine Your Power Needs
The first step in building your own portable solar generator is figuring out your expected power needs. Consider the following:
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Which devices and appliances will you want to run? Make a list with estimated wattages. Focus on essentials like lights, phones/tablets, laptops, small fans or pumps, and battery chargers.
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How many hours per day will you need to power those devices? Estimate runtime.
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How many days will your camping trip last? Account for multiple days of usage.
By totaling your watt-hour needs (wattage x hours used per day x number of days), you can properly size the solar panels, inverter, and batteries for your generator. Allow for at least 20% extra capacity as a safety buffer.
For a weekend camping trip powering LED lights, charging phones, and running a small laptop, you may only need around 200 watt-hours per day. But for extended off-grid use, plan for 500+ watt-hours daily.
Choose Your Solar Panels
Once you know your needed watt-hours per day, determine how many solar panels to include. Some key solar panel specs to consider:
- Output wattage - Add up panels to meet your daily watt-hours.
- Voltage - Most small panels output 12V or 24V.
- Current - Measured in amps (A); higher is better.
- Dimensions - Consider portable size but bigger can collect more solar energy.
For portable use, monocrystalline panels provide the highest efficiency in smaller panels. But polycrystalline and thin-film panels can work well too. Buy a solar charge controller to go along with your panels.
As an example, two 100W 12V panels wired in parallel provide 200W and around 17A of charge current - enough for the weekend camping trip example above running on two sunny days.
Select a Power Inverter
Inverters convert the DC electricity from solar panels and batteries into standard 120V AC power to run household devices. For a portable solar generator, use a modified sine wave inverter rated for your expected wattage needs.
Match the inverter's input voltage to your solar array and batteries (commonly 12V or 24V). Size the wattage for 20-30% over your highest appliance/device wattage. Include automatic low battery shutdown to prevent over-draining your batteries.
So for the 200W 12V example system, a 300W 12V inverter would work well. Adding a power switch and outlets to your generator housing finishes the inverter side.
Choose Appropriate Batteries
Deep cycle lead-acid, absorbed glass mat, or lithium-ion batteries are good options for solar storage. Lead-acid is inexpensive but very heavy. Lithium-ion costs more but offers lightweight storage. Make sure to buy batteries suited for solar charging and deep discharging.
Battery capacity is measured in amp-hours (Ah). Choose enough Ah capacity to cover your needed watt-hours, accounting for the battery voltage. Allow for only 50-80% maximum discharge to preserve battery life.
For the 200W-hour per day example, two 100Ah 12V batteries provide 200Ah total at 50% discharge, or 1200Wh - plenty for several days. Connect batteries in parallel to add Ah capacity. The solar charge controller will manage charging from the panels and prevent overcharging.
Build the Portable Housing
For the generator housing, use a protective enclosure like a tool box, gun case, or plastic storage container. The box should be large enough to hold the panels, batteries, inverter, wiring, outlets, and any control switches. Make cutouts for ventilation.
Mount the solar panels to the lid or to brackets so they can be tilted to face the sun. Secure all components safely inside the housing. For easy transport, install handles and wheels if desired.
Follow Safety Practices
When working with batteries, inverters, and wiring, be sure to use proper:
- Circuit protection - Fuses or breakers
- Cabling - Sized for expected loads
- Grounding - Grounded system for safety
- Connections - Tight and corrosion-resistant
Don't exceed the voltage and current specs for any component. Enclose batteries to avoid accidental contact. Use insulated tools when working with the system.
With quality components, sound electrical design, and safe construction, you can build a portable solar generator perfect for powering your essentials on off-grid camping trips for years to come! Let the sun provide the power while you enjoy nature.