The Solar Wagon can be used as a portable or emergency energy system to charge laptops, cell phones, LED lights, or computer speakers. It is made from a re-purposed garden cart with a custom-built solar panel frame and off-the-grid solar electronics shelf. The project budget ranges from $500-$1500 depending on the materials, tools and solar components that you buy or might already have. If you have not welded or worked on solar electronics before, take a class or collaborate on this project for best results.
For more info on our Solar Charging Station projects and workshops see:
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Step 1: Getting Started
Collect all the tools and materials needed for this project.
Build a frame on top of a sturdy steel garden cart to hold the solar panel and electronics (bolt or weld together).
Extra: waterproof the electronics box, make the wagon lockable, add graphics, add a bike hitch.
Material Supply Options
- www.altestore.com (off-the-grid solar components) http://www.altestore.com/learn/ (resources)
Check out the alt E store system calculator: http://www.altestore.com/store/calculators/off_grid_calculator/
- Local Steel / Electrical Supply
- Little Giant Wagon (globalindustrial.com) or try and InStep bike trailer
- “Photovoltaic Design and Installation Manual”
Step 2: Wagon Frame
- Select a small but sturdy cart with 4 wheels. Consider if you will need to take it apart for transport or storage.
- Measure and prepare the wagon for the solar frame.
- Measure and cut the flat bar / angle iron steel /aluminum frame parts to fit your wagon and solar panel.
- Make sure the angle of the solar panel is your location's latitude (37° in San Francisco).
- Tools (drill, band saw, welder, grinder, wire strippers, screwdriver, wire crimpers).
- Paint wagon with an outdoor metal paint (Rust-o-leum).
- Hardware (1/4-20 1"-2" machine screws, lock washers, bolts).
- Bolt the frame to the wagon and then bolt the solar panel on top.
Step 3: Electronics Panel / Frame
- Measure and cut the steel /aluminum frame parts to fit your wagon and solar electronics board.
- Weld / bolt frame together with 1” angle.
- Use 16 gauge perf. steel /aluminum sheet for electronics wall.
- Add holes to bottom of legs to bolt to wagon floor in 4 places.
- Use webbing straps to secure the battery -- to the wagon floor.
Step 4: Solar Components
- 60 Watt Solar Panel (20-60 watts are best)
- 12 Volt 35 AMH Sealed AGM Battery
- USB outdoor socket
- Sun Saver MPPT 15 Amp charge controller
- Sun Saver 300 Watt inverter
- Morningstar Sun Saver remote meter
- Breakers / bus bar for the solar panel, battery, and inverter (load)
- Label maker (label - / + wires)
- Black and Red wire
*Wire the electronics with the help of a solar electrician or take a solar class
*Review battery safety steps
Step 5: How to Use the Solar Wagon
- Add custom solar info graphics to attract attention and share information on solar.
- Make sure the wagon is facing South in the direct sun when charging up the battery and that the breakers are switched on.
- Use a bike lock to keep the wagon secure while charging.
- Keep the Solar Wagon in a clean dry area when inside.
- Turn the breakers off when not in use. (Do not drain the battery)
- Do not leave in the rain without water-proofing the electronics.
- Bring it to a picnic or event to play music and charge cellphones!
- Use during power outages.