I want to share how I built a DIY solar panel system that powers my entire home for under $200. With some basic materials and following the steps below, you can build your own affordable solar panel system as well.
What You Need To Get Started
To build a solar panel system on a budget, you'll need the following materials:
- Solar cells - I purchased silicon solar cells on eBay for about $1 each. You'll need around 40 cells for a 200W system.
- Plywood - Use a large sheet of plywood as the panel backing. Look for inexpensive or free scrap plywood.
- Plexiglass - A plexiglass sheet will cover the solar cells. Check your local hardware store for offcuts.
- Copper strips - Copper strips connect the solar cells together. I used recycled copper but you can find them cheap online.
- Enphase microinverter - Converts the DC power into AC power for your home. I found a used one for $20.
- DC disconnect - Safely connect and disconnect the system. I used a simple knife switch.
- MC4 connectors - To connect the solar panels and wiring. I salvaged these.
- Miscellaneous - Nuts, bolts, wiring, conduit for mounting the panels. I used scrap materials.
With these basic components and some DIY spirit, you can build your own budget solar panel system! The rest of this article will walk through the process step-by-step.
Determining How Many Solar Panels You Need
The size of solar panel system you need depends on your energy usage. Follow these steps to determine how many panels your home needs:
- Examine your electricity bills - Check the kWh usage on several months of electricity bills to understand your average monthly usage.
- Calculate your daily average usage - Take the monthly kWh amount and divide by 30 to get your average daily electricity needs.
- Determine how many watts your system needs - In general, you'll need about 20W of solar panels per 100 watts of power usage. So if your daily average is 30kWh (30,000 watts), a 6000W (6kW) system should meet your needs.
- Calculate how many 200W panels you need - Divide your total system watts by the output of each panel (I used 200W panels) to get the number of panels required. For my 6000W system, I needed 30 x 200W panels.
Constructing the Solar Panel Frame
With the number of panels needed figured out, it's time to build the panel frame:
- Cut the plywood backing - Measure and cut a large piece of plywood into smaller pieces for each panel. Make them around 24in x 24in.
- Create the side border - Attach 1in x 2in wood strips around the edges of the plywood to create a border. This allows the plexiglass to sit flush on top.
- Seal and prime the wood - Seal the wood and painted primer on the panels to protect them from weathering outside.
Now you have sturdy solar panel backing ready for the solar cells and wiring.
Connecting the Solar Cells
Here is the process I used to connect 40 solar cells together into a single 200W panel:
- Lay out the solar cells - Arrange 40 silicon solar cells evenly across the plywood backing in a series. Each cell generates around 5 watts.
- Solder the copper strips - Solder 10" copper strips between the front of each cell to electrically connect them together. This combines all 40 cells into a single circuit.
- Insulate solder points - Use silicone to cover the solder points between cells to prevent shorts. Let the silicone dry completely.
- Wire the panel - Solder lengths of 10 gauge wire to the positive and negative ends of the panel circuit. Attach MC4 connectors to wire.
Connecting all the solar cells in series combines their power output into a single 200W solar panel.
Completing the Solar Panel
The last steps are finishing touches to complete the DIY solar panel:
- Install the plexiglass cover - Lay the plexiglass sheet over the solar cells glued to the plywood border. The plexiglass protects the solar cells.
- Seal the panel - Caulk any gaps around the plexiglass to seal it to the frame. This prevents moisture damage.
- Add a junction box - Attach a small junction box to the rear of the panel to house the MC4 panel connections.
With that, your homebuilt 200W solar panel is ready to be mounted and wired into the system!
Wiring Multiple Solar Panels Together
For a solar system with multiple panels, they need to be wired in parallel:
- Connect positive terminals - Use 10 gauge wire to connect all the positive panel terminals together via MC4 connectors. This combines the current.
- Connect negative terminals - Similarly, connect the negative terminals from each panel together using MC4 connectors and 10 gauge wire.
- Connect to the microinverter - Run positive and negative wires from the combined panels to the Enphase microinverter inputs.
Wiring the panels in parallel combines their current while maintaining the voltage. Follow the microinverter wiring instructions to complete the connections.
Mounting and Installing the Solar Panels
Now it's time to mount the DIY solar panels and get them producing power:
- Obtain mounting hardware - I used basic brackets, rails, and lag bolts to securely mount my panels on the roof. Always use galvanized or stainless steel hardware.
- Determine the angle - Face the panels towards the southern sky and tilt them at an angle equal to your latitude for optimal year-round production.
- Mount the panels - Securely attach the mounting feet to the back of the solar panels, spaced evenly across the frame. Then mount them onto the roof rails using the appropriate lag bolts.
- Run the wiring - Route the positive and negative wires from the panels inside through conduit to where the microinverter will be located.
With the panels installed, you're ready to connect them into your homes electrical system.
Connecting to the Electrical System
The final stage is connecting the solar panel system into your home's electrical grid:
- Install the microinverter - Mount the Enphase M215 microinverter on an interior wall near the main electrical panel. Follow the wiring diagram. Connect the leads from the solar panels to the microinverter.
- Connect to an outlet - Plug the microinverter output into a regular 110V electrical outlet. This interfaces it with your home's electrical system.
- Monitor your power production - Enphase provides monitoring software so you can track your solar power production in real-time!
Once connected to the electrical system via the microinverter, your DIY solar panels will begin producing free, clean energy to power your home!
Safety Considerations
When working with solar panels and electricity, be sure to take proper safety precautions:
- Turn off the main breaker before wiring into the electrical system.
- Follow all electrical codes and obtain a permit if required by your local regulations.
- Have a licensed electrician inspect the connections and sign off on the solar system.
- Use extreme caution when working on the roof, wear safety equipment and secure yourself so you don't fall.
By following good safety practices, you can install your DIY solar system safely.
Conclusion
Building your own solar panel system is a very rewarding project that will provide free renewable energy for your home. In this article, I walked through the complete process I used to create a 200W solar system for under $200. Follow the steps outlined here to create your own affordable DIY solar panel system to power your home! Let me know if you have any other questions.