Introduction
Installing solar panels on your home can reduce or even eliminate your electricity bills. With solar panel prices dropping, DIY solar panel systems are now an affordable option for many homeowners looking to go green and save money. In this guide, I will walk you through the entire process of designing, sourcing components, and installing a DIY solar panel system on your home.
Determine Your Energy Needs
The first step is to analyze your home's electricity consumption to properly size your solar panel system.
Calculate Your Monthly and Annual Electricity Usage
- Review 12 months of electricity bills to get your average monthly kilowatt-hour (kWh) usage.
- Multiply your average monthly usage by 12 to get your annual usage.
- My home uses 900 kWh per month, so my annual usage is 10,800 kWh.
Factor In Future Electricity Needs
- Consider any plans to purchase electric vehicles, heating systems, or appliances.
- Increase solar array size by 20-30% to account for future electric loads.
- With expected electric vehicle purchase, I will size my system for 13,000 kWh annual production.
Understand Your Electricity Rates
- Check your utility's energy charges per kWh and meter fees.
- These determine the savings from replacing grid electricity.
- My utility charges $0.15 per kWh and $8 meter fee monthly.
Calculate Required Solar Array Size
- Use PVWatts Calculator to determine needed system size in kilowatts (kW).
- Factor in your location, electricity usage, and average sun hours.
- For my 13,000 kWh need in my region, ideal system size is 5 kW.
Select Solar Panels
Next, research and purchase solar panels for your system.
Types of Solar Panels
- Monocrystalline - Most efficient but most expensive.
- Polycrystalline - Lower efficiency, cheaper price.
- Thin-film - Lowest efficiency, cheapest price.
For a residential DIY build, polycrystalline panels provide the best balance of efficiency and cost.
Determine Number of Panels
- Solar panels are typically 250-400 watts each.
- Divide your total system size by panel wattage to get the number of panels.
- For my 5 kW system, I will need 12 x 300W panels (5,000W / 300W = 12 panels).
Purchase Panels and Racking
- Buy quality polycrystalline 60-cell panels and sturdy aluminum racking.
- Cost should be around $1-1.50 per watt for panels and $0.20 per watt for racking.
- For my 5 kW system, budget $6,000 for 12 x 300W panels and $1,000 for racking.
Obtain Remaining System Components
You will also need cables, conduit, disconnects, and other electrical components.
Inverter
- The inverter converts DC solar power into AC for your home.
- Choose a string inverter appropriately sized for your system.
- Budget $0.20-0.30 per watt, so $1,000-1,500 for a 5 kW system.
Batteries (Optional)
- Adding batteries allows energy storage for use when the sun isn't shining.
- Lithium-ion batteries provide the best balance of performance and cost.
- Budget $500-600 per kWh of storage capacity.
Racking, Wiring, Conduit
- Use copper wiring in conduit for connecting panels and running to inverter.
- Ensure proper circuit breakers and disconnects are in place.
- Budget $1000-2000 for parts and cabling.
Rooftop Attachments
- For roof mount, flashing kits seal attachments and prevent leaks.
- Include any necessary lag bolts, flashing, sealants, and hardware.
- Budget $200-500 for rooftop attachments.
Install the Solar Panel System
With all the components and parts purchased, it's time for installation.
Mount Racking and Panels
- Arrange racking and orient panels for maximum sunlight exposure.
- Securely bolt lateral and vertical support rails into roof rafters.
- Attach panel mounting hardware and solar panels to racking.
Run Conduit and Wiring
- Run conduit from panels to inverter with copper wires inside.
- Use proper conduit bends and junction boxes.
- Connect panels in series to combine voltage.
Connect Inverter and Switchboard
- Securely mount inverter on wall near main electric panel.
- Connect conduit to inverter and connect solar wires.
- Connect inverter AC cables to switchboard.
Activate System
- Have your municipal inspector review the installation.
- Activate the anti-islanding feature for grid tied systems.
- Monitor your solar production on sunny days!
Maintain and Troubleshoot Your Solar System
It's important to properly maintain your solar system to maximize production.
Inspect Connections and Mounts
- Check all wiring connections twice a year for corrosion and looseness. Tighten as needed.
- Ensure all panel and racking mounts remain properly secured.
Clean Solar Panels
- Clean panels 2-4 times per year to remove dust, dirt, and debris.
- Use a soft brush and mild soap and water solution. Be gentle.
Check Inverter Operation
- Ensure the inverter is functioning properly and converting DC to AC power.
- Reboot inverter if any error codes appear.
Monitor Production
- Review system performance monthly for expected kWh output.
- If low, inspect area shading, panel dirt, and system faults.
Conclusion
Installing a DIY solar panel system takes research, planning, and some hard work, but it can pay off for many years through electricity bill savings. With a properly sized and installed system, you can generate your own renewable power for little to no electric bill indefinitely.