How to Build a DIY Solar Panel System For Your Home That Saves 80% On Energy Costs

Installing a DIY solar panel system can significantly reduce your electricity bills and carbon footprint. With some planning and effort, you can build an efficient solar system that powers your home and saves up to 80% on energy costs. Here is a step-by-step guide on how to build your own DIY solar panel system:

Choosing the Right Solar Panels

The first step is selecting the right solar panels. Here are some factors to consider:

• Panel efficiency - More efficient panels produce more electricity with the same amount of sunlight. Look for monocrystalline or polycrystalline panels with at least 15% efficiency.

• Panel wattage - Higher wattage panels produce more power. For a residential system, select 250W to 300W panels.

• Panel quantity - Determine how many panels you need based on your energy usage. Typically, 20-30 panels are enough for a home system.

• Panel certification - Opt for UL or IEC certified panels that meet quality and safety standards. Reputable brands like Renogy, Rich Solar, and Grape Solar are good options.

I chose 300W polycrystalline solar panels from Renogy for my system. With 25 panels, I can generate 7.5kW of power. This is sufficient for my household's daily energy consumption.

Sizing Your Solar System

The solar panel size should match your energy requirements. Here's how to size your system:

• Review electricity bills - Analyze your monthly electricity usage to understand your needs. Notice seasonal variations too.

• Account for future needs - If you plan on buying electric vehicles or adding appliances, account for increased energy demand.

• Determine panel wattage - For grid-tied systems, multiply your average daily usage by 1.5 to get the total panel wattage needed.

• Factor losses - Derate the wattage by 20% to account for system losses. This gives the actual panels wattage to install.

My home uses 45kWh daily on average. After derating, I calculated a 7.5kW system would comfortably meet my energy needs.

Selecting a Solar Inverter

The inverter converts the DC electricity from solar panels to usable AC electricity. Here are the key considerations:

• Continuous and peak power - The inverter must have sufficient capacity to handle the solar array's rated peak wattage.

• Grid-tie vs off-grid - Grid-tie inverters sync to the electric grid while off-grid ones charge batteries.

• Pure vs hybrid sine wave - Pure sine wave inverters offer higher quality AC power compatible with sensitive electronics.

I went with a 6kW Enphase grid-tie microinverter system to match my 7.5kW solar array. The pure sine wave output ensures clean power for my appliances.

Mounting and Positioning Solar Panels

Optimal mounting and placement maximize solar panel efficiency:

• Rooftop mounting - Elevated rooftop mounting provides maximum sun exposure.

• Ground mounting - Ground mounts are suitable if rooftop space is inadequate.

• Tilted angle - Angle panels at latitude minus 15 degrees to maximize year-round production.

• Direction - Face panels south (in northern hemisphere) to capture maximal sunlight.

• Shade-free - Ensure panels have unobstructed sunlight, especially during peak generation hours.

I installed my panels on the south-facing section of my roof at a 25 degree tilt. This provides ample sunlight as the sun tracks across the sky.

Connecting Panels and Wiring

Follow electrical safety codes when wiring up your solar components:

• String configuration - Wire panels in series to form strings based on inverter specs. My inverter takes 2 panel strings.

• Wire gauge - Use recommended copper wire size based on current and distance. 10-12 AWG is commonly used.

• Overcurrent protection - Install fuses or breakers for safety. One per string is typical.

• Disconnects - Include a manual disconnect to safely shut off the DC side.

• Grounding - Properly ground all equipment. The rack, panels, and inverter must be grounded.

I wired 2 strings of 12 panels in 12 AWG copper with 30A fuses and a rotary disconnect switch. Proper grounding was ensured.

Monitoring and Maintenance

To keep your solar system performing optimally:

• Inspect periodically - Check wiring, connections, and components for damage. Address issues immediately.

• Clean panels - Clean dust and grime off panels seasonally with water and a soft brush.

• Trim vegetation - Keep overhanging trees and bushes trimmed to avoid shading panels.

• Monitor production - Use inverter monitoring to track system performance. Verify optimal kWh output.

I check my Enphase portal monthly to monitor production. I also inspect the panels and wiring twice a year and clean the array annually. This keeps my system in tip-top shape.

With some effort and attention to details, you can definitely build an efficient DIY solar panel system. Proper sizing, quality components, and good installation practices are key. Stay within local regulations and use certified products. With a well-designed solar array, you can easily save thousands in energy costs annually.