Solar panel installation is more than just mounting panels on your roof—it's a comprehensive process that involves engineering, electrical work, permitting, and ongoing support. Understanding what goes into the package helps you evaluate quotes accurately and avoid surprise costs down the road. Here's what actually happens when you go solar.
Site Assessment and Design
Before anything gets installed, a solar company sends a representative to evaluate your property. They'll measure your roof dimensions, check for shade patterns throughout the day, review your energy bills, and assess structural integrity. This assessment typically takes 1–2 hours and is usually free.
From this data, engineers design a system customized to your home. They'll determine panel count, inverter type, and mounting configuration to maximize your electricity production. You'll receive detailed drawings showing exactly where components go, expected annual energy output (measured in kilowatt-hours), and estimated payback timeline. Good installers walk you through this design before moving forward.
Permitting and Inspections
Permits are non-negotiable. Your installer handles submitting paperwork to your local building department and utility company—but this responsibility shouldn't fall entirely on them. Most reputable installers include permitting in their quote, though costs vary by location ($200–$800 typically).
Once installation is complete, a municipal inspector verifies the work meets code. They check electrical connections, grounding, structural mounting, and fire safety measures. The utility company also conducts an inspection before "interconnection"—the official approval to feed excess power back to the grid. Budget 2–4 weeks for this entire process.
Equipment and Materials
Here's what physically gets installed:
- Solar panels (usually 15–25 units for residential systems)
- Inverter (converts DC power to usable AC electricity)
- Mounting hardware (racking, rails, brackets for roof attachment)
- Wiring and conduit (electrical connections between components)
- Disconnect switches and safety equipment
- Monitoring equipment (tracks real-time energy production)
- Batteries (optional; adds $8,000–$15,000 for home backup power)
Equipment quality varies significantly. Higher-tier panels from Sunpower or LG offer better efficiency and longevity but cost more upfront. Budget-friendly options from Jinko or Canadian Solar deliver solid performance at lower prices. Inverters from Enphase or SMA are industry standards. Don't let an installer push you toward unfamiliar brands without justification.
Installation Labor and Timeline
The actual installation typically spans 1–3 days, depending on system size and roof complexity. Installers:
- Remove sections of roofing where needed
- Install mounting hardware and secure it to roof rafters
- Mount and wire panels in series strings
- Install the inverter (usually on a garage wall or outside)
- Run electrical conduit and make all connections
- Install monitoring hardware
- Seal all roof penetrations to prevent leaks
A standard 6–8 kilowatt residential system usually takes 1–2 days on-site. Flat commercial roofs or systems requiring extensive electrical work may take longer. Weather delays happen—rain, high winds, or extreme heat can push timelines back.
Electrical Work and Interconnection
This is often overlooked but critical. Your installer must:
- Upgrade your electrical panel if capacity is insufficient (adds $1,000–$3,000)
- Install a new breaker for the solar system
- Ensure proper grounding throughout
- Set up net metering with your utility company
Net metering allows you to sell excess solar generation back to the grid at retail rates. Without it, your system's economic benefit drops significantly. Confirm your utility offers this before signing a contract.
Warranty and Monitoring Setup
Standard warranties include:
- 25-year equipment warranty (panels typically degrade 0.5–0.8% annually)
- 10-year labor warranty (coverage for installation defects)
- 25-year inverter warranty (some manufacturers offer this; others warrant 10 years)
Most systems come with a mobile app or web dashboard to monitor daily production, catch issues early, and track savings. Familiarize yourself with how to use it during handoff.
Hidden Costs to Ask About
Ask installers explicitly whether these are included:
- Electrical panel upgrade
- Roof repairs or replacement under panels
- Homeowners insurance adjustment
- Tree trimming for shade removal
- Conduit and wiring labor
- Monitoring hardware and software
Frequently Asked Questions
Q: How long does the entire process take from quote to flipping the switch? A: Typically 4–8 weeks, depending on permit processing times in your area and installer scheduling. Some fast-track projects finish in 3 weeks; complex electrical upgrades can stretch to 12 weeks.
Q: Should I get quotes from multiple installers before choosing? A: Absolutely. Equipment and labor costs vary by 15–30% between installers, and warranty terms differ significantly. Compare at least three detailed quotes covering the same equipment specifications.
Q: What happens if my roof needs replacement before installation? A: Address this upfront. Roofing repairs (typically $5,000–$15,000) are your responsibility, and most installers won't warranty panels on a roof that fails within 10 years of installation.
Ready to compare vetted solar installers in your area? Mercoly helps you find and evaluate trusted solar installation providers side-by-side, so you can make a confident decision.