Going solar involves a lot more than just mounting panels on your roof. Between getting quotes, pulling permits, passing inspections, and getting your utility to flip a switch, the average homeowner waits 4–12 weeks from contract signing to system activation. Knowing what to expect at each stage makes the process far less stressful.
This guide walks you through all 8 steps of a residential solar installation, with realistic timelines, red flags to watch for, and the questions every homeowner should ask before signing anything.
The Full Timeline at a Glance
| Stage | Who Does It | Typical Duration |
|---|---|---|
| 1. Get quotes | You + installers | 1–2 weeks |
| 2. Site assessment | Installer | 1–2 hours |
| 3. Permit filing | Installer | 2–8 weeks |
| 4. Utility interconnection | Installer + utility | 2–8 weeks (can overlap) |
| 5. Installation day | Install crew | 1–3 days |
| 6. City/county inspection | Inspector | 3–10 days after install |
| 7. Utility meter upgrade | Utility company | 1–4 weeks |
| 8. Monitoring setup | You + installer | 1 hour |
Step 1: Get Multiple Quotes
Start with at least 3 quotes from different installers. Never sign with the first company that knocks on your door or calls you — high-pressure solar sales is a genuine industry problem, and the first quote is rarely the best price.
Where to Find Installers
- EnergySage: The most popular online marketplace. Installers compete for your business, which often results in lower pricing. You can compare side-by-side.
- SEIA member directory: Solar Energy Industries Association maintains a list of vetted members.
- Local referrals: Ask neighbors who have recently installed solar — firsthand experience with an installer is worth a lot.
- Direct installer websites: Large national companies (Sunrun, SunPower, Tesla Energy) have their own channels; compare these against local installer quotes.
What Every Quote Must Include
- Panel brand, model, and exact wattage
- Inverter brand and type (string, micro, or power optimizer)
- Total system size in kW and estimated annual production in kWh
- Price per watt (allows apples-to-apples comparison)
- Whether permits are included
- Equipment warranties and workmanship warranty
- Projected payback period and year-one savings estimate
Step 2: Site Assessment
After you choose an installer and sign a contract, they will schedule a site assessment. A qualified technician or engineer visits your home to:
- Inspect your roof condition, age, and orientation
- Measure available roof space and identify obstructions
- Evaluate your electrical panel — if it's an older 100-amp panel, it may need upgrading to 200 amps (typically $1,500–$3,000 extra)
- Note shading from trees, chimneys, and neighboring structures
- Confirm internet connectivity for monitoring equipment
If they find the roof needs repair, do the repair first — reroofing after solar is installed is expensive and complicated. Most installers won't proceed on a roof with less than 10 years of remaining useful life.
Step 3: Permits and System Design
After the site assessment, your installer creates a detailed system design and submits permit applications to your local building department and, separately, to your utility for interconnection approval.
You don't need to do anything during this phase — just be responsive if your installer needs your signature on documents or additional information. The interconnection application tells your utility you'll be adding a solar system and requesting a bi-directional meter for net metering.
Step 4: Utility Interconnection Approval
Your utility reviews the system design and approves (or requests modifications to) the interconnection. This is separate from the local building permit. The utility needs to confirm:
- The system size won't overload the local grid segment
- The inverter meets IEEE 1547 anti-islanding safety standards
- Your meter can be upgraded to a bi-directional net metering meter
Most utilities approve residential systems within 2–6 weeks. Some rural cooperatives and municipal utilities are slower. Your installer handles all of this — you just need to be patient.
Step 5: Installation Day
This is the exciting part. A crew of 2–6 technicians arrives early in the morning. Here's what happens:
Morning (Hours 1–3): Roof Work
- Crew marks panel positions and locates roof rafters using stud finders
- Lag bolts are drilled into rafters and flashed (sealed) to prevent leaks
- Aluminum racking rails are mounted on the lag bolts
Midday (Hours 3–6): Panel Mounting
- Panels are hoisted to the roof and clipped onto racking rails
- DC wiring is run between panels in series (or per-panel for microinverters)
- Conduit is routed from roof to the electrical service panel
Afternoon (Hours 6–8): Electrical Connections
- Inverter is mounted (usually in garage or utility room)
- AC disconnect and production meter are installed
- System is wired into your main electrical panel
- Monitoring gateway is connected to internet router
At the end of installation day, the crew will do a basic system check — but they cannot fully power it on until the city inspection and utility approval are complete. The system sits ready but inactive.
Step 6: City/County Inspection
A municipal building inspector visits to verify the installation meets local electrical and structural codes. The inspector checks:
- Racking attachment and flashing
- Electrical conduit routing and connections
- Proper labeling of disconnect switches (required by NEC 690)
- Ground fault protection and arc-fault protection devices
Most installations pass first inspection. If there are corrections needed, your installer schedules a re-inspection. Once the inspection is passed, you receive a Permission to Operate (PTO) from the city — this is separate from the utility PTO.
Step 7: Utility Meter Upgrade and Final PTO
After city inspection passes, your installer submits the approval to the utility. A utility technician visits (you usually don't need to be home) to swap your standard meter for a bi-directional net metering meter. The utility then issues the final Permission to Operate (PTO).
This step takes anywhere from 1 to 4 weeks depending on your utility's schedule. Once you receive the utility PTO, you're clear to turn the system on.
Step 8: System Activation and Monitoring Setup
Your installer will either be present or walk you through remotely activating the system — usually just flipping a few switches in sequence. Within hours, you'll see production data in the monitoring app.
Monitoring Apps by Inverter Brand
- Enphase Enlighten: Panel-level monitoring, available for iOS and Android
- SolarEdge App: Panel-level monitoring via power optimizers
- SMA Sunny Portal: String inverter monitoring
- Tesla App: Integrated solar + Powerwall monitoring
Check your monitoring app during the first sunny day to confirm production looks reasonable. A 7 kW system on a sunny day should produce 35–45 kWh (5–6.5 hours × 7 kW).
How to Choose the Right Solar Installer
The installer matters as much as the equipment. Here's what to verify before signing:
Certifications to Look For
- NABCEP (North American Board of Certified Energy Practitioners) — the gold standard
- State contractor's license for electrical work
- General liability insurance ($1M minimum)
- Workers' compensation insurance
Questions to Ask
- "How long have you been in business in this state?"
- "Can I see 3 recent customer references?"
- "Do you use subcontractors for installation?"
- "What's your workmanship warranty?" (10 years minimum)
- "What happens if your company closes during my 25-year panel warranty?"