TL;DR: Hiring a solar panel contractor involves more than just getting a quote. From verifying licenses and reviewing proposals to understanding installation timelines and post-installation support, this checklist walks you through every stage so you can hire with confidence and avoid costly mistakes.
Going solar is one of the smartest financial and environmental decisions a homeowner can make. But the process of getting there? That’s where things can get confusing fast.
The solar industry has grown rapidly over the past decade. According to the Solar Energy Industries Association (SEIA), the U.S. installed enough solar capacity to power 22 million homes as of 2023. With that growth has come a surge in contractors—some excellent, some not. Knowing how to evaluate and work with a solar panel contractor is just as important as choosing the right panels.
This guide walks you through every stage of the process: what to look for before you sign anything, what happens during installation, and what good post-installation support actually looks like. Whether you’re weeks away from making a decision or just starting your research, this checklist gives you the framework to move forward with clarity.
What Should You Look for Before Hiring a Solar Contractor?
Before any panels go on your roof, the groundwork you lay during the vetting stage will determine how smoothly everything else goes. Here’s what to check.
Is the Contractor Licensed, Certified, and Insured?
This is non-negotiable. A reputable solar panel contractor should hold a valid state electrical or contractor’s license, carry general liability insurance, and ideally hold a certification from the North American Board of Certified Energy Practitioners (NABCEP)—the gold standard credential in the U.S. solar industry.
Ask for proof of each. A legitimate contractor will have no hesitation providing documentation. If they do hesitate, that’s your cue to move on.
How Many Years of Experience Does the Solar Contractor Have?
Experience matters, but context matters more. A contractor who has been in business for 10 years installing commercial systems may not be the best fit for a residential rooftop installation. Ask specifically about their experience with projects similar to yours in terms of size, roof type, and system complexity.
Request references from past customers and, where possible, visit a completed installation. Photos are helpful; firsthand accounts are better.
What Brands and Equipment Does the Contractor Use?
Solar panels, inverters, and mounting hardware vary significantly in quality and warranty coverage. Top-tier panel manufacturers include LG, SunPower, Panasonic, and REC Group. Leading inverter brands include Enphase, SolarEdge, and SMA.
A trustworthy contractor will explain why they recommend specific equipment—and back it up with data on efficiency ratings, degradation rates, and warranty terms. Be cautious of contractors who push proprietary or obscure brands without a clear rationale.
How Many Quotes Should You Get Before Choosing a Solar Contractor?
Get at least three quotes. This gives you a realistic sense of market pricing and lets you compare proposals side by side—not just on cost, but on system size, equipment quality, timeline, and warranty coverage.
The lowest quote is rarely the best one. Solar systems are long-term investments; cutting corners on equipment or installation quality can cost you significantly more over a 25-year system lifespan.
What Does a Solar Proposal Actually Include?
Once you’ve shortlisted contractors, each will submit a proposal. Knowing how to read one is critical.
A comprehensive solar proposal should include:
- System size (measured in kilowatts, or kW)
- Estimated annual energy production (measured in kilowatt-hours, or kWh)
- Equipment specifications (panel brand and model, inverter type, mounting system)
- Itemized pricing (equipment, labor, permits, and any additional fees)
- Projected savings and payback period
- Available incentives, including the federal Investment Tax Credit (ITC), state rebates, and net metering details
- Warranty coverage for panels, inverters, and workmanship
If any of these elements are missing or vague, ask for clarification in writing before you proceed.
What Financing Options Should You Expect a Solar Contractor to Offer?
Most reputable solar contractors offer multiple financing paths: cash purchase, solar loans, lease agreements, and Power Purchase Agreements (PPAs). Each has different implications for ownership, tax credit eligibility, and long-term savings.
Cash purchases and solar loans typically allow homeowners to claim the federal ITC (currently 30% through 2032, per the Inflation Reduction Act). Leases and PPAs generally do not. Make sure your contractor clearly explains which incentives apply based on your financing method.
What Happens During the Solar Permitting and Design Phase?
After you sign a contract, there’s usually a gap of several weeks before installation begins. This phase involves system design, permitting, and utility coordination—and it’s largely handled by the contractor on your behalf.
Here’s what’s happening behind the scenes:
Site assessment and system design: A solar contractor or their design team will review your roof dimensions, shading analysis, energy usage history, and structural integrity to finalize the system layout.
Permit applications: Solar installations require permits from your local municipality. Processing times vary widely—from a few days in some jurisdictions to several weeks in others.
Utility interconnection application: Before your system can feed excess power back to the grid, your utility company must approve the connection. This process, called interconnection, runs concurrently with permitting.
A reputable contractor will handle all of this and keep you updated throughout. If weeks pass without any communication, follow up proactively.
What Should You Expect on Solar Installation Day?
Installation day is typically the most straightforward part of the process—provided the pre-work was done correctly. For most residential systems, installation takes between one and three days.
Here’s the general sequence:
- Roof inspection and preparation: The crew checks the mounting surface, makes any necessary reinforcements, and installs flashing to waterproof penetrations.
- Racking installation: The mounting rails that hold the panels in place are secured to the roof.
- Panel placement: Panels are mounted to the racking system according to the approved design layout.
- Electrical wiring: Panels are wired together and connected to the inverter. The inverter is typically installed in the garage or utility area.
- Monitoring system setup: Most modern solar systems include a monitoring app that tracks energy production in real time. The contractor should configure this and walk you through how to use it.
On the day of installation, expect some noise, foot traffic on your roof, and temporary disruption to your electrical service. These are all normal.
What Inspections Are Required After Solar Installation?
Installation isn’t the finish line. Before your system can be turned on, it must pass two separate inspections.
Municipal inspection: A local building inspector will verify that the installation meets code requirements. This is typically scheduled by your contractor within a few days of installation.
Utility inspection: Your utility company will send a representative to approve the interconnection and install a new meter (often a bidirectional meter that tracks both consumption and export). This step is required before your system can legally operate and before you can benefit from net metering.
The time between installation and final utility approval—sometimes called “Permission to Operate” (PTO)—can range from a few days to several weeks. During this period, your panels are on your roof but not yet active.
What Should You Do If There Are Issues During Inspection?
If an inspection reveals a problem, your contractor is responsible for correcting it at no additional cost to you—provided the issue stems from their workmanship. This is why a strong workmanship warranty (typically 10–25 years from reputable contractors) matters so much.
Document any issues raised during inspection in writing, and confirm with your contractor in writing how and when they’ll be resolved.
What Does Good Post-Installation Support Look Like?
The relationship with your solar contractor shouldn’t end when the panels go live. Over a 25-year system lifespan, you’ll likely need occasional support.
Here’s what post-installation support should cover:
- System monitoring assistance: Your contractor should help you interpret your monitoring data and flag any production anomalies.
- Warranty claims handling: If a panel or inverter fails, a good contractor will manage the manufacturer warranty claim on your behalf.
- Annual performance review: Some contractors offer yearly check-ins to compare actual production against projections. This helps identify underperformance early.
- Roof and system maintenance: While solar panels require minimal maintenance, periodic cleaning and inspections (especially after severe weather) help sustain performance.
Ask your contractor directly: “What happens if I call with a problem in five years?” Their answer will tell you a lot about how they run their business.
Your Complete Solar Contractor Checklist at a Glance
Before hiring:
- Verified state license and NABCEP certification
- Confirmed general liability and workers’ comp insurance
- Reviewed at least three quotes
- Checked references and past installations
- Understood equipment brands and warranty terms
Reviewing the proposal:
- System size and projected production are clearly stated
- Itemized pricing with no hidden fees
- Tax credits, rebates, and net metering details included
- Financing options explained with tax implications
During installation:
- Site assessment completed before installation day
- Permits pulled and approved
- Monitoring system configured and explained
After installation:
- Municipal inspection passed
- Utility Permission to Operate received
- Workmanship and equipment warranties documented
- Post-installation support process confirmed
Make the Right Call Before You Sign
Choosing a solar panel contractor is a long-term commitment. The decisions you make during the vetting process—equipment, warranties, contractor track record—will shape your experience for decades, not just the weeks surrounding installation.
Use this checklist as your baseline, ask hard questions, and don’t rush the process. A contractor confident in their work will welcome your scrutiny. And when you find the right one, the transition to solar will be exactly what it should be: straightforward, well-supported, and genuinely worth it.
Frequently Asked Questions About Solar Panel Contractors
How long does the entire solar installation process take from start to finish?
The full process—from signing a contract to receiving Permission to Operate—typically takes 6 to 12 weeks. Most of that time is spent on permitting and utility interconnection, not the physical installation itself, which usually takes one to three days.
What is NABCEP certification and why does it matter?
NABCEP (North American Board of Certified Energy Practitioners) certification is the most widely recognized professional credential in the U.S. solar industry. Contractors with NABCEP-certified installers have demonstrated a verified level of training and field experience, making it a reliable indicator of quality.
Can a solar contractor help me claim the federal Investment Tax Credit?
A solar contractor can provide the documentation you need to claim the federal ITC, but they cannot file your taxes or guarantee your eligibility. The 30% ITC applies to cash purchases and solar loans; it generally does not apply to leases or PPAs. Consult a tax professional to confirm your eligibility.
What happens if my solar panels underperform after installation?
If your system produces significantly less energy than projected, start by reviewing your monitoring data and comparing it against your proposal’s estimates. Contact your contractor with documented evidence. Reputable contractors will investigate production issues and, where applicable, file warranty claims on your behalf.
Is it normal to pay a deposit before solar installation begins?
Yes, most solar contractors require a deposit—typically 10–30% of the total project cost—upon signing. Be cautious of contractors who request full payment upfront. A structured payment schedule tied to installation milestones is standard practice and protects both parties.
What should a solar workmanship warranty cover?
A workmanship warranty covers defects resulting from the installation itself—things like improper wiring, roof leaks caused by poor flashing, or mounting failures. Reputable contractors offer workmanship warranties ranging from 10 to 25 years. This is separate from the manufacturer warranties on your panels and inverter.
