Going solar is one of the most significant investments you’ll make in your home. It promises decades of lower electricity bills and a smaller carbon footprint. But choosing the right partner is crucial to realizing those benefits. The difference between a smooth, profitable experience and a costly nightmare often comes down to asking the right questions upfront.

To help you navigate this complex decision, here are the 25 most important questions to ask solar companies. Asking these questions empowers you to thoroughly vet installers, compare quotes accurately, assess company stability, evaluate equipment quality, ensure installation safety, and measure long-term value.

This guide offers a comprehensive checklist that breaks down everything you need to know before getting started with solar energy.

Company Background & Credentials

Your solar installation is a 25+ year commitment. You need to ensure the company you choose will be around to honor its warranties. Start with these foundational questions to ask solar companies about their history and qualifications.

1. How long has your company been in business?

Longevity often indicates financial stability and experience. A company that has weathered market fluctuations is more likely to be around to service your system in 10 or 15 years.

What to look for in their answer: Ideally, you want a company that has been installing solar for at least 5 years. This shows they have a proven track record and have moved beyond the initial startup phase.

Red flags to watch for: Companies that are less than 2-3 years old, have recently changed their name, or can’t provide a clear history. While new companies aren’t always bad, they carry more risk.

2. What licenses and certifications do you hold?

Proper licensing ensures the company is legally permitted to perform the work and meets state and local standards. Certifications from reputable bodies like the North American Board of Certified Energy Practitioners (NABCEP) indicate a higher level of expertise and commitment to quality.

What to look for in their answer: A clear list of their state and local license numbers (e.g., general contractor, electrical contractor licenses). Mention of NABCEP certification is a significant plus, as it’s considered the gold standard in the solar industry.

Red flags to watch for: Hesitation to provide license numbers or claims that they “don’t need them.” Always verify their provided licenses with your state’s licensing board.

3. Can you provide local references from recent customers?

Online reviews are helpful, but speaking directly with past customers provides unfiltered feedback about the entire process, from sales to post-installation support. Local references also prove they have experience in your specific area.

What to look for in their answer: A list of 3-5 recent customers in your area whom you can contact. A reputable company will be proud of its work and happy to connect you with satisfied clients.

Red flags to watch for: Refusal to provide references, only offering old references, or directing you only to pre-written testimonials on their website.

4. What happens to my warranty if your company goes out of business?

This is one of the most critical questions to ask before getting solar panels. Many installers offer a “workmanship warranty” covering installation errors. If they go under, this warranty could become worthless, leaving you to pay for repairs.

What to look for in their answer: First, your equipment (panels, inverters) warranties are backed by the manufacturer, so they remain intact. Second, they should offer solutions like a third-party insured warranty or primarily use equipment from highly stable, bankable manufacturers whose warranties are robust.

Red flags to watch for: Dismissing the question or saying, “We’re not going anywhere.” A professional company will have a contingency plan and be transparent about it.

Equipment & Technology

Not all solar technology is created equal. The panels, inverters, and mounting hardware they use will directly impact your system’s performance, longevity, and return on investment. Here’s what questions to ask when buying solar panels and their components.

5. What are the panel’s key performance metrics for my home?

This question moves the conversation beyond generic brands and into the specific technologies that differentiate modern solar panels. It challenges the installer to prove they aren’t just selling a one-size-fits-all solution, but are instead acting as a true energy consultant.

This question shifts the discussion from brand names to the technologies that actually impact performance. It ensures the installer tailors their recommendation to your situation rather than offering a one-size-fits-all solution.

What to look for in their answer:

• Site-Specific Factors: How your location, surrounding environment, roof orientation, and array layout influence performance and panel selection.
• Key Specs: Efficiency (power per sq. ft.), Temperature Coefficient (performance in heat), and Degradation Rate (annual power loss).
• Cell Technology & Layout: Options may include Half-Cut Cells for better shade tolerance, Shingled Cells for higher power density, or advanced N-Type cells (TOPCon, HJT) for lower degradation and higher efficiency than older P-Type cells.
• Durability & Longevity: Look for dual-glass construction, special coatings, or other features that improve performance in challenging environments such as coastal, humid, or high-temperature areas.

Red flags to watch for: Vague claims like “high-quality panels” without details. Avoid installers who cannot justify why a panel fits your home’s unique conditions.

6. How does this inverter support my goals and future plans?

The inverter is the brain of your solar system, converting DC power from the panels to the AC power your home uses.

A clear explanation of why they chose a specific inverter type for your home and goals. They should discuss the pros and cons based on your roof layout and local utility rules. For example:

Using PowMr inverters as an example:

• All-in-One inverter might be great for off-grid or a battery backup system, but most models do not support selling excess power back to the grid (grid-tied exporting). This would make you ineligible for net metering credits.
• In contrast, hybrid inverters are designed for both battery backup and grid interaction. A critical point is whether you need a split-phase model (typical for U.S. homes) or a three-phase model (for certain properties or equipment).
  Since rules vary by state and utility, confirm that the proposed inverter meets local safety standards and carries the necessary certifications, such as UL 1741, to ensure legal grid interconnection.

Red flags to watch for: A failure to discuss local grid interconnection requirements is a major warning sign. Always ensure the proposed inverter is certified and approved for use in your area.

7. How will this battery operate daily and during an outage?

A solar battery is more than a backup supply, it’s a financial tool that manages your home’s energy to maximize the value of every kilowatt-hour, regardless of your utility’s specific rate structure. You need to understand this economic engine.

The solar company should recommend a battery technology and capacity suited to your needs and explain how it adapts to your utility plan.They should describe one or more of the following scenarios:

• Time-of-Use (TOU) Rate Plans: Charge during low-cost solar hours and discharge during expensive peak hours to avoid high grid rates.
• Net Metering with Low Export Rates: Store excess solar instead of selling cheaply, then use it at night to avoid high utility costs.

• Demand or Non-Bypassable Charges: Discharge during high-usage moments to reduce peak charges.
• Outage Protection: Maintain a reserve to provide seamless, automatic backup power to essential circuits during grid outages, regardless of financial strategy.

Red flags to watch for: Battery system not scaled to current and future needs. Too small or large impacts efficiency and wastes money. Limited expandability options.

C. Installation Process

The installation team’s quality is just as important as the equipment. A poor installation can lead to roof leaks, electrical hazards, and underperforming systems.

8. What is the complete installation timeline, from signing to turn-on?

This sets clear expectations and reveals how organized the company’s operations are. The physical installation is short, but the entire process involves permits, inspections, and utility approvals that can take months.

What to look for in their answer: A realistic, multi-stage timeline: “After signing, design and permitting takes 4-6 weeks. The on-site installation itself is only 1-3 days. After that, final city and utility inspections can take another 2-4 weeks before you get Permission to Operate (PTO).”

Red flags to watch for: Vague answers or an unrealistically short timeline like “we’ll have you running in two weeks.” This often ignores the bureaucratic steps they don’t control.

9. What’s your process for roof assessment?

Before installation, the company must confirm your roof’s structural integrity can handle the added weight of the panels. A thorough assessment prevents future problems.

What to look for in their answer: They should describe a multi-step process that includes an on-site inspection of the roof structure (often from the attic), measuring rafters, and assessing the condition of the roofing material. They may also use drone imaging or engineering reports.

Red flags to watch for: Companies that only use satellite imagery (like Google Maps) and don’t perform a physical inspection of the roof structure itself.

10. Who will be doing the actual installation work? Are they employees or subcontractors?

This is one of the best questions to ask a solar company. Companies that use their own in-house, certified installation teams generally have better quality control, communication, and accountability than those who subcontract the work to the lowest bidder.

What to look for in their answer: The ideal answer is “We use our own dedicated, in-house teams who are fully trained and NABCEP certified.” If they use subcontractors, they should explain how they vet them and that they are held to the same standards.

Red flags to watch for: Evasiveness about who does the work or if they can’t name the subcontracting company they regularly partner with.

Financing & Contracts

Understanding the financial aspect is paramount. Misinterpreting the contract or choosing the wrong financing can erase your potential savings. This is where a sharp solar sales rep should be able to provide clear answers.

11. What financing options do you offer?

Companies offer various ways to pay for solar, including cash purchase, solar loans, leases, and Power Purchase Agreements (PPAs). Each has different implications for ownership, tax credits, and long-term savings.

What to look for in their answer: A clear presentation of all available options, with the pros and cons of each explained without bias. They should be able to provide details on interest rates, loan terms, and partner lending institutions.

Red flags to watch for: Hard-selling only one option (especially a lease or PPA) without explaining why it’s the best fit for your specific financial situation.

12. Can you explain the difference between leasing vs. purchasing?

Purchasing (with cash or a loan) means you own the system and get the federal tax credit. Leasing or a PPA means the company owns the system on your roof, and you pay them a monthly fee for the power. Ownership is the key difference.

What to look for in their answer: They should explain who gets the tax credit and incentives, compare the long-term savings of ownership versus leasing, and note ownership’s impact on home value. A clear explanation of lease or PPA contract terms, including escalators, maintenance, and buyout options, is essential for understanding financial outcomes.

Red flags to watch for: Calling a lease “free solar” or downplaying that you will not own the system or receive tax incentives is misleading. Be cautious if installers push one option, make vague “no-cost” claims, skip tax credit details, or avoid clarity on contracts, escalators, or long-term costs.

13. How much is the total Investment, including all costs?

The initial quote should be comprehensive. You need to protect yourself from surprise charges for things like permitting, interconnection, main panel upgrades, or trenching.

What to look for in their answer: A professional installer will provide a line-item quote clearly stating the total installed cost, inclusive of all permits, labor, and equipment. The only exception should be major, unforeseen structural issues that cannot be anticipated in advance.

Red flags to watch for: Watch for vague or incomplete quotes, hidden fees, or installers who hesitate to provide a detailed breakdown. Avoid companies that only give ballpark figures or refuse to commit to an all-inclusive final price.

Warranty & After-Sales

Your relationship with the solar company doesn’t end after installation. The system needs to perform for many years. A strong warranty and reliable after-sales support are non-negotiable.

14. What warranties come with the system?

Warranties protect your investment and ensure long-term system performance. Knowing what is covered, for how long, and by whom helps you avoid unexpected repair costs or performance issues.

What to look for in their answer: A clear explanation of product, performance and workmanship warranties, including the duration of each and coverage details.

Red flags to watch for: Only mentioning the manufacturer’s warranty and offering a very short (1-2 year) workmanship warranty. This indicates a lack of confidence in their own installation quality.

15. Who handles maintenance and repairs?

When something goes wrong, you need a single point of contact. You don’t want the installer blaming the manufacturer and vice versa.

What to look for in their answer: The installer should clearly state whether they provide maintenance and repair services directly or if you rely on the manufacturer. They should outline response times, service coverage, and costs. Some companies offer ongoing service plans and these should be explained in detail.

Red flags to watch for: Generic statements such as “covered under warranty” without specifics, very short warranty periods, or unclear responsibility for repairs indicate potential risks.

16. What monitoring system do you provide?

A monitoring app allows you to see your system’s production in real-time. It’s essential for verifying that the system is performing as promised and for quickly identifying any issues.

What to look for in their answer: The solar company should explain how you can access performance data (mobile app, web portal, alerts), what metrics are tracked (energy production, battery status, faults), and if monitoring is included or requires a subscription.

Red flags to watch for: No monitoring included, charging extra for monitoring, or offering a system that only shows total production instead of individual panel performance.