What questions are vital to ask solar installers when you vetting both local and national companies?

Knowing the questions to ask a solar panel company can help you make an informed decision when choosing an installer.

Installing solar panels is a big commitment, so you must ensure you’re confident in the company you hire for the job. Research on solar panel adoption shows that having clear information can help demystify the installation process, counter concerns and myths, and promote greater confidence in decision-making.

This guide explores some of the most important questions to ask a solar panel company to ensure you hire a good installer and minimise potential issues.

Pro tip: Avoid upsells and confusing packages—choose a provider with a clear, fixed-price quote that won’t change. Heatable, a Which?-approved solar installer, offers transparent pricing with no surprises.

What Questions Should You Ask a Solar Company?

You should ask each potential installer the following questions:

1. Is Your Company Certified and Accredited?

Your first inquiry should involve the company’s certifications and accreditation. Certification and accreditation by independent industry organisations ensure the company can do the job according to industry standards and protect you as a consumer. Certifications and memberships to look out for include:

• MCS certification — The Microgeneration Certification Scheme (MCS) is a recognised UK certification scheme that demonstrates the quality and reliability of installation companies and approved products. The scheme protects you by ensuring the company can install the panels competently, safely, and to the expected level of quality.

• HIES membership — The Home Insulation & Energy Systems Contractors Scheme (HIES) protects you by ensuring the company installs the solar panels professionally according to scheme rules and code of practice. It also requires the company to offer comprehensive guarantees for high protection and peace of mind.

• RECC membership — Membership to the Renewable Energy Consumer Code (RECC) ensures the company is committed to a consumer code. It guarantees high service standards throughout the process, from pre-installation to post-installation, including not engaging in high-pressure selling techniques.

2. What Warranties Do You Offer for the Panels and Installation Work?

Warranties are vital since they can give insight into the manufacturer’s confidence in their product and ensure you’re covered if any issues or defects arise.

When asking about warranties, ensure you inquire about the product warranty for the panels and inverter and the installer’s warranty for the installation work.

An extended product warranty is a good indicator of the durability and quality of the panels. The installer or labour warranty ensures the company will repair or fix any issues arising from the installation. For example, Heatable offers a 2-year workmanship warranty.

Solar panels usually have a 25-year warranty, while inverters have a 10-year warranty. However, these can be shorter or longer depending on the company, so ensure you get the specifics for your system.

3. What Type of Solar Panels Do You Install?

There are different types of solar panels, and the kind you get will impact the overall cost and your system’s quality, efficiency, longevity, and performance.

Panels can be categorised into tiers relating to the manufacturer to help investors assess quality. However, you can also use it to determine quality, with Tier 1 being the highest.

They can also be monocrystalline, polycrystalline, or thin-film. Monocrystalline panels offer the best quality, efficiency, and durability but are expensive. Polycrystalline panels cost less but feature lower efficiencies and shorter lifespans than monocrystalline panels.

Ask the company about the specific make and model of the panels they plan to install so you can research their performance and reliability.

4. How Much Energy Will the System Produce?

You should also ask the solar panel company to estimate the system’s annual energy production in kilowatt-hours (kWh). This will give you a practical measure of what your system can produce over a year under optimal conditions.

For example, a 4kW system can generate around 3500 to 4500 kWh of electricity annually under typical UK irradiance. However, the figure can vary based on location, panel tilt, orientation, efficiency, and shading.

Ensure the company provides you with the proposed system’s kilowatt (kW) rating and estimated annual kWh production. Such information makes it easier to compare quotes more effectively and allows you to determine whether the system size can effectively meet your needs.

5. How Does My Energy Consumption Impact the Size and Cost of the System?

Understanding your home’s energy consumption will help determine the correct solar panel system size. Ask the company to review your electricity bills and have them explain how they use the information to determine the proper size for your system.

They should clearly explain how your current energy consumption translates into the recommended size and expected energy production. Such figures are essential since larger systems can have higher upfront costs, while a small system may not be able to meet your needs.

6. What Estimated Savings Can I Make Yearly?

Ask the company to estimate potential annual savings you can make from your solar panels. The savings should be based on your current electricity consumption, the proposed system size, and the sunlight conditions in your area.

The estimate can help you determine the potential financial benefits of your investment and how long the payback period can be.

You can save money from reduced grid electricity use and the payments you get through the Smart Export Guarantee (SEG) for exporting excess energy.

The company should give you estimates for both. For example, according to the Energy Savings Trust, solar panels can save you up to £690 annually with SEG in London if you’re home all day.

Validation from industry bodies like the Energy Performance Validation Scheme (EPVS) can help ensure the estimates are credible. EPVS offers independent validation so you can get accurate and realistic figures. This protects you from inflated claims so you can make investment decisions based on trustworthy information.

7. Have You Considered the Roof’s Structural Soundness, Tilt, and Orientation?

Before installation, you must ask the company to determine if your roof is strong enough to handle the added weight of the panels. Ask them about their structural assessment for roof integrity and how they’ll securely attach the panels and prevent rainwater breaches.

The tilt and orientation of your roof will impact the efficiency of your solar system. South-facing roofs are ideal in the UK since they allow maximum sunlight exposure, but south-west and south-east orientations are also practical. A tilt angle between 30 to 40 degrees is also recommended.

Ask the company how they’ve factored your roof’s orientation and tilt into the solar system’s design. Such inquiries present an opportunity to discuss potential roof adjustments, replacements, or repairs that may be necessary before installation. Addressing such issues beforehand is generally more cost-effective.

8. Are You Doing the Installation or Subcontracting It Out?

Some companies may pose as installers, but they’re middlemen who take a cut and pass the work to a third party.

Knowing who is carrying out the work may be challenging in such cases. You may also receive a higher price due to the third-party margin or end up with sub-standard work.

Ask the company if they’re responsible for the work on your property so you can know who to contact if issues arise during or after the installation. If they use subcontractors, you should ask about the vetting process and how they ensure quality control and competency.

9. How Long Have You Been Operating?

Experience is essential in solar panel installations and can impact your system’s safety, efficiency, and durability.

Companies that have operated for a few years and built a good track record of success tend to be more reliable. Ask the company about their history and experience with similar projects and if they have relevant case studies or references.

Ask about testimonials and reviews or if previous customers will talk with you. Customers who had their panels installed a few years ago are the best to talk to.

The information they provide or their current sentiments on the work done can give you confidence in the company’s ability to handle your installation effectively.

10. What Is Your Timeframe for Installation?

Knowing the timeline of the solar panel installation and any possible disruptions allows you to plan accordingly. Ask the company how long you’ll wait before installation begins and how long the process will take until the project’s completion.

Factors affecting the timeline include planning permissions, the company’s schedule, and the time needed to prepare materials and equipment.

A typical residential installation can take one to three days to complete. However, it can take longer if your roof is challenging to access or requires scaffolding.

A reliable company can give you a clear and realistic schedule and ensure timely completion without compromising quality.

11. Do You Perform Aftercare?

Ask the company if they provide aftercare services after installation. It can include ongoing maintenance or handling potential repairs, issues, or hardware replacements when things go wrong. Aftercare services ensure your system is operating efficiently and make it easier to fix minor issues before they develop into costlier problems.

Final Thoughts on Questions to Ask a Solar Panel Company

Asking the right questions makes it easier to choose the most suitable company to install your solar panel system.

Don’t be afraid to make inquiries and compare responses from different companies. A good company will answer all your questions and provide detailed, transparent information about their services and products.

And remember never accept hard sale tactics and don’t feel pressured to make an instant decision. We recommend seeking at least three quotes from three different solar companies.

Sources and References

• https://energysavingtrust.org.uk/advice/solar-panels/
• https://assets.publishing.service.gov.uk/media/60edea3b8fa8f50c7f08ae1e/uk-rooftop-solar-panel-behavioural-research.pdf