How to Choose a Solar Panel Installer: Key Questions for Homeowners
For many homeowners, deciding to install solar panels involves not just selecting the technology but also identifying a trustworthy installer. This is critical because initial quotes often appear similar, with two installers possibly offering systems with identical panel counts and comparable battery sizes. However, the real distinctions lie in the finer details. Essential considerations include how well the system is tailored to your home, the realism of savings estimates, the specifics of warranties, and the availability of long-term support. Therefore, choosing a solar panel installer demands more than mere price comparisons; it requires evaluating whether the company comprehends your property, can justify its recommendations, and remains helpful long after installation.
Start with Accreditation and Credibility
The initial checks are straightforward yet vital. First, ensure the installer is accredited through recognised schemes like MCS or Flexi-Orb. Lack of proper certification should raise major concerns. Ed Janvrin, director of franchise at OVO, emphasises: "If the installer isn’t MCS certified, the customer won’t be eligible to sign up for the Smart Export Guarantee (SEG)." However, accreditation alone is insufficient. Alfie Ireland, head of operations at Sunsave, advises scrutinising customer reviews and the company's broader track record. Homeowners should inquire about the installer's credibility, including high Trustpilot scores, and assess its likelihood of remaining operational over decades. Since solar systems are designed to last, an installer that disappears after a few years could void promises of support or workmanship cover.
Examine Quoting and Survey Processes
A reputable installer should not provide a meaningful quote without thoroughly understanding your property. This doesn't necessarily require an in-person visit initially; many now begin with remote assessments using satellite imagery, digital tools, and customer-supplied photos. Janvrin notes that OVO's process starts with a 10- to 30-minute consultation, followed by a virtual survey to evaluate the roof, loft, electricity meter, and scaffolding access. Ireland adds that remote assessments are increasingly common for delivering tailored quotes and savings estimates. The key is thoroughness, regardless of whether the survey is virtual or physical. A proper assessment should cover roof condition, usable space, pitch, orientation, shading, tile type, scaffolding complexity, and wiring routes. Importantly, a good installer will honestly advise if your home is unsuitable for solar. Janvrin states this is a core function of surveys: confirming genuine benefits. "Not every home will benefit from it, and we’d rather inform a customer up front," he says. This honesty prevents the sale of poorly fitting systems. If proceeding, a detailed technical survey may follow, including in-person checks for safety hazards and practical realities, as OVO does post-quote acceptance, or requests for photos of areas like the loft and battery location.
Assess System Design and Customisation
A quality quote should demonstrate that the solar panel system is designed around your property and energy usage. This begins with panel numbers. Janvrin explains that OVO sizes systems based on annual energy consumption, site-specific solar yield, and roof safety, aiming to cover at least 50% of household electricity needs. Ireland adds that effective designs maximise suitable roof space within safety limits; if only about six panels fit, proceeding is rarely worthwhile. Inverter choices must also be justified. Ireland notes that standard string inverters suffice for most installations, with microinverters typically reserved for significant unavoidable shading. Similarly, battery sizing should align with panel count and energy use. Janvrin suggests asking installers directly: why a specific battery size was chosen and how it relates to usage patterns. Recommendations should be grounded in surplus generation and actual electricity consumption, not generic upselling.
Identify Common Overselling Tactics
Solar technology is mature, but quotes aren't always straightforward. Ireland highlights that overselling often involves unnecessary microinverters or optimisers, which increase costs and are frequently avoidable; shading issues can often be mitigated through better design, like placing panels on different strings. Janvrin points to another common issue: battery sizing without clear rationale. If an installer cannot explain why a particular capacity suits your home, it raises red flags. Bigger isn't always better if mismatched to generation and usage. Savings projections also warrant scrutiny. Homeowners should ask how estimates are calculated, the assumptions behind them, and whether these are realistic for their electricity habits. The goal isn't to assume exaggeration but to ensure quotes are based on design logic, not sales tactics.
Pay Attention to Omissions in Quotes
Underselling can be as problematic as overselling. Ireland notes that bird protection is a frequent omission. This add-on prevents pigeons from nesting under panels, avoiding mess, noise, reduced output, and safety issues. Excluding it may lower initial quotes, but retrofitting it later is costlier due to potential scaffolding reinstallation. Warranties are another area where details may be glossed over. Janvrin warns that some installers emphasise panel and inverter cover but neglect wiring, fixings, and fittings. Buyers should ensure comprehensive coverage across all system components. Additionally, check if the installer handles necessary paperwork. Ireland mentions that installations with inverters over 3.68kW typically require Distribution Network Operator permission via a G99 application before grid connection; competent installers should manage this process.
Understand Meaningful Warranties
Solar quotes often feature impressive warranty language, but distinguishing between product cover and real support is crucial. Systems involve multiple warranty layers: product warranties on panels, inverters, and batteries; performance warranties on panels and batteries; and workmanship warranties from installers. In practice, however, the situation is mixed. Ireland observes that workmanship warranties often last only two to five years, short compared to solar panels' 30- to 40-year lifespan. He also notes that batteries and inverters may need replacement before panels, and homeowners might struggle to assess underperformance against warranty terms. Thus, aftercare is vital. Ireland argues that long-term maintenance support is as important as warranties, preventing homeowners from navigating faults and claims alone. Janvrin emphasises stronger workmanship promises, with OVO offering a 10-year workmanship warranty alongside 25-year panel performance warranties. Regardless, buyers should ask who will assist if failures occur years later.
Inquire About Post-Installation Support
While survey and installation days are focal points, a good installer should also outline post-installation processes. Janvrin says OVO's installer helps set up monitoring apps for real-time generation tracking and provides a handover pack with the MCS certificate for SEG sign-up. Ireland adds that most homes receive app access from installers or inverter manufacturers to monitor generation, storage, and export. However, monitoring differs from ongoing support. Ireland contends that many homeowners won't recognise if output drops indicate issues, making installer monitoring and long-term maintenance invaluable. This distinction separates companies focused solely on installation from those committed to sustained system support.
Key Questions Before Paying a Deposit
When comparing quotes, a concise list of questions can reveal much about an installer. Are you accredited by MCS or Flexi-Orb? How was my savings estimate calculated? Why recommend this specific number of panels, inverter, and battery size? Which warranties are included, and who honours them? What happens if a fault appears years later? Does the quote include bird protection? Who handles DNO applications and paperwork? What monitoring will I get, and will anyone help interpret data? A strong installer should answer these clearly and without defensiveness.
Avoid Choosing Solely on Price
Remember, the cheapest quote isn't always the best value. Low prices may reflect weaker support, inadequate warranties, missing extras, poor design, or inferior equipment. Conversely, the most expensive option isn't automatically superior. If one installer is significantly cheaper, investigate what has been omitted, simplified, or assumed. With solar, the objective isn't merely installing panels; it's achieving a system that performs reliably, receives proper support, and delivers long-term value. By prioritising thorough evaluation over price alone, homeowners can secure a sustainable and efficient solar solution.
