While solar technology is widely regarded as one of the safest and most reliable sources of renewable energy, professionals insist that the greatest risks do not come from the panels themselves but from the quality of installation, materials used, and the competence of installers.
Industry experts say that when installed according to engineering standards using quality components, rooftop solar systems rarely pose safety concerns. However, they warn that poorly executed installations can lead to roof leakages, structural damage, electrical faults, and, in extreme cases, fire outbreaks.
Poor Workmanship Behind Most Roof Leakages
Past President of the Nigerian Institute of Building (NIOB) and pioneer President of the Building Collapse Prevention Guild (BCPG), Kunle Awobodu, identified poor workmanship as one of the major challenges associated with rooftop solar installations in Nigeria.
According to him, rooftop solar panels are generally safe and do not present direct health hazards when installed correctly. However, he noted that incompetent installation can create serious problems for homeowners.
Awobodu explained that one of the most common complaints is roof leakage, particularly during the rainy season in buildings roofed with aluminium sheets.
He attributed the problem largely to inexperienced installers who fail to properly seal roof penetrations during installation, stressing that leakages resulting from poorly installed solar panels have become a growing concern across the country.
Structural Safety Should Come First
Speaking on the engineering implications of rooftop solar installations, Dr. Arc. Otuoke Augustine said every building should undergo structural evaluation before solar panels are mounted on its roof.
According to him:
"Structural risks from solar panel installations primarily involve weight distribution problems and roof integrity issues if the installations were not taken into at conception of the design of a building. Solar panels add approximately 2-4 pounds per square foot to your roof, which can strain older structures or roofs not designed for additional loads. Poor weight distribution creates stress points that may lead to sagging, cracking, or structural failure over time."
He further explained that the condition and age of a roof are critical factors in determining whether it can safely accommodate solar panels.
"Roof age and condition play a critical role in installation safety. Roofs older than 15 years or those with existing damage may not withstand the mounting process or long-term panel weight. Structural integrity assessments should evaluate load-bearing capacity, rafter spacing, and overall roof condition before installation begins."
Augustine warned that even the installation process itself can compromise a roof if proper procedures are ignored.
"The mounting process itself can damage roof materials. Drilling penetrations for mounting hardware weakens the roof structure, while improper fastening techniques can cause immediate or gradual deterioration. Heavy equipment used during installation may crack tiles, damage membranes, or stress underlying support structures."
He stressed that engaging qualified structural engineers before installation can prevent expensive repairs later.
"Professional structural evaluations identify potential problems before they become costly repairs. Engineers can determine whether reinforcement is needed and specify appropriate mounting systems for your specific roof type and condition."
Why Roof Leaks Occur
Augustine also highlighted the technical reasons many buildings begin to leak after rooftop solar systems are installed.
According to him:
"Roof leaks from solar installations typically result from improper penetration sealing and flashing installation errors. Every mounting point creates a potential water entry path, and inadequate sealing around these penetrations allows water infiltration that can cause extensive structural damage over time."
He added that poor flashing installation remains one of the leading causes of water penetration.
"Flashing installation requires precise technique and high-quality materials. Poor flashing work around mounting points, conduit penetrations, and roof transitions creates immediate leak risks. Many installers lack proper roofing experience, leading to substandard waterproofing that fails during the first heavy rain."
Augustine further warned that careless handling during installation can damage roofing materials.
"Roof membrane damage during installation creates additional leak sources. Walking on fragile roof materials, dropping tools, or using inappropriate fasteners can puncture membranes or damage protective coatings. These issues may not become apparent until water damage appears inside the building."
He also reminded homeowners that maintenance remains essential throughout the lifespan of a solar system.
"Long-term waterproofing concerns include sealant degradation, thermal cycling effects on seals, and maintenance access issues. Sealants require periodic inspection and replacement, but many building owners do not realize this ongoing maintenance responsibility until leaks develop."
Common Installation Mistakes
Beyond leaks, Augustine identified several installation errors that affect both safety and system performance.
He said:
"Common installer errors include improper mounting techniques that compromise both system performance and roof integrity. Using incorrect fasteners, inadequate spacing, or poor alignment creates immediate problems and long-term reliability issues. Shortcuts during installation often result in premature system failures and safety hazards."
He also warned against bypassing regulatory requirements.
"Inadequate permits and code compliance represent serious installation mistakes. Unpermitted installations may not meet safety standards, can complicate insurance claims, and often require costly corrections to achieve compliance. Professional installations should always include proper permitting and inspections."
On equipment quality, Augustine noted:
"Poor-quality equipment selection affects system longevity and performance. Some installers use substandard components to reduce costs, leading to premature failures and reduced energy production. Quality equipment from reputable manufacturers provides better long-term value despite higher upfront costs."
He concluded:
"Installation shortcuts that compromise system performance include inadequate cable management, poor electrical connections, and insufficient system testing. These issues may not become apparent immediately but can lead to reduced efficiency, safety hazards, and expensive repairs over the system's lifetime."
'Solar Installations Are Good, but…'
Former Deputy President of the Nigerian Institution of Structural Engineers (NIStructE), Engr. Johnson Adeyoye, maintained that solar energy remains a dependable alternative power source when installed professionally.
According to him:
"Solar installation is good if properly installed and if handled by competent professionals, qualified engineers, technicians, installers. Solar power system consists of solar panels on top of roofs, solar charge controller, inverter and batteries which can be tubular(with acid/distilled water), dry cell or lithium ion."
He described lithium batteries as the best option despite their higher cost.
"Lithium batteries are the best, but slightly more expensive. Decision on the type of batteries depend on the pocket and economics."
Adeyoye also stressed the importance of using quality cables and electrical components.
"Solar energy installations if properly installed, are safe and durable. Even the quality of transmission cable/ wire used in the insallation is very important, provided it is not the cheap Chinese made wire/ cable."
He continued:
"Nigerian made cables/wires of the appropriate diameter/rating are known to be more durable, slightly more expensive and therefore preferable. The China made cables/wires imported into Nigeria are not of standard quality. Solar power installations are safe if properly installed."
Sharing his personal experience, he added:
"On a personal note, I have been using solar power for well over a decade and because of proper installation with the right materials (quality wise), it has been very good."
Certified Installer Explains Best Practices
Certified solar panel installer Ikechukwu Henry also dismissed the notion that solar panels themselves are responsible for most reported incidents.
He said:
"Rooftop solar systems are generally safe when they are properly designed, installed, inspected, and maintained. Most incidents involving fires, roof leakages, or structural damage result from poor workmanship, substandard materials, inadequate maintenance, or failure to comply with established engineering standards rather than from solar technology itself."
Henry explained that roof leakages usually arise when installers fail to observe proper waterproofing procedures.
According to him, common causes include poorly sealed roof penetrations, unsuitable mounting techniques, corrosion around mounting bolts, and fasteners becoming loose due to expansion and contraction over time.
To minimise these risks, he advised homeowners to:
"Use appropriate flashing and waterproof sealants, employ non-penetrating mounting systems where suitable, conduct periodic roof inspections and follow manufacturer installation guidelines."
He also recommended thorough structural assessments before any rooftop installation.
According to Henry, engineers should evaluate the additional dead load created by the solar panels, wind uplift forces, roof deflection, corrosion risks and any damage that could occur during installation.
He urged prospective solar users to insist on structural assessments, wind-load analysis, compliance with engineering design codes and the use of corrosion-resistant mounting materials to ensure both the safety of buildings and the long-term performance of their solar systems.