Safety first: Unlocking solar on fragile rooftops and how lightweight modules make installation safe and feasible

Commercial and industrial (C&I) rooftops across Europe hold enormous potential for solar energy. Warehouses, factories, logistics centers and office complexes offer large surface areas that could be turned into energy assets. Studies suggest that EU rooftops could generate around 2.7 petawatt-hours of electricity per year, roughly equal to the region’s current consumption, if all roofs were structurally suitable for photovoltaic systems (Sciencedirect,2024) with Germany,France, Italy and Poland holding the largest country-level rooftop PV potentials, which are projected to grow by around 30% by 2060.

Yet many buildings remain excluded from this opportunity. A large part of Europe’s commercial building stock was constructed in the mid-20th century, when developers prioritized low-cost, large-span roofs. These lightweight structures offered little margin for extra load. Decades later, many of them can no longer support the additional weight of conventional solar modules, ballast and snow,making safety the first concern in any rooftop solar project.

Risks on fragile rooftops and how the Hi-MO 10 Guardian Light Design addresses them

Structural overload is the most immediate risk. Conventional single-glass PV modules typically weigh 12–15 kg/m². Combined with mounting, ballast and snow, this canexceed what older lightweight roofs can safely carry. While many modern C&Iroofs are typically designed for 100–150 kg/m², older structures often havereserves of ≈ 50 kg/m² or less, so standard systems may require reinforcement (CROSS Safety,2022). This iswhere Light Design helps. Each module weighs only 16.3 kg, which equals 7.2kg/m², making it up to 32 percent lighter than conventional single-glassmodules and opening solar access for weight-restricted rooftops (LONGi, 2025).

Roof penetrations are another concern. Traditional bolt-through methods can compromise waterproofing, allowing moisture ingress and accelerating roof degradation (Arka360, 2023). Because Light Design modules reduce overall system weight and are compatible with conventional clamp mounting systems, EPC partners can design racking with fewer reinforcements and minimized penetrations, helping preserve the roof surface and extend service life (LONGi, 2025).

Beyond structural concerns, electrical safety is equally critical, particularly the risks of fire and hotspot formation. PV systems remain energized during daylight, so poor connections can create ignition points (Lockton, 2023). Light Design modules are tested and certified according to IEC 61730 fire safety standards. Their HPBC 2.0 back contact architecture reduces operating temperatures and limits hotspot formation, while a multi-protection cell design lowers the risk of cracking and recovers up to 70 percent power under shading (LONGi, 2025).

Weather extremes are another factor. Snow loads can exceed 200 kg/m² in Central Europe and reach 500 kg/m² in Alpine or Scandinavian regions, while in coastal and Western regions, Atlantic storms drive strong uplift forces. Central Europe increasingly faces large hail, which has caused significant damage in recent summers. Aging roofs may already be stressed by snow, wind or hail. Light Design modules are certified to withstand 3,600 Pa of front load, which equals about 367 kilograms per square metre. That is roughly the same as five adults standing on one square metre of the module. It is also tested to withstand2,400 Pa rear load, providing resilience against strong winds. This figure is comparable to the force of a hurricane-level wind pulling on each square metre of the module. The Light Design module is additionally certified to withstand hail impact of 25 mm at 23 m/s, covering the typical requirements for C&I projects in Europe (LONGi, 2025). This combination ensures reliable operation even under harsh weather conditions.

Lightweight modules turn fragile rooftops into energy assets

Light Design modules are engineered for safety and long-term reliability in challenging rooftop environments. Their light weight, reinforced structure and compatibility with clamp-based racking make them the ideal choice for buildings with limited load reserves. Safety extends beyond structure: back contact technology minimizes hotspots, the multi-protection cell design reduces cracking, and full-cycle quality control across 200+ technical standards ensures performance over decades.

For C&I building owners, the Light Design module makes solar adoption both feasible and reliable by combining low weight with enhanced safety features and minimal roof impact. EPC partners benefit from streamlined project execution, while property owners gain access to rooftops that would once have been ruled out or required costly refurbishments. And with Light Design modules, timelines are accelerated- installations can be completed up to 34 days faster thanks to clamp-based mounting and the reduced need for structural reinforcement

Businesses may start by reassessing their solar potential

For many commercial and industrial property owners, particularly in sectors such as warehousing and logistics, manufacturing, retail, transport, food processing and agriculture, rooftop solar has long seemed out of reach because of structural limitations. Lightweight and carefully engineered modules change this picture. By reducing weight, minimizing roof impact and ensuring compliance with international safety standards, a light-weight module turns delicate rooftops into an opportunity for clean power generation.

If your company operates warehouses, factories or logistics centers with aging or delicate roofs, now is the right time to reassess your solar potential.

By choosing Light Design modules, EPC partners can deliver safe, lightweight and reliable solar projects without costly roof reinforcements. LONGi has analysed that atypical reinforcement project in Europe adds around €0.18 per watt, or approximately €180,000 per megawatt of capacity. By avoiding these costs, Hi-MOX10 Guardian Light Design modules deliver a clear economic advantage alongside its safety benefits.

We work closely with trusted installers and engineering firms to ensure that every project meets the highest safety standards.

Contact us to connect with our partner network and learn how Light Design can turn even challenging rooftops into long-term energy assets.

Link to the product page: https://eu.longi.com/hi-mo-x10-guardian-light-design

Link to the datasheet: https://short.longi.com/Guardian-LR7-60HVHL

Email: Europe@longi.com