As the global energy transition accelerates, distributed photovoltaics are shifting from ground‑mounted power plants to rooftop applications closer to end users. Among industrial, commercial, and public buildings, metal roofs – thanks to their light structure, fast installation, and good durability – have become a key carrier for PV installations. In 2024, the field of solar mounting on metal roofs has seen an explosion of technological solutions: from a wave of new clamp‑based systems to breakthroughs in BIPV (Building‑Integrated Photovoltaics) products and the formal implementation of industry technical standards – the entire sector is undergoing a quality transformation driven by innovation.

1. Market Background: Commercial Rooftop PV Exceeds 63 GW, Metal Roof Share Continues to Rise

The rapid growth of the metal‑roof PV mounting market is no accident. Industry data show that in 2024, global installed capacity of commercial rooftop PV reached 63 GW, with projects mounted on metal roofs accounting for as much as 66% – a significant jump from 54% in 2020. Metal roofing is expanding at a rate of nearly 200 million square metres per year. Combined with the huge demand for retrofitting existing buildings, this constitutes a very promising incremental market.

Driven by this trend, the integration of PV with metal roofs is also evolving – from traditional add‑on racking systems to highly integrated BIPV solutions and renovation systems for ageing roofs. A variety of technical paths are being actively explored and applied.

2. Mainstream Mounting Solutions: Three Technical Routes, Each with Its Strengths

2.1 Non‑Penetrating Clamp Systems – The Preferred Option for Maintaining Roof Integrity

For standing‑seam metal roofs, the most mature technical solution in 2024 is the clamp‑based non‑penetrating mounting system. Using dedicated clamps (e.g. T‑clamps, standing‑seam clamps) these systems attach PV rails or modules directly to the raised ribs of the metal roof panels, completely avoiding any penetration of the roof surface and therefore eliminating leakage risks.

In real‑world projects, such systems have proven their wind uplift resistance. For example, at the Vaisala headquarters in Colorado, USA, S‑5! clamp systems were used on both the existing metal roof and vertical curtain wall. The rooftop PV system reached 228 kW and successfully passed a rigorous wind load test at wind speeds up to 145 mph.

2.2 Dedicated Brackets for Trapezoidal Corrugated Sheets – Many New Products in 2024

2024 marked a technology iteration peak for special mounting brackets for trapezoidal corrugated metal roofs. In the second half of 2024, Austrian racking specialist AEROCOMPACT launched new TLE25 and TLE38 rail bridges in its COMPACTMETAL TL product line. These integrate 80 mm high elastomer pads and can be laid directly along the ribs of the trapezoidal sheet without pre‑drilling, greatly simplifying installation.

At the same time, French mounting system provider EPC Solaire introduced its iNovaR system for corrugated metal roofs. Made of fully French‑manufactured aluminium alloy, the system replaces traditional insulation/waterproofing materials (approx. 20 kg/m²) with a lightweight composite insulation layer (8 kg/m²). It allows PV modules to be installed without changing the original roof structure and comes with a 10‑year waterproofing warranty.

2.3 BIPV Integrated Solutions – Roof and PV Become One

The highest level of technical integration is achieved with BIPV solutions. BIPV uses PV modules directly as part of the roof envelope, replacing conventional roofing materials while simultaneously providing power generation and building enclosure functions.

In 2024, Chinese companies also made significant moves in BIPV. During the SNEC PV Expo in June, Xinmingguang Technology together with Tianjin University New Energy released the “Tianxin” series of three BIPV products: a 360° standing‑seam snap‑on system, a snap‑on composite metal panel system, and a flexible adhesive‑bonded system. The snap‑on composite metal panel system incorporates a patented technology that integrates a polymer waterproof membrane with the metal sheet, fully meeting the Level‑1 waterproofing requirements of the mandatory Chinese standard GB55030‑2022, with a roof service life of up to 40 years. LONGi Green Energy Technology and its subsidiary LONGi Sertada built a 10.397 MW BIPV project at the Jiumu Group production base in Quanzhou, using a mix of methods including metal roof replacement, concrete roof extension, and new integrated roof installation to handle complex site conditions.

3. Technical Breakthroughs & Industry Standards: Comprehensive Upgrades in Safety and Reliability

S-5! Adds 50 Patents in a Single Year – Innovation Intensity of a Market Leader

In December 2024, S-5!, a global leader in metal‑roof PV mounting, announced that it had added 50 new patents in a single year, bringing its total to 194 (since its first patent application in 1991). These 50 patents were granted across 13 countries and regions – 9 in China, 12 in the EU, 8 in the US, and 6 in India.

Notably, S-5! made significant progress in third‑party product certifications in 2024. Its Ensolro system (using the PVKIT HUR 2.0 rail‑free direct‑mount solution) received FM 4478 certification, and its standing‑seam clamps were approved for use in Florida’s High‑Velocity Hurricane Zone (HVHZ) – the first product of its kind to obtain such certification.

China’s First Technical Specification for BIPV on Curved Metal Roofs Takes Effect

On 1 August 2024, the standard T/CET 402‑2024 “Technical specification for crystalline silicon module building‑integrated photovoltaics on metal structure curved roofs” was officially implemented. This standard was issued by the China Electric Power Technology Market Association and drafted jointly by Sertada Group, LONGi Green Energy Technology, LONGi Sertada and several other leading companies. It covers basic requirements, components & materials, construction & safety protection, design, installation, acceptance, operation and maintenance – the entire lifecycle. This is China’s first group standard specifically for BIPV on curved metal roofs, marking the beginning of a new phase of standardised development for this niche.

4. Notable Project Results in 2024

Several representative metal‑roof PV projects were completed in China in 2024, demonstrating the feasibility of different technical approaches:

Xuancheng Conch BIPV Project (3.65 MW) : One of the first true zero‑carbon or near‑zero‑energy projects in Anhui Province. It integrates PV curtain walls, flat PV tiles and metal PV roofs, generating 4.5279 million kWh annually and reducing CO₂ emissions by 3,749.1 tonnes per year.

Jihua Ice & Snow · Xi’an Ice & Snow Centre (2.5 MW) : LONGi Sertada installed 4,550 “Long Roof 3.0” BIPV modules on the metal roof of the largest indoor ice & snow sports centre in Northwest China. The project achieves an overall energy saving rate of 99.86%, and over a 25‑year life is expected to generate 59.2687 million kWh.

Jinghong Zero‑Carbon Henan Jinkai Chemical BIPV Project (2.62 MW) : Using colour‑coated steel BIPV products, the project is estimated to produce 67.1019 million kWh over 25 years, saving 819.62 tonnes of standard coal each year.