Introduction: Clamps – The “Invisible Joints” of PV Mounting Systems

In PV mounting systems, rail clamps are the key components that connect PV modules to rails, and rails to roof structures. Although small in size, their design directly affects installation efficiency, system stability, and the overall lifespan of the power plant. In early 2024, multiple companies around the world launched an innovation race around clamp technology – from numerous patent breakthroughs by Chinese companies, to hidden aesthetic designs by US firms, and pre‑assembled clamp systems that meet local manufacturing requirements. Rail clamps are transforming from simple “functional parts” into “technology carriers”.

Part One: Chinese Companies – Multiple Patent Breakthroughs Lead Technology Upgrades

1. PowerChina Chongqing Company: Patented Clamp for Standing Seam Metal Roofs

In May 2024, PowerChina Chongqing Engineering Co., Ltd. received a utility model patent from the China National Intellectual Property Administration for a “Standing Seam Metal Roof Balance Clamp and Roof System”.

Technical solution: The clamp is used to connect rails to standing seams. Through the cooperation of a balance plate, vertical clamping plates, folded‑edge clamping plates, and a locking member, the clamp can adjust the centre of gravity, thereby adjusting the levelness of the rail layout and ensuring stable placement of PV modules.

Application scenario: This patent is mainly applied to distributed PV projects on colour‑coated steel sheet roofs, solving the problem of uneven module placement caused by uneven roof structures.

At the same time, the company also received two additional patents: a “PV connector plug‑in fastening tool” and an “integrated tool for fastening and removing PV module MC4 connectors”. These target rapid plug‑in of MC4 connectors and maintenance/replacement scenarios, improving electrical connection efficiency during construction and ease of maintenance during later operation.

2. Zhengxin Optoelectronics: Flexible PV Module Mounting Component Patent

In September 2024, Zhengxin Optoelectronics Technology Co., Ltd. filed a patent for a “Flexible PV module mounting component and mounting method” (Publication No. CN 118694272 A).

Technical solution: The mounting component includes a rail section, on the upper side of which the flexible PV module is mounted, and on the lower side of which it is connected to the mounting surface via clamps. The rail section is provided with connecting slots and limit slots, and the limit slots are connected to limit arms.

Key features:

Integrated mounting structure: fast installation, high strength, detachable, easy to disassemble

Installation method: at least two clamps are arranged under each rail section; the rail section is connected to the clamps using second bolts and slide nuts

This patent provides a solution that combines convenience and reliability for the special installation needs of flexible PV modules.

3. Mibet: Standing Seam Clamps Used in 13.6 MW Flexible Module Project

In January 2024, Mibet provided compatible mounts for a 13.6 MW flexible module project at GAC Era in Guangdong. The project was built on a factory roof covering approximately 130,000 square metres.

Technical solution: The main approach was an adhesive bonding solution for flexible modules – clamps are fixed to the metal roof, rails are laid over them and tightly connected, then adhesive is applied to the rail surface to secure the flexible modules. The system wind load is set at 0.5 kN/m² to suit the local climate.

Clamp features: The clamps used in the connection structure are Mibet‘s standing seam clamps, which can be stably installed on different types of standing seam metal roofs. The structure is simple and robust, and the clamps are compatible with various PV modules on the market.

4. HUEG: Patented Clamp Design Increases System Strength by 20%

In December 2024, Chinese PV mounting manufacturer HUEG released a new C‑section zinc‑aluminium‑magnesium coated steel ground mounting system, featuring a patented new portable clamp design.

Technical breakthrough: Unlike traditional systems that require multiple flange holes in the rails, HUEG’s design eliminates this need, enhancing the structure‘s bending resistance and overall stability. The clamp design reportedly increases system strength by 20%.

Material advantages: The system is made of zinc‑aluminium‑magnesium coated steel, which offers excellent corrosion resistance and self‑healing properties, with a design life exceeding 35 years.

Part Two: European and US Markets – Local Manufacturing and Aesthetic Design Advance Together

1. K2 Systems: US Local Manufacturing + Pre‑assembled Clamps

In June 2024, K2 Systems announced that it would move production of two of its solar attachments to the United States in order to comply with the domestic content requirements of the Inflation Reduction Act (IRA).

CrossRail system: A rail‑based mounting system suitable for various roof types (composition shingles, tiles and metal). It features pre‑assembled universal connection clamps that simplify the installation process.

MiniRail Comp system: A new solar mounting solution specifically designed for composition shingle roofs. The bracket is only 5 inches long, with a partial rail, and is attached to the roof using four self‑tapping screws and an integrated flashing. It allows connection at different positions along the module frame and supports both portrait and landscape module layouts.

K2 Systems stated: “Our goal is to help customers maximise eligibility for tax credits and bonuses while promoting US manufacturing.”

2. Kinetic Solar: Hidden End Clamp Achieves “Invisible” Installation

In August 2024, Kinetic Solar launched the Hidden End Clamp, combining functionality with aesthetic design.

Technical highlights:

Integrated spring and bolt mechanism: ensures continuous, secure clamping of the module frame hem

Rail flush with module: the clamp allows the rail end to be flush with the module, creating a clean appearance

Precise positioning: the kit includes end caps and positioning bars to ensure accurate placement and easy connection for every installation

The product is compatible with all PV modules that have a hemmed frame, ensuring a secure fit without compromising appearance. It is suitable for residential and commercial projects where aesthetics are a high priority.

Part Three: Industry Trends Summary

The early‑2024 rail clamp market exhibits the following technology trends:

Outlook

Looking ahead to the second half of 2024 and beyond, the rail clamp industry will continue to evolve in the following directions:

Standardisation and modularity: As more patented technologies are commercialised, clamp products will become more standardised, reducing installation errors

Growing aesthetic demand: The residential PV market‘s need for “invisible installation” will drive the adoption of hidden clamps

Localised supply chains: Policies such as the US IRA will encourage more companies to manufacture clamps and other accessories locally

New material applications: Zn‑Al‑Mg coated steel, high‑strength aluminium alloys and other materials will be used more widely in clamps

Installation efficiency revolution: Pre‑assembled, quick‑fit clamp designs will further shorten construction periods

In a Nutshell

In early 2024 – from PowerChina Chongqing‘s standing seam clamp to Zhengxin’s flexible module mounting component, from K2 Systems‘ US‑manufactured pre‑assembled clamps to Kinetic Solar’s hidden aesthetic design – rail clamps are evolving along smarter, more attractive and more reliable technical paths, supporting the move of PV mounting systems toward an “invisible” era.