Analysis of Technological Evolution of Leak Sensors for Safety in Renewable Energy Facilities

Leak detection technology has continuously evolved from basic point-type sensors to advanced film-type sensors utilizing special metallic layers. This study aims to systematically classify leak sensors into five generations based on their structural and functional principles, and to analyze their technological evolution in terms of detection mechanisms, sensitivity, reusability, and field applicability. To achieve this, a comprehensive literature review was conducted covering academic journals, industry catalogs, and government reports. Quantitative performance indicators such as detection limit, response time, and false alarm rate were also compared across generations. Early-generation sensors, including resistive cable-type and optical point-type sensors, exhibited limited durability and poor chemical resistance. Subsequent developments in film-based and fluoropolymer-layered sensors improved performance through real-time detection and extended area coverage. The most recent fifth-generation sensors, featuring dual-structured separation films and advanced conductivity-based materials, enable selective detection between water and hazardous chemicals, with adjustable sensitivity and enhanced resistance in corrosive industrial environments. Field case studies from semiconductor, petrochemical, energy, and public infrastructure sectors demonstrate significant improvements in accident response time, detection accuracy, and false alarm reduction. The findings offer strategic insights for future leak sensor development, especially for safety-critical and smart industrial systems.