High-Temperature Mechanical Properties of Basalt Fibers: A Step Towards Fire-Safe Materials for Photovoltaic Applications

Amidst the urban energy transition towards clean and renewable energy, distributed photovoltaic (PV) systems are emerging as critical infrastructure. However, the evolution of PV rack and mount systems has lagged, particularly in addressing cost efficiency and fire safety This study focuses on the high-temperature mechanical properties of basalt fibers (BFs), a key component of basalt fiber-reinforced polymer (BFRP), to establish a foundational understanding for future BFRP applications. The experimental results demonstrate that basalt fibers retain approximately 150 MPa residual tensile strength at 600 °C (30–40% of room temperature strength of Q235B steel) and 94 MPa at 800 °C, outperforming steel under similar conditions. Furthermore, the decomposition of wetting agents and Fe2+ oxidation at 600 °C was observed to stabilize after 100 min, maintaining structural integrity. These findings validate the high-temperature performance of BF, paving the way for subsequent studies at the BFRP composite level, which will address structural optimization and fire-resistance strategies for PV rack and mount systems. This research provides a critical step toward improving the safety and sustainability of urban PV systems.