A major new railway hub in Shaanxi province is set to become a pioneer in green energy generation, moving from being a significant energy consumer to a producer of clean power.

The Xi'an East Railway Station, poised to be the largest railway passenger hub in northwest China with a designed annual passenger capacity of 36.5 million, is on track to achieve partial self-supply of green electricity for its daily operations. This milestone will be reached with the imminent commissioning of a building-integrated photovoltaic (BIPV) system installed across its station roof.

All the green power generated will be consumed on-site by the station, marking a critical step forward for China's major transport hubs in exploring near-zero-carbon operations. The project was planned from the outset according to the three-star green building standard, with the solar power system integrated into the roof's design.

The system has a total installed capacity of 7.25 megawatts, utilizing 11,080 photovoltaic modules. It is projected to generate approximately 7.61 million kilowatt-hours of electricity annually, with an estimated total output of about 190 million kilowatt-hours over 25 years. This green energy production is equivalent to reducing carbon dioxide emissions by 186,000 tons.

The electricity will be fully integrated into the station's operational systems, including lighting, air conditioning, elevators, and equipment maintenance. During peak power consumption periods, the rooftop solar generation will partially offset the station's reliance on the public grid.

The station's architectural design, inspired by the Qin Mountains and Wei River along the ancient Silk Road, features a complex, staggered diamond-shaped double-curved roof. While the chosen aluminum-magnesium-manganese roofing material offers excellent ductility for this intricate shape, its significant thermal expansion and contraction posed a major challenge for installing a stable photovoltaic system.

Given the railway sector's stringent safety requirements, a key technical hurdle was ensuring the system's effective integration with the irregular curved surface without compromising the roof's waterproofing, wind resistance, and fireproofing capabilities.

To address the technical challenges of the unique double-curved roof, the project team conducted multiple rounds of evaluation, ultimately selecting the LONGi Hi ROOF S power generation system from Longi Green Energy Technology Co., Ltd. based on a comprehensive assessment of safety, aesthetics, and power generation efficiency.

A company representative explained that this system, equipped with HPBC 2.0 high-efficiency cells, offers superior power output per unit area. Its full-coverage design is particularly suitable for hub projects with limited roof space and high aesthetic demands.

For installation, a dual-connection solution combining adhesive and clamps was employed to secure the system reliably without damaging the roof's waterproof layer. The frameless photovoltaic modules were installed using a "straight-for-curve, wave-following" technique, meticulously leveled piece by piece to blend seamlessly with the diamond-shaped curved roof, achieving harmony between power generation functionality and architectural aesthetics.

In recent years, China Railway Xi'an Group Co., Ltd. has been actively promoting photovoltaic applications. As of May this year, the group has built 19 standardized photovoltaic power stations with a total installed capacity of 22.7 megawatts, cumulatively generating over 40 million kilowatt-hours of electricity. The Xi'an East Station project is the largest single installation among them and one of the first in the national railway system to implement building-integrated photovoltaics on a large scale on a double-curved roof.

A representative from Longi Green Energy Technology Co., Ltd. noted that the utilization of roof space on large public buildings for on-site photovoltaic power generation is still in an exploratory and promotion phase in China. The construction practice at Xi'an East Station provides a referable technical pathway for applying photovoltaic systems on complex roof structures at super hubs and offers a practical case study for public buildings exploring the optimization of their energy consumption mix.