This research presents a method for reducing peak power in the high-speed railway traction power supply system by using a photovoltaic plant on the roof of a train station. Generally, when a high-speed train stops to pick up passengers at a station platform and then it starts to accelerate to gain its top service speed, this is the time when the highest power is reached. High-speed train station buildings are usually large. When installing solar panels on the roof, the energy obtained may be sufficient to cut the accelerating power. Considering the adequacy of roof space is the main goal in order to conduct the study for the reduction of peak power and energy consumption from railway power feeding lines. This study uses the Don Muang high-speed railway station of the Thai-China high-speed railway project in Thailand as a case study. The results reveal that the available roof spaces of the high-speed railway station are sufficient to supply the train power during acceleration.