In Japan, the electricity consumption of stations that account for about 20% of the electricity used by railway operators has increased year by year. In order to prevent this trend, companies have begun to use photovoltaic power generation systems and LED lights at stations.

Among them, the “Environmental Station” project promoted by JR East Japan is a good example. The first demonstration station of the project is the Yotsuya Station in Tokyo (Figure 1). The station became the first environmentally friendly station in the spring of 2012. The photovoltaic power generation system was installed on the roof of the station and adjacent commercial facilities, and only 50 kW of electricity was available on the roof of the station.

JR East Japan is promoting an "environmental station" project that uses energy-saving technologies and renewable energy at stations. The first demonstration station was the Shibuya Station, which introduced LED lights and photovoltaic power generation systems.

The lights on the platform and lobby of the Shibuya Station use LED lights. An LED is also used for the electronic display board such as the station name and the backlight of the monitor for the vehicle length. In addition, a skylight is installed, the lights can be turned off during the day, and a domestic fuel cell is used in the station facility.

The goal is to reduce CO2 emissions from Yotsuya Station by approximately 40% compared to 2008 through these measures. According to JR East Japan, the environmental protection station will be gradually added in the future. The next eco-friendly station after Yotsuya Station will be JR JR Makuhari Station in Chiba Prefecture.

Energy saving through lighting control

Replacing traditional fluorescent lamps and incandescent bulbs with LED lamps can reduce the amount of electricity used, and if the LED lamps are controlled according to the situation, the power consumption can be further reduced. For example, the Freedom Hill Station of the Tokyu Electric Railway has introduced Panasonic‘s LED lights and its control system.

The human sensor of the lighting control system is installed at each position of the station, and the brightness of the LED lamp can be automatically adjusted according to the number of people. For example, dim the lights when there are few pedestrians.

A human sensor integrated brightness sensor is installed on the platform to ensure a certain brightness in the station. That is to say, the lights will be dimmed during the sunny day and the lights will be illuminated during the rainy day.

Not only brightness, but also automatic adjustment of color temperature. The LED lights in the hall change the color temperature according to the time period. For example, in the morning work hours, in order to make people awake, adjust to a "daylight color" with a color temperature of about 5000K, and adjust the color temperature to about 4000K in the evening to become an ordinary "white to warm white". In the evening, in order to calm down, adjust to a "bulb color" with a color temperature of 3000K.