Theme of the lighting plan is "Light to feel nature".
A walkway slope is made toward the embankment of the river which is famous for cherry blossoms, or Sakura. The same breeze that carries their petals provides a part of the power for this lighting. We used LED lamps, which emit enough brightness with electricity generated with small windmills. 280 LED fixtures are recessed on a walkway. Each LED fixtures have 2 blue, one white and four red LED lamps.
With the consideration of urban environments, small windmills are designed around 6m high with 0.5 m blades. They turn smoothly to avoid noise and generate 2W electricity by 2 meters per second (5mph) wind, 6W by 3 meters per second (7mph) and so on. White and red LED lamps in each fixture are connected to commercial electricity. Usually they turn on with the pink color like a cherry blossom. A prismatic acrylic sheet is put on LED lamps to spread the lights to make it visible from the upper part of the slope.
The blue LED is connected to the wind generated electricity and it changes the emitted color of the fixtures from pink to purple. With an increase of wind, the number of switched-on blue LED lamps will increase. Purple ripples flood and ebb the walkway in accordance with the wind power on the walkway. People can recognize the wind power by the amount of color changing fixtures.
January 8, 2006, project "Ripples on a Walkway" was awarded IESNA Paul Waterbury Award of Excellence.
The year 2006 is the centennial anniversary of IESNA (Illuminating Engineering Society of North America). Celebrating its great history, "Designs That Predict 21st Century" was announced by two people from committee on the awarding ceremony. It was a great surprise that our project, among quite a few historical preceedings selected from the period between 1906 and 2005, won another honor at this occasion.
"I was deeply impressed," says Chikada, "when the presenter introduced our project as 'hybrid powered lighting.' I hope my future designs live long even after 100 years."
