Kyocera’s “green curtain” competes with the air-conditioning unit

Environment-friendly and cheap: Plant curtain saves energy

28 August 2009

Kyoto / Neuss − The Japanese technology corporation Kyocera, a leading producer in the field of fine ceramic components, is fitting its company premises in Japan out with “green curtains”. Placed in front of the office windows, foliage plants climb up trellises until they are fully covered. Closely intertwined, the leaves form a green wall and thus protect the interiors against direct sunlight – preventing the offices from heating up too quickly. This lowers the load on the air-conditioning system, saves energy and thus protects the environment. Planted vegetables spice up the menus in the canteen.

The idea is very simple really: all that is needed for the green curtain is an inexpensive trellis and a suitable plant, such as a morning glory for example. This is enough to shade the Kyocera offices and protect the employees against direct sunlight. As a result, the interior rooms also remain cool during the hot Japanese summer months. Measurements have shown that the temperature on a sheltered outer wall is up to 15°C (27° F) lower than on unsheltered walls where no green curtain has grown. This greatly reduces use of the air-conditioning system in the buildings. The twin positive effects are a saving of energy and a reduction in CO2 due to photosynthesis. What is more, the vegetables that grow are harvested by the employees and prepared as specialities in the works canteen.

Kyocera introduced the green curtain as part of its energy-saving programme at its Nagano works back in 2007. Now there are 12 factories with green curtains in front of the windows. All in all, the various green curtains at Kyocera measure a total length of 294 metres (965 ft) and cover an area of 775 m² (8,342 ft2). Some 2,713 kg CO2 (5,981 lb-CO2)* are broken down by the plants each year, equivalent to 194 cedar trees**.
Nobuhiko Kitagawa, plant manager at Kyocera: “The green curtain not only helps to save energy but also promotes environmental awareness among our employees.
A particularly popular constituent of the green curtain with the Kyocera employees is the goya plant. It grows well and quickly, has a dense foliage and is delicious. The species of pumpkin it bears is a typical summer vegetable in Okinawa and an ingredient of many popular menus in the canteen.

*CO2 absorption (3.5kg) X Area of Green Curtain (m2) = Volume of yearly CO2 absorption. (Source: Rural Culture Association Japan)
**One cedar tree absorbs 14kg/year of CO2. (Source: Forestry Agency of Japan)