KYOTO, Japan — Kyocera Group has planted edible "green curtains" stretching thousands of feet across facilities in Japan, Thailand and Brazil in a bid to keep its buildings cool and greenhouse gas emissions low.
The IT equipment and industrial ceramics manufacturer installed the viney plants to block direct sunlight from the windows of 20 manufacturing and office buildings to help prevent increases in surface temperature of the structures. 
This lessens the loads of their air conditioning units, while the green curtains also give workers a bounty of cucumbers, peas and bitter gourd called goya, which land on their cafeteria menus.
Using infrared thermograhic measurement, Kyocera confirmed the green curtains results in lower outer wall temperature than unshaded walls. "In addition, we were able to confirm that the Green Curtains can decrease the temperature by as much as 15 degrees C (27 degrees F)," the company said.
At the same time, the green curtains are working to absorb an estimated 23,481 pounds of carbon dioxide emissions, which is roughly the same amount that can be absorbed by 761 cedar trees.
The green curtains cover roughly 32,750 square feet (3,043 square meters), and measure 2,379 feet (725 meters) in length.
Kyocera has set up a website with information on the green curtains, including some fairly detailed instructions and photos from its own experiences (see below) to help readers grow green curtains at home.
Images courtesy of Kyocera Group.
LED lights have a payment
LED lights have a payment return period of around 8 months. Its a pretty cash tight environment that cant justfy these capital expenses...
In regards to just the
In regards to just the reduction in energy used for cooling the building, what do they add back for energy needed for more artificial lighting due to the loss of daylighting and also the additional cooling needed to offset the heat from this additional lighting? Also assume non-LED lighting due to high cost for most decisions based on ROI. I am sure that the "add-back energy" is still insignificant to the savings in cooling energy, but I would like to understand the whole picture.
Japanese office and
Japanese office and government buildings typically have more windows than you shake a stick at, on all sides so they wouldn't be turning on the lights to compensate. Also, the Japanese are a lot more efficient and careful about their energy use simply because they have to be (no natural resources). This means that in many offices during the day, the lights simply are not turned on. Air conditioning is used but it is set at around 27C. In winter, many buildings are not heated in their entirety - only rooms are through space heaters. Except for in the north, for example, most Japanese schools do not have have central heating.. and students bundle up in the classroom and use a space heater.
In the West, a lot of people still have trouble understanding why you should turn off the lights when you leave a room, while the Japanese have already progressed to the point where they understand that you should turn off the heat and air conditioner when you leave the room.