NTT Urban Development Corp. and NTT Facilities, Inc., announced on October 30, 2006, the results of their joint tests for mitigating the heat island effect by installing sweet-potato hydroponics systems on rooftops. The results show that the system produces a substantial insulating effect, which absorbed about 80 percent of the actual heat from the sun (total energy falling to earth from the sun minus the energy reflected from the surface of earth) by evaporation from sweet potato leaves.

The companies measured the difference in temperatures between an area covered with sweet potatoes and a non-vegetated area. The results show that air temperature in the non-vegetated area reached a high of 55 degrees Celsius, while that in the vegetated area peaked at 28 degrees Celsius, with the overall daily temperature varying by only 3 degrees. This data proves that vegetation on rooftops is effective in alleviating the heat island effect.

Based on these results, NTT Facilities will continue to make efforts to improve the system and reduce costs, with a view to improving marketability of this type of cultivation as an effective measure to combat the heat island effect.


- Sweet Potato Cultivation on NTT Rooftop to Reduce Urban Heat (Related JFS article)
http://www.japanfs.org/db/1556-e

Posted: 2007/01/22 09:32:34 AM
Japanese version

TAG Ecosystem , Food/Water , Global warming , Non-manufacturing industry