Although the exact answer is not given, according to (p.24), SK Telecom "began testing systems related to natural air-conditioners in 2001 and supported efforts by

manufacturers to improve their systems for use in base stations. Based on test results at our base stations collected from 2003 to 2005, we had invested a total of KRW 8.0 billion to install 570 units by the end of 2007."

(p.39) mentions about the amount of Green purchase.

"In 2007 alone, SKT purchased KRW 3.6 billion worth of green products

including office furniture, OA equipment and office supplies. "