-- now building a Tier 4 datacenter in Tseung Kwan O -- also refused to comment on energy sources. The facility -- to be completed by Q3 this year -- will support up to 1,200 racks with a total power load of 8MWm, said Jonathan Leung, head of Hosting Services, HKEx. "We are committed to sustainability," said Leung. "Our facility has attained the LEED (Leadership in Energy and Environmental Design) certification at the gold level."

However, energy sources and usage is only one among many areas the LEED certification measures. A green building rating-system developed by the US Green Building Council, LEED formally recognizes the adoption of environmentally friendly practices in a construction project. There are four levels of certification --certified, silver, gold, and platinum.

Joe Locandro, director, Group Information Technology, CLP, said Hong Kong is limited by its geographical location and the lack of space in renewable energy development. "Wind farms and solar farms require lots of space," said Locandro. "In addition, renewable energy should be [considered] part of the overall datacenter-power mix as wind, water, and sunshine are never as stable as we desire." CLP is piloting an off-shore wind farm 10km off Sai Kung, he said.

Greenpeace urged the local IT sector to take the use of renewable energy seriously. As the peak load of Hong Kong has become static in recent years, the expansion of datacenters might be the only reason for increased capacity, the activist organization said. "The local IT sector can have a strong positive influence by setting a renewable energy-friendly siting policy and buying wind power," Yeung noted.

To global tech players who might or might not set up datacenters in Hong Kong, he said: "These big boys have colossal profits annually. Renewable energy sources only cost these firms a tiny fraction of the money they earn."