The Western Cape is aiming to become the "green economic hub" of South Africa by encouraging renewable energy, Premier Helen Zille said on Friday.

"Our government is finalising the draft Green Procurement White Paper, which will provide general principles and guidelines for integrating environmental criteria into supply chain management," she said.

One of the objectives was to reduce energy and water use by 10 percent in provincial offices and other buildings, such as hospitals.

The province was also preparing to build wind and solar energy farms.