MTN, Africa's largest mobile, has unveiled southern Africa's first data-center solar cooling system in a bid to tackle the growing problem of unreliable electricity from the power grid.

The system, for the carrier's data center in Johannesburg, consists of 242 solar mirrors covering 484 square meters, which track the sun to generate pressurized hot water. The hot water powers an absorption chiller that produces chilled water that is then circulated into the data center, MTN said.

MTN South Africa CEO Zunaid Bulbulia said that the solar cooling system for the data centers "will substantially reduce consumption and release additional capacity for the national grid."

Several Southern African Development Community (SADC) countries including South Africa, Zambia, Zimbabwe, Malawi and the Democratic Republic of Congo are facing increased power shortages.

In addition, there has also been a sharp increase in electricity rates by power utility companies in the region who claim that the increases are necessary to invest in new power projects to meet growing demand.

Persistent power shortages and the hike in electricity tariffs have further added to the high cost of running data centers and doing business in Africa, as most mobile service operators and business outsourcing facilities are forced to use generators to power installations.

This has caused mobile operator MTN to increase investments in renewable energy technologies in order to avoid reliance on the national grid power.

For example in 2010, MTN's head office in South Africa became the first building in the country to receive a "silver certification" from U.S.'s States Green Building Council's Leadership in Energy and Environmental Design (LEED) program.

Africa's subscriber base for voice communications is still expanding but the growth curve has began to flatten in the region's more mature markets, including South Africa, Nigeria and Kenya, forcing operators to compete more aggressively on the provisions of data services.

The rise in data services has been fueled by a number of undersea cables now servicing the region. Cable companies are competing for customers and have lowered wholesale broadband pricing to mobile operators.

Operators also have invested in data centers in Zambia, Nigeria and Kenya in a bid to ease the region's reliance on Europe and U.S. for data backup and broadband services.

"Solar energy is the only solution for operators especially when it comes to the running of data centers and powering base stations because high electricity tariff coupled with power supply unreliability may make operators to operate at a loss," said Andrew Makanya, managing director for Internet Solutions Zambia.