April 27 - Constrained power supply holds back economic growth in Africa, but capacity is steadily being built to feed this electricity-hungry region.

According to Roland Cumings, director of heavy lift, specialised transport and installations specialist Vanguard, almost half of the global population that live without electricity are located in sub-Saharan Africa, equating to roughly 70 percent of the population in the region.

As demand for electricity in Africa is expected to grow by almost 70 percent between 2016 and 2040, substantial investment is being directed not only into new capacity, but also into the refurbishment of existing power and distribution networks.

Global power demand will increase by about 2 percent annually, but demand in Africa will be double that figure at closer to 4 percent a year, said Vanguard.

Efforts to address South Africa's power shortfall include state utility Eskom's modular spares programme, which involves maintaining a large strategic store of components at its power stations. Eskom reduces downtime by having critical components like transformers, rotors and stators on hand when operational units need to be replaced or maintained.

As part of this programme, Vanguard recently transported a 325-tonne stator from the Port of Richards Bay to a power station in Mpumalanga. At Kusile power station, Vanguard is also engaged with the lifting and transportation of various out-of-gauge loads - including a 360-tonne transformer - to the site.

The company has also been active in contracts relating to independent power producers (IPP) in South Africa, which Cumings says are taking a growing share of the country's energy generation profile.

Playing a key role in keeping the lights on recently were the Avon and Dedisa peaking power projects near Durban and Port Elizabeth respectively. These open-cycle, gas turbine installations - implemented by international energy group GDF Suez - feed power into the national grid in periods of peak power demand.

Vanguard's contracts involved port handling, lifting, transporting and installing generators, turbines and transformers destined for the two sites. For Dedisa, two sets of 191-tonne gas turbines, 231-tonne generators and 140-tonne transformers were transported from Coega port to the project site in the Coega industrial development zone.

The Avon project involved transporting cargoes over 144 km from the Port of Richards Bay to the site on a structurally sensitive route that required increased planning to minimise axle loads.

Vanguard has also seen a growing number of successful IPPs in South Africa's renewable energy sector, having assisted with lifting and transport operations at wind farm sites in the Western Cape, Eastern Cape and Northern Cape.

As the industry develops, manufacturers have increased the generating capacity of wind turbines, meaning that components have also grown in size and length, creating added challenges for transport and lifting providers, noted Cumings.

Electrical substation moves have also kept Vanguard busy, having recently completed a contract to deliver transformers from Walvis Bay in Namibia to the Democratic Republic of Congo, where older units were being replaced.

The project involved moving loads over 3,000 km and crossing bridges over both the Kapolowe River and Lualaba River.

In Zambia, the upgrading of the national electricity network has seen Vanguard move transformers, ranging in weight from 80 to 200 tonnes, from South Africa to sites across the African nation.

Meanwhile, Vanguard transported an emergency replacement transformer from Johannesburg to northwestern Mozambique, planning and executing the 2,300 km move in three weeks, overcoming poor infrastructure and a steep mountain pass.