Hidroeléctrica de Cahora Bassa: Placing the nation’s power supplies in its own hands

The development of economies across the African Continent has been greatly helped by maintaining links with former colonial rulers for many countries. In Mozambique, the Cahora Bassa Dam has delivered energy across Southern Africa for over thirty years and has benefitted from ties with Portugal.

HidroIn April 2012 Mozambican President Armando Guebuza and Portuguese Prime Minister Pedro Passos Coelho signed an agreement in Maputo under which the Mozambican state will obtain, by 2014, 100 per cent of the shares in Hidroeléctrica de Cahora Bassa (HCB), the company that operates the Cahora Bassa dam on the Zambezi.

Up until 2007, the Portuguese state was the majority shareholder in HCB – Portugal held 82 per cent of the shares, and Mozambique just 18 per cent. That year negotiations were concluded in a deal whereby most of the Portuguese shares were sold to Mozambique for $700 million. The money was obtained as a loan from a consortium of French and Portuguese banks, which is being paid off out of HCB’s profits.

Portuguese company REN (Redes Energéticas Nacionais), which operates the Portuguese national electricity grid, will relinquish its holding in HCB, in exchange for shares in the company that will operate a new electricity transmission line from Tete province to Maputo.

The new line, known as the Cesul (Centre-South) project, but usually referred to as the “backbone” of the Mozambican electricity grid, is necessary because the existing line, from Cahora Bassa to the Apollo substation in South Africa, cannot carry any more power

The Cahora Bassa Dam was built during the Portuguese occupancy of Mozambique in the 1960s and early 1970s. Despite its relatively short lifespan, this icon of colonialism has survived a civil war, sabotage attempts, financial disputes and international political unrest.

The history of the project, which supplies hydroelectric power, has been intrinsically-linked to the company which built and subsequently maintained the dam: Hidroelectrica de Cahora Bassa (HCB).

The dam is the largest hydroelectric power scheme in southern Africa and the Cahora Bassa Lake, at 250 kilometres long and 38 kilometres wide, and covering a flooded area of 2,700 square kilometres, is the fourth largest artificial lake in the whole of Africa.

Work got underway on the construction of the Cahora Bassa System back in 1969 and it took a full 10 years to complete the project, with HCB focussing on generating, transmitting and selling clean electricity.

However, a brutal civil war which ran for 15 years began in 1977 and wreaked havoc on energy supplies. Indeed, the dam’s transmission lines were regularly sabotaged to the extent that 1,895 towers needed to be replaced and 2,311 refurbished over a distance of 893 km on the Mozambican side of the line.

The original project also involved South Africa as a stakeholder, in an agreement that stated Portugal would be responsible for the construction and operation of a hydroelectric generating station at Cahora Bassa as well as a high-voltage direct current (HVDC) transmission system, delivering electricity to the border of South Africa.

As the civil war in Mozambique drew towards its end, HCB selected South African organisation Trans-Africa Projects (TAP) to carry out construction management, quality assurance and design support service for the rehabilitation of the project. Restoration work began in August 1995 but was far from easy given the difficult terrain and climate. Additionally, workers had to contend with live land mines which made the job even more hazardous.

Today, the dam system that HCB operates on the Zambezi river system contains five 415 mega watt turbines. Most of the electricity generated at Cahora Bassa is sold to the South African power companies.

In 2006, Cahora Bassa transmitted approximately 1,920 megawatts of power, but the site announced its intention to upgrade the infrastructure which would result in increased production output.

In 2011, global power transmission company Opten announced that it had implemented an Airborne laser survey on about 1,800 kilometres of overhead power transmission lines in Mozambique, as part of the first phase of a project with HCB.

In the meantime, HCB was reaching record levels of hydro-electric production. In 2009 the company produced 16,574 gigawatt-hours, an increase in excess of 12 per cent on the previous year and a level that raised 8,380 million meticais in revenue.

The improved output was very much the result of having access to more generator sets and better transmission and conversion systems – a legacy of the refurbishment work carried out at the power production station in the previous 3 years.

With South Africa coming to terms with a much-publicised strain on energy supplies, HCB has also benefitted from supplying its neighbour with power. Indeed almost 80 per cent of Cahora Bassa’s output is delivered to South Africa’s recently upgraded Apollo power station.

Whilst South Africa struggles to meet energy demand, Mozambique has the second largest capacity to produce clean energy in the region, making companies like HCB potentially lucrative and attractive investment partners.

The handover of HCB to Mozambique will very much place the nation’s energy capabilities back in its own hands and could herald exciting times with sufficient levels of investment.