Powering business

Electricity remains a scarce commodity in Africa, and will continue to be well into the future. This is considering already limited electrical generation and transmission capacity against a backdrop of rapid urbanisation and industrialisation on the continent.

Many experts in the global energy-supply industry are sceptical about Africa’s ability to bridge this growing divide quick enough by deploying conventional centralised generation models.

The current slow rate of rollout of large base-load power stations mirrors this sentiment. Not only do these projects take extremely long to conceptualise, but their delivery is also hampered by abilities to execute them on time and within budget. This is compounded by the massive investment needed to develop extensive transmission infrastructure just to get the energy from the power station to the point of consumption. In some instances, this jeopardises the feasibility of many of these projects.

According to some experts, this insatiable demand for electricity can only be met through unconventional energy planning that embraces technologies that are quicker to implement. Many have become staunch proponents of driving smaller builds that are manageable and therefore less risky to execute.

Meanwhile, world markets have shied away from mega builds due to the significant costs and risks associated with bringing them to fruition. The state of international capital markets at the time of writing has also placed a damp cloth on large and costly infrastructure delivery programmes, including hydropower stations.

However, Africa’s energy woes have been turned into opportunity for many international companies. The continent has opened itself up to independent power production, co-generation and mini-grids, as well as a host of technologies that either augment existing generation output from state-owned utilities, or help large energy consumers manage their electricity consumption.

The changing business models of electricity supply and transmission also bodes well for players in the field, with large consumers of energy looking for technologies that enables them to become energy generators, and reducing their reliance on erratic supply from electricity utilities.

Bullish about energy 

Alastair Gerrard, general manager of Zest Energy, tells African Energy Journal that he is extremely optimistic about opportunity on the continent for a company that offers a host of energy production and management solutions.

He says that the company has been able to maintain a competitive edge on the continent by its ability to integrate its various solutions – including power generation, electrical infrastructure and mobile generation systems – into existing and future energy systems of its clients, ranging from mines and other large industrial undertakings through to utilities.

Gerrard says this also calls for an ability to forecast the long-term electrical infrastructure planning and requirements of both utility and its customers. At times, this means that energy solution providers need to be able to forecast at least 10 to 15 years ahead when designing a bespoke system.

Zest Energy’s ability to tailor unique energy solutions is also complemented by its ability to draw from the Brazilian multinational WEG, which is the principal of Zest WEG Group Africa. WEG Group has factories in 12 countries and more than 35 international product offerings. Locally, Zest Energy leverages on Zest WEG Group Africa’s already-established footprint on the continent. This is a significant competitive edge especially when it comes to the maintenance of the solutions it deploys.

As Gerrard notes, many of Zest Energy’s clients operate in remote areas of the continent, and back-up support is critical to ensuring a solution that operates optimally. The company navigates the continent via a network of agents and offices in most of the growth zones in sub-Saharan Africa.

Power now

The African mining industry remains a significant market for Zest Energy.

As Gerrard points out, the African mining industry will remain under significant pressure to find ways of operating in areas where there is either limited generation or transmission infrastructure, or where grids are simply unstable and cannot support large operations.

At this point in time, the mining industry on the continent relies extensively on on-site diesel generation but, as he says, mines are increasingly looking to co-generate or to consider alternative energy sources to ween them off their dependence on costly diesel.

As such, Gerrard sees a bright future in hybrid-systems, employing a combination of usually diesel and renewable energy as fuel sources. Meanwhile, he says co-generation opportunities are also emerging in the industry, with South Africa one of the countries on the continent that is driving towards the development of this field.

He tells African Energy Journal that the company has been involved in a number of steam power co-generation initiatives. This includes designing and installing a 48 megawatt (MW) turbine generator set at Mondi’s operation in Richards Bay, KwaZulu-Natal, South Africa. The turbine generator comprised a TGM CTE63 multi-extraction, condensing steam turbine, as well as a WEG EM 57 megavolt-ampere (MVA), 11 kilovolt (kV), two pole generator. The scope of works also covered the supply of the ancillary equipment, including the condenser and lubrication-oil systems, turbine control panel, as well as generator protection and synchronisation panel with back-up battery systems. It also covered the overall installation and commissioning of the turbine generator system. Zest Energy provided a 98% availability guarantee on the plant and post-handover operational assistance for four weeks, according to Gerrard.

Zest Energy was also contracted to be part of building biogas plants on two different Johannesburg Water sites. The first site was at the Northern Waste Water Treatment Works (WWTW) and the second at the Driefontein WWTW. He says that the scope of works included installing 380kW containerised biogas generators. They featured a 400 volt (V) alternator, cooling systems and synchronisation switchgear, as well as heat recovery systems. Gerrard informs that the biogas plant electrical integration solution included 6,6/11kV step-up transformers, medium voltage (MV) switchgear, a containerised control room, import and export control system, as well as a control system to manage and shed non-critical loads in the event of island mode operation.

Diesel power

While Gerrard sees a significant future for these power plants, mining companies are still heavily exposed to diesel as a fuel source and will probably continue to be so for the foreseeable future. This has been a significant driver of business for the company.

Two of its milestones in the field include its involvement in the G5 andG6 plants for African Barrick Gold’s Bulyanhulu mine in Tanzania. Both power stations typically consist of six containerised generator sets, comprising 2 250kW diesel engines and 2 250kVA, 400V alternators, as well as six 2 500kVA, 400/6,6kV step-up transformers.

Included in the scope of works was a containerised 6,6kV medium voltage (MV) substation housing six 630 ampere (A) incoming plant feeder breakers and a BTU system with local control panel.

Gerrard informs that both plants were integrated with the existing power and control networks. In addition to designing the civil works, Zest Energy designed and installed the earthing systems, installed the supporting auxiliary electrical equipment and commissioned the plants.

The company was also involved in a diesel power generation solution at one of the Mopani mines near Kitwe, Zambia. As opposed to the project in Tanzania, this was an indoor plant solution comprising six open-type generator sets, each featuring a1 600kW  diesel engine and a 2 000kVA, 400V alternator.

Included in the design and installation of the plant were six 2 250kVA 400/11kV dry-type transformers, designed specifically for use within the power plant building, due to the limited space available on site. This was complemented by an 11kV MV substation, comprising six 630 ampere (A) generator incomer breakers, a 1 250A plant feeder breaker and a BTU system with local control panel.

The plant solution also features a complete fuel system and day tanks, while Zest Energy was involved in electrical installation, design and development of the synchronisation system and overall commissioning of the plant.

Rolling power in

Back-up power and supporting electrical infrastructure solutions have become equally important considering the limited capacities of grids on the continent. This is exactly why Gerrard is excited about the future of the company’s mobile solutions which, he maintains, is already enjoying significant growth and expects it to continue doing well into the future.

On the generation front, it designed four 2,5MW mobile generator plants, each comprising a 20V 4000G63L MTU diesel engine and a 3 125kVA, 6,6kV WEG alternator. Mounted on purpose built trailers, each plant features a cooling system radiator, MV switchgear and synchronisation system and a purpose-built MV cable reel with quick couplers for easy connection and integration with the site infrastructure. Four 4 500l fuel storage tanks were also supplied, mounted on separate trailers, for ease of transport and connection to the mobile generator plants.

The project was undertaken on behalf of Harmony Gold as a safety measure to help evacuate workers from its underground operations during unexpected load shedding or other incidences of grid failure.

Meanwhile, the company has complemented this solution with its mobile substation systems, including 40MVA 132/88//33/22kV, 20MVA 132/88//22/11kV and 10MVA 33/22//22/11kV units.  They feature custom designed mobile transformers from WEG Brazil and high voltage (HV)/MV switchgear with protection systems, all installed on trailers engineered to comply with road ordinance requirements. The mobile substation designs are all in accordance with the specifications of Eskom, the South African utility. More are also expected to be sold to municipalities in South Africa as they embark on a nationwide upgrade and maintenance drive. The substations will allow them to replace or refurbish their existing fixed infrastructure without disrupting day-to-day activities and thereby ensure supply availability in their jurisdictions.

However, Gerrard says that there are also other significant opportunities to be tapped into elsewhere on the continent. It is already a major supplier to a host of African utilities and mining companies, and it is gearing up to grow its other integrated solutions throughout the continent.

For example, the company sees itself playing a larger role in mini hydropower projects. Zest Energy has some experience in the hydropower sector having  already supplied hydro alternators in the Democratic Republic of Congo. Its scope of work included supplying eight WEG hydro alternators. Four were 6 500kVA, 6,6kV hydro alternators and four were 6 300kVA, 11kV units. He reports that the company was also involved in supplying tooling and spare parts for two years of operation as well as providing site supervision services during the  installation and commissioning project phases.

Yes, there is immense opportunity to be had in the African energy landscape, but being part of it requires more than just being able to supply an off-the-shelf solution!

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