Electricity + Control

As demand for electricity throughout Africa continues to present numerous challenges, Zest WEG Group, the generator set manufacturer/electric motor supplier, remains a significant player in the provision of power to the people of the continent.

With more than 37 years of experience in Africa, the Zest WEG Group, a subsidiary of leading Brazilian motor and controls manufacturer WEG, continues to dominate sub-Saharan Africa's power landscape.

Demanding environments call for robust diesel generators

Since formation in the 1960s, the company has become the largest electric motor and variable speed drive supplier in Africa, servicing 45 countries. From providing low and high voltage electric motors, power and distribution transformers, containerised substations and switchgear to developing customised diesel generator sets, Zest WEG Group is well-equipped to meet the energy needs of its clients.

Zest WEG Group diesel generator sets, in particular, are a common feature across sub-Saharan African businesses and industrial sites, providing power for a range of applications from construction and mining to health and retail as well domestic households.

The company's largest project to date was the completion of the Syrah Balama power plant in Mozambique in December, 2016. Zest WEG Group designed and installed seven 3000 kVA MTU/WEG gensets, supplying 11 kV of continuous power to a graphite mine.

Louis Kotze, Chief Operating Officer, Zest WEG Group Generator Set Division had this to say: "This was an exciting project for us. We normally provide solutions for the platinum, coal, ferrochrome and gold industries because South Africa is a mining economy, but this was new in terms of graphite and, being a conductive material, we had to come up with a special solution to counteract the conductivity on the electrical equipment".

During 2017, Zest WEG Group installed 1600 kVA and 2000 kVA acoustically treated, containerised generator sets at the new Netcare Christiaan Barnard Memorial Hospital in Cape Town, where the world's first heart transplant was performed in the 1960s. During the installation, the team faced logistical challenges while offloading the generator sets. Roads had to be closed while the generator sets were positioned on top of the hospital's roof using special cranes. The generator sets were put into containerised units, specially designed for noise reduction.

The company was behind another major project, installing eleven 630 kVA Volvo units at the V&A Waterfront, a popular tourist retail and commercial complex in Cape Town. The generator sets were installed in the only space available in the basement parking area, where the team had to contend with low ceilings and narrow corridors while moving the generator sets into their operating position. Extensive work had to be carried out on the exhaust extensions, which were manufactured up to three stories high through the ventilation shafts.

“The Zest WEG Group Generator Sets division can offer customised solutions to industrial and strategic, as well as critical applications, where lives depend on back-up electrical power,” says Kotze.

“Standby diesel generators are vital for businesses that have process plants or are involved in production. Wastage of product in the production process, when a power outage occurs usually outweighs the cost of a generator over time,” Kotze explains.

But while Zest WEG Group excels in making and installing customised solutions, Kotze hopes the company will continue to build on its standard and premier ranges of generator sets (10 kVA-3350 kVA, 50/60 Hz).

"In addition to being able to do a project that is complex, we are looking at developing our standard range of equipment because there are still so many countries without electricity looking for a solution. This would enable us to enter different markets and extend our distributor network."

With the increasing call for gensets in standby power applications, it is necessary for specifiers to fully understand the operational requirement of these units, and then apply this knowledge to the engine selection.

“An area where cost savings can be achieved without impacting on the reliability or operation of a standby genset, is the engine,” Kotze explains. “An engine in a standby power application will run for limited duration during power outages, yet we often see tenders requesting top-of-the-range premium brand engines that are completely over-specified for this function. Not only is this a waste of capital expenditure but it could also affect the operating costs.”

Kotze says it is far more pragmatic to allow the genset original equipment manufacturer (OEM) to assist in advising and specifying a fit-for-purpose engine. He explains that the engine in a standby genset would have an estimated run time of 250 hours a year with a maximum of 80% average load factor.

Zest WEG Group, which has eight branches in South Africa, as well as registered businesses in Mozambique, Zambia, Namibia, Liberia and Ghana, already has distributors in Angola, Botswana, Cameroon, the DRC, Madagascar, Mali, Mauritania, Mauritius, Mozambique, Namibia, Nigeria, Senegal, Ivory Coast, Zimbabwe and Zambia.

Kotze believes that in time the generator set industry will turn towards hybrid applications saying that the company was recently contacted by an engineering consultant in Cape Town to assess the design development of a desalinisation plant to deal with water shortage. "They were considering a dual fuel solution, and we were able to suggest a hybrid scenario using gas and diesel," he said.

He says the next 50 years in Africa will be interesting, as renewable energy costs decrease. However, he cautions, it is not that easy to execute a renewables project in Africa because the logistics are challenging and, despite the increasing trend towards renewables, a generator set will always be required as a dispatchable power base to meet demand.

Speaking to Zest WEG Group's future, Kotze sees it aligning towards microgrid solutions, especially for communities; moving into power pools; and establishing more plants such as Syrah Balama in Mozambique. The challenge here is that every country in Africa has its own localisation programme, which makes it difficult, as the skills in each country are not always available. Zest WEG Group manages this by training local people who will work at the power plant and, by doing so, adds value.

"As an integrated energy solution provider, we supply and install an array of products from our many divisions across the Zest WEST Group. This positions us well for decades to come in the future," Kotze concludes.