Energy will continue to be a highly sought-after commodity in Africa.

Many companies help to address the continent's insatiable need for electricity, but not many have the ability to take a holistic approach and integrate their solutions with the electrical infrastructure of mines and other industries, as well as utilities.

This is Zest Energy's competitive edge. It not only offers comprehensive power generation, electrical infrastructure and mobile solutions, but has the ability to assimilate them into existing and, more importantly, future infrastructure requirements.

By taking a long term outlook, Zest Energy is able to design and implement integrated solutions that will cater for expansions planned over at least a 10 to 15 year horizon.

Complementing these capabilities, Zest Energy draws from the vast global footprint of its international principal, WEG Group. The Brazilian multi-national boasts 55 years' experience in the engineering and power systems sector, and has more than 35 international product certifications.

Being part of Zest WEG Group gives Zest Energy access to an enormous sub-Saharan African footprint, comprising established offices and representatives in major centres, while allowing it to tap into its extensive experience in major mining destinations on the continent.

Zest Energy offers diesel, heavy fuel oil, gas, steam, hydro-power and hybrid type generation systems. Its electrical infrastructure solutions include outdoor and indoor substations and overhead lines, as well as substation refurbishment services and power factor correction systems.

These are completed by its mobile solution offerings, which cover power generation solutions as well as switching stations, mobile substations, mobile circuit breakers and skid-based substation solutions.

These three core constituents of its project-based business have been successfully deployed in many areas of the continent, with some milestones in the mining industry including:

• A diesel power generation plant for a gold miner in Tanzania:

Zest Energy provided the mine with a custom power plant solution that comprised six 2 000 kVA containerised diesel generators, six 2 500 kVA 400/6,6 kV step-up transformers and a containerised 6,6 kV MV substation.

The power plant was designed to integrate with the existing electrical network and to safely operate in both island mode as well as parallel mode with the utility, whereby synchronisation had to take place across three incoming utility transformers. Zest Energy undertook the civil designs, design and installation of the plant earthing system, electrical installation, as well as overall plant and system commissioning.

• A diesel power generation solution for a copper miner in Zambia:

Zest Energy designed a power plant solution for the mine that consisted of six
2 000 kVA open type diesel generators with six 2 250 kVA 400/11 kV dry-type step-up transformers and an 11 kV MV substation. Again, the plant was designed to safely operate in both island mode as well as parallel mode with the utility.
The overall solution features fuel filtration systems and fuel day tanks. The scope of work included the complete electrical installation, as well as the generator synchronisation systems and commissioning of the plant. 

• An outdoor substation for a copper miner in the DRC

Zest Energy designed and built a complete 5 MVA, 120/11 kV outdoor substation with a 120 kV tap-off structure to feed utility power to the mine. The project included the development of a synchronisation system that facilitates the safe and controlled operation of four 800 kVA generator sets with the substation.

•  Mobile generation solution for a South African gold miner

Zest Energy designed a 2,5 MW mobile diesel generator solution for the gold miner. The generation equipment is mounted on a purpose-built trailer and includes the cooling system, custom-designed cable reel with quick type MV couplers and the fuel storage system. The overall solution involved the design and installation of extensible type outdoor MV switchgear at selected operational mine shafts, into which the generators can be safely and easily connected. It was also involved in the complete testing and synchronisation of the generators at each of the selected mine shafts.

•  Mobile substations offer optimum flexibility

Zest Energy supplied three mobile substations to South Africa's electricity public utility. The three units, 40 MVA, 20 MVA and 10 MVA, are used during fixed type substation refurbishments, maintenance and breakdowns and to improve the grid network reliability by limiting the duration of power interruptions. The substation equipment is mounted on custom engineered trailers that comply with South African road ordinance legislation in regard to weight and overall equipment dimensions. Mobile substations are not limited to utilities; these solutions can easily be designed to suit the requirements of the mining industry.