Mining companies in Tanzania continue face the challenge of ensuring continuous and stable power to their operations, while ensuring that their carbon footprint is reduced. Global energy services provider Aggreko, a company specialising in temporary power solutions, aims to support its mining clients in this regard by providing hybrid power solutions for Tanzanian mines, as it has elsewhere in the world.
Aggreko’s temporary power and electrical distribution systems provide mines with appropriate power supply based on their needs and environment without requiring them to make large capital investments.
The intermittent nature of hydropower creates the challenge of fluctuations on the grid, especially during times of reduced dam inflow. Power stability is also impacted on by the ability of the country to distribute power to remote mine sites.
For some mines, grid power reliability and quality issues result in significant operational challenges, equipment damage and production loss. Other mines face a different challenge of operating entirely off grid.
Aggreko Africa MD John Lewis emphasises that Aggreko’s hybrid power systems are ideal for the global mining industry, including in Tanzania.
“We have been active at all the major mines in the country in terms of power generation solutions. This includes backup power solutions for on-grid mines, main sources of power for critical underground operations, and bridging power for mines in their construction or development stages.
He notes that Aggreko’s solutions are used to power critical mine processes, and that the current energy situation in Tanzania has ensured that renting these solutions from Aggreko “has a lot of benefits”.
Lewis adds that the company can provide rapid response equipment during power outages, owing to regional centres allowing for quick delivery and installation.
The company also provides a turnkey service, which ranges from initial assessments to service backup on site. The installed capacity of a power system can also be increased or decreased depending on the mine’s power needs to ensure that the cost of power is in line with operational requirements over time, something that cannot be achieved through fixed capital investments in power assets.
“Renting equipment also eliminates the need for high capital expenditure associated with purchasing. Customers can avoid large down payments and interest costs, preserving capital. We work with mines to set flexible terms that make sense for their businesses.”
He also emphasises that power supplied by Aggreko equipment is reliable and can run 24/7 if required, and that the company is fully accountable for the equipment, its people and the operation of the hybrid power plant.
This reduces the mine’s exposure to any associated risks, particularly for complex hybrid projects, as Aggreko completely absorbs the technology risks through performance guarantees.
Meanwhile, Lewis stresses that the current uncertainty instigated by changing mining laws and regulations in Tanzania impacts on the mining industry, but particularly on the applications for permits and licences.
“We are trying to reduce capital costs for our customers in these uncertain times. We are involved in more than ten feasibility and bankable studies for new mining projects that have yet to come onstream. This year, we also expect two mines to start construction, and have already signed a power purchase agreement for one of the projects.”
Lewis cites Aggreko’s involvement in the North Mara underground gold mine operation, located in the Tarime district of the Mara region, in Tanzania.
The mine requires power 24 hours a day, which requires 5 MW of prime power.
“Off-grid power plants comprising diesel, oil or gas generators are typically designed to maintain enough power in spinning reserve to instantly respond to contingency requirements, such as the sudden loss of a generator or a rapid change in load,” he explains.
He adds that systems which integrate renewables, such as solar or wind, have an even higher requirement of spinning reserve, owing to the need to balance fluctuations in power generation, usually from changes in the weather, within milliseconds to maintain a high level of resilience.
Lewis compares these off-grid power plants to thermal plants, which can create spinning reserve capacity by running extra generators. This, however, results in a lower loading of the plant, and higher fuel consumption.
“Adding battery storage for spinning reserve enables our systems to serve the same load using fewer generators. If a generator were to trip or a large motor to start up, the battery immediately provides the required capacity to ensure continued performance of the plant without the need for any diesel dependent spinning reserve.”
He points out that adding batteries to a mine’s energy storage system not only increases the average efficiency across all generators but also results in less run time on the displaced generator.
“Overall, the Aggreko hybrid approach delivers considerable fuel savings, better generator use in terms of reduced runtime, lower generator operation and maintenance costs, as well as lower carbon emissions.”
The company plans to continue building its presence in the country through developing market-leading products, improving fuel efficiency and environmental impacts, broadening its range of energy sources, and maintaining an efficient and optimally sized fleet.