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A solar-powered future

Published by
World Coal,


Matthew Fredericks, Aggreko, South Africa, outlines the future potential of hybrid solutions for onsite mining power generation.

A solar-powered future

Efficiency continues to be a priority for miners – and with good reason. As operations become deeper, more remote and more intense, finding innovative ways to cut costs and improve productivity is an ongoing challenge.

The nature of the industry at the moment means that miners are carefully analysing their operational expenditures. Reducing fuel and power generation costs is an obvious place to focus attention.

Remote locations and limited access to local grid infrastructure means that the mining industry places significant demand on diesel generation for electricity. Fuel costs are a considerable issue here and the volatility of oil prices makes it difficult for diesel-reliant mines to manage those fluctuations and protect profit margins. Aggreko has seen it through its work with miners, throughout Africa in particular, and, as such, is constantly looking at ways to improve fuel efficiency.

While onsite power brings a level of independence and self-sufficiency, this reliance on diesel can bring potential threats to an operation if supply or access is limited. Improving the efficiency of generation infrastructure will reduce fuel demand, but finding innovative, alternative power sources is a more effective solution in the long term.

Working in partnership with miners to develop a new reliable, future-proof energy source is a priority and a worthwhile investment for onsite power providers. Turning to the renewables sector is indeed an obvious choice; however it’s not without complications.

Hybrid solutions

Hybrid energy solutions continue to be developed and implemented within the mining industry, improving efficiency and bottom lines. Whether the mine uses waste products or renewable sources, the high risk of intermittency and unreliability means diesel will continue to play a significant role.

Working with miners to develop a self-sufficient power source is not a new concept for Aggreko. In partnership with Sibanye Gold, Aggreko delivered an innovative and environmentally-friendly alternative source of power to its Beatrix gold mining operations in South Africa. The infrastructure allowed the operation to use naturally occurring methane gas intersected during underground mining operations. This not only created a self-sufficient, free source of fuel but also avoided the need for gas flaring, which had its own environmental benefits.

Using waste gas is becoming a realistic alternative, as is using other sources of renewable power. In key markets throughout Africa and South America, solar power is an obvious solution. Specifically, solar photovoltaic (PV) and diesel hybrid solutions are what most mines are looking into. The significant drop in costs for solar panels – as much as 70% in the last year or so – makes them an economical investment for mining houses.

Using a hybrid solar/diesel power generation for onsite mining operations offers many positives and, as developments in renewable energy technologies continue to advance, hybrid solutions are starting to show how they can be beneficial. Where grid infrastructure in emerging markets is not particularly stable, having your own source of power is essential and smaller mines, for example, are starting to see how they can protect themselves from the increasing cost of diesel generation.

A perfect fit

Hybrid solutions enable diesel generators to operate lower loads, which reduce operating and maintenance requirements. Solar/diesel hybrids work by prioritising the solar power and, only once they drop or become intermittent, are the diesel generators brought back to capacity. Integrating hybrid power solutions, such as adding wind or solar to existing diesel systems, can cut mining companies’ energy costs by 10% – 20%.1 Furthermore, they require very little maintenance, helping save mining companies on personnel and resource costs.

Where a mine would previously run on 80% diesel power, for example, this could eventually be reduced down as far as 20%. That said, if black-start is required, diesel generators can be used to get a plant running. Or if intermittency (no sun or UV) causes risk to reliability, modular power provides a back-up power source.

Where renewable power sources are useful for more stable loads, diesel packs the punch that renewables cannot in order to get a motor started. Of course, there are some limitations holding back many companies from investing heavily in hybrid power solutions. Solar generation is very space intensive – as much as 2 ha. could be required to produce 1 MW of power, which is perhaps a luxury for some.

In recent years, the mining sector has watched on with envy as other sectors have successfully adopted a hybrid power solution to operations. Manufacturing plants for example, as well as farming and agriculture, have reaped the benefits of such an approach. More and more examples are cropping up of hybrid solutions being used, not just in the mining sector, but in other sectors across the world.

Investing in or adopting hybrid power solutions will not provide savings in isolation. A mine operator also needs a rapid fleet, flexibility and experience at their disposal. Aggreko has the largest fleet of reciprocating engines in the world, so the company knows how these machines work. It knows, for example, that its machines and engine capabilities are well suited to working with renewable energy technology due to their fast ramp-up times.

A shift in the dynamic?

There will always be a need for onsite diesel power. All mines have motors: large ones for winders, mills, fans and pumps, conveyors, cutters or other machinery that require hundreds of thousands of kilowatts to operate. To withstand that large in-rush of current, they require diesel power to back-up the renewable or alternative source.

So is the dynamic between the mining industry and renewable technology really shifting? Interest in renewable energy for the sector has been long standing, though not always acted upon. Mining companies’ interest in renewables, specifically solar, seems to have gained traction in the last twelve months.

This is because renewable energy continues to provide evidence that it can offer more competitive costs compared to conventional energy. In remote locations where grid connection is not possible, for example, it is starting to prove useful by taking the burden off diesel generation. The other factor is the need to meet carbon footprint requirements.

The mining industry has not traditionally adopted renewable energy technology for onsite power generation with much enthusiasm but many working within the sector and at mining companies are in agreement that renewable, innovative power solutions are the way forward, especially for mining in remote areas. Aggreko is no different. The company listens to its customers and monitors the market very closely, which now sees the company working on new technologies and methods to suit this way of thinking.

However, despite the positive outlook, doubt around full adoption of renewables remains. Until new alternatives become the mainstream power source within the industry, their role within the mining energy mix will continue to grow. What is clear is that renewable, self-sufficient generation will complement rather than compete with traditional, diesel energy sources in what will become a successful relationship.

References

  1. ’Case Study 03: Alternative Energy in Mining‘ (GIZ ProSPECT/SAIIA). Accessed at: http://www.saiia.org.za/special-publications-series/607-sadc-business-barriers-case-3-alternative-energy-in-mining/file

Further reading

  • ‘Hybrid diesel-PV system saves big in Ecuador’ Energy Business Europe (15 May 2014). Accessed at: http://www.energybusinesseurope.com/2014/05/15/hybrid-diesel-pv-system-saves-big-ecuador/

Read the article online at: https://www.worldcoal.com/special-reports/14102016/a-solar-powered-future/


 

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