Mining smart management and storage

At a glance, it may appear as if the mining industry and renewable sector do not happy project partners make. Renewables and extractive industries can superficially appear to be polar opposites of the technology spectrum. However, a shrinking cultural clash between renewables and the resources sector, with solar at the helm, appears to be fueling growth in this fast-developing sector. There is little doubt the potential is huge.
Many within solar have long understood how with solar’s rapidly falling costs and the mining industry’s reliance on trucked diesel or piped natural gas for the vast quantities of energy that it requires, PV deployment can deliver lower energy costs and positive environmental outcomes. Energy security too can be enhanced through solar deployment in the mining industry with energy supply lines often stretched long distances leaving them vulnerable to extreme weather events or civil unrest.
“At the beginning of this year, two major announcements triggered huge interest in the topic of renewable energy and mining,” explains Thomas Hillig, founder of THEnergy consulting, which specializes in renewable application in the mining industry. “It can be expected that this is only one step in a major shift toward renewable energy in mining .” The projects Hillig references are the 10.6 MW PV array that Sandfire Resources intends to develop at its copper mine in Western Australia. The project would be ten times as big as the largest existing solar-diesel hybrid plant in the mining sector.
The second project is at the Sibanye Gold operations in South Africa, which would see a 150 MW PV power plant constructed to supplant 20% of the mine’s total costs. And while these major projects are particularly promising, activity at the smaller end of the sector is also heating up.

Tailor-made

Hillig notes that a number of smaller projects have also been launched that have been tailored to the specific economics underpinning mining operations. Often mine operations will have a short lifetime, if only on paper, and shifting commodity prices can lead to the shuttering of operations. In these cases, a 15-year renewable energy investment is not suitable. But tailored solutions are being offered by the solar sector to meet this particular challenge.
“The concept of re-deployable solar plants overcomes the barriers and risks associated with permanent installations,” says Hillig. “Redavia built its first 63 kW PV power plant in Tanzania last year and Laing O’Rourke finished a 144 kW plant in Australia this year.” Rented or leased solutions may also help overcome renewables relatively high Capex.
Increasingly, battery storage and smart energy management are entering with flexible or portable solutions best suit the mining companies’ purpose.
“Containerized solution for inverters, power management systems (PMS) and batteries can allow for easy and prompt relocation in case the mine reaches the end of its life cycle,” says Nidec ASI’s Maurizio Delucchi. Nidec, hailing from Italy, recently supplied a 208 kWh battery system, integrated into a container solution along with inverter and power management system to a mining camp in Chile. “Nidec’s PMS is highly flexible and is easily adaptable to new grid configurations [making it suitable to be deployed in various locations].” Delucchi is an energy systems engineer with the company that has over 100 years experience in the power electronics space.
Nidec’s Chilean mining project was originated by compatriot’s Enel Green Power and it supplies the mining village of Ollague, in the country’s remote and mountainous border with Bolivia. The village was previously supplied with electricity by a diesel gen-set, with Nidec’s Delucchi reporting that its capacity was insufficient to supply the needs of the village.
“Our scope of activity was to integrate the diesel generator set with a “green” microgrid solution including a PV plant, wind generator and battery system,” explains Delucchi. “We also supplied the power management system (PMS) to control the energy flow creating a local, stand-alone micro-smart-grid (MSG) to supply the entire village’s energy needs.” The storage component was incorporated to provide energy shifting when the PV was not producing electricity and when the wind was not blowing. Here, the Nidec PMS was crucial in providing real-time balancing between the various energy sources and the storage.
“In every instant, power generated must be equal to the sum of the power required by the loads, which may vary significantly from instant to instant,” says Delucchi. “The energy storage acts as a buffer for the power difference between generators and loads, what we refer to as the stability effect. It also provides energy to the load when renewable generation is not available, which we call energy shifting.” Nidec was the single-source supplier of the power electronic, battery and PV components, along with the PMS and micro grid infrastructure.

Accommodation to operation

Providing electricity to keep mining camps lit, fed and warm – or indeed cool – is a major challenge on remote mine sites, and here renewables and storage can play a key role. However when it comes to mine operations, there remain xAdvertisementchallenges in both meeting the energy-intensive requirements and also the high expectations of the mining engineers.
Operational down time on a mine site, due to a power cut, can cost phenomenal amounts of money on a minute-by-minute basis, and mining engineers are understandably conservative about moving away from proven electricity sources such as diesel gen-sets and piped gas. However, here too renewables and PV are making inroads, especially when paired with traditional energy sources.
“Providing power supply for mining by renewable sources only would be challenging because usually mines require high power with a very large range of variations in power supply,” says Nidec’s Delucchi. “To guarantee the requested power under any condition, the storage system might have to be oversized and the return of investments might not be convenient. Renewable power sources together with conventional power sources, such as power from the main grid or diesel generation, could be the winning compromise.” And indeed hybrid deployment is the predominant trend emerging in the industry and demonstrated in THEnergy’s database of renewable projects at mining sites. Consultant Thomas Hillig notes that established gen-set companies, with a track record in the mining sector, are moving into the space. “In recent months we could observe that traditional gen-set companies with a footprint in mining such as Caterpillar seem to be entering the market by integrating renewable energy solutions into their portfolio,” says Hillig. Nidec ASI itself has a long history in supplying the oil and gas sector with power electronic solutions.

Culture shift

In what he describes as a “culture shift” within the mining sector, THEnergy’s Hillig says that visibility of renewable potential in mining operations is increasing. The cost advantage integrated renewable solutions can provide over conventional fossil-fuel sources is becoming well understood, reports Hillig, and even with the recent declines in oil costs, PV itself sports a 50% – 60% cost advantage over diesel in remote locations.
In a counterintuitive development, some oil extraction operations may be forced to turn to renewables as a cost cutting measure, due to decreased revenues based on depressed end-market pricing.
One such example, in which storage also plays a prominent role, is the Duhkan oil field in Qatar, where 40,000 Sunica.plus batteries will be provided by Saft at oil wells, to be coupled with PV. The $10 million contract was awarded to Saft by Kentz, an engineering company providing corrosion protection services.
Alongside cost advantages, Hillig also notes that mining companies can profit from renewable energy adoption, sending a clear signal to financial markets and that they are recognizing that threats regarding energy costs and security need to be addressed. It can also help mining companies in terms of perception, from an environmental standpoint.
“The usage of renewable energy is interpreted by the financial markets as a signal for a flexible and forward-looking decision making process; mining companies that are first movers in actively integrating renewables are considered as progressive and better managed,” concludes Hillig.

Cheaper, cleaner, better

Contrary to some misnomers, projects such as Nidec’s in the mining village of Ollague, an integrated and intelligent system, incorporating storage, can in fact deliver higher a reliability factor than a diesel gen-set. Even in trying environments, such as 4,000m above sea level along Chile’s Bolivian border, such applications are forging the way for mining companies and renewable energy providers to form long-term, reliable and potentially profitable partnership.