https://www.miningweekly.com

Mines could reap significant savings by incorporating renewables into their energy mix

24th February 2017

By: Donna Slater

Features Deputy Editor and Chief Photographer

     

Font size: - +

Renewable-energy systems, including solar photovoltaic (PV) power, hold significant benefits for mining operations in sub-Saharan Africa, says renewable-energy solutions company juwi Renewable Energies MD Greg Austin.

These renewable-energy solutions can offer mining industry operators a saving of between 2% and 3% on the bottom line – a saving which is directly attributable to savings on energy costs through the use of solar power in pure self-consumption mode, which can replace diesel or heavy fuel oil (HFO).

He states that energy costs can amount to as much as 30% of the operating cost of a mine. Therefore, pure self-consumption of power generated by solar power generators can replace between 7% and 10% of the diesel/HFO-related electricity cost. “This saving goes straight to the bottom line”.

Integrating solar PV into power stations “clearly makes good sense”, says Austin. By synchronising a solar PV plant into an existing captive diesel minigrid, mines can reduce diesel consumption significantly during the day.

For example, Australian copper/gold producer Sandfire’s De Grussa copper/gold mine, in Western Australia, is the largest hybrid and off-grid system in the world; juwi Renewable Energies’ integration of solar PV and diesel at the De Grussa plant resulted in a 20% reduction in diesel consumption. This will assist in the mine reaching its target of 300 000 t/y of high-grade copper concentrate.

Austin further elaborates that, at a mine in Limpopo, solar PV systems provide 60% of the 1.6 MW of power required. “In this high solar irradiation area, the cost of solar PV electricity is about half that of diesel over the 20-year operating life of a typical plant.”

Buying electricity at a 50% reduction in cost is a “pretty compelling argument”, as miners everywhere look for increasing efficiencies within their existing operations, he adds.
“The more remote the mine, the higher the fuel bill, and it is not unlikely that the prospect of cheaper operating costs using solar power will lend viability to investment opportunities that would otherwise not be realised.”

One of the drivers for the marked increase in interest in solar-diesel hybrids noted by juwi is the 30% reduction in the cost of solar modules over the past 12 months. “With the cost of the solar panels accounting for about half of the system cost, this is an effective facility cost reduction of 15%,” states Austin.

He highlights that the cost of operating a mine currently depends on the internationally traded price of oil, with the primary fuel for the mine being diesel or HFO. “Herein lies the second clear advantage for miners, in that the long-term (20 years and longer) costs for the solar power contribution to their overall generation is known and secured in advance.”

As oil prices increase erratically, this stability in pricing is of “tremendous value” from a planning perspective, Austin adds.

In terms of reliability and predictability for mines operating in sub-Saharan Africa, solar PV solutions offer a degree of redundancy for electricity security, even for grid-connected mines, as many power grids in this region are unreliable and weak.

However, in terms of power storage from solar PV solutions, for use at night, Austin says storage plays an integral part because, “. . . as the price of batteries continues to drop, they will be increasingly incorporated into hybrid energy systems”.

Edited by Martin Zhuwakinyu
Creamer Media Senior Deputy Editor

Comments

The content you are trying to access is only available to subscribers.

If you are already a subscriber, you can Login Here.

If you are not a subscriber, you can subscribe now, by selecting one of the below options.

For more information or assistance, please contact us at subscriptions@creamermedia.co.za.

Option 1 (equivalent of R125 a month):

Receive a weekly copy of Creamer Media's Engineering News & Mining Weekly magazine
(print copy for those in South Africa and e-magazine for those outside of South Africa)
Receive daily email newsletters
Access to full search results
Access archive of magazine back copies
Access to Projects in Progress
Access to ONE Research Report of your choice in PDF format

Option 2 (equivalent of R375 a month):

All benefits from Option 1
PLUS
Access to Creamer Media's Research Channel Africa for ALL Research Reports, in PDF format, on various industrial and mining sectors including Electricity; Water; Energy Transition; Hydrogen; Roads, Rail and Ports; Coal; Gold; Platinum; Battery Metals; etc.

Already a subscriber?

Forgotten your password?

MAGAZINE & ONLINE

SUBSCRIBE

RESEARCH CHANNEL AFRICA

SUBSCRIBE

CORPORATE PACKAGES

CLICK FOR A QUOTATION