CONTENT POD 3: Optimizing Renewable Energy for Mines

OPTIMIZING RENEWABLE ENERGY FOR MINES

Because on-site power generation is responsible for a large portion of mining’s carbon footprint, leading many miners around the world to choose to self-generated renewables, the third content pod at the Energy and Mines Virtual World Congress 2020 explored ways to optimize renewable energy options in microgrids.

MORE EFFICIENT MICROGRIDS

By now, miners have a few years of renewable microgrid experimentation behind them, and success factors are becoming better known. First, companies should clearly state their emissions reduction ambition, and map the renewable resources available to them. “We are systematically studying opportunities and potential sources of renewable energy very upstream of the project. It has to be done as the very first step,” said Pierre Gueudet, Energy and Climate Director at Eramet, during a panel chaired by Jennifer Berger, Managing Principal at Stantec. Then, geography and mine life should be considered to design the best solution for each specific site.

Renewable technology has evolved tremendously in recent years, to the point where miners see little to no technical risk in their implementation. Solar energy can now provide baseload 24/7 power: Bruce Anderson, Chairman and CEO of 247Solar, explained that a small gas turbine, modified to produce electricity from high-temperature ambient pressure air heated by a receiver that concentrates solar energy, can work just like a redeployable generator set.

While technical challenges are now easily overcome thanks to this type of innovation, miners still have to contend with contractual and optimization challenges coming from the combination of very different energy sources. “It’s important to choose partners whom you are confident can execute,” notes Sunil Kumar, Senior Director of Energy Strategy and Engineering at Kinross Gold.

LEVERAGING ENERGY STORAGE

Recent developments in energy storage are increasing the reliability of renewable microgrid projects. “We’ve introduced batteries to push renewable penetration, as batteries respond faster than generators,” said James Koerting, Manager, Energy, Australasia, at Gold Fields, noting that the price of batteries is the only thing holding the company back from increasing its storage capacity. However, storage integration also adds complexity to microgrids, requiring specialized training and contract flexibility. “One of the challenges is how to handle performance guarantees and warranties: you may have performance guarantees from your solar provider, for the genset, for the batteries, but who is responsible to make it all work together when the plant is operating as a hybrid,” warned Mark Kennedy, Business Development Manager, Energy Solutions at Wärtsilä Canada.

Storage, energy management systems and accurate forecasting were all cited as key to optimizing microgrid efficiency. And working with a partner that can deliver a turnkey solution encompassing all energy sources along with storage was seen as an advantage. Lars Stephan, Market Development Manager, Renewable/ Hybrid/Storage at Aggreko, noted that such a partnership ensured guaranteed reliability, fuel and commercial flexibility. “It allows customers to change power systems following their needs throughout the life of the mine, with one single hybrid contract,” he added.

SPONSORS’ CORNER

Saturn Power laid out what should be miners’ priorities in storage integration into microgrids: functional specifications should be well structured, forecast assumptions should be confirmed from a credible source, load analysis should be performed on one-second interval load data, and contractual alignment should be achieved ahead of time.

Scatec argued that by using a leasing approach and movable equipment, it is possible to achieve attractive solar pricing in a five-year PPA.