A Saft lithium-ion battery energy storage system (BESS) is playing a key role in helping Gold Field’s Agnew mine make the switch from fossil fuels to wind and solar power, according to the Paris-based company.

In Saft’s first project for EDL, the BESS has been installed within a hybrid renewable microgrid with an installed capacity of 56 MW. This is the first microgrid to incorporate wind power on a large scale at an Australia mine, the company said, with the energy storage critical in enabling the EDL microgrid to maintain power quality as it integrates an increasing level of volatile and unpredictable renewable energy.

EDL Chief Executive Officer, James Harman, said: “The Agnew hybrid renewable microgrid was completed on May 1, 2020, and has proven to be a great success – under the right weather conditions, the microgrid has delivered up to 85% of the site’s power requirements with renewable energy.

“The BESS is critical to this success. That’s why we selected Saft’s Li-ion technology – it offered a complete solution with a proven track record. We’d be happy to work with Saft again.”

The Agnew gold mine is an underground operation 1,000 km northeast of Perth in Western Australia. The site covers over 600 sq.km and has the capacity to process 1.3 Mt/y of ore.

The remote off-grid location means the Agnew site must generate its own electricity, with Gold Fields committed to sustainable and innovative power solutions. It engaged EDL in a 10-year agreement to build and operate Australia’s largest hybrid renewable energy microgrid.

The first project phase involved the construction of a 4 MW solar farm and a 21 MW gas/diesel engine power plant. This was followed by five wind turbines for 18 MW of generation, a microgrid controller and Saft’s 13 MW/4 MWh energy storage system.

The turnkey BESS at the Agnew mine comprises six of Saft’s Intensium® Max+ 20M, 20 ft (6.1 m) containers together with a power conversion system, transformer and MV switchgear installed in three 40 ft containers. Its main role is to provide power quality support for the microgrid to maximise the usage of variable renewable energy, according to Saft. It also provides “ultra-fast reacting spinning reserves” to help maintain grid stability and minimise the need for fossil fuel-based generation units to run idle for this purpose.

The Intensium Max+ 20M design meant no modifications were required to ensure a long operational life in the demanding dusty and sandy desert conditions, where peak temperatures can reach 48°C, Saft said. To maintain maximum uptime and availability for the BESS, Saft is providing remote monitoring together with a service contract including yearly on-site maintenance.

The Intensium Max+ 20M is fully fitted out and tested by Saft at its manufacturing hub in Jacksonville, Florida. As a result, the containers were delivered to site ready to ‘plug and play’.