Chile has found another use for dams that hold the liquid waste from massive copper mining operations: power generation.

Calling it the first project of its kind in the world, Anglo American has installed 256 photovoltaic panels at the tailings dam for its Los Bronces complex, in Chile. The panels are floating atop the sometimes toxic ground minerals and effluents blasted out of rocks dug up at the mine. The pilot project is expected to generate 150 000 kWh/y and help power the operations there, the company said in a statement this month.

While it does not amount to much electricity in the grand scheme of things, Chile Mining Minister Baldo Prokurica hailed the solar project as yet another example of how the country – the world’s largest cooper producer – is leading the way in improving how miners treat waste. Chile was the first to ban so-called upstream dams, which are cheaper to maintain but have led to deadly accidents, such as the collapse of one at a Vale mine in Brazil that killed at least 180 people in January.

“We are advancing towards a more sustainable mining activity by actively developing new solutions and stimulating other ways of thinking and working,” said Patricio Chacana, VP of operations at Los Bronces.

The panels at Los Bronces were specially designed to resist the extreme conditions of the Andes mountains, where the mine is located. At 3 400 m above sea level, the area is constantly hit by snow and heavy rains. The panels can withstand winds of 210 km an hour, according to the company.

Preserving Water

Another upside, Anglo said, is that the panels will shield the liquid in its dam from direct sunlight, reducing evaporation by 80% and improving water recovery rates. Recycled water makes up about 45% of an operation’s total water demand.

Apart from the solar project, Chile’s government was also looking to start a pilot to monitor the operations of tailings deposits live, Prokurica said. Local communities would receive phone alerts should an emergency occur at one of the dams. The country already regulated the minimum distance between urban centres and mining waste deposits.