Samarco's conveyor belts become a power source in Mariana

A pilot at the Germano Complex turns the weight of ore rolling downhill into electricity — and shows how to cut energy consumption without building anything new.

Samarco completed, at the Germano Complex in Mariana (MG), a pilot project for recovering energy on conveyor belts that run on downhill stretches. The technology harnesses the weight of moving ore to generate electricity, instead of merely consuming it.

The principle behind the pilot is simple to explain and rarely seen applied at scale in Brazilian mining: on a downhill belt, the weight of the load helps drive the system. In that regime, the motor stops drawing energy from the grid and starts working as a generator — the same effect an electric bicycle uses to recharge its battery going downhill. Regenerative inverters capture that energy and feed it back into the plant's internal grid, available for other equipment to use. On a belt fitted with two 400 hp motors, operating 80% of the time at 60% of load capacity, Samarco estimates recovery of about 166,000 kWh per month — equivalent to the annual consumption of 69 households. International studies indicate that regenerative systems on downhill stretches recover between 30% and 45% of the energy a conventional system would consume on the same route. The gap between that number and zero doesn't come from any exotic equipment: it comes from reconfiguring how the plant already handles energy that today is lost as heat in the brake.

Energy is one of the largest operating cost items in any mine, and the standard answer for cutting it tends to be investing in new generation — a solar plant, a renewable energy contract, more efficient motors. Here the answer came from within the conveyor circuit itself, without depending on any additional generation source. For a plant with a target to cut greenhouse gas emissions by 30% by 2032, as is the case with Samarco, this kind of retrofit competes on cost with larger investments and executes faster, because it uses infrastructure the mine already has.