Energy and Emissions //
Energy Consumption and Intensity
Energy is one of our most significant operating costs. Its two main uses at our operations are as fuel for transport and electrical power. Diesel and gasoline are used in transporting products and people. Stationary energy is comprised of purchased electricity (all three of our operations draw from state power grids), diesel for generators, and natural gas for the smelting furnaces at Guanaceví.
Our total energy consumption in 2016 was approximately 636,000 GJ over 722,378 GJ in 2015, a 12% reduction. Energy intensity measures the amount of energy required to process each tonne of material. Measuring energy intensity enables us to understand the efficiency of our processes and monitor the progress of our energy-reduction efforts. In 2016, our average energy intensity was 0.44 GJ/tonne of processed material, a reduction from 0.47 GJ/tonne in 2015.
The reductions in both energy consumption and intensity were mainly due to the reduction at El Cubo in generator usage due to lower production, and the switch from diesel to the electric grid at Bolañitos.
In 2016 there was one initiative to reduce energy consumption at Guanaceví, where a new camp for security personnel was constructed and solar heaters were installed to heat the showers.
Purchased electricity remains our biggest source of emissions, followed by diesel for mobile equipment. Diesel used for mobile equipment includes heavy and light vehicles used in the mining process and for the transport of our personnel. Propane, gasoline for mobile equipment, and the use of explosives form only a minimal source of emissions.
Our total direct and indirect greenhouse gas emissions in 2016 were 73,407 tonnes of CO2 equivalent (tCO2e), representing a decrease of 8.7% over 79,798 tonnes of CO2 equivalent (tCO2e) in 2015. This was predominantly attributed to the reduction in the use of diesel for generators at both El Cubo and at Bolañitos.
Guanaceví has the highest energy emissions of our mines, as it purchases more power and consumes more propane, for use in the dry-stack tailings process, as well as the pumping of excess groundwater, and power for the campsite, which is heated in winter and air conditioned in summer. The higher propane consumption comes from the kitchen in the dining facility (other locations have no kitchen) and the hot water heaters for showers.
Our greenhouse gas emissions intensity decreased by 1.4% in 2016 to 0.050 tCO2e per tonne of processed material, compared with 0.051 tCO2e in 2015. In addition to energy consumption reduction, total company-wide production was approximately 100,000 tonnes less than in the previous year, making the final emissions intensity calculations similar.
Since 2015, the Mexican government has mandated the reporting of greenhouse gas emissions. In 2016, only one of our mines – Guanaceví – was above the threshold established by the Ministry of Environment. In preparation for the mandatory independent verification, which will begin in 2017, we had an external party (KPMG) conduct an assessment of how we measure, track, and calculate our GHG emissions. There were no major recommendations and their report was used to put a systematic procedure in place to track and calculate GHG emissions at all our operations.