In calculating the savings achieved by the introduction of VentSim™ CONTROL Ventilation on Demand (VOD), we investigated the way the ventilation system would otherwise have operated. In the case of the auxiliary fans, a base case was first established, to estimate how much power would be consumed by each fan if no VOD system was available. We looked at the records over a 96 day period and scaled the figures up to one year. This demonstrated a reduction, over the twelve month period, of 15,000 MWh, which at the prevailing energy costs brought a saving of $1,200,000.
Additional savings arose from running the main surface fans in 'speed optimiser' mode, and decreasing the fan's speed for around 1.5 hours at the end of each shift. Comparing electricity consumption with figures from a previous period showed that the annual energy saving in the main fans was about 9,500 MWh. The cumulative cost saving was calculated to be around $1,700,000. Savings in energy costs thus totalling $2,900,000.
Further benefits are that the mine has the flexibility to draw more air where required, maximising production and responding quickly to any adverse conditions; such as extreme cold or hot weather, power outage, communication loss, or anything else that may arise. In addition, the system optimises production by minimising blast clearing times, which enable workers to get back to work more quickly. Such control would not have been possible without the use of the advanced control system of the VentSim™ CONTROL system. While these benefits bring great economic advantages to the system, the wider value of the VentSim™ CONTROL VOD system, in reducing both costs and carbon footprint, is clear.