Mining company engineers are continuously looking for practical ways to drive down operational costs at mine sites, without sacrificing the safety of miners.
If miners come up against a multitude of hazards during the day, then under the cloak of darkness during the night safety must be even more crucial. Traditionally mine sites have used metal halide lighting to provide luminance, however in more recent times LED has emerged as an equally effective and less costly alternative.
IndustrySearch recently spoke to Andrew McAdam, General Manager at PROMAC, a specialist manufacturer of lighting about how LED lighting on mine sites – specifically their Greenlite tower series – covers all bases and is the way forward, potentially rendering the metal halide setup a technology of the past.
IndustrySearch: How does LED lighting cut operating costs for a mine site?
Andrew McAdam: Direct savings are from lower fuel consumption, lower repair and maintenance costs, lower servicing costs and improved productivity – typically in the region of $20,000 per machine annually, measured against a comparable metal halide product.
Fuel consumption is the largest contributor, with each unit saving around 12,000 litres of fuel annually.
Repair and maintenance savings, mostly through the reduced rate at which globes have to be replaced can account for another $3,000 to $4,000 per year.
Our LED panels are warranted for three years and we expect upwards of 50,000 hours effective performance before change-out – many sites see only a few hundred hours from metal halide globes due to their fragile nature, where stone damage and vibration damage account for most failures.
Productivity is improved through the 'instant' light performance of LED. The units can be turned 'on' and 'off' with no requirement for the 15 minute cooling period (known as restrike) which affects metal halide lamps. The fact that the LED tower will run for up to 10 nights also means your service team are not having to make so many visits to the units.
Studies conducted with clients typically show direct annual savings in the region of $20,000 per machine. We're seeing a very rapid acceptance and take-up of the technology especially among new mines, small and mid-tier mining companies who have identified energy savings as key addition to their profitability.
The critical aspect is that the use of LED requires no change to established mining or operational practices – you're simply using a different product to light your site.
There are also a range of qualitative benefits including lower emissions (CO2 reduced by 60 per cent) and lower pollution levels, and improved light quality and visibility conditions for equipment operators. Whilst these factors are harder to value in dollar terms, they all benefit the site, employees and the environment.
IS: What sectors of the mining industry is LED lighting applicable?
AM: We have products working successfully in gold, coal, oil and gas, mineral sands, salts and nickel projects on sites across Australia, Indonesia and PNG – just about any application that requires mobile lighting.
The lighting performance has progressed to such a level that the machines can be deployed in almost any capacity onsite, whereas previously they had been most effective in ancillary roles – go-line, crusher feeds, car parks etc.
We are also preparing to launch our compact LED tower, which is targeted at the civil construction, road-building, emergency response and events markets. The unit is designed to replace up to 6000w metal halide towers and utilises a compact trailer design. It's important that we have an appropriately sized unit to service the needs of those sectors, as the mining trailer was physically too large and carried with it higher production, mobilisation and logistics costs.
IS: How does Greenlite LED lighting address other critical aspects of the mining industry – safety, long lifespan, and durability?
AM: Safety is the start point of our design requirements, with direct reference to AS/NZ standards, Australian Design Rules and Mining Regulations. The units are equipped with a full mine and safety specification as standard and can also be optioned to meet the specific requirements of the NSW coal mining industry (MDG15 and MDG41).
Our new LED towers have now switched from 240v AC to 48v DC power, reducing the risk of electrical injury. LED lights don't emit the same levels of UV radiation and heat as a metal halide lamp, so you're less likely to suffer skin damage or burn injuries when working around the machines.
Feedback from truck drivers for example, highlights the lower levels of glare experienced with LED lights when compared to metal halide – it's critically important that operators are able to see clearly when driving a 200-ton machine.
Lifespan and durability are the hallmarks of LED lights. Had there been an alternative, metal halide lamps would never have been used on a mine site – they're extremely fragile when hot and vulnerable to both vibration and impact.
Our LED clusters sit behind a 2-inch thick lens which protects them from stones which would smash a metal halide globe. We're confident enough in the strength and performance of our panels to offer a 3-year warranty.
IS: From a mine lighting products specialist's perspective, what are some other ways a mine can reduce operating costs?
AM: Look at the 'low-hanging fruit' – some suggested changes that can be made quickly, easily and without major expense. To name just a few ways:
- Retrofit of LED panels to existing metal halide products if you're not in a position to dispose and purchase new LED towers;
- Review deployment models to consider 'own vs lease vs hire' to see which structure best suits your project life, operational demands, budgets and corporate strategy;
- Fixed installation of LED panels can cut energy consumption by 70 per cent in comparison to metal halide fittings. PROMAC installed panels inside our workshop and on the exterior of our office buildings and we have a number of clients installing fixed LED lighting at go-lines, crushers and on processing plant;
- Fitting GPS units to lighting towers allows remote start-stop operation and monitoring of the machines, reducing the amount of time spent switching them on/off, preventing excess running and enabling easy location.
IS: What does the future hold for mine lighting; will metal halide technology ultimately become obsolete?
AM: Effectively, metal halide is a dead technology. LED performance has progressed to the point where we can now replace up to 10,000w metal halide products with an equivalent LED – but at approximately 30 per cent of the power consumption for the same lighting performance.
Our product mix is now approximately 90 – 95 per cent LED towers, from 50-50 LED vs metal halide only 12 months ago as the machines have proven their performance.