While solar power has a reputation as being something that goes along with tofu, beans and knitted beanies, it is actually a technology that can benefit mining companies working in remote locations.
According to companies like Orion Solar and iMark Communications, their products – based on photovoltaic solar panels – are perfect for remote sites. While neither company offers solar products capable of generating enough power to run a whole processing plant, both offer specific solutions that can be used by the mining industry.
Orion's product range, for instance, is based around solar-powered LED lights from Canadian company Carmanah, which are primarily used in safety, road and hazard lighting.
The products, explains managing director John Holliday, were originally designed for usage at sea and have subsequently been applied across a number of different markets, and those include marine navigation lights, aviation lights for landing and taxi lights, roadways and hazard warning lights.
"Our safety lights, which were originally designed as a navigation light out at sea with a visibility of say, two nautical miles, are now used to mark the correct routes for trucks to negotiate. BHP Billiton and Rio Tinto have both bought the lights.
"Last year … the mining industry became our largest sector. They were buying a number of these products that were originally intended for other industries but buying them for hazard markers on opencut mine roads and things like that, pedestrian hazard warnings where there were trucks coming through," he said.
"All of these lights are manufactured for rugged environments."
The LEDs come in a number of different configurations depending on requirements and the solar units power everything from roadside cats-eye lights to traffic lights, marking lights and hazard warning lights.
The lights also have sensors so they come on automatically when it gets dark and switch off when it becomes light again, after charging during the day in the sun, even in cloudy or rainy conditions. After only eights hours of light, the units will have absorbed enough energy to power the light for 12 hours, and the company says they work even in shady areas.
Ultracapacitor batteries are used in the units instead of standard rechargeable batteries, which will last for over 10 years and possibly even indefinitely without needing to be replaced, Orion said. Ultracapacitors have also shown little tendency to degrade over multiple charges.
The lighting units themselves are small and easy to install, as well as being tough and durable enough to withstand temperate ranges from minus 40C to plus 80C, according to Orion.
"These are usually smaller than the sort of solar panels you'd see on a rooftop and they're encapsulated in an epoxy which makes them extremely rugged," Holliday explained.
The cost savings from installing the lights come primarily from the fact that companies are not required to lay wires for the lights, change batteries or conduct regular maintenance, according to Holliday.
"The solar powered [lighting] is a tremendous advantage – they're easy to [install], they require no maintenance and there's no cost in replacing batteries," he said.
Imark Communications offers a different sort of solar powered technology for remote operations. So far, the company's solar products have been used primarily by the Australian Defence Force, but managing director Owen Smart said the company's solar power systems would be suitable for mining operations.
"There are two main areas we offer solar equipment for – one is the standalone DC-only operation, the likes of which is used for powering remote radio sites on hills, where the equipment works on 12 volts. This involves batteries to store energies overnight," he explained.
This equipment can be used as standalone power for communications equipment in remote sites.
The 12 (or 24V) DC systems also allow for five days of cloud cover, and the batteries in the system that hold the solar power are never allowed to discharge more than 50% to maintain the lifespan of the system.
"The other application is for 240V systems, derived from solar, with back-up generators. These are generally referred to as RAP systems – Remote Area Power systems – and we've done those … in sizes up to 90kW," Smart said.
"That can be used for powering offices or camps. We've installed various sizes for various applications."
Smart said a typical installation of one of the systems at a camp would be somewhere where there were alternating periods of high usage and very little use, such as a remote camp that saw staff come and go. The solar power system would be installed with photovoltaic panels and batteries, and a diesel generator as well.
"In those periods [when] there are washing machines and repair equipment going, and keeping food cool, it's the whole camp up and running. In those situations, the generator runs," he said.
"In certain periods when the load is very low, when all we need to do is provide lights and work the toilets and that sort of thing, in those cases, the solar will provide the baseload, and the generator runs when there's a peakload," he said.
"It's a generator interactive system, which means the generator will start automatically if the battery is low, of they haven't collected enough solar, or there is a peak demand. The software in the inverter controls when the generator starts and stops, and you can have periods when the generator is not allowed to run.
"If you want to run a generator 24-7, you can imagine in the middle of the night when nothing is happening, you're running the generator just in case someone decides to go to the loo."
The system can also be adjusted for different load profiles, Smart said, depending on the power needs of the site – the company installs systems from 21W up to 90kW – and each system is sized on a case-by-case basis, according to the user's load profile.
The main advantage of this RAP system is that it enables the diesel generators to be used intelligently, while giving the solar power a back-up, meaning less power – and hence less fuel – from the generators is wasted.
