For something that comes from the sky, there’s an astoundingly large amount of digging that takes place to get solar energy working. It’s obvious when you think about it, but have you ever really wondered where solar power comes from?
The reflectors are made of silicon and therefore need digging up. Solar panels and electronics need pure silicon, harvested from the sand on select beaches or, more commonly, mined from within the Earth. But even though silicon is one of the most plentiful substances on earth, extracting it is not a simple process.
There’s no such thing as a silicon mine. Instead, gadget-makers and solar providers must unearth pure quartz and extract silicon from within it.
By now, you’ll be thinking silicon must be worth a fortune. After all, it’s awkward to get hold of, right? Absolutely. Even though silicon is one of the Earth’s most widely distributed resources, the type of pure silicon needed by the solar and electronics industries is rarer than a unicorn’s steak dinner. It’s found in just a few places, such as North Carolina, around the modest town of Spruce Pine.
It’s a quaint place, littered with classic American diners and encircled by the Blue Ridge mountains. It has just 2,000 residents and yet its fortunate position makes it America’s silicon mining capital.
High-purity quartz is hauled from within the Blue Ridge mountains, fetching £30,000 a tonne. From this, silicon is extracted and turned into wafers for chip manufacture and solar panel production. At that price, and with the global population facing both a growing digital dependency, as well as a drive towards cleaner energy, it’s easy to see why owning silicon resources is a licence to print money.
Quartz mining is Spruce Pine’s only sizeable industry. It’s a town built entirely on the fortunes of the digital age, and while its residents are unlikely to see a dip in demand any time soon, those buying its wares are doing so in smarter ways than ever before, in an effort to reduce their reliance on silicon stocks.
To fully understand the drive for greater efficiencies in silicon use, we have to travel back in time.
Sharp’s legacy in Solar began in 1959 with pioneering solar research. By 1963 the company had begun mass production of solar cells and in 1978 it launched the world’s first solar-powered calculator. It set a trend in desktop solar power that continues to this day, but its legacy is much more than workplace convenience.
Fast forward to 2011, and Sharp’s influence over solar is enormous. What’s more, the ramifications of that first solar calculator are starting to make an impact on a much larger scale. The same amorphous silicon technology that made its debut in calculator solar cells is finding a home in much larger solar installations.
Now a world-leading manufacturer of commercial and residential-grade solar panels, Sharp is looking at new ways to reduce the amount of silicon going inside its solar products, starting with amorphous silicon technology from familiar pocket calculators.
Sharp’s newest thin-film solar modules are, in essence, the same as those found in calculators, but their scale is much larger. They use a tandem structure with an amorphous and a microcrystalline silicon layer, generating an efficiency between 8.5% and 9.5%, compared to more traditional crystalline modules, which boast up to 15% of module efficiency.
However, while less efficient at first glance, thin-film solar panels have several groundbreaking advantages that are propelling their rising popularity.
Their production is easier and cheaper. They can be stacked, to maximise the use of space, and thin-film solar cells can even be made translucent by treating them with a laser, so they’re perfectly suited for use over windows or semi-transparent roofs. Quite simply, thin-film solar cells can generate power in places their predecessors could never reach.
Sharp is driving thin-film solar technology forward because it conserves resources and cuts costs. The creation of a thin-film solar panel uses just 1% of the silicon used by a more traditional crystalline module. It’s thinner, and lighter too, so transporting a thin-film solar cell from the factory to its installation is more efficient.
Until recently, amorphous silicon thin-film cells were generally perceived as inefficient by comparison to their weightier crystalline cousins, but their unique abilities are now encouraging engineers to use them to solve problems, and increase adoption of solar power generation.
Sharp’s established distribution channels and expertise in large-panel LCD screens are also helping it make headway, since thin-film solar technology shares some of the characteristics of big screen TV advancements, Sharp’s experience is paying dividends.
In the future, thin solar cells could have a dramatic impact to the way green energy is generated, and as the race for eco-friendly energy merges with the battle for silicon required for chip manufacture, both sides will need to use less of the precious material to achieve the same result.
While dwindling fossil fuels and increased awareness of climate change is forcing a green energy revolution, so high grade silicon could soon become a factor in electronics. Thankfully, companies like Sharp are already putting us well on the way to a more efficient solar future.