The year 2008 saw a lot of novel inventions with long-term and short-term benefits, from the Large Hadron Collider to commercially-available DNA testing. But with 2008's global recession looming over the end of the year, renewable energy has come under fire for not being able to compete with fossil fuels in terms of cost. Solar power is especially notorious for being too expensive and too inefficient. This year, several companies have attempted to address that problem in the form of mass-produced thin-film solar cells. More durable and cheaper to make than traditional crystalline silicon solar cells, mass-produced thin-film solar cells have the potential to transform solar power from a luxury item into a viable energy source.
The biggest problem with crystalline silicon solar cells are the polysilicon crystals generally inside them. They have two major problems that make them expensive to manufacture. First, they need to be relatively thick to properly absorb light. Thanks to oil prices skyrocketing for the past two years, the demand for solar panels also went up, causing a shortage of the polysilicon used to make them. This in turn made silicon crystals even more expensive. Second, crystalline silicon is extremely brittle. This negates the ability to produce it in large quantities because of the delicate handling needed to keep it intact.
Thin-film solar cells, on the other hand, use alloys such as amorphous silicon or copper indium gallium selenide (CIGS), which are far more versatile and durable. Thin-film technology has been around for a decade, but its two biggest drawbacks were inefficient energy production and a still-fragile process requiring a vacuum chamber to apply the conductive compound to glass sheets. What changed in 2008 were the completion of numerous factories by various companies using semiconductive ink and a roll-to-roll process, allowing the solar cells to be printed onto metal sheets like a newspaper printing press. This made them far less expensive to produce and far more accessible to consumers.
There's still plenty of room for improvement in thin-film solar cells, however. They're still not as cheap as traditional energy sources and still only work best during the day. Technological advancements in photovoltaics, nanotechnology, energy storage, and silicon production are needed if solar power is ever going to be a major source of alternative energy. However, 2008 has seen only the first practical uses of thin-film solar cells thanks to new manufacturing methods. It's clear that this invention isn't just a flash in the pan.