Cheaper Solar Power is Finally Coming

“The energy that reaches earth from sunlight in one hour is more than that used by all human activities in one year”. - Prof. Ashton Partridge, Diector of Nanomaterials at Massey University (New Zealand) Research Centre

Plastic (organic or flexible) solar cells are extremely desirable because they are inexpensive and light weight compared to silicon, which is bulky and convert up to 12 percent of impinging light to useful electrical power.

Dr. Wayne Campbell and researchers describe green solar cells as more environmentally friendly than silicon-based cells. “The refining of pure silicon, although a very abundant mineral, is energy-hungry and very expensive. And whereas silicon cells need direct sunlight to operate efficiently, these cells will work efficiently in low diffuse light conditions,” Dr .Campbell says. “The expected cost is one 10th of the price of a silicon-based solar panel, making them more attractive and accessible to home-owners.”

Dr Wayne Campbell and researchers in the centre have developed a range of coloured dyes for use in dye-sensitised solar cells.

New Zealand is not without competition. Wake Forest (North Carolina) researchers hope to reach 10 percent efficiency by creating "nano-filaments" within light absorbing plastic, similar to the veins in tree leaves. This allows for the use of thicker absorbing layers in the devices, which capture more of the sun's light even in low-light conditions. Three percent was the highest efficiency ever achieved for plastic solar cells until 2005 when David Carroll, director of the Wake Forest nanotechnology center, and his research group announced they had come close to reaching 5 percent efficiency.

Dr. Carroll's research is partially funded by the United States Air Force, which is interested in more efficient, light-weight solar cells for satellites and spacecraft.

Molten Eagle prediction: Within 5 years, solar cells will exhibit operating efficiencies exceeding 19%. Unless a global manufacturer (Siemens, GE, Fuji, etc.) buys the related patents, costs will be 25% of today's silicon-based panels per watt. Aside from their initial cost, the greatest problem with solar panels is their need for frequent replacement. Much improved durability is required and fragile technologies do not stand up to direct sunlight and inclement weather (e.g. hailstones). The winner will be the technology that works in low-light, and lasts as long as a microwave oven ( over 7 years).