Let the Sun Shine In

Solar energy may finally be ready to solve the world's energy problems and drastically reduce the production of greenhouse gases said to be a leading cause of global warming.

You probably already know that the amount of sunlight that strikes the Earth each day could, if properly collected, easily support our electrical needs as a race. The problem, of course, has been in figuring out how to effectively and economically convert sunlight to electricity.

Traditional solar cells are made from silicon, the main component of sand. Silicon solar cells are expensive to manufacture. The process itself requires a lot of energy, so much so that some have questioned the overall benefit of solar energy cells.

In addition, the yield (the amount of electricity created from the light striking the cell) of traditional solar cells is low, somewhere in the range of 10-20% (depending on who you talk to).

The high cost and low yields have held the technology back as a viable alternative to fossil fuels. However, a number of recent announcements may help solar energy regain the limelight.
Here are some of the ones I've stumbled across over the past several weeks:

• At Massey University (Albany, New Zealand), they've created solar cells from an organic dye that mimics the sunlight-collecting abilities of plants. While the yields of these cells is much lower than that of silicon-based cells, they cost up to 90% less to manufacture and are more effective environments where light is more diffuse (e.g. cloudy Seattle).
  
  
• Last December, Spectrolab (a wholly owned subsidiary of The Boeing Company) was able to boost the yield of traditional solar cells to 40%.
  
  
• Researchers at The University of New South Wales (Sydney, Australia) have discovered how to use more of the area inside a solar cell to collect energy. They expect this discovery to increase yield by 20% while reducing costs by 30%.
  
  
• At Wake Forest University (South Carolina, USA), they've increased the yield of plastic-based solar cells to 12%. While that modest given the recent advances with silicon, it represents a 400% increase in yield for plastic-based cells and also suggests applications beyond traditional solar cells, perhaps even a solar energy collecting coating that could be applied to the windows of office buildings and skyscrapers.

When you take these discoveries in context, it looks like the cost of rewiring your home to use solar energy is going to become much cheaper, perhaps as much as 90% less, in the near future. While today's conversion prices vary wildly based on your goals, the price of a $10,000 conversion could theoretically drop to $1,000 in the near future.

If that's the case, then conversion becomes a no-brainer. In our home, for example, we spend ~$800 annually for electricity. At today's prices, it would take about 13 years for a conversion to pay off economically. At 1/10th that cost, however, the project pays for itself within the first fourteen months. In addition, I imagine a conversion would add quite a bit to a home's resale value.

The true benefit, though, would appear rapidly over the next few years. I'll talk about that in my next post.

Photo credit: NASA