Solar Power: One Small Change Can Make Such a Difference

Introduction

As many of us know, the issue of finding alternative means of power and fuel is at hand. As days go by it seems like the cost of fuel just keeps rising, which then in turn also brings up the cost of power such as electricity. So what is there to do about this dilemma? Well there are many different answers to that question depending on each person's own opinion and what they believe. Some say that hydrogen fuel cells are going to be the savior and others believe that developing a more abundant and less expensive liquid fuel is the way to go [1]. Well in my opinion, I believe that we should turn our heads towards solar energy. Until recently solar power has been a rather expensive form of energy for the little amount that is gained. But I believe that the way to make solar power more economical is by looking into solar cells made with silicon nanocrystals.

What is a solar cell?

First off a solar cell, as defined by Britannica's Online Encyclopedia, is any device that directly converts the energy in light into electrical energy through the photovoltaic effect. The photovoltaic effect, also defined by Britannica's Online Encyclopedia, is a process in which two dissimilar materials in close contact produce an electrical voltage when struck by light or other radiant energy [2]. This process is what gives us our solar energy that we use today in devices such as calculators and other solar powered objects.
The difference between a regular solar cell and a solar cell made with silicon nanocrystals is that instead of having multiple thin layers of different materials, it has a single layer of silicon nanocrystals. Then underneath the nanocrystals are possibly one or two more layers of different materials. These extremely small silicon crystals enable the solar cell to create between two and three electrons per one photon of high-energy sunlight. Unlike the solar cell with no nanocrystals, which can only produce one electron per photon [3].

Is Bigger Always Better?

The problem with our solar cells today is that most of the large scale cells are made with either expensive or somewhat limited materials. Not only that, but the total percentage of energy captured by these solar cells only ranges from 10 percent to 35 percent [4]. Despite the fact that we are getting some energy from "nothing", it still doesn't seem to be too practical. But if we take a look at the new solar cells, we'll see that there is a big difference.
Due to the size of the crystals, the crystals' cheap cost of production, and the smaller amount of materials needed, these new solar cells can dramatically cut the cost of making solar energy. In fact, it can possibly cut the cost up to 80%. If that is true, then the cost of solar power would be on the same level if not less than the current price of power today[5].
Not only does adding nanocrystals to the solar cell cut the cost dramatically, but it also cuts the amount of energy wasted in half [6]. This is due to the fact that by producing two, sometimes three electrons from one photon not as much energy is being turned into heat and then wasted during the reaction. Due to the fact that fuel cells can become much more cost effective and more efficient, I'd say that the feat of making solar power more economical is not too far away.

Just how Effective?

Just how much more energy can adding silicon nanocrystals to a fuel cell really make? Well according to Kevin Bullis, the author of Silicon Nanocrystals for Superefficient Solar Cells, the new cells can convert from 40 percent to 60 percent of the light captured into elerctrical power [3]. That nearly doubles the amount of electical power made from the current solar cells. Also, by adding highpowered mirrors and lenses to focus the light even more then it already is, into the equation, the total estimated amount of power that can be produced is well over 60 percent [6].

Whats Next?

According to Victor Kilmov, a leader of silicon nanocrystal research, "Solar cells that use the these methods could become practical in two to three years" [4]. In reality, this is actually a very short period of time for such a large stride in making solar power more economical. Then a little further down the road, about ten years or so, it is believed that these solar cells will produce power at a minimal $1 per peak watt. That is one fourth of what the cost of a peak watt is today [5].

Conclusion

To put the amount of potential solar energy around us into perspective, think of a one square mile plot of land. In that one square mile, there is $200,000 worth of power in terms of today's cost. But by using the means we have now of harnessing that power, it would cost around $50 million [4]. That is why I believe we need to make solar power more economical, and a perfect example of how to do reach this goal is by looking into silicon nanocrystal solar cells.

References

  1. Greenemeir, Larry. 29 June 2008. "Solar Sell: Companies that Mass Marketed PCs Turn to Photovoltaics." SCIAM. http://www.sciam.com/article.cfm?id=ibm. Acessed 29 September 2008.
  2. "Solar cell." 2008. Britannica Online Encyclopedia. http://www.britannica.com/EBchecked/topic. Acessed 29 September 2008.
  3. Bullis, Kevin. 15 August 2007. "Silicon Nanocrystals for Superefficient Solar Cells." MIT Technology Review. http://www.technologyreview.com /energy/a19256. Acessed 1 October 2008.
  4. Patch, Kimberly. 9 June 2006. "Solar crystals get 2-for-1." TRN. http://www.trnmag.com/Stories/2004/051904/Solar_Crystals. Acessed 1 October 2008.
  5. Wald, Matthew. 14 June 2004. "New Design Could Make Solar Cells Competitive." NY Times. http://query.nytimes.com/gst/fullpage.html?res =9D0DE7d. Acessed 28 September 2008.
  6. Slaouri, A. 18 May 2003. "Silicon Nanocrystals - A Luminescense Convertor Applied to Silicon Solar Cells." IEEE. p 2734-37.

Acknowledgements

I would like to give thanks to my friends Kelsey, Tara, and Korey who helped me out by finding articles for me. I would also like to thank Korey for letting me borrow his computer since mine broke.