We get our solar energy from indirect sources, such as the foods we eat, and we free it from storage when we burn fuels. But although it was once widely viewed as an inefficient, impractical source of alternative energy, solar energy capture and use – which has worked for crabgrass and kudzu for eons – has recently made a good deal of headway in human use, especially in efficiency improvements that may allow us to utilize it in the same manner as our green co-inhabitants.
Consider, first of all, that approximately 5.7 x 1024 joules of solar energy are irradiated to the earth's surface on an annual basis. That enormous figure in itself suggests that harnessing that power could constitute a major part of the solution to the current energy crisis. However, one of the major problems with solar energy capture has been the amount of energy at any one point on the earth’s surface is not well-concentrated, and increasing the concentration elevates solar costs, although lenses and mirrors have been able to make some improvements. (http://www.fao.org/docrep/w7241e/w7241e06.htm#TopOfPage)
Still, the use of solar power has been expanding rapidly, growing an average of 40 percent per year since the beginning of this decade,(http://www.cleanedge.com/reports/pdf/USA_Study.pdf). A new study from Clean Edge says that solar energy could reach cost parity with retail-electricity rates in most regions of the U.S. in only a few years. http://www.renewableenergyworld.com/rea/news/story?id=52813) Even more optimistically, in their Scientific American article, “A Solar Grand Plan,” authors Ken Zweibel, James Mason and Vasilis Fthenakis predict that the U.S. could get 69 percent of its electricity from solar sources by 2050.
Obviously, then, there’ve been improvements driving solar power’s shift to viability. This winter, for example, Sandia National Laboratories and Stirling Energy Systems set a new solar-to-grid system conversion efficiency record, measured by net energy delivered to the grid divided by solar energy hitting dish mirrors, by achieving an unprecedented .25 percent net efficiency rate. The system is comprised of dish units formed by 82 mirrors to economically concentrate and focus the light onto a receiver. (http://www.sciencedaily.com/releases/2008/02/080213172955.htm)
Among other advancements, SemiSouth Laboratories, Inc. and the Center for Advanced Vehicle Systems have produced an enhancement-mode silicon carbide (SiC) Junction Field Effect Transistor (JFET), which reduces the power semiconductors use by as much as 50 percent. In addition, these units are less costly than their conventional predecessors to produce.(http://www.reuters.com/article/pressRelease/idUS231788+10-Apr-2008+BW20080410)
Meanwhile, thin-film players such as Miasolé and Nanosolar are working with their investment dollars to produce and distribute low-cost, non-silicon alternatives, raising the possibility that a change in medium may provide the link to a commercially viable photovoltaic cell.
(http://www.siliconbeat.com/entries/2005/06/09/nanosolar_miasole_stir_up_solar_cell_market.html)
Assuming these improvements pan out as they are expected to, if our country is at least partially powered by solar energy, we’d be better off in a number of ways. While fossil fuel sources are limited and their costs are volatile, solar energy is virtually inexhaustible and thus would offer more stable pricing. Compared to coal-, nuclear- or gas-fired power plants, solar energy operations require no input materials to fuel them – besides, of course, sunlight – and would have low maintenance costs. Sunlight is widely available and, even in areas where it would not be able to provide the exclusive energy source, solar energy could at least supplement others and alleviate grid congestion in regions with high energy demand, especially during peak-use hours.
It seems likely, then, that solar power will soon hit economies of scale as utilities step up bulk purchasing and deployment, as conventional fuel prices continue to skyrocket. While humans have traditionally been more drawn to attractive gizmos like iPods and Corvettes, which we see as both high-tech and exciting, it turns out that the efficiency of plants like dandelions and monkey grass is just as sophisticated. When we use them as models for energy generation, they actually have a lot to offer society. It’s worth rethinking, and in the meantime, rest assured that the outlook for solar power is “bright,” to say the very least.