Continued improvements to solar power are imperative to future space travel. As missions blaze farther and farther into deep space, sunlight wanes. A 1-meter square (3.2-foot) solar panel that produces about 400 watts near Earth would have to be 2,000 times bigger to generate the same amount of power in Pluto's neighborhood [source: NASA].
Thankfully, there are other promising products in development. Another NASA partner, MSGI Technology Solutions, recently unveiled solar cells that incorporate tiny carbon pillars, called nanotubes, into the solar cell design.
The nanotubes help reduce reflected light, using the pillars to snag photons that would bounce off of a traditional flat panel. Also, the nanotubes increase the surface area of the panel, giving the product more room to capture light and produce more energy.
That's not all. Solar panel makers also face problems associated with dust and dirt. A tiny dust deposit of 0.1 ounce (2.8 grams) of dust per square yard (0.9 meters) can reduce solar panel efficiency by as much as 40 percent. That's why NASA employees working with non-NASA scientists developed a dirt-repelling coating for the panels, which was first developed for use in space environments [source: Solar Power Engineering].
The so-called self-cleaning panels have a thin, transparent and electrically conductive layer. When embedded sensors detect accumulated dust, a cascading electrical charge is sent through the coating, in effect pushing the dirt off with electromagnetic waves.
This kind of cleaning technology is critical for two reasons. One, it's not based on mechanical, moving parts, which would be prone to breakdowns. And two, it doesn't require hand washing, a painstaking chore that would devour far too much time and clean water, especially if the panels were installed in a very remote, dusty location -- say, for instance, on the surface of Mars.
All of these advancements to solar power are relevant here on Earth, too. A multitude of consumer products, from toys and camping gear to radios, now use modernized solar panels. Solar advancements are applicable on a larger scale as well and could even help us energize a totally new type of power plant.
In the early 2000s, NASA and some private companies were seriously considering space solar power systems. In theory, satellites equipped with huge solar panel arrays would collect sunlight and beam its energy down to power stations on Earth. Although NASA isn't currently pursuing the concept, other countries (such as Japan) are, and we'll undoubtedly see even more improvements to solar tech as a result.
As you can see, without NASA's involvement, solar power technology would likely still be a fledgling science. But thanks to enterprising NASA scientists and private entrepreneurs, sun-powered products will continue to improve, both in space and on Earth.
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- PennWell press release. "PV Cells with Nanotube Pillars on Metal Substrates: Technology Update from MSGI." PennEnergy.com. March 3, 2011. (March 8, 2011)http://www.pennenergy.com/index/power/display/9461599590/articles/Photovoltaics-World/industry-news/2011/3/pv-cells-with-nanotube-pillars-on-metal-substrates-msgi.html
- Shuttle Press Kit. "Photovoltaic Array Assembly (PVAA)." Shuttlepresskit.com. November, 9, 2000. (March 8, 2011)http://www.shuttlepresskit.com/STS-97/payload81.htm
- Solar Power Engineering. "Solar Panels, Clean Thyself...So They Do." Solarpowerengineering.com. August 27, 2010. (March 8, 2011)http://www.solarpowerengineering.com/2010/08/nasa-technology-translates-into-self-cleaning-solar-panels/