Tuesday, September 13, 2011

Unleash the Power of the Sun

As I write this blog entry, a team of men who call themselves PlanetSolar are readying their solar-powered yacht to journey across the Gulf of Thailand.  Three hundred and fifty one days ago, these men set out from Monaco on a mission to make a complete around-the-world trip using only solar power.  So far they have made it across the Atlantic, through the Panama Canal, across the Pacific, around Australia, past the Philippines, through the South China Sea and are currently in the vicinity of Vietnam.  This project’s goal is to show how “high-performance solar mobility can be realised today by making innovative use of existing materials and technology,” and they’re doing it by sailing the world’s largest solar-powered vessel around the globe using nothing but energy from the sun.  How cool!  Go Team PlanetSolar!

Of course, solar-powered vehicles have been a goal of modern technology for a while, and PlanetSolar isn’t the only specially-designated team aiming at it.  For the last twenty years or so, the Stanford Solar Car Project has been working to put solar-powered vehicles on the road.  And it’s not just vehicles getting the solar treatment; solar power is up-and-coming as a use for powering homes.  Over on Long Island in New York, BP Solar and the Long Island Power Authority (LIPA, as the locals call it) have been building a massive solar farm in Brookhaven.  Once completed, this farm should be able to power thousands of homes, as well as offering researchers a great opportunity to test out a big solar farm.  And remember that artificial leaf I told you about several months ago?  Solar power is hitting new strides all over.

The Brookhaven Solar Farm in the making.
So we’ve got solar-powered cars coming along, solar-powered houses in the works, and now, a group of Australian engineers are aiming to create solar-powered soldiers

No, we’re not talking about cyborgs (Although, how cool would that be?  Someday!).  The idea is this: Soldiers out in the field carry around tons (well, pounds, at least) of equipment: radios, lights, etc., and all of this equipment is battery-operated, so each soldier is weighed down with battery packs.  In an attempt to lighten the load, a group at the Australian National University (ANU) has proposed using a special kind of small, lightweight solar panel.

Marvel's idea
of a solar-soldier.
Not quite what
ANU has in mind.
These unique solar panels are called Sliver cells.  Unlike the typical big bulky solar panel, Sliver cells come in the form of long silicon strips, incredibly thin (40-60 micrometers), and very flexible.  The first big advantage of these strips is that they use less silicon than a traditional solar cell, making them more cost-effective, and their small size and flexibility means they can be put to a long list of versatile uses.  This is where the solar-powered soldiers come in.  A collection of these strips placed onto the clothing and gear of a soldier can help power the soldier’s electronic equipment without the hassle of carrying around heavy battery packs.  The Sliver cell team is hoping to try out this technique in the next few years.  For a more detailed (and rather flashy) description of the Sliver cells, check out their flier.

Now, all these solar-powered innovations are great, but the long-standing problem in the field of solar energy is this: the sun only comes out during the day.  People need energy just as much (perhaps more) at night, when they need electricity to turn on the lights, cook dinner, and read awesome blogs on the internet.  So the ideal solar set-up would be having solar cells to absorb the energy during the day, and a battery to store and release the energy at night.  But that’s a lot of energy to store, and you’d need an enormous volume of battery to store it.  Not to mention that batteries wear down after a while, especially if they’re dealing with such massive quantities of energy. 

MIT's liquid battery.
But, as with all scientific and technological conundrums, all we need is time (although money is great, too).  A group at MIT has been working on a new fancy liquid battery.  It’s like a regular battery, except that the components inside of it are molten.  This has a handful of useful consequences: the materials needed to make it are cheap, it won't wear down quickly, and it can handle much higher electrical currents than traditional batteries.  The designers imagine using it to store large amounts of solar power or wind power during the times when the sun isn’t shining or the wind isn’t blowing.

How does it work?
  Ask the guy in the video.

For a long time, solar power has felt like a thing of the future, something we’re waiting for but not getting just yet.  But as we speak, a giant solar-powered boat is circumnavigating the Earth using only the power of the sun.  Seems to me the future is getting pretty close.

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