Whorled View

June 24, 2007

Space-Based Solar Optics to Power and Protect Earth

Further brainstorming over a solar array / weapons defense system did produce one interesting possibility: a low-cost space-based mirror array for CSP (concentrated solar power). The idea seems silly at first glance because it seems far easier to place the optics on earth close to the energy converting apparatus – however some out-of-the-box thinking (as shown below) reveals that space-based optics could be far easier, cheaper, maintenance free, and effective than an earth-based solution (note that optics can be the biggest cost and maintenance for CSP):

1) Orbiting the earth are giant concave mirrors (parabolic in shape), each 7 square miles in area made from ultrathin reflective fabric (like mylar) stretched between 3 structural points (2 miles between each point in this example). Each mirror keeps its parabolic shape by solar wind. Secondary optics are also located at the focal point of the mirror and continually adjust to redirect the beam of concentrated light back to a receiving solar plant on the earth where the suns rays would be converted to usable energy.

Space Based Parabolic Reflective Fabric Mirrors
Above: a small section of a giant array of parabolic reflective fabric mirrors.

2) Innumerable additional 7 sq.mile mirrors can be simply added, each requiring only one additional structural point, 7 more square miles of reflective fabric, and optics at the focal point of each mirror to send the concentrated solar power to a receiving solar plant on earth.

3) The incoming solar power would be distributed among receiving solar plants strategically placed on earth, so each plant would receive the maximum amount of suns possible without damaging the energy conversion facilities. Maintenance could be performed on these earth-based solar plants at night.

The solar reflectors, being in the vacuum of space, would never require any kind of maintenance. Periodic adjustments can be made to keep them approximately facing the sun via temporarily collapsing one mirror to let solar wind push the array back into orientation. The focal point optics necessary to send each mirrors rays to the right location on earth would be powered by solar power of course.

Oh yeah, another thing … this can indeed also be used as an anti-missile defense system if multiple arrays are used, providing round-the-clock protection, while being tons cheaper than any other Star-Wars type technology. It overcomes all the problems of the Solar Missile Defense scenario posed below and has countless advantages.

Also, nighttime surveillance in other parts of the would could be as easy as turning on a light bulb, and can you imagine the psychological effect it could have on the enemy?

June 23, 2007

World largest Solar Array as Anti-missile Defense

Just now one of my neurons dedicated to solar power just misfired into the part of my brain reserved for missile defense technology and I had a Reese’s moment … why don’t we mix the two?!

Solar Two Heliostat Array
Solar Two facility in California

All the top scientists agree that the best renewable energy is CSP (concentrated solar power), and 100’s if not 1000’s of CSP plants need to be deployed if solar is to provide the bulk of our nation’s energy. Refocusing all 1 million mirrors on the incoming missile is just a matter of a million stepper motors and calibration (could periodically done with a satellite, one mirror at a time).

Another beautiful hypothesis destroyed by an ugly fact.

I’m certain that focusing the power of a million suns on a warhead will destroy the electronics within a few seconds rendering the missile useless.

Then the other neuron in my brain kicked in and reminded me that solar arrays only work 10 hours/day (oh yeah, duh!). Besides, due to the curvature of the earth it won’t work until the missiles are nearly in striking range (again, oh yeah, duh!).

Okay. Another beautiful hypothesis destroyed by an ugly fact. Make that 2 ugly facts. I’m sure I could think up some more ugly facts if given more time. Back to the drawing board. I suppose we could always use solar purely for the far less glitzy cause: saving the planet. Ho hum.

May 9, 2007

An More Inconvenient Truth

Filed under: ecology,economics,energy,environment,Politics — lullabyman @ 12:58 pm

I watched Mr “used to be president” Al Gore (as he likes to call himself) last night, as he spent over 90 minutes proclaiming the woes of global warming.

Hear! Hear!

At least there is something he and I can agree on. Then again, I can say that for most politicians.

If you haven’t seen it, please do. At some points the documentary becomes too much about him (like when he wallows in sorrow over his lost presidential election – here’s an incovenient truth: we’re sick of him whining about that), but those moments only last a few minutes here and there, and are worth bearing through in order to get to the other stuff.

“… he did a diservice to himself by not
being more forthright with truths
which are inconvenient to the global
warming hypothesis.

Here’s some other warnings: far too often he throws up graphs without giving you the scale of the y-axis, and sometimes the x-axis does not appear to be linear. The validity of data sources are also often taken for granted. Also statistical noise and data ranges is only mentioned in one of the many graphs he gives. Then there were the projections that were based on what – linear interpolation of that last few data points (shudder)? Who knows, he didn’t say. Lastly his time frames are often way too short – but then this can be attributed to a lack of data – nevertheless the results should be considered in reference to the entire epoch of sapient life. In short if you know much about statistics you might find it painful.

That said, I think he did a diservice to himself by not being more forthright with truths which are inconvenient to the global warming hypothesis. He’s a politician and in politics it does well to overstate your case and conveniently ignore unsupporting data, assuming your opponent will cover those things. In science, however, that’s not a good practice – as it seems to indicate a bias in the mind of the scientist which makes the audience more skeptical. One of the last things you want to say is that you bought into a theory before there was even sufficient statistical data or before you were able to investigate it independently – but that is exactly what Gore said he did. Gore said he was an instant advocate the moment he saw just one graph covering just a handful of years that a professor showed a class. Lucky for Gore that the professors hypothesis was right, but it did Gore a diservice when he admitted he was sold on so little data, and it does little to endear the trust of his audience.

“The more inconvenient truth is that
alternative industry funds
are controlled by lobbyists.
That’s wrong, and it’s killing the planet.”

I’m a skeptic of everything though (which has been known to bug those around me to no end), and even being the skeptic that I am, and knowing the critics response, I have always felt that prudence is the best policy for the health of the planet.

And that’s where I think this film fails the audience: encouraging implementation of the best policies. Recently we’ve seen the scientific community plead with the world to curb greenhouse gases, and nothing good has resulted. On the contrary, we’ve seen every alternative energy enteprenuer / company vying for more and more money with little regard from the governments where the best, cheapest, and fastest implementations exist. I mentioned this in my last post, but I could go so much further. The alternative industry funds are controlled by lobbyists. That’s wrong, and it’s killing the world. The money is not going to the right places and merely implementing policies to force capitalism to fix the problem isn’t good enough or quick enough.

Gore also failed to tell people enough on how to conserve: Quit buying gas guzzlers. Carpool whever you can. Shop locally, or online. Take a vacation this summer closeby instead of far away. When you buy a house live close to work – I’m convinced that one thing could cut our emissions in half. If you’re driving an hour to work each way then you’re driving too far – carpool with 2-3 others, move, or get a different job.

“The most inconvenient truth though
is that massive restructuring of our
energy economy is needed to save
the environment.”

The most inconvenient truth though is that massive restructuring of our energy economy is needed to save the environment. And not just us, but all other nations must do the same (oh, they talk the talk, but UN talk is incredibly cheap). It means politicians making unpopular decisions while in office. It means serious and pain inflicting government mandates, not to just automakers, but to power companies, and that will disrupt the economy and will result in many lost jobs.

On the otherhand there will be lots of new jobs building efficient solar-thermal plants (not solar-PV) in Nevada and new jobs building windfarms across the country. Or we quite possibly experience hell on earth. Hmmmm … what will it be?

May 2, 2007

The most viable energy solution

Filed under: ecology,economics,energy,environment,Miscellaneous,Politics — lullabyman @ 3:13 pm

Pundits everywhere are screaming we need to spend more money on alternative energy solutions, with little regard to what’s viable.

“Most of the proposed solutions to global warming that get serious attention employ technologies that continue to warm the planet at an alarming rate. Politicians also talk about the Hydrogen economy as if it’s a solution! It takes enormous energy to create hydrogen fuel.”

Wind, solar, geothermal, hydro, nuclear, and tidal are the only potentially saving solutions – but they’re too expensive, too difficult, or too restrictive. Or are they? Depends on how they’re done. My biggest bets are on wind and solar thermal (not the more popular solar-PV). Solar thermal, done right, seems to be the most immediately scalable, the cheapest, and the least restrictive.

Get used to seeing this.  It's the future.
The Parabolic Trough – the future of electricity.

I used to work in the solar-PV (PV = photovoltaic – the kind that go on your roof) industry – and let me tell you … what a boondoggle. All the research money goes to PV solar cells (which I used to make), instead of going to solar-thermal. The problem is – PV costs so much to make and takes so much time and space to purify the needed silicon, and the energy required to do so comes at such a high price as to make a mass adoption of the technology absolutely impossible for the next 100 years.  That isn’t to say it will always be that way … in fact there’s good reason to believe that PV will be the solution in 10-20 years because costs are going down fast.  But we need solutions NOW, not in 10 to 20 years.

Electricity generated from Solar-Thermal power fits that profile, it’s cheap easy and can supply the worlds needs at a ridiculously faster and more economical rate than PV with no technological bottlenecks. It’s simple too:

1) Cheap way: A parabolic trough concentrates sunlight onto a black pipe with circulating oil. More expensive: Parabolic Dish to focus on a single point for sterling engine use or to generate H2 for the hydrogen economy.  There are other focusing mechanisms too like fresnel (pronounced: freh-nail’ ) lenses, fresnel mirrors, but regardless of what mechanism used, it’s very cheap.

2) Thermal fluid expansion converts the thermal energy into physical energy to spin an electric generator. You can incidentally also skip the electric portion and directly spin a rotor to pump water, grind wheat, etc, instead of spinning an electric generator.

How it generates electricity

The largest solar-PV plant in the world generates only 12MW but by comparison the largest solar-thermal plant in the world generates 354MW (SEGS in Mojave Desert – uses cheap parabolic trough design) and it was built 20 years ago! That 20 times more!

And how many people even know about solar-thermal electricity? Squat (relatively speaking of course). There is at least 10 to 100 times more money spent on relatively worthless PV solar than what is spent on Thermal solar which is 10 to 100 times more promising for power plants.The current cost of electricity with solar-thermal is comparable to grid – about $0.10/KWh, but it is expected within the next 15-20 years that cost will drop to 1/2 if not 1/3 of regularly produced electricity ($0.035 /KWh)! How many plants are being built with this technology? Practically zippo (relatively speaking). See http://www.parc.xerox.com/research/publications/files/5706.pdf

So what do the cost numbers tell us? Scalability. Technologies can only be scaled up if they are very profitable. Solar Thermal is far more profitable than any other alternative energy candidate and will be for dozens of years . It doesn’t require exotic or highly refined or technologically advanced materials, and maintenance per MW is comparable to any coal powered plant. It seems a slam dunk, but instead solar-PV gets all the money despite that it’s only advantage is portability and distributed integration (solar thermal is largely a power-plant technology only).

“Solar Thermal Electricity is 10X more viable to fix our environment than Solar PV, but it gets less than 1/10th the grant and development money that solar PV gets. It’s an upside down pyramid.”

Now don’t get me wrong about solar PV. It isn’t a completely worthless technology, and eventually it will probably replace Solar-Thermal in terms of cost, maintenance, and expandability but none of the best experts see that happening any time soon and we can’t wait that long, but PV development is critical, which is why I still strongly support PV subsidies (not to mention that it’s needed to compensate for fossil fuel subsidies).

Europe's Pnergy Plan

Europe is already sold on parabolic trough technology (see the CSP plants above, concentrated solar power = trough technology), expecting it to play largest role in their future. The US on the other-hand is far more ideal for the technology (see world map above) and despite amazing success from the 20 yr old Mohave Desert plant solar trough implementation has approached a relative standstill since then. Solar troughs plants however have the potential to supply our continents electricity all from Nevada, and ultimately cost less than what we’re paying right now per kWh.

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