Comments on: An Absurd “Plan” http://academicvc.com/2009/10/25/an-absurd-vision/ Stephen Fleming's blog about academia, venture capital, and spaceships Fri, 23 Jul 2010 13:32:09 -0400 http://wordpress.org/?v=abc hourly 1 By: stephenfleming http://academicvc.com/2009/10/25/an-absurd-vision/comment-page-1/#comment-1336 stephenfleming Tue, 27 Oct 2009 20:49:08 +0000 http://academicvc.com/?p=1513#comment-1336 Donna -- it would be so pretty if that were true. Unfortunately, it's not. I recommend you take a look at my presentation on "The Hydrogen Myth" at http://www.stephenfleming.net/files/Fleming_HydrogenMythV5.pdf . Believe me, I would love to be looking forward to a hydrogen-powered future, but it's just not going to happen. Donna — it would be so pretty if that were true. Unfortunately, it’s not. I recommend you take a look at my presentation on “The Hydrogen Myth” at http://www.stephenfleming.net/files/Fleming_HydrogenMythV5.pdf .

Believe me, I would love to be looking forward to a hydrogen-powered future, but it’s just not going to happen.

]]> By: Donna Rennemo http://academicvc.com/2009/10/25/an-absurd-vision/comment-page-1/#comment-1335 Donna Rennemo Mon, 26 Oct 2009 18:57:06 +0000 http://academicvc.com/?p=1513#comment-1335 Hydrogen has tremendous potential to become the fuel ofthe future. It can be produced from viable and sustainable sources and can contribute to meeting the growth in global energy demand. Hydrogen power, the greenest of all energy sources, could be used to support transport, home, and business energy needs. Hydrogen has tremendous potential to become the fuel ofthe future. It can be produced from viable and sustainable sources and can contribute to meeting the growth in global energy demand. Hydrogen power, the greenest of all energy sources, could be used to support transport, home, and business energy needs.

]]> By: stephenfleming http://academicvc.com/2009/10/25/an-absurd-vision/comment-page-1/#comment-1334 stephenfleming Mon, 26 Oct 2009 15:02:00 +0000 http://academicvc.com/?p=1513#comment-1334 Jjpro -- thanks for commenting, but I disagree with you on every point. The gravimetric density is meaningless. What's important when designing a vehicle is the density PER LITER, not per kilogram. Liquid hydrogen is "fluffy." Indeed, there are more hydrogen atoms in a liter of gasoline than in a liter of liquid hydrogen! Hydrogen has been "the fuel of choice" for one very visible portion of the space program (Space Shuttle Main Engines)... arguably one of the least affordable mechanisms built in the history of mankind. Irrelevant for mass transportation needs (airliners, ships, locomotives). Denser fuels (alcohol, kerosene, solids) are increasingly more popular for space launchers. Nuclear waste isn't a problem if you reprocess. All of France (80% nuclear? that's from memory) generates a couple of cubic meters of nuclear waste per year. There's plenty of uranium in the ground... and, if not, we can build thorium reactors. And I'm allowed to call a plan "absurd" when it IS absurd. Which this one is. Misleadingly absurd, because it comes with the imprimatur of an occasionally-authoritative magazine. Jjpro — thanks for commenting, but I disagree with you on every point.

The gravimetric density is meaningless. What’s important when designing a vehicle is the density PER LITER, not per kilogram. Liquid hydrogen is “fluffy.” Indeed, there are more hydrogen atoms in a liter of gasoline than in a liter of liquid hydrogen!

Hydrogen has been “the fuel of choice” for one very visible portion of the space program (Space Shuttle Main Engines)… arguably one of the least affordable mechanisms built in the history of mankind. Irrelevant for mass transportation needs (airliners, ships, locomotives). Denser fuels (alcohol, kerosene, solids) are increasingly more popular for space launchers.

Nuclear waste isn’t a problem if you reprocess. All of France (80% nuclear? that’s from memory) generates a couple of cubic meters of nuclear waste per year.

There’s plenty of uranium in the ground… and, if not, we can build thorium reactors.

And I’m allowed to call a plan “absurd” when it IS absurd. Which this one is. Misleadingly absurd, because it comes with the imprimatur of an occasionally-authoritative magazine.

]]> By: jjpro http://academicvc.com/2009/10/25/an-absurd-vision/comment-page-1/#comment-1333 jjpro Mon, 26 Oct 2009 14:49:33 +0000 http://academicvc.com/?p=1513#comment-1333 The gravimetric density of hydrogen is over 3 times that of gasoline. That is why hydrogen is the fuel of choice for the space program. Nothing beats hydrogen when it comes to energy density on a per kg basis. You say that nuclear energy is clean, safe, and abundant. Well, the waste is neither clean nor safe, and uranium is not abundant. The Rocky Mountain Institute has a lot of good research on this. You shouldn't call a plan "absurd" just because it is optimistic. The gravimetric density of hydrogen is over 3 times that of gasoline. That is why hydrogen is the fuel of choice for the space program. Nothing beats hydrogen when it comes to energy density on a per kg basis.

You say that nuclear energy is clean, safe, and abundant. Well, the waste is neither clean nor safe, and uranium is not abundant. The Rocky Mountain Institute has a lot of good research on this.

You shouldn’t call a plan “absurd” just because it is optimistic.

]]> By: Twitted by StephenFleming http://academicvc.com/2009/10/25/an-absurd-vision/comment-page-1/#comment-1331 Twitted by StephenFleming Sun, 25 Oct 2009 19:05:20 +0000 http://academicvc.com/?p=1513#comment-1331 [...] This post was Twitted by StephenFleming [...] [...] This post was Twitted by StephenFleming [...]

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