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We have a large and wonderful fusion reactor fully operational and running already, at a safe distance of 1.5e11 meters. All we have to do is harvest its energ

by mohawk 12y ago

We have a large and wonderful fusion reactor fully operational and running already, at a safe distance of 1.5e11 meters. All we have to do is harvest its energy output, with solar panels, windmills, or hydroelectric. The price of panels has been going down by 15% a year for the last couple of years. What's more likely, incremental improvements to solar panels and batteries that make them the cheapest energy source, or a breakthrough in nuclear fusion? My bet is on the small but steady improvements... I think fusion power is a useful thing to research though, in case the sky goes dark one day.

jimktrains2 12y ago
> I think fusion power is a useful thing to research though, in case the sky goes dark one day. "Someone started a war, and no one knows who, but it was known that it was mankind who blotted out the sky, attempting to deprive the machines of the solar power they required to function." or perhaps: Johann Johannsson - Sun's Gone Dim (https://www.youtube.com/watch?v=Iv4CuIIspdE https://www.youtube.com/watch?v=Iv4CuIIspdE) Moreover (and more seriously), though, fusion could be incredibly useful in terms of rocketry and power generation further out in the solar system.
- mohawk 12y ago
  In the long run, the sky going dark is not such an unlikely scenario. Big asteroid impact or a large volcanic eruption would be enough. Or some big war, sadly we tend to have them quite frequently. I forgot that was the background story to The Matrix... :-) I agree that fusion power would also be great for travelling into deep space. In the reeeally long run, there is no other choice for mankind.
nmeofthestate 12y ago
I think fusion power or nuclear in general is a vital area of research, given the massive problems we need to overcome for solar (or "solar-indirect") renewables to ever have a hope of sustaining civilisation as it is now.
- quonn 12y ago
  Solar power is making progress all the time, so I fail to see how there are "massive problems". In fact, it seems like the massive problems are with fusion - after decades of government-backed research and very little progress.
  - spot 12y ago
    how about it doesn't work at night?
    - a3n 12y ago
      There are other ways to get electricity at night or on dark days, including storage. Nothing has to be all or nothing.
gjm11 12y ago
> harvest its energy output At most pi r_earth^2 / (4 pi d_earth_sun^2) = 1/2billion of its energy output. Unless we build a Dyson sphere or something.
- mohawk 12y ago
  A pretty big number if you do the math. If you need more, sure, go for nuclear fusion. Until then, just remember slow and steady usually wins the race.
DennisP 12y ago
Doesn't the sky go dark every day? Energy storage at the scale that would be needed to run civilization on solar is a difficult problem. Tom Murphy's Do the Math blog has a lot of articles on how hard it would be to run civilization on renewables alone. For example: http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-battery/ http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-bat...
- digikata 12y ago
  In that article, Murphy calculates the difficulty of doing it with lead acid batteries which seems more of a strawman than a serious attempt to estimate requirements for a storage technology to match up to renewable power sources.
  - DennisP 12y ago
    He says he picked lead-acid because it's the cheapest and lead is relatively abundant. The situation isn't any better with other technologies. Even the new liquid-metal "grid-scale" batteries that have been in the news don't work out too well. A while back I ran the numbers to see; to run the world on them we'd need thousands of years' worth of our current annual production of the metals they use. Storage with hydro works pretty well but it's geographically limited. Murphy wrote another post on that. No way it can scale far enough. Storage at civilization scale is hard. I think we'll crack fusion first. If not that, then advanced fission (molten salt reactors, fast reactors).
    - mohawk 12y ago
      Nobody needs can't-do engineers. So he found out that lead-acid batteries aren't enough. 1) A fleet of electric/plug-in hybrid cars are a pretty big battery. Build more of those. 2) Power-to-gas seems like a good avenue, too. It also has an existing infrastructure. http://www.eon.com/en/media/news/press-releases/2014/9/1/eon-power-to-gas-pilot-unit-falkenhagen.html http://www.eon.com/en/media/news/press-releases/2014/9/1/eon... You can also generate methane instead of hydrogen. Not super-efficient at the moment, i know. But a solvable problem. But this article originally stated we would need fusion to be able to survive without conventional fuels. Solving the storage problem of renewables just seems so much easier than achieving nuclear fusion.

by mohawk 12y ago

jimktrains2 12y ago

> I think fusion power is a useful thing to research though, in case the sky goes dark one day. "Someone started a war, and no one knows who, but it was known that it was mankind who blotted out the sky, attempting to deprive the machines of the solar power they required to function." or perhaps: Johann Johannsson - Sun's Gone Dim (https://www.youtube.com/watch?v=Iv4CuIIspdE https://www.youtube.com/watch?v=Iv4CuIIspdE) Moreover (and more seriously), though, fusion could be incredibly useful in terms of rocketry and power generation further out in the solar system.

mohawk 12y ago
In the long run, the sky going dark is not such an unlikely scenario. Big asteroid impact or a large volcanic eruption would be enough. Or some big war, sadly we tend to have them quite frequently. I forgot that was the background story to The Matrix... :-) I agree that fusion power would also be great for travelling into deep space. In the reeeally long run, there is no other choice for mankind.

nmeofthestate 12y ago

I think fusion power or nuclear in general is a vital area of research, given the massive problems we need to overcome for solar (or "solar-indirect") renewables to ever have a hope of sustaining civilisation as it is now.

quonn 12y ago
Solar power is making progress all the time, so I fail to see how there are "massive problems". In fact, it seems like the massive problems are with fusion - after decades of government-backed research and very little progress.
- spot 12y ago
  how about it doesn't work at night?
  - a3n 12y ago
    There are other ways to get electricity at night or on dark days, including storage. Nothing has to be all or nothing.

gjm11 12y ago

> harvest its energy output At most pi r_earth^2 / (4 pi d_earth_sun^2) = 1/2billion of its energy output. Unless we build a Dyson sphere or something.

mohawk 12y ago
A pretty big number if you do the math. If you need more, sure, go for nuclear fusion. Until then, just remember slow and steady usually wins the race.

DennisP 12y ago

Doesn't the sky go dark every day? Energy storage at the scale that would be needed to run civilization on solar is a difficult problem. Tom Murphy's Do the Math blog has a lot of articles on how hard it would be to run civilization on renewables alone. For example: http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-battery/ http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-bat...

digikata 12y ago
In that article, Murphy calculates the difficulty of doing it with lead acid batteries which seems more of a strawman than a serious attempt to estimate requirements for a storage technology to match up to renewable power sources.
- DennisP 12y ago
  He says he picked lead-acid because it's the cheapest and lead is relatively abundant. The situation isn't any better with other technologies. Even the new liquid-metal "grid-scale" batteries that have been in the news don't work out too well. A while back I ran the numbers to see; to run the world on them we'd need thousands of years' worth of our current annual production of the metals they use. Storage with hydro works pretty well but it's geographically limited. Murphy wrote another post on that. No way it can scale far enough. Storage at civilization scale is hard. I think we'll crack fusion first. If not that, then advanced fission (molten salt reactors, fast reactors).
  - mohawk 12y ago
    Nobody needs can't-do engineers. So he found out that lead-acid batteries aren't enough. 1) A fleet of electric/plug-in hybrid cars are a pretty big battery. Build more of those. 2) Power-to-gas seems like a good avenue, too. It also has an existing infrastructure. http://www.eon.com/en/media/news/press-releases/2014/9/1/eon-power-to-gas-pilot-unit-falkenhagen.html http://www.eon.com/en/media/news/press-releases/2014/9/1/eon... You can also generate methane instead of hydrogen. Not super-efficient at the moment, i know. But a solvable problem. But this article originally stated we would need fusion to be able to survive without conventional fuels. Solving the storage problem of renewables just seems so much easier than achieving nuclear fusion.