3 ms·

I originally argued against the statement that we will have a "lower energy budget" in 90 years. In short, I am arguing about developments that will come home

• rbanffy 17y ago
  I originally argued against the statement that we will have a "lower energy budget" in 90 years. Given increasing population, how much more energy do you expect to be able to use? While true we may be able to increase our energy usage, I doubt most of mankind will be able to use as much as we do. Also, do you realize how much effort (and energy expenditure) would it be to manufacture 10 square meters for every human being alive? Count 10 billion people - that's 100 billion square meters, not counting replacing damaged solar cells. Nuclear fission is also a point that could be much improved, but it is pretty much a dead end unless we discover some new laws of physics. Nuclear facilities are horrendously expensive to build and to safely manage. There are safer designs, but how much safe is safe in a world you have to guard nuclear fuel (and waste) and keep if from people who are willing to blow themselves up? As for fusion, you could add the chances of success if they were completely different approaches, but they are not. Also, giving them even a 10% chance of success is very optimistic. There is no reason to panic, but there is reason to proceed carefully and think through what we are doing and what we are going to do.
  • berntb 17y ago
    >>Also, do you realize how much effort (and energy expenditure) would it be to manufacture 10 square meters for every human being alive? Please think before writing. Even today, much less energy is used making solar cells than they create... For material, the latest thin film is not a heavy weight per square meter... (also a hint, we're not running out of silicon for glass...). In fact, this would take very little resources compared to what a person need to live. If you want to make a coherent point, you'd note that my "energy budget" didn't include transportation or industry. We can apply all the clean energy sources we will have in twenty years, for that. Note that I'm just arguing known sources in one-two decades, assuming the remaining decades are without developments! And you can't answer even that. Let us assume space based solar in twenty years... 90? I can't even guess. http://www.npr.org/templates/story/story.php?storyId=121531373 http://www.npr.org/templates/story/story.php?storyId=1215313... Did you have any counter arguments against Thorium reactors? Or you're silent because you lack arguments? >>100 billion square meters [is a lot of area, sic] You must be unique on this site to never have thought about how many square meters go into a square km. :-) 10 km X 10 km == 100 million square meters. Enough to give 10 square meter to 10 million people, a BIG city. Go check a map, that area is less than the area of the roofs of such a city... (Most people will live in cities, it seems.) Enough of the pre-high school math lesson... >>As for fusion, you could add the chances of success if they were completely different approaches, but they are not. I don't think you know what you're talking about. Please explain how a known success/failure of one of the three projects I mentioned would influence the likelihood of the others? I can honestly not see how you could argue that. I am sorry, but I wonder if you're a troll. I can't be bothered with the rest.
    • rbanffy 17y ago
      Thorium produced in breeder reactors are object of research for many decades, but very few (if any) commercial examples exist. I remember something out of India, but I am not quite sure. There has been some movement around them in China lately, IIRC, but it must be something on a tech demonstration level or we would all be hearing a lot about it. I believe that when someone pull this off, they will brag about it all over the media. The General Fusion, TriAlpha and Polywell are all a bit far-fetched. GF's thingie has a couple practical problems, like, for instance, extracting tritium from their liquid lead-lithium mix. There are a lot of problems with liquid-metal heat exchange itself, specially on a scale like the one they propose. Radioactive liquid alkali metal exchangers elevate the NIMBY complains to a whole new level. I would give them a 1%. The TriAlpha approach requires higher temperatures than Hydrogen-Deuterium fusion. I would give it about 0.5% chance of success in the next 100 years. If the conditions the GF machine are to operate can be called extreme, I lack superlatives to name what happens inside a Tri Alpha device. As for Polywell... I am an optimist. I would give them a 5% chance. There are some issues on the geometry of the fields (they had some leaks in the "corners") but I expect them to improve steadily enough for sustained operation. But we are not aiming at technology demonstrators running sustainable reactions. We are aiming at commercial production on megawatt-scale generators. It's not just rescaling your AutoCAD model, even if you don't consider your whole supply chain. As for solar, you seriously propose replacing the roofs of every home in the planet with solar panels. I live in an apartment, on a 50's building that's not very tall. There are 40 people living in the same building that has about 200 m2 of roof. That's 4 square meters per person on a not very dense arrangement. It's one of the least dense blocks in my region. Most of my friends live on 1 square-meter of roof per person or less zones (taller, newer buildings). This math will hardly work out. As it is, we have a pretty green energy matrix - mostly hydro. Even our cars run on sugarcane ethanol, but, still, ethanol production takes up a lot of land that could be used to grow food and that may be needed for that if the climate goes south and agriculture takes a hit. You are more optimistic than I am. Things change, but they change slowly. Unless there is a huge political drive behind this, I don't believe we will see much of it before it's too late. We need politicians who can focus on periods longer than their terms. I am not sure where to find them.