3 ms·

Also, conversion losses do matter, because a lot of efficiency calculations cheat by forgetting (or perhaps "forgetting") to include them, as a hidden form of e

Also, conversion losses do matter, because a lot of efficiency calculations cheat by forgetting (or perhaps "forgetting") to include them, as a hidden form of externalising energy costs. For example: > [If we compare] the thermal efficiencies from modern cooking stoves with those from stoves used in poorer households, we see that the improved biomass stoves in developing countries beat our "high-tech" cooking technology with a factor of two to three (graphic below). > The main discrepancy with these figures is caused when one doesn't take into account that electricity first needs to be produced in power plants which sometimes convert less than a third of the primary energy into electricity. This is not an issue with gas or biomass stoves, where a primary fuel is directly converted into heat for cooking. > Evidently, there is something wrong with the western approach to sustainability. Converting heat into electricity which is then converted back into heat, at 20-40% efficiency, is similar to building a Rube Goldberg machine; it's a needlessly complex operation compared to simply converting the primary fuel into heat to boil water. Essentially, any electric cooking device is an insult to the science of thermodynamics. http://www.lowtechmagazine.com/2014/06/thermal-efficiency-cooking-stoves.html http://www.lowtechmagazine.com/2014/06/thermal-efficiency-co... ... huh, I guess that's last sentence where I got my thermodynamics remark from.

Turing_Machine 9y ago
"Also, conversion losses do matter" Not when it comes to the fusion reactions occurring in the sun. Cooking stoves aren't really relevant here at all, but of course the reason we use these so-called "Rube Goldberg" methods is so that we don't have to go chop wood and then attempt to regulate the temperature of a wood-burning range. If you haven't done that, you (and the author of your linked article) should try it sometime. Hint: it's not easy. Both of my great-grandmothers could bake fancy cakes in a wood-burning oven, to take just one example, but that's a skill I will never have.
- vanderZwan 9y ago
  Are you wilfully trying to not see the point I'm making or something? Electric cooking is always sold as more energy efficient than the alternatives, while it turns out that gas is by far the most energy efficient option for Western cooking if you do the actual calculations. And you still don't have to chop your own wood that way. When it comes to growing corn: of all the sunlight that comes in, how much of that is converted into potential energy by growing corn? How much external energy and resources does it cost to grow corn otherwise? How much energy and resources does it cost to turn that corn into biofuel? By comparison, how much sunlight can be converted to electricity by photovoltaics? How much of that energy is lost when getting that electricity into an electric vehicle? How much extra overhead do the batteries have compared to fossil fuels due to extra weight, given their lower energy density? Those are all questions of conversion losses. If you honestly want to say that they are not, or that they don't matter, I would like to know why. Because I do not understand what the comparison with the Sun's generated energy has to do with anything.
  - Turing_Machine 9y ago
    "Are you wilfully trying to not see the point I'm making or something?" No, I'm pointing out that: 1) "Efficiency" isn't the only goal in life. It would be more "efficient" for the entire population to live in barracks and eat some kind of nutritional gruel for every meal, but few would choose to live that way. We do things "inefficiently" for our convenience and pleasure all the time, and there is nothing wrong with that. For instance, I'll bet you have your own computer rather than using a shared computer at the public library, even though that would be more "efficient". 2) It doesn't really matter how "efficient" the conversion of solar energy to carbohydrate is, because it's free. That matters for other energy inputs in the process (e.g., the gas burned in running tractors) but not the sun itself.
    - vanderZwan 9y ago
      > We do things "inefficiently" for our convenience and pleasure all the time, and there is nothing wrong with that It is when we are discussing the limits of sustainability and growth, and to deny that is the equivalent of sticking your head in the sand. If you prefer to not think about that and on a personal level keep up the American tradition of wasting tenfold more resources than the rest of the developed world for practically zero gain in quality of life, be my guest, but stay out of conversations about what method of energy production is and isn't sustainable > It doesn't really matter how "efficient" the conversion of solar energy to carbohydrate is, because it's free. You are so incredibly blatantly wrong here. It might be free in the sense that nobody owns the sun. It's not free in the sense that we have a limitless supply of it. In the latter sense, the thermodynamic sense[0], we have a limited amount of solar power to go around. Unless we ever figure out how to build Dyson spheres or something. Last century's advances are largely built on spending fossil fuels that were basically millions of years worth of stored solar energy, we can't keep wasting more of it forever. We're on a finite planet, with finite resources, including energy, and an increasing amount of people. [0] https://en.wikipedia.org/wiki/Thermodynamic_free_energy https://en.wikipedia.org/wiki/Thermodynamic_free_energy
      - Turing_Machine 9y ago

Turing_Machine 9y ago

"Also, conversion losses do matter" Not when it comes to the fusion reactions occurring in the sun. Cooking stoves aren't really relevant here at all, but of course the reason we use these so-called "Rube Goldberg" methods is so that we don't have to go chop wood and then attempt to regulate the temperature of a wood-burning range. If you haven't done that, you (and the author of your linked article) should try it sometime. Hint: it's not easy. Both of my great-grandmothers could bake fancy cakes in a wood-burning oven, to take just one example, but that's a skill I will never have.

vanderZwan 9y ago
Are you wilfully trying to not see the point I'm making or something? Electric cooking is always sold as more energy efficient than the alternatives, while it turns out that gas is by far the most energy efficient option for Western cooking if you do the actual calculations. And you still don't have to chop your own wood that way. When it comes to growing corn: of all the sunlight that comes in, how much of that is converted into potential energy by growing corn? How much external energy and resources does it cost to grow corn otherwise? How much energy and resources does it cost to turn that corn into biofuel? By comparison, how much sunlight can be converted to electricity by photovoltaics? How much of that energy is lost when getting that electricity into an electric vehicle? How much extra overhead do the batteries have compared to fossil fuels due to extra weight, given their lower energy density? Those are all questions of conversion losses. If you honestly want to say that they are not, or that they don't matter, I would like to know why. Because I do not understand what the comparison with the Sun's generated energy has to do with anything.
- Turing_Machine 9y ago
  "Are you wilfully trying to not see the point I'm making or something?" No, I'm pointing out that: 1) "Efficiency" isn't the only goal in life. It would be more "efficient" for the entire population to live in barracks and eat some kind of nutritional gruel for every meal, but few would choose to live that way. We do things "inefficiently" for our convenience and pleasure all the time, and there is nothing wrong with that. For instance, I'll bet you have your own computer rather than using a shared computer at the public library, even though that would be more "efficient". 2) It doesn't really matter how "efficient" the conversion of solar energy to carbohydrate is, because it's free. That matters for other energy inputs in the process (e.g., the gas burned in running tractors) but not the sun itself.
  - vanderZwan 9y ago
    > We do things "inefficiently" for our convenience and pleasure all the time, and there is nothing wrong with that It is when we are discussing the limits of sustainability and growth, and to deny that is the equivalent of sticking your head in the sand. If you prefer to not think about that and on a personal level keep up the American tradition of wasting tenfold more resources than the rest of the developed world for practically zero gain in quality of life, be my guest, but stay out of conversations about what method of energy production is and isn't sustainable > It doesn't really matter how "efficient" the conversion of solar energy to carbohydrate is, because it's free. You are so incredibly blatantly wrong here. It might be free in the sense that nobody owns the sun. It's not free in the sense that we have a limitless supply of it. In the latter sense, the thermodynamic sense[0], we have a limited amount of solar power to go around. Unless we ever figure out how to build Dyson spheres or something. Last century's advances are largely built on spending fossil fuels that were basically millions of years worth of stored solar energy, we can't keep wasting more of it forever. We're on a finite planet, with finite resources, including energy, and an increasing amount of people. [0] https://en.wikipedia.org/wiki/Thermodynamic_free_energy https://en.wikipedia.org/wiki/Thermodynamic_free_energy
    - Turing_Machine 9y ago