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# Experiments in food return on energy invested

I'm starting a page Experiments in food return on energy invested. For now it's just an uninteresting stub (though positive comments are welcome) but hopefully it will become something useful.

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1.

I changed the title to make only the first word capitalized.

When you say present-day FROEIs are 10:1, I guess you mean 10 calories of energy are expended to create one calorie of food energy? It might be good to make that clear, though it's obvious with a bit of thought.

Comment Source:I changed the title to make only the first word capitalized. When you say present-day FROEIs are 10:1, I guess you mean 10 calories of energy are expended to create one calorie of food energy? It might be good to make that clear, though it's obvious with a bit of thought.
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edited May 2011

[Wrong stuff deleted]

Comment Source:[Wrong stuff deleted]
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3.

John said:

When you say present-day FROEIs are 10:1 [...] It might be good to make that clear

yes, I'll certainly do that. I haven't done anything in the last days, but I intend to work on it.

Btw, I now think a large part of the 10:1 is due to processing of food (it seems so, based on a graph in one of the references) so I think ti would make sense to partition the FROEI in three parts, to allow for better historical comparison:

• how much energy is needed to grow the food

• how much energy is used to transport, process etc the food (during the chain from farmer to consumer)

• how much energy does the consumer spend (cooking etc)

I suppose the cooking (burning wood) is what makes the FROEI go up to 1:1 for early farmers, but I'll check.

Comment Source:John said: > When you say present-day FROEIs are 10:1 [...] It might be good to make that clear yes, I'll certainly do that. I haven't done anything in the last days, but I intend to work on it. Btw, I now think a large part of the 10:1 is due to processing of food (it seems so, based on a graph in one of the references) so I think ti would make sense to partition the FROEI in three parts, to allow for better historical comparison: - how much energy is needed to grow the food - how much energy is used to transport, process etc the food (during the chain from farmer to consumer) - how much energy does the consumer spend (cooking etc) I suppose the cooking (burning wood) is what makes the FROEI go up to 1:1 for early farmers, but I'll check.
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Whenever I cook food on a gas stove I think about how much heat energy goes into the air instead of into the food, and burning wood in a primitive setup seems just as inefficient or even worse. I may be wrong but I imagine that in a microwave oven a much greater proportion of the energy goes into actually heating the food.

Comment Source:Whenever I cook food on a gas stove I think about how much heat energy goes into the air instead of into the food, and burning wood in a primitive setup seems just as inefficient or even worse. I may be wrong but I imagine that in a microwave oven a much greater proportion of the energy goes into actually heating the food.
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5.
edited June 2011

David MacKay has written about some ways to heat water for pasta. This appears limited to cooking that works via immersion in fully boiling water of course; when the water is in the food it may well be different.

Comment Source:David MacKay has [written about some ways to heat water for pasta](http://withouthotair.blogspot.com/2009/11/how-to-boil-water-sequel.html). This appears limited to cooking that works via immersion in fully boiling water of course; when the water is in the food it may well be different.
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MacKay is great. I'm saddened to hear that a microwave oven is a hopelessly inefficient way to boil water for pasta, and amazed that apparently all the wasted energy goes into heating the "internal organs" of the microwave oven.

There should be a way to cook pasta, or beans, where you heat the water and food to boiling and then, thanks to a heavily insulated container, only need to administer a tiny amount of extra heat to keep it all at that temperature.

This would be more useful for something like beans, which take a long time to cook.

Comment Source:MacKay is great. I'm saddened to hear that a microwave oven is a hopelessly inefficient way to boil water for pasta, and amazed that apparently all the wasted energy goes into heating the "internal organs" of the microwave oven. There should be a way to cook pasta, or beans, where you heat the water and food to boiling and then, thanks to a heavily insulated container, only need to administer a tiny amount of extra heat to keep it all at that temperature. This would be more useful for something like beans, which take a long time to cook.
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7.

What about a high-pressure kettle? (More as a reminder for myself, I'll look it up because it fits in the content of this experimental page)

For heating already cooked food a microwave oven is still the best, I thought.

I also found higher figures for boiling water with the lid on, up till 15 % energy is saved.

Comment Source:What about a high-pressure kettle? (More as a reminder for myself, I'll look it up because it fits in the content of this experimental page) For heating already cooked food a microwave oven is still the best, I thought. I also found higher figures for boiling water with the lid on, up till 15 % energy is saved.