James Bowery <jabow...@gmail.com> wrote:
> If you live in the desert southwest of the US, you would require an area > 500m^2 to gather enough insolation for one person -- and that's assuming > they are strict vegetarians. That's 0.1 acres. That is not enough to grow enough for one person. Not in an outdoor garden in Georgia or Pennsylvania. You can grow a surprising amount of food in that much space, but not enough for year-round sustenance, in my experience. With an indoor factory you can easily grow enough for several people in that amount of space. In my book, I looking into the numbers for the Cosmoplant food factory, which is now defunct. I was assisted by Prof. Takatsuji of Tokai U., who reviewed my numbers, so I think I got it right. See chapter 16. This factory used artificial lighting, not natural sunlight. This factory took up 0.01 ha and produced as much as a 20 ha outdoor farm, an improvement by a factor of 2,000. Food factories using sunlight are less efficient. Quoting myself: Despommier’s food factory designs would use mainly sunlight rather than artificial light, so they use far less energy than the Cosmoplant factory, but the crops do not grow at night, so production takes longer and the factories would not save as much space. Despommier estimates: “Year-round crop production; 1 indoor acre is equivalent to 4-6 outdoor acres or more, depending upon the crop (e.g., strawberries: 1 indoor acre = 30 outdoor acres),” whereas in the Cosmoplant factory, 1 indoor acre = 1,000 outdoor acres. (Should be "2,000 outdoor acres." Demonstrating once again that I cannot do simple arithmetic.) > The year-round insolation of places like Sweeden is less than half that > of the desert southwest US so it would be more like 1000m^2. Sweden is a net exporter of agricultural products. Evidently they have plenty of sunlight. Only 7% of the land is used for farming. - Jed
