Photosynthesis is actually a fairly inefficient process. 20GWh of sunlight on a hectare of land over a year might yield 30MWh of Wheat (8,000kg).
But if we have cheap power we can make a reasonable proportion of animal feeds from CO2 and Water using chemical processing (simple glycerol, triglycerides) with relatively high efficiency and low costs. We can then breed algae and animals to make better use of those artificial foods to make oils, meat, possibly eggs and diary products for us to eat (fish like salmon are already very efficient converters - 1.1kg feed per kg of fish) while using far less agricultural input. This would probably make a lot of well-fed westerners very angry, but would be a nice way to reduce human population pressures on the world. On 19 February 2012 15:54, James Bowery <jabow...@gmail.com> wrote: > Humans burn calories at a rate greater than 100W. Photosynthesis, in the > best conditions (algae) converts only about 6% of insolation to biomass. > The plants typically used in vertical gardening are more like 1% efficient > at generating biomass, and of that biomass only about 20% is actually > edible calories. 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. 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. Remember that is 1000m^2 per person of > south-facing window, and we haven't even started on protein requirements > for non-vegetarian diets. > > On Sun, Feb 19, 2012 at 6:21 AM, Jouni Valkonen > <jounivalko...@gmail.com>wrote: > >> Hello, >> >> First multistory vertical farm is being build into Linköping! It has in >> sun facing side a vertical farm and dark side is for offices. This is the >> way to go! Vertical farms may be initially costly, but they will get >> eventually cheaper, when technology evolves. >> >> Imagine this map to be wholly green: >> http://en.wikipedia.org/wiki/File:Europe_land_use_map.png >> >> I hope that this full scale pilot project will open people's eyes for the >> future technological possibilities. >> >> –Jouni >> >> >> Växthuset skjuter i höjden >> http://www.nyteknik.se/nyheter/bygg/byggartiklar/article3406014.ece >> >> >> Google translated version: >> >> Greenhouse soar >> >> By: Charlotta von >> Schultz<http://translate.googleusercontent.com/translate_c?hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=sv&tl=en&twu=1&u=http://www.nyteknik.se/ovrigt/redaktionen/charlotta_von_schultz/&usg=ALkJrhh3ZCJgH1HcDaFm6hr9Z9_SFlRAaA> >> >> Published February 10, 2012 14:5545 >> comments<http://translate.googleusercontent.com/translate_c?hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=sv&tl=en&twu=1&u=http://www.nyteknik.se/nyheter/bygg/byggartiklar/article3406014.ece&usg=ALkJrhiNU2eWWWC5lebMRxqqSRuLB-Vp7A#comments> >> <http://translate.googleusercontent.com/translate_c?hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=sv&tl=en&twu=1&u=http://www.nyteknik.se/nyheter/bygg/byggartiklar/article3406014.ece&usg=ALkJrhiNU2eWWWC5lebMRxqqSRuLB-Vp7A#latest-comment> >> >> *Locally grown vegetables are reaching new heights. Now we build a 54 >> meter high greenhouse in Linköping.* >> >> http://translate.google.com/translate?sl=sv&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwww.nyteknik.se%2Fnyheter%2Fbygg%2Fbyggartiklar%2Farticle3406014.ece >> > >
