Hi Hakan & Joe, Hakan, where do you find 5-7 kwm^-2 for solar incoming energy? That seems a bit high - Joe's figure seems closer.
The CRC Handbook of Chemistry and Physics gives a solar constant of 1.34kwm^-2, which for N. Lat. 40deg corrects to a ground surface solar energy input of about 0.7kwm^-2, if one averages for the earth's inclination at summer and winter solstices. Of course a tracking collector would collect the entire 1.34kwm^-2 on a clear cloudless day regardless of one's latitude, but here we're talking about photons heating grains of sand so the ground surface figure is the correct one. I'm with you on the hang glider advice :-). Joe, I'm not enough of an atmospheric expert to answer whether your last suggestion would improve or worsen things in earth's weather patterns. The Principle of Unintended Effects would make me hesitant to go that route, though. I would love to use Kim's sig of "Bright Blessings", but she's earned that one, so I'll just say Cheers to all, Bob (the one in West Linn, OR) ----- Original Message ----- nFrom: "Hakan Falk" <[EMAIL PROTECTED]> To: <Biofuel@sustainablelists.org> Sent: Wednesday, August 31, 2005 4:03 PM Subject: Re: [Biofuel] Solar panals or wind > > Joe, > > Depends on where you are. Incoming yearly average in northern US is 5-6 > kW/m2. > > I would not fly any hang glider in 100 feet per minute, because you > will end up at top of a thunderstorm and come back down as an ice > block. It has happened more than once by happy people who did not > study hang gliding properly. Do not do it!!!! > > Global warming is caused by higher absorption of the Earth and Air > pollution that stops the reflection to escape. By capturing energy, > to transform and use it in other ways, maybe the Global warming would > be reduced, but it must be in a massive scale. I do not think solar > capture have any weather effects even on very large scale. Our > changes to the Earth surface and air, have many times larger effect. > > Hakan > > At 19:30 31/08/2005, you wrote: >> As a further note to the discussion of high efficiency solar >> arrays a question occured to me. The average incoming radiation >> from the sun is something like 1Kw /sq.m >>This is a substantial amount of energy and much of it goes into >>heating up a shallow layer of the surface and much gets re-radiated >>back to the air as longwave radiation or heat not just during the >>day but at night as well. Anyone who doubts the amount of solar >>energy re-radiated to the atmosphere needs only to consider a >>towering cumulonimbus cloud or better yet to get a real up close and >>personal gut feel for that energy take up the sport of hang gliding >>and experience what it is like being yanked skyward at over 1000 >>feet per minute by convective air currents generated by this solar energy. >> Supposing that some dirt cheap mass production technique allows >> us to produce rolls and rolls of film with very high efficiency >> organic solar cells one day. This technology could solve one of >> our needs in terms of energy generation and would allow >> unprecedented growth resulting in an ever increasing percentage of >> the earth's surface being covered up by solar arrays. Assume for >> the moment that these arrays are 90%efficient. Now granted that >> the energy collected in this way would be used in processes that >> have their own efficiency numbers and some energy would always be >> lost as waste heat but since we are always striving towards higher >> efficiencies in all processes, assume as well that these energy >> consuming processes are quite efficient and that therefore only a >> small amount of this energy is released back into the environment >> as waste heat. What effect could this have on the weather? >> >>Joe >> >> >>des wrote: >>> >>>Garth & Kim Travis wrote: >>> >>> >>>> >>>>Greetings, >>>> >>>>I am a fan of using solar collectors to fire a stirling engine that >>>>can also be fired with methane. Small solar panels for stuff that is >>>>used primarily in the daytime, wind power that can be home repaired. >>>>And the generator that is fire by the stirling can be run off the pto >>>>of the tractor on biodiesel, or from a tire of the car. Lots of >>>>overlap and back up. If one part of the system malfunctions, the meat >>>>in the freezer does not thaw. I have yet to figure out how to put a >>>>1/4 of a cow in there at a time.<grin> >>>>Bright Blessings, >>>>Kim >>>> >>>> >>> >>>A system I've been working on, and redesigning throughout the years is >>>going more toward solar heat. A solar concentrator, (reads: recycled >>>10' diameter satellite dish covered with little squares of mirror >>>salvaged from the glass shop's dumpster) and a Stirling engine are >>>integral, the engine integrating the conversion from solar heat to >>>electricity, but then the question arose, "do I really want to be >>>dependent on a system that stores its power in batteries?" So the >>>system has shifted to collecting heat, and storing that. Then, draw >>>from that, the energy I need for electricity, and still have heat for >>>water, or home space. And on a medium cloud cover, I can still focus >>>infrared rays and collect heat. Solar panels tend to do less well with >>>clouds. >>> >>>doug swanson >>> >>> >>_______________________________________________ >>Biofuel mailing list >>Biofuel@sustainablelists.org >>http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org >> >>Biofuel at Journey to Forever: >>http://journeytoforever.org/biofuel.html >> >>Search the combined Biofuel and Biofuels-biz list archives (50,000 >>messages): >>http://www.mail-archive.com/biofuel@sustainablelists.org/ > > > > _______________________________________________ > Biofuel mailing list > Biofuel@sustainablelists.org > http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org > > Biofuel at Journey to Forever: > http://journeytoforever.org/biofuel.html > > Search the combined Biofuel and Biofuels-biz list archives (50,000 > messages): > http://www.mail-archive.com/biofuel@sustainablelists.org/ > > _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
