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#11
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New House Thermal
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#12
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New House Thermal
Le mardi 27 juin 2017 07:02:56 UTC+2, a écritÂ*:
No. Only a miniscule amount of the sunlight is turned into electricity. At this level, (electricity out / total solar energy in) the efficiency of PV panels is *buggerall*. The solar farm will probably not only not produce thermals, it will increase your energy costs. Shift to France where they have cheap nuclear AND you can go gliding in the alps! Well, physics doesn't seem to be part of your world. Today's photovoltaic solar panels run at an efficiency of about 20%. The definition of efficiency is electric power produced, divided by incident solar power. These 20% of the incident solar power are not available for heating. And if you call nuclear power "cheap", economics does seem to bother you either... As for the French Alps (where you see solar farms popping up everywhere) - that's where I fly most of the time. |
#13
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New House Thermal
On Tue, 27 Jun 2017 02:11:21 -0700, Tango Whisky wrote:
Well, physics doesn't seem to be part of your world. Today's photovoltaic solar panels run at an efficiency of about 20%. The definition of efficiency is electric power produced, divided by incident solar power. These 20% of the incident solar power are not available for heating. Indeed. There's a smallish solar panel farm installed across the road from where I fly. I haven't noticed any thermals (or Cu forming) above it. OTOH many years ago I got a 600 ft climb late in a cloudy, still, summer afternoon from a stationary 100m diameter patch of sunlight on an otherwise shaded ploughed field. That was in an SZD Junior. -- martin@ | Martin Gregorie gregorie. | Essex, UK org | |
#14
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New House Thermal
On 27/06/2017 19:11, Tango Whisky wrote:
Le mardi 27 juin 2017 07:02:56 UTC+2, a écrit : No. Only a miniscule amount of the sunlight is turned into electricity. At this level, (electricity out / total solar energy in) the efficiency of PV panels is *buggerall*. The solar farm will probably not only not produce thermals, it will increase your energy costs. Shift to France where they have cheap nuclear AND you can go gliding in the alps! Well, physics doesn't seem to be part of your world. Today's photovoltaic solar panels run at an efficiency of about 20%. The definition of efficiency is electric power produced, divided by incident solar power. These 20% of the incident solar power are not available for heating. And if you call nuclear power "cheap", economics does seem to bother you either... As for the French Alps (where you see solar farms popping up everywhere) - that's where I fly most of the time. Physics and economics are both a good part of my world. You're just sniffy because I see it differently from you. Efficiency from solar panels is actually about 15-16% at best and when new. And of course it's hard to keep those panels facing the sun the whole 24 hours and the output is also *buggerall* in a lot of places for half the year as well. Overall? *Miniscule* is a good word. Where your physics - and economics - fall apart is when seeing in the dark and not freezing at night is factored in. Then the coal or oil fired power stations - which would be both cheap and bloody efficient during the day as well - really come into their own and make it clear that the PV panels are a just a first world sop to a warped sense of morality, defective understanding of atmospheric science and gullibility in the face of mass media hype... ....and yes, I know they're popping up all over, but lots of people being stupid doesn't lessen the degree of each one's stupidity. -- GC |
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New House Thermal
Le mardi 27 juin 2017 13:33:56 UTC+2, a écritÂ*:
On 27/06/2017 19:11, Tango Whisky wrote: Le mardi 27 juin 2017 07:02:56 UTC+2, a écrit : No. Only a miniscule amount of the sunlight is turned into electricity. At this level, (electricity out / total solar energy in) the efficiency of PV panels is *buggerall*. The solar farm will probably not only not produce thermals, it will increase your energy costs. Shift to France where they have cheap nuclear AND you can go gliding in the alps! Well, physics doesn't seem to be part of your world. Today's photovoltaic solar panels run at an efficiency of about 20%. The definition of efficiency is electric power produced, divided by incident solar power. These 20% of the incident solar power are not available for heating. And if you call nuclear power "cheap", economics does seem to bother you either... As for the French Alps (where you see solar farms popping up everywhere) - that's where I fly most of the time. Physics and economics are both a good part of my world. You're just sniffy because I see it differently from you. Efficiency from solar panels is actually about 15-16% at best and when new. And of course it's hard to keep those panels facing the sun the whole 24 hours and the output is also *buggerall* in a lot of places for half the year as well. Overall? *Miniscule* is a good word. Where your physics - and economics - fall apart is when seeing in the dark and not freezing at night is factored in. Then the coal or oil fired power stations - which would be both cheap and bloody efficient during the day as well - really come into their own and make it clear that the PV panels are a just a first world sop to a warped sense of morality, defective understanding of atmospheric science and gullibility in the face of mass media hype... ...and yes, I know they're popping up all over, but lots of people being stupid doesn't lessen the degree of each one's stupidity. -- GC It seems that you don't really get it, but that's actually not my problem. Just go ahead and enjoy all those PV thermals ;-) And no, I'm not necessarily promoting PV energy, I just stated that nuclear energy is not cheap at all. End of discussion for me. Bert TW |
#16
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New House Thermal
Rainy day mental exercise...
Calculate the mass of a thermal. Calculate the heat capacity of a thermal. Calculate the energy input required to heat the thermal some small amount for buoyancy, say 2 deg C. Compare to the heat output of terrestrial sources. A Nuc powerplant is typically a few GW (thermal). Most other anthropogenic sources are smaller. Sit back in awe and ponder the wonders of nature. I'm a big fan of gravitationally confined fusion power. -Evan Ludeman / T8 |
#17
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New House Thermal
OK - back to the subject at hand (solar farms as thermal generators). I'm not an engineer or physicist but I suspect that part of the consideration is the mass of the structure and it's ability to hold enough heat to effectively transfer it to the air around it. So plowed fields, rock faces on mountains, and heavy metal silos do well to form thermals. But the light weight frames that hold the solar panels don't hold the heat well - and they shade the ground below them. And despite what people think they "should' do - they really don't generate thermals very well.
ROY |
#19
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New House Thermal
Question: How much energy does it take to produce a solar array (Aluminum mining, refining, manufacture, Silicon panel manufacture, etc.)? How does it compare to the energy output of the array over its life?
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#20
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New House Thermal
Question: Does the previous question add anything to the discussion on solar farms creating thermals? There has to be a forum out there that is better suited for environmental debates. Let's focus on soaring.
I routinely fly high over the Florida Power & Light solar farm near the northeast side of Lake Okeechobee. Occasionally, there are pronounced markers indicating a thermal is cooking off the panels. It's a smaller solar farm, so I'm really eager to see what the mega-solar farm does for us. Paul A. |
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