Global warming?
in [Design]
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From: dagmargoodboat on 13 Jan 2010 23:36 On Jan 13, 10:18 pm, "JosephKK" wrote: > On Wed, 13 Jan 2010 13:59:40 -0500, Phil Hobbs wrote: > >On 1/13/2010 12:42 AM, JosephKK wrote: > >> Rough cut, solar cell efficiency 15%, 93 W/ft^2. 2000 ft^2 house, 1/3 of > >> roof with solar cells (won't be over 1/2 without special design). 666 ft^2 > >> * 92 W/ft^2 * .15 = 9 kW max peak. Over one days time averaged over a year > >> ~= .636 * 1/2 * 9 kW ~= 3 kWh per day. Falls a bit short. But enough to > >> noticeably help. > > >That's quite optimistic. A good rule of thumb for average power/peak > >power over a year is 1/6, even for tracking collectors. > > > Thanks for touching up my rough cuts. I knew there were a bit optimistic. > For real fun, try designing the electronics that feed the solar power back to > the grid safely. It would have to be in phase and very low harmonics, handle > peak power and marginal source power, and disconnect rather completely overnight. But your estimate assumes only one hour a day. Don Lancaster says mean output's roughly as 5 hours of peak output daily. So, 5 hours x 9 kW = 40 kWh/day. Caveats: That's about $50k worth of solar stuff, pre- green-graft. DL's "5 hours per 24" rule might be for his home base, Arizona! Efficiency's more like 10-12% ain't it? Rooftop, your panels won't be broadside to the sun. Cut output accordingly. Clouds? They're killers. My panel puts out 2-5% on cloudy days. -- Cheers, James Arthur
From: dagmargoodboat on 13 Jan 2010 23:58 On Jan 8, 8:57 pm, Bill Sloman <bill.slo...(a)ieee.org> wrote: > On Jan 8, 10:56 pm, dagmargoodb...(a)yahoo.com wrote: > > > On Jan 8, 7:02 am,Bill Sloman<bill.slo...(a)ieee.org> wrote: > > > > On Jan 8, 1:32 am, John Larkin wrote: > > > > On Thu, 7 Jan 2010 15:25:39 -0800 (PST), dagmargoodb...(a)yahoo.com > > > > wrote: > > > > >Not to worry, we're still doomed: > > > > > http://abcnews.go.com/Technology/wireStory?id=9495864 > > > > > Another Ice Age would be "just a blip in the long-term heating trend." > > > > I think you are letting your over-fertile imagination run away here. > > > > > Just keep extending the definition of "weather" and "climate" as suits > > > > your political needs. > > > > The way you do? You and James Arthur do seem enthusiastic about > > > confusing weather models > > > You're confused--you invented that. > > > > (which are susceptible to the butterfly > > > effect) and climate models (which are deliberately onstructed so that > > > they aren't). > > > What construction, and how does it guarantee that? Diagrams, please. > > Ask your own tame expert. You won't understand her answer, but if she > is any good she should be able to give you a better answer than I > could, and with a lot less effort. My "tame expert" contradicts you, so I wondered what you know that (s) he doesn't. I understand how the GCM are built--FEA applied to cell models, iterated. How does that prime example of sensitive dependence on initial conditions(*) avoid such dependence? (*) (Chaos theory started when someone noticed that, in weather simulations, differences in floating point rounding accumulated to where they flipped the forecasts inside out when the same programs were run on different computers.) -- Cheers, James Arthur
From: Bill Sloman on 15 Jan 2010 00:35 On Jan 14, 5:58 am, dagmargoodb...(a)yahoo.com wrote: > On Jan 8, 8:57 pm,Bill Sloman<bill.slo...(a)ieee.org> wrote: > > > On Jan 8, 10:56 pm, dagmargoodb...(a)yahoo.com wrote: > > > > On Jan 8, 7:02 am,Bill Sloman<bill.slo...(a)ieee.org> wrote: > > > > > On Jan 8, 1:32 am, John Larkin wrote: > > > > > On Thu, 7 Jan 2010 15:25:39 -0800 (PST), dagmargoodb...(a)yahoo.com > > > > > wrote: > > > > > >Not to worry, we're still doomed: > > > > > > http://abcnews.go.com/Technology/wireStory?id=9495864 > > > > > > Another Ice Age would be "just a blip in the long-term heating trend." > > > > > I think you are letting your over-fertile imagination run away here.. > > > > > > Just keep extending the definition of "weather" and "climate" as suits > > > > > your political needs. > > > > > The way you do? You and James Arthur do seem enthusiastic about > > > > confusing weather models > > > > You're confused--you invented that. Nice try. I'm nowhere near confused enough to believe that particular lie. > > > > (which are susceptible to the butterfly > > > > effect) and climate models (which are deliberately onstructed so that > > > > they aren't). > > > > What construction, and how does it guarantee that? Diagrams, please. > > > Ask your own tame expert. You won't understand her answer, but if she > > is any good she should be able to give you a better answer than I > > could, and with a lot less effort. > > My "tame expert" contradicts you, so I wondered what you know that (s) > he doesn't. > > I understand how the GCM are built--FEA applied to cell models, > iterated. > > How does that prime example of sensitive dependence on initial > conditions(*) avoid such dependence? > > (*) (Chaos theory started when someone noticed that, in weather > simulations, differences in floating point rounding accumulated to > where they flipped the forecasts inside out when the same programs > were run on different computers.) Find an expert who knows what they are talking about, and ask them, and save the folk-mathematics for an audience that is dim enough to swallow it. Wikipedia credits Henri Poincaré with the discovery of mathematical chaos, back in the 1880s, when he was working on the three-body problem in orbital dynamics. Edward Lorenz's work on weather prediction came a lot later, in 1961. In the meantime, if you actually do want to find out how climate models differ from weather models, here is a good place to start doing a bit of reading. http://www.aip.org/history/climate/GCM.htm Von Neumann seesm to have found an answer that satisfied him. No doubt you are going to tell us that your tame expert has proved von Neumann wrong - s/he does seem to provide you with a lot of convenient, if implausible, information. -- Bill Sloman, Nijmegen
From: JosephKK on 15 Jan 2010 01:18 On Wed, 13 Jan 2010 20:36:39 -0800 (PST), dagmargoodboat(a)yahoo.com wrote: >On Jan 13, 10:18 pm, "JosephKK" wrote: >> On Wed, 13 Jan 2010 13:59:40 -0500, Phil Hobbs wrote: >> >On 1/13/2010 12:42 AM, JosephKK wrote: > >> >> Rough cut, solar cell efficiency 15%, 93 W/ft^2. 2000 ft^2 house, 1/3 of >> >> roof with solar cells (won't be over 1/2 without special design). 666 ft^2 >> >> * 92 W/ft^2 * .15 = 9 kW max peak. Over one days time averaged over a year >> >> ~= .636 * 1/2 * 9 kW ~= 3 kWh per day. Falls a bit short. But enough to >> >> noticeably help. >> >> >That's quite optimistic. A good rule of thumb for average power/peak >> >power over a year is 1/6, even for tracking collectors. >> >> >> Thanks for touching up my rough cuts. I knew there were a bit optimistic. >> For real fun, try designing the electronics that feed the solar power back to >> the grid safely. It would have to be in phase and very low harmonics, handle >> peak power and marginal source power, and disconnect rather completely overnight. > >But your estimate assumes only one hour a day. > >Don Lancaster says mean output's roughly as 5 hours of peak output >daily. So, 5 hours x 9 kW = 40 kWh/day. OK, i will take that correction. > >Caveats: > That's about $50k worth of solar stuff, pre- green-graft. > DL's "5 hours per 24" rule might be for his home base, Arizona! > Efficiency's more like 10-12% ain't it? > Rooftop, your panels won't be broadside to the sun. Cut output >accordingly. > Clouds? They're killers. My panel puts out 2-5% on cloudy days. Thanks for the cloudy day numbers. I had no idea it was so low.
From: Nobody on 16 Jan 2010 02:42
On Sun, 10 Jan 2010 18:58:13 -0800, Charlie E. wrote: >>Or, more glibly: the plural of "anecdote" is not "data". >> >>The people claiming that isolated weather measurements are evidence for or >>against climate change (but note: it's only ever the deniers who do this) >>*know* that the argument is nonsense. It's essentially a "shibboleth", a >>means by which members of the tribe can identify themselves to each other. > > Only deniers? When for years, every hurricane, tornado, or heat spell > was just another indicator of global warming? Where have you been? To clarify: I only see the deniers doing it *here*. I expect the general public to have a tenuous grasp of the concept of statistical significance (or of logic generally, for that matter), but when it's coming from someone with a hard science background, I'm inclined to assume intent. |