Solar panel efficency
in [Design]
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From: Robert Baer on 2 Jun 2010 01:45 Michael A. Terrell wrote: > Robert Baer wrote: >> Tim Wescott wrote: >>> On 05/31/2010 08:38 AM, Jim Thompson wrote: >>>> On Sun, 30 May 2010 17:21:25 -0700, Tim Wescott<tim(a)seemywebsite.now> >>>> wrote: >>>> >>>>> On 05/30/2010 03:16 PM, Spehro Pefhany wrote: >>>> [snip] >>>>>> The usual efficiency criteria for ground-based applications is $/peak >>>>>> watt. >>>>> And I _still_ think that the criteria should be the net energy return >>>>> over the whole lifetime of the product -- mean _after_ you take into >>>>> consideration the entire extract/manufacture/install/dispose cycle of >>>>> the panel into account, _including_ the trees you'll need to chop down >>>>> to make room for them and some projections of the proportion of panels >>>>> that will be retired early due to defects, obsolescence, vandalism, >>>>> remodeling, and just plain accident. >>>>> >>>>> Because I think that in principal the whole idea of renewable energy is >>>>> a Really Good Thing, but it seems to be in the hands of a bunch of >>>>> poly-anna ditzle-brains who turn off all thought processes when >>>>> confronted by anything "green", and who are opposed by a bunch of >>>>> mean-spirited ditzle-brains who let their thought processes get turned >>>>> off by bibles long ago. >>>> Huh? I think most opposition to "green" energy solutions lies in only >>>> two camps... >>>> >>>> (1) NIMBY's >>>> >>>> (2) Those of us who want green, but not at the cost of immediate >>>> turn-off of existing energy sources... Obamanation-style :-( >>> Well, I don't _know_ that green energy is a net positive enterprise or >>> not. But I've been an engineer for long enough that I've seen entire >>> herds of non-technical types go thundering after technologies that can't >>> do anything but cost more than they return. Quite frankly, this whole >>> green energy thing is showing a lot of the same hallmarks. >>> >>> My fear is that the true cost accounting just isn't being done, or is >>> being done exceptionally belatedly (take biofuel, for instance). It >>> seems that any time you start talking about "green energy" half the >>> world gets all googley-eyed and starts talking about how it's going to >>> Save the World, and the other half starts talking about how it's an >>> Excuse to Abrogate our God Given Rights. >>> >>> And any time people start talking in all caps I get suspicious that >>> they've stopped thinking. >>> >>> It'd be a shame if we put all our resources into "green energy" and find >>> out that it's really blacker than oil. >>> >> I do not care about "green" in this case, just a method to reasonably >> supply some power to run each school. >> A foot powered generator is another possible solution. > > > Replace Gym class and detention with kids running in giant hamster > wheels. They will be too winded to use their cell phone in class, and > too tired to cause trouble on the way home from school. > > Wrong country - try India; wrong culture - try untouchable.
From: Robert Baer on 2 Jun 2010 01:50 Paul Keinanen wrote: > On Tue, 01 Jun 2010 09:15:00 +0100, Martin Brown > <|||newspam|||@nezumi.demon.co.uk> wrote: > >> But in more southerly climes where peak sun corresponds with a peak >> demand for aircon it could make more sense to have PV arrays deployed. > > Or use absorbtion chillers for air conditioning and avoid the > inefficient light to electricity conversion. > Huh??
From: Grant on 2 Jun 2010 03:07 On Tue, 01 Jun 2010 22:50:31 -0700, Robert Baer <robertbaer(a)localnet.com> wrote: >Paul Keinanen wrote: >> On Tue, 01 Jun 2010 09:15:00 +0100, Martin Brown >> <|||newspam|||@nezumi.demon.co.uk> wrote: >> >>> But in more southerly climes where peak sun corresponds with a peak >>> demand for aircon it could make more sense to have PV arrays deployed. >> >> Or use absorbtion chillers for air conditioning and avoid the >> inefficient light to electricity conversion. >> > Huh?? Solar airco -- sidesteps the need for lots of electricity to drive compressors to make cold air. A forgotten technology? Sorta like how they made ice before electricity, in the steam age. Grant. -- http://bugs.id.au/
From: Martin Brown on 2 Jun 2010 03:31 On 02/06/2010 08:07, Grant wrote: > On Tue, 01 Jun 2010 22:50:31 -0700, Robert Baer<robertbaer(a)localnet.com> wrote: > >> Paul Keinanen wrote: >>> On Tue, 01 Jun 2010 09:15:00 +0100, Martin Brown >>> <|||newspam|||@nezumi.demon.co.uk> wrote: >>> >>>> But in more southerly climes where peak sun corresponds with a peak >>>> demand for aircon it could make more sense to have PV arrays deployed. >>> >>> Or use absorbtion chillers for air conditioning and avoid the >>> inefficient light to electricity conversion. >>> >> Huh?? > > Solar airco -- sidesteps the need for lots of electricity to drive > compressors to make cold air. A forgotten technology? Sorta like > how they made ice before electricity, in the steam age. I presume you mean something sorbtion based along the lines of this German website (in English on this page) http://www.solarserver.de/solarmagazin/artikeljuni2002-e.html I can't recall ever seeing one of these in the UK, but we hardly ever have more than a half dozen days a year when aircon would be essential. It is an affliction of high rise glass office buildings that they need it because they were built like greenhouses with no opening windows. Shops containing lots of electrical goods tend to need aircon too. Regards, Martin Brown
From: dagmargoodboat on 2 Jun 2010 09:28
On May 31, 6:39 pm, Tim Wescott <t...(a)seemywebsite.now> wrote: > On 05/31/2010 08:38 AM, Jim Thompson wrote: > > > > > On Sun, 30 May 2010 17:21:25 -0700, Tim Wescott<t...(a)seemywebsite.now> > > wrote: > > >> On 05/30/2010 03:16 PM, Spehro Pefhany wrote: > > [snip] > > >>> The usual efficiency criteria for ground-based applications is $/peak > >>> watt. > > >> And I _still_ think that the criteria should be the net energy return > >> over the whole lifetime of the product -- mean _after_ you take into > >> consideration the entire extract/manufacture/install/dispose cycle of > >> the panel into account, _including_ the trees you'll need to chop down > >> to make room for them and some projections of the proportion of panels > >> that will be retired early due to defects, obsolescence, vandalism, > >> remodeling, and just plain accident. > > >> Because I think that in principal the whole idea of renewable energy is > >> a Really Good Thing, but it seems to be in the hands of a bunch of > >> poly-anna ditzle-brains who turn off all thought processes when > >> confronted by anything "green", and who are opposed by a bunch of > >> mean-spirited ditzle-brains who let their thought processes get turned > >> off by bibles long ago. > > > Huh? I think most opposition to "green" energy solutions lies in only > > two camps... > > > (1) NIMBY's > > > (2) Those of us who want green, but not at the cost of immediate > > turn-off of existing energy sources... Obamanation-style :-( > > Well, I don't _know_ that green energy is a net positive enterprise or > not. But I've been an engineer for long enough that I've seen entire > herds of non-technical types go thundering after technologies that can't > do anything but cost more than they return. Quite frankly, this whole > green energy thing is showing a lot of the same hallmarks. > > My fear is that the true cost accounting just isn't being done, or is > being done exceptionally belatedly (take biofuel, for instance). It > seems that any time you start talking about "green energy" half the > world gets all googley-eyed and starts talking about how it's going to > Save the World, and the other half starts talking about how it's an > Excuse to Abrogate our God Given Rights. > > And any time people start talking in all caps I get suspicious that > they've stopped thinking. > > It'd be a shame if we put all our resources into "green energy" and find > out that it's really blacker than oil. Three categories: - conservation (voluntarily changing behavior) - using insulation and simple tricks to use less energy - Raw, bulk energy from "green" sources Conservation makes sense, zero technical risk, and saves loads. (so to speak) Can be done instantly, as soon as one understands it. Simple tricks, like better fan blades and eliminating tight right- angle bends in pipes and ducts, could save huge amounts. Amory Lovins (physicist, rmi.org) is big on that, with numbers. Last category--allowing us all to live like Al Gore--is the ultimate goal, but presently a moonshot. Solar thermal can be decent. Inspired by David L. Jones' "Solar Sponge" and a few others, I designed a really cool, improved efficiency passive solar house heater last winter. Small hitch--no sun! So, it was really cool indeed. Dang. -- Cheers, James Arthur |