Solar panel efficency
in [Design]
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From: Joel Koltner on 3 Jun 2010 15:03 "Don Lancaster" <don(a)tinaja.com> wrote in message news:86pv8oFvhiU1(a)mid.individual.net... > The overwhelming vast majority of pv cell users are happy as a clam paying > over FIVE HUNDRED DOLLARS PER KILOWATT HOUR for their electricity. pv is > well suited and an excellent match to this market. Are those the same people who'll pay THOUSANDS OF DOLLAR PER SQUARE FOOT for a home that has thousands of extra square feet that they'll probably never use? Or perhaps use a few days a year for guests?
From: krw on 3 Jun 2010 19:47 On Thu, 03 Jun 2010 08:26:59 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Thu, 03 Jun 2010 08:15:38 -0700, Don Lancaster <don(a)tinaja.com> >wrote: > >>On 6/2/2010 7:42 PM, AZ Nomad wrote: >>> On Thu, 03 Jun 2010 12:10:11 +1000, Sylvia Else<sylvia(a)not.here.invalid> wrote: >>> >>>> I don't really see the link. Certainly PV cells are an uneconomic source >>>> of electricity. They also produce power when it suits them (daytime, >>>> sunlight) rather than when it's required, which makes then unsuitable >>>> for peaking (or much else, indeed, without expensive resource consuming >>>> batteries). >>> >>>> But that does not in itself mean that they're necessarily energy sinks, >>>> though I'm not arguing that they're not. >>> >>> If you compare the upfront cost with their lifetime energy reception, >>> you'd probably find that they never break even. Good for some portable >>> applications or remote locations, but not much else. > >You've got to add the mounting stuff, the labor to hack up your walls >and wire it up, the dc/ac inverter, some control electronics, the cost >to remove and replace it when it makes your roof leak, the cost to >remove and dispose of all that junk when it quits working. > >> >>The overwhelming vast majority of pv cell users are happy as a clam >>paying over FIVE HUNDRED DOLLARS PER KILOWATT HOUR for their >>electricity. pv is well suited and an excellent match to this market. >> >>Calculators, of course. >> >><http://www.tinaja.com/etlink1.asp> > >A small lithium battery would power a calculator for 20 or 30 years >and work better in dim light. A polysilicon solar cell is probably >very cheap, cheaper than a lithium battery maybe. > >Lithium batteries run in the roughly $300 to $1000 per KWH range. > What's a Toyota Pious battery cost? Certainly they're bigger than a coupla kWH.
From: krw on 3 Jun 2010 19:51 On Thu, 3 Jun 2010 12:03:10 -0700, "Joel Koltner" <zapwireDASHgroups(a)yahoo.com> wrote: >"Don Lancaster" <don(a)tinaja.com> wrote in message >news:86pv8oFvhiU1(a)mid.individual.net... >> The overwhelming vast majority of pv cell users are happy as a clam paying >> over FIVE HUNDRED DOLLARS PER KILOWATT HOUR for their electricity. pv is >> well suited and an excellent match to this market. > >Are those the same people who'll pay THOUSANDS OF DOLLAR PER SQUARE FOOT for a >home that has thousands of extra square feet that they'll probably never use? A few square million$? ;-) >Or perhaps use a few days a year for guests? I have a bedroom, with full bath, suite (probably 400 sq ft) that's only been used three times in the year and a half I've lived here. I only paid $120/sq. ft., though. ;-)
From: Joel Koltner on 3 Jun 2010 20:35 <krw(a)att.bizzzzzzzzzzzz> wrote in message news:fpfg0691l2jqrqijhkfrv4bqc5gh3rmunc(a)4ax.com... > On Thu, 3 Jun 2010 12:03:10 -0700, "Joel Koltner" > <zapwireDASHgroups(a)yahoo.com> wrote: >>Are those the same people who'll pay THOUSANDS OF DOLLAR PER SQUARE FOOT for >>a >>home that has thousands of extra square feet that they'll probably never >>use? > > A few square million$? ;-) Just about. :-) For me if the choice were between, say... $50k for an extra room in the house that I never expected to use vs. $50k in PV panels... I might just go for the PV panels. Actually I'd probably get a $50k RV, knowing full well I'd never use it nearly enough to make it cheaper than staying in a four-stay hotel every tiem I travelled. :-) > I have a bedroom, with full bath, suite (probably 400 sq ft) that's only > been > used three times in the year and a half I've lived here. I only paid > $120/sq. > ft., though. ;-) Knock a door into the side of the house there and rent it out? I'd seriously consider doing something like that if I were single, but being married there's no way my wife would agree to it! In college I spent half-a-year living in this really cool old house that looked a lot like a scaled-down version of the White House ... albeit with only two big white pillars in front. Beautiful hardwood floors throughout, and nice big bedrooms -- one (not mine) even had a door to a roof patio that was another good 400 sq. ft. or so. It'd been student housing for quite some time, though, and they'd even converted the old single-car garage into its own little apartment. ---Joel
From: Bill Bowden on 3 Jun 2010 23:00
On Jun 2, 11:55 pm, Martin Brown <|||newspam...(a)nezumi.demon.co.uk> wrote: > On 03/06/2010 00:39, Bill Bowden wrote: > > > > > On Jun 2, 8:45 am, Don Lancaster<d...(a)tinaja.com> wrote: > >>> There are many sources claiming net (solar panel) energy > >>> payback is far greater than the energy cost of production. > > >> These claims are utterly bogus as they treat subsidies as assets, rather > >> than as much larger "iceberg" liabilities. The key issue is addressed at > >> <http://www.tinaja.com/whtnu10.asp#d05-31-10> > > >>> And I know people in the business making a good living at it. > > >> So do I. Including the few remaining honest pioneers that have all the > >> arrows in their backs. And when you get them drunk enough or stoned > >> enough, they freely admit they are stealing federal and state dollars > >> just like everybody else does. > > >> <http://www.tinaja.com/blig/nrglect2.pdf> > > >> -- > >> Many thanks, > > >> Don Lancaster voice phone: (928)428-4073 > >> Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552 > >> rss:http://www.tinaja.com/whtnu.xml email: d...(a)tinaja.com > > >> Please visit my GURU's LAIR web site athttp://www.tinaja.com > > Junk science. > > > > > Well that's nice. Now if you can just give me a couple other > > references, not written by you, I will be a believer. > > That isn't going to happen. Although the myth that solar panels never > pay back their energy investment is widespread. They may never pay back > the cost to make, install and use them over their lifetime, but that is > an entirely different matter. And the economics is shifting as someone > demonstrated there appear to be panels on the market now at $2/W. > > > > > > > Here's another one you don't want to read. > > >http://en.wikipedia.org/wiki/Photovoltaics > > > "Energy payback time and energy returned on energy invested > > > The energy payback time is the time required to produce an amount of > > energy as great as what was consumed during production. The energy > > payback time is determined from a life cycle analysis of energy. The > > energy needed to produce solar panels is paid back in the first few > > years of use.[79] > > > Another key indicator of environmental performance, tightly related to > > the energy payback time, is the ratio of electricity generated divided > > by the energy required to build and maintain the equipment. This ratio > > is called the energy returned on energy invested (EROEI). This should > > not be confused with the economic return on investment, which varies > > according to local energy prices, subsidies available and metering > > techniques. > > > Life-cycle analyses show that the energy intensity of typical solar > > photovoltaic technologies is rapidly evolving. In 2000 the energy > > payback time was estimated as 8 to 11 years,[80] but more recent > > studies suggest that technological progress has reduced this to 1.5 to > > 3.5 years for crystalline silicon PV systems.[74] > > > Thin film technologies now have energy pay-back times in the range of > > 1-1.5 years (S.Europe).[74] With lifetimes of such systems of at least > > 30 years[citation needed], the EROEI is in the range of 10 to 30. They > > thus generate enough energy over their lifetimes to reproduce > > themselves many times (6-31 reproductions, the EROEI is a bit lower) > > depending on what type of material, balance of system (or BOS), and > > the geographic location of the system.[81] " > > You can't always trust Wiki but there is also stuff in the peer reviewed > literature that refute his bogus claim (which to be fair might once have > been true decades ago when solar cells were *much* thicker). > > See Richards & Watt (2007) > > http://www.inference.phy.cam.ac.uk/sustainable/refs/solar/Myth.pdf > > Regards, > Martin Brown Interesting article. Also found this article about a 250MW solar project by a SCE in the southern California area. Must have some value if SCE wants to build it. http://solar.energy-business-review.com/news/sce_to_place_250mw_solar_panel_project_on_prologis_warehouse_roofs_100510/ "Southern California Edison (SCE) and ProLogis have reached an agreement to place up to 40% of SCE's 250MW solar panel project on ProLogis distribution warehouse roofs in the Inland Empire region of Southern California." -Bill |