Solar cell
in [Design]
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From: krw on 18 Apr 2010 23:55 On Sun, 18 Apr 2010 21:52:18 -0600, hamilton <hamilton(a)nothere.com> wrote: >On 4/18/2010 7:49 PM, krw(a)att.bizzzzzzzzzzzz wrote: >> On Sun, 18 Apr 2010 16:55:07 -0600, hamilton<hamilton(a)nothere.com> wrote: >> >>> On 4/18/2010 2:09 PM, krw(a)att.bizzzzzzzzzzzz wrote: >>>> On Sun, 18 Apr 2010 12:47:41 -0600, hamilton<hamilton(a)nothere.com> wrote: >>>> >>>>> On 4/18/2010 9:31 AM, Don Lancaster wrote: >>>>>> On 4/18/2010 7:21 AM, Dirk Bruere at NeoPax wrote: >>>>>>> On 18/04/2010 08:02, eryer wrote: >>>>>>>> On 17 Apr, 21:14, Don Lancaster<d...(a)tinaja.com> wrote: >>>>>>>>> They also often fail to include the synchronous inverter costs, >>>>>>>>> which in >>>>>>>>> many situations will consume 150 percent of the value of ALL the >>>>>>>>> electricity sent through iit. And not using a synchronous inverter, of >>>>>>>>> course, is ridiculously more costly. >>>>>>>> >>>>>>>> Interesting...any link? >>>>>>>> >>>>>>>> About my first post, any suggestion? >>>>>>>> Thanks >>>>>>> >>>>>>> This is like saying that PC power supplies will dissipate more power >>>>>>> than the rest of the PC combined. If you want to see where the market is >>>>>>> going on converters, look to the PC PSU market and costs for a mature >>>>>>> and very similar example ie 5c a Watt and 80%+ efficiency >>>>>>> >>>>>> >>>>>> >>>>>> If a naive homeowner tries to buy a synchronous inverter for a 1500 watt >>>>>> system, its typical retail cost (plus shipping and installation, of >>>>>> course) will be around $2500. >>>>>> >>>>>> It thus gobbles gone all pv electricity sent through it and then some. >>>>>> >>>>>> There is no reason the $2500 device should cost more than $9. >>>>> >>>>> Its a free market. >>>>> >>>>> Build them and sell them for $2000. >>>>> >>>>> This would start the price war and within, says 6 weeks, the price will >>>>> drop to $9. >>>>> >>>>> Isn't the free market the way to go ?? >>>>> >>>> >>>> Nah, free markets are so last century. We're into government subsidies now. >>> >>> So the new free market model is "Government Subsidies" . >> >> Wooosssshhhhh! > >Sorry, There is no free market, just "Government Subsidies". Wooosssshhhhh! <...>
From: Robert Baer on 19 Apr 2010 01:07 Paul Keinanen wrote: > On Sun, 18 Apr 2010 01:43:09 -0700, Robert Baer > <robertbaer(a)localnet.com> wrote: > >> eryer wrote: >>> Hi, >>> I want to realize (for hobby) a battery charger using solar cell. I've >>> found this sensor >>> http://www.clare.com/Products/SolarCell.htm >>> Its output voltage is high and can be used without step-up transformer >>> (like any typical solar cell). So, i can use >>> * a typical solar cell (with millivolt output voltage) and a step-up >>> transformer >>> * this sensor >>> For you, what is the best (performance) solution? >> Well, for starters, solar cells can output around 1.3V with a >> reasonable load - a lot more that "millivolt output". >> Secondly, the current capability of those Clare "cells" is a bit >> miserly. To be fair tho, that is expected with such dinky arrays. > > What material would produce 1.3 V ? > > Silicon cells produce about 0.6-0.65 V so quite a few in series are > required for any usable voltage levels in power production. > > In any switchers with bipolar components, at least one junction > voltage drop is lost in switch Vce voltage drops, thus at least solar > cell should be added to a panel to compensate for the switcher losses. > > Thus the panel should have a high output voltage and hence a lot of > cells, thus adding one or two cells to compensate for the switcher > losses does not matter so much. > > With very low output voltage panels, some low Rds FETs may have to be > used as switches and rectifiers. > The cells in solar powered garden lights output 1.3V or better and there is only one per unit / light; they are advertised as being silicon cells of a more modern AKA efficient design.
From: Robert Baer on 19 Apr 2010 01:09 mpm wrote: > On Apr 18, 1:56 am, Paul Keinanen <keina...(a)sci.fi> wrote: >> On Sat, 17 Apr 2010 21:14:57 +0100, Dirk Bruere at NeoPax >> >> >> >> >> >> <dirk.bru...(a)gmail.com> wrote: >>> On 17/04/2010 20:39, Jan Panteltje wrote: >>>> On a sunny day (Sat, 17 Apr 2010 11:25:32 -0600) it happened hamilton >>>> <hamil...(a)nothere.com> wrote in<hqcqu9$7v...(a)news.eternal-september.org>: >>>>> On 4/17/2010 10:41 AM, Jan Panteltje wrote: >>>>>> On a sunny day (Sat, 17 Apr 2010 08:57:14 -0700) it happened Don Lancaster >>>>>> <d...(a)tinaja.com> wrote in<82u42oFov...(a)mid.individual.net>: >>>>>>> There is NO best solution. >>>>>>> All of photovoltaics is an outright scam to steal state and federal funds. >>>>>>> Not one net watthour of pv energy has EVER been produced! >>>>>> Bad day? >>>>> Ok, the link now works. >>>>> Dons argument is what the non-green types have been saying for years. >>>>> It costs too much to develop and manufacture green technologies then to >>>>> stick to the 'tried-n-true' fossil fuels. >>>>> He does have a point, the cost to early adapters will never be paid back. >>>>> But, I think we need to start somewhere, and PV solar needs to have >>>>> money to continue to develop and innovate. >>>>> As time passes and science has the money to continue, they will get >>>>> there. ( maybe not in my lifetime, but they will get there ) >>>>> hamilton >>>> Yes, there are for example investors in Europe planning a solar plant in the Sahara desert IIRC. >>>> Billions have been raised, DC very high voltage lines to carry it all over Europe. >>>> With all that unrest I think the biggest obstacle is a political one. >>>> US has Mojave desert, would be a nice place for solar .. >>>> but the same greens that want solar also want to protect the bugs and snakes that live there ;-) >>>> Just wait until get get cold feet, they will change their mind. >>>> OTOH nuclear seems to be the only real option right now. >>>> And if 'electric cars' were to really happen, then all bets are off, >>>> new grid, new power plants... >>>> Dunno. >>> That's why Spain is the ideal location. >> The Desertec plan and the existing stations in Spain and US are based >> on concentrated solar thermal power, not PV cells, apparently for >> economical reasons. >> >> In solar thermal plants, the sun heats a fluid which then drives a >> conventional gas or steam turbine. It would make even more economical >> sense, if the excess heat available on the "cold" end of the turbine >> could be used for something useful, such as running absorbtion >> chillers or desalination plants. >> >> PV panels on individual houses will make economical sense only in hot >> countries if the cost of energy changes on an hour or shorter bases. >> During hot sunny afternoons, the electric consumption will reach the >> annual peak due to air conditioning. >> >> Much of the power during those hours needs to be produced with simple >> cheap gas turbines (used only a limited number of hours each year), >> but the overall efficiency is low and they need to use more expensive >> fuels such as natural gas or oil. >> >> If this extra cost during summer day hours is charged from the >> consumers, it would make sense for the consumer to use individual PV >> panels for running the air conditioning, thus avoiding buying >> expensive peak electricity from the power company. In such cases there >> would be less need to have an expensive inverter to feed power back to >> the grid. >> >> Of course, simple thermal collectors could be used to drive an >> absorbtion cooler, even if the cooler efficiency is lower than a >> compressor cooler, this avoids the low efficiency light to electricity >> conversion in PV cells.- Hide quoted text - >> >> - Show quoted text - > > I read a stat somewhere (not sure where, or how true it was, but...) > If the US built 91 miles square (~ 8300sq mi) of solar-thermal, it > would completely satisfy our energy needs, including enough to power > all our cars once converted to electric / hybrids. > I believe that figure also included upgrading the transmission lines. > > We have the desert southwest.... > Do we have the will or desire? > > Maybe we should spend the trillion dollars or so, build this thing, > and finally solve the US energy problem and geopolitical > destabilization problem the oil dependency causes. > Though I wonder if stopping the hemorrhaging of our wealth to oil rich > nations doesn't bring its own problems. Yup! Just print (yet) another trillion dollars backed by NOTING...
From: Paul Keinanen on 19 Apr 2010 03:56 On Sun, 18 Apr 2010 21:07:47 -0800, Robert Baer <robertbaer(a)localnet.com> wrote: >Paul Keinanen wrote: >> On Sun, 18 Apr 2010 01:43:09 -0700, Robert Baer >> <robertbaer(a)localnet.com> wrote: >> >>> eryer wrote: >>>> Hi, >>>> I want to realize (for hobby) a battery charger using solar cell. I've >>>> found this sensor >>>> http://www.clare.com/Products/SolarCell.htm >>>> Its output voltage is high and can be used without step-up transformer >>>> (like any typical solar cell). So, i can use >>>> * a typical solar cell (with millivolt output voltage) and a step-up >>>> transformer >>>> * this sensor >>>> For you, what is the best (performance) solution? >>> Well, for starters, solar cells can output around 1.3V with a >>> reasonable load - a lot more that "millivolt output". >>> Secondly, the current capability of those Clare "cells" is a bit >>> miserly. To be fair tho, that is expected with such dinky arrays. >> >> What material would produce 1.3 V ? >> >> Silicon cells produce about 0.6-0.65 V so quite a few in series are >> required for any usable voltage levels in power production. >> >> In any switchers with bipolar components, at least one junction >> voltage drop is lost in switch Vce voltage drops, thus at least solar >> cell should be added to a panel to compensate for the switcher losses. >> >> Thus the panel should have a high output voltage and hence a lot of >> cells, thus adding one or two cells to compensate for the switcher >> losses does not matter so much. >> >> With very low output voltage panels, some low Rds FETs may have to be >> used as switches and rectifiers. >> > The cells in solar powered garden lights output 1.3V or better and >there is only one per unit / light; they are advertised as being silicon > cells of a more modern AKA efficient design. Did you expect the wafer in a greater detail ? My guess is that there is a narrow break through the wafer and those two parts are connected in series. With the typical silicon pn junction voltage drop of 0,65 V, thus 2x0,65 V = 1,3 V.
From: Dirk Bruere at NeoPax on 19 Apr 2010 08:11
On 19/04/2010 06:09, Robert Baer wrote: > Yup! Just print (yet) another trillion dollars backed by NOTING... It's actually backed by the goodwill of China -- Dirk http://www.transcendence.me.uk/ - Transcendence UK http://www.blogtalkradio.com/onetribe - Occult Talk Show |