Solar cell
in [Design]
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From: Phil Hobbs on 18 Apr 2010 13:27 Paul Keinanen wrote: > On Sat, 17 Apr 2010 13:20:26 -0400, Phil Hobbs > <pcdhSpamMeSenseless(a)electrooptical.net> wrote: > >> Don, you're out of date: a pal of mine at IBM is doing a 30 kW peak >> system for the Saudis, using very low cost tracking technology and a new >> type of Fresnel lens concentrators that run at above 2000 suns. (The >> trick is cooling them, but he's also the guy that invented the liquid >> metal thermal interface that Apple has used on their higher end machines.) > > The problem with concentrated systems is that you have to track the > sun. This would not be an issue, if the panel could be operated in a > protected environment, such as indoors :-). Unfortunately strong > winds, sand, dust, snow and ice require quite strong tracking motors > and possibly some security mechanism for parking it in a safe position > during extreme conditions (horizontally in high winds, but this would > not be a good idea, if much snow is expected). > > Especially in desert areas the dust/sand storms can deposit much dirt > on the panel, so these panels will have to be cleaned quite often. For > manual cleaning, the elements should have a limited size, in order to > avoid building special fixtures just for cleaning. > >> Flat plate silicon collectors are a crock, I agree. > > The good thing about fixed non-concentrating panels is that sturdy > mounts can be used, but due to the lower annual collection capability, > the PV cell price should drop by one or two orders of magnitude, to be > truly economically viable. > My pal and I actually have a patent on a cute method of doing this--you use a hard-coated plastic sphere about 2 feet in diameter, full of water, with a flat mirror shaped like a pagoda, so as to compensate for the horrible spherical aberration of the sphere. The tracker was my contribution. It's an all-passive system--no motors, no electricity--based on buoyancy, and (I calculated) could easily achieve accurate enough tracking for 2000 suns concentration. (Without being too mysterious, it combined the principles of the Crookes radiometer, the Edmund Scientific drinking bird, and the coffee percolator.) I demoed the coarse tracking servo, but I left IBM before we had a chance to build a whole system. It's a pretty cool gizmo--the water is the lens, cooling system, and the mechanical stabilization system all in one. You just dump 'em off the back of a truck, hook up the wires, and drain the Colorado River to fill them up. ;) Then they Just Work. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal ElectroOptical Innovations 55 Orchard Rd Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
From: dagmargoodboat on 18 Apr 2010 14:28 On Apr 18, 11:14 am, "Andrew" <anbyv...(a)yahoo.com> wrote: > <dagmargoodb...(a)yahoo.com> wrote in message news:94be2bb7-3879-4851-9931- > > = PV isn't economic in the US, where we get twice Germany's insolation, > = yet it's economic there? What's their secret? > > Heavy taxes on everything else, standard european procedure. > > How about $5.5 per gallon of regular gasoline? > > -- > Andrew Yes, that's it of course. If you can't make solar cheaper, make conventional power cost 4x more and the world adapts accordingly. Here's a QBASIC kludge I whipped out for costing PV systems. It's crude, but fun to play with. Right now it's set roughly with current, realistic ball-park numbers (including subsidies) for Southern California, USA. It figures that a batteryless system never pays for itself. (It costs $4.50/watt, and will only pay back $0.41 net over the 25 year lifetime of the system.) Cheers, James Arthur =================== 'Solar Photovoltaic Power Costing Widget ' 6/27/2008 by James Arthur ' 4/18/2010 cosmetic changes. ' 'NOTES: ' o Doesn't account for panel degradation, or loss from dirty panels ' o Assumes that 100% of any solar power produced is used or sold on the ' grid at full retail price. ' ' o Note that break-even from a consumer's point of view is quite different ' from a utility's. The utility's cost to generate power is typically ' around $0.04-0.05 per KWHr, or 1/2 to 1/3rd of what they sell it for. ' ' o A grid-tied no-battery PV system costs significantly less to buy and operate. ' To simulate that, set batteryCostDollarsPerWatt to zero. '========= Simulation parameters ========= cellCostDollarsPerWatt = 4 'the cost of the panels themselves, dollars per watt cellLifeYears = 25 inverterCostDollarsPerWatt = .5 'inverter cost batteryCostDollarsPerWatt = 0! 'battery cost batteryLifeYears = 10 'batteries don't last forever! interestRate = 6 'interest rate for borrowing money, percent per year inflationPerYear = 1.035 insolationHours = 5 'The equivalent hours of peak sun per day 'for a given location. 5 is common in the USA, '2.5 in northern Europe. initialElectricityPricePerKWH = .14 'This price will be adjusted upward at the 'specified inflation rate. solarDaysPerYear = 300 'allows for cloudy days. Production on 'a cloudy day is 1-5% of a sunny day, per 'my measurements. systemEfficiency = .94 'allows for wiring and misc. losses electricityPricePerKWH = initialElectricityPricePerKWH DIM daysPerMonth(12) FOR i% = 1 TO 12 READ daysPerMonth(i%) NEXT i% balance = cellCostDollarsPerWatt + inverterCostDollarsPerWatt balance = balance + batteryCostDollarsPerWatt originalInvestment = balance PRINT "Solar PV system economic simulation." a$ = "" battAge = 0 'start with a new battery FOR year% = 1 TO cellLifeYears productionPerDay = insolationHours * (solarDaysPerYear / 365) * (electricityPricePerKWH / 1000) * systemEfficiency PRINT "Operations summary for year"; year% PRINT USING "Inflated price of electricity = $##.### per KWh"; electricityPricePerKWH PRINT " energy interest Balance" PRINT " Month production expense owed" p = 0: intr = 0 FOR month% = 1 TO 12 days% = daysPerMonth(month%) production = productionPerDay * days% interest = (interestRate / 100) * (days% / 365.25) * balance balance = balance + interest - production p = p + production intr = intr + interest PRINT USING " ## $##.### $#.#### $#.###"; month%; production; interest; balance NEXT month% PRINT " ------- -------" PRINT USING " Results: $#.#### _- $#.#### _= $$#.####"; p; intr; p - intr; IF p > intr THEN PRINT " profit"; ELSE PRINT " (loss)"; END IF PRINT ", per watt" battAge = battAge + 1 'buy a battery if need be IF battAge > batteryLifeYears THEN battAge = 0 balance = balance + batteryCostDollarsPerWatt END IF 'factor in the effects of inflation electricityPricePerKWH = electricityPricePerKWH * inflationPerYear batteryCostDollarsPerWatt = batteryCostDollarsPerWatt * inflationPerYear PRINT : PRINT "hit any key for next year's summary, or 's' to skip to the end"; IF a$ <> "s" THEN a$ = INPUT$(1) 'Conditionally wait for the user to hit a key ' CLS LOCATE , 1 PRINT SPACE$(79); LOCATE , 1 NEXT year% PRINT " ============== FINAL REPORT ==============" PRINT " Assumptions:" PRINT " Initial Cost Inflation Interest Rate Price Per System" PRINT " (per watt) rate (%) kWh Lifetime" PRINT USING " $##.## ##.##_% ##.##_% $##.## ## years"; originalInvestment; 100 * (inflationPerYear - 1); interestRate; initialElectricityPricePerKWH; year% - 1 PRINT USING "Final balance owed = $##.## (per cell watt purchased)"; balance IF balance >= 0 THEN PRINT "Sorry, your system never paid for itself. It cost more than" PRINT "grid power, and you lost money going solar." ELSE PRINT "Congratulations, your system paid for itself." 'Compute yield as the n-th root of the ratio of present to initial value of the investment yield = 100 * (EXP(LOG((-balance) / originalInvestment) / (year% - 1)) - 1) PRINT USING " Net savings over grid power were $##.## per system watt, equivalent"; -balance PRINT USING " to a ##.##_% annual yield on your original investment."; yield END IF DATA 31,28,30, 30,31,30, 31,31,30, 31,30, 31
From: Don Lancaster on 18 Apr 2010 14:46 On 4/18/2010 11:28 AM, dagmargoodboat(a)yahoo.com wrote: > > > It figures that a batteryless system never pays for itself. (It costs > $4.50/watt, and will only pay back $0.41 net over the 25 year lifetime > of the system.) > No battery system can, of course, even remotely compete with a synchronous inverter for cost, safety, efficiency, lifetime, reliability, or convenience. Curiously, storage via a synchronous inverter is a super efficient electricity-to-coal coverter. When used, the pile of coal outside the conventional power plant does not diminish as fast. ------------------- The kicker is that today's pv technology is so "8-track tape". Because of emerging CIGS and similar developments, any current technology pv system bought today is exceptionally unlikely to still be in full service four years from today, let alone 25. Upgrades would be overwhelmingly compelling. <http://www.tinaja.com/glib/pvlect2.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: don(a)tinaja.com Please visit my GURU's LAIR web site at http://www.tinaja.com
From: hamilton on 18 Apr 2010 14:47 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 ?? hamilton > Except for subsidies. >
From: dagmargoodboat on 18 Apr 2010 15:55
On Apr 18, 1:46 pm, Don Lancaster <d...(a)tinaja.com> wrote: > On 4/18/2010 11:28 AM, dagmargoodb...(a)yahoo.com wrote: > > > > > It figures that a batteryless system never pays for itself. (It costs > > $4.50/watt, and will only pay back $0.41 net over the 25 year lifetime > > of the system.) > > No battery system can, of course, even remotely compete with a > synchronous inverter for cost, safety, efficiency, lifetime, > reliability, or convenience. But all PV systems need inverters--batteries just make the economics even worse. <snip> > Because of emerging CIGS and similar developments, any current > technology pv system bought today is exceptionally unlikely to still be > in full service four years from today, let alone 25. Upgrades would be > overwhelmingly compelling. > > <http://www.tinaja.com/glib/pvlect2.pdf> PV /is/ neat--who doesn't like running stuff off sunlight?--it just isn't anywhere near cost parity yet, not even for grid-tied systems, and especially not when you need storage. -- Cheers, James Arthur |