Talk:Photovoltaics

Capacity factor

25%? Isn't that a tad high? 20% is much more reasonable. Can you supply a reference that gives the capacity factor of photovoltaics? This one shows CF estimates for the United States from 15 to 20%.[1] Since Germany is going to be even lower, I would suggest sticking to 20%, especially when in the next sentence you use 25% to estimate how much electricity is being generated by photovoltaics. 199.125.109.54 (talk) 03:52, 14 February 2008 (UTC)

I agree, stating under 25% implies quite a bit for solar, but that (less than)number is a direct quote from the only remaining reference that still works.--202.168.102.96 (talk) 21:42, 15 February 2008 (UTC)

Dealing with Peak Oil

Since the energy watch group proclaimed Peak Oil for 2006, it's interesting how photovoltaic could help to deal with the decreasing oil production. Here my studies about the subject:

How many kWh electric power are necessary to replace 1 litre oil product

How much crude oil can be replaced with 30% or 50% yearly increase of the photovoltaic world market

Extrem fast increase could replace 50 Million Barrel oil a day until 2018 --Pege.founder (talk) 12:43, 2 March 2008 (UTC)

Interesting inglish (sic) - "To avoid an oil crisis would be a more fast increase better." I don't see any reason to call 50% a year an extreme fast increase, especially because it does not intercept world energy needs without a huge collapse in energy requirements for 15 or 20 years. Most people don't realize the point that a 50% increase per year takes you from 0.05% to 80% in only 18 years give or take. However if anyone saw the danger facing the U.S. and the world today, a far greater danger than faced at the start of WWII when all U.S. production was stopped and turned into a total war effort to produce tanks, ships, bombs and planes, etc., and a similar "war effort" went into producing wind turbines, photovoltaics and hydrostorage, we could stop criminally burning oil and coal in maybe two or three years - certainly within 5 years, and not miss a beat. 199.125.109.113 (talk) 06:50, 3 March 2008 (UTC)

I do not call 50% increase extreme. But there is also a scenario where government pushes the production by 200% a year up, until at last 1000 GW peak yearly production. With this sceanrio, we could replace 50 million barrel crude oil a day until 2018. I see now, I did a mistake at this link, I corrected now this link. --Pege.founder (talk) 12:21, 3 March 2008 (UTC)

PV really replace fossil fuels? Signs not good.

It would be great if PVs could supplant Fossil Fuels and even supply 25% of our energy needs by 2030. However, It appears companies in the industry are minded to produce materials required in far too small quantity to make a difference. I calculate we need 16 million tonnes of polysilicon a year, and adequate PV cell and panel production to match:

 2005 Fossil Fuel consumption rate 		1.23E+013	watts
 Total global energy use rate 2005		1.50E+013	watts
 Global demand growth rate			2.00%	
 Projected energy use rate 2030			2.46E+013	watts
 Projected annual energy consumption 2030	2.16E+017	Watt-hours P.A
 Energy output from 1 watt solar cell		1.20E+003	Watt-hours P.A
 Installed PV capacity required to meet
 25% of our needs by 2030			4.49E+013	Watts peak
 Polysilicon required to make PV		8 		grams/watt peak
 Total polysilicon required if PV will 
 meet 25% of 2030 requirements			3.59E+014	grams
 Annual polysilicon production required 
 to meet 25% of our needs by 2030		1.63E+013	grams per year
 Or						16331486.94	Metric tonnes per year

Perhaps the problem is that the management at traditional manufacturers of polysilicon have not had the paradigm shift to imagine production volumes (and the associated economies of scale) necessary to make enough polysilicon to begin to replace fossil fuel. We need new people making and investing in polysilicon production. Both the tool manufacturers and the polysilicon producers are used to making polysilicon on the scale necessary to satisfy manufacturers of semiconductor electronic components. Nick R Hill (talk) 20:55, 5 May 2008 (UTC)

Polysilicon production is highly capital-intensive, and it take about two years to bring a polysilicon plant online after ground has been broken. These are the reasons for the shortage in purified silicon right now -- nobody wanted to put up the money for a plant until they were sure the market was there, but once they were sure the market was there it was too late to ensure enough supply. A lot of polysilicon plants are under construction right now -- so many, in fact, that I recently heard of one being canceled because the manufacturer is afraid we'll be in an oversupply situation in a few years.--Squirmymcphee (talk) 15:49, 9 May 2008 (UTC)

From looking at shares sites for manufacturers of polysilicon, it appears to me worldwide production is well under 100,000 tonnes per year. In 2005, worldwide production was 31,280 tonnes. New capacity is coming on-line, which will ease the short-term shortage, and perhaps double the 2005 supply rate. The rate of supply needs to increase to 522x 2005 supply. We need to make as much every 16 hours as was made in the whole of 2005 if PV is to provide just 25% of energy production in 22 years time.

There are other technologies which avoid the use of polycrystalline silicon, but these generally have a much lower conversion ratio so will not necessarily be as competitive and effective as polysilicon based cells, produced in adequate quantities, and at low enough cost, may be. And so far, they have not scaled to take Polysilicon's share of the market.Nick R Hill (talk) 21:20, 5 May 2008 (UTC)

One fairly plausible scenario by the Planetary Engineering Group[2] calls for increasing PV production by 200% per year until it reaches 1000 GW/year and then increases by 10%/year. It would reach 100% of current oil energy usage by 2022. At that point production would be 2600 GW per year, which will require 325,000 Metric tonnes per year. All I can say is start shoveling sand. There certainly is no shortage of raw materials, as that is only 203,000 cubic meters, or 0.203 sq. km by 1 meter. Since the Mojave desert is 57,000 km² did I make a mistake or is that a pretty insignificant requirement? I would get started with hydro-storage too, though, as photovoltaics only on average produce full power about 19% of the time, and wind only about 35%, leaving on average somewhere between 54% and 65% of the time with nothing, other than what can be provided from hydro-storage or other storage, such as vehicle-to-grid. 199.125.109.57 (talk) 19:08, 6 May 2008 (UTC)

Please remember that the purpose of this talk page is to discuss possible improvements to the article. Thanks. 19:15, 6 May 2008 (UTC)

Highly relevant. Relates to the sections on plausibility and growth. I just want someone to check my numbers. 199.125.109.57 (talk) 20:38, 6 May 2008 (UTC)

The article strongly suggests to me that PV can replace traditional sources of energy, such as Fossil Fuels. I have published these numerical facts I have pulled together after reading this article (and coming to the false assumption that PV may be on-course to replace fossil) and sharing the figures, to draw to the attention of those editing the page, how very far away from the goal of PV substantially replacing fossil fuels, we, as the human race, are. We can prevent people coming under a misapprehension by pointing out that we will not automatically move towards a PV based economy by making clear: a) how far away from that goal we are, b) how we are nowhere near on target to reach that goal, c) How there doesn't yet appear to be the level of investment and mind-set in the industry and d) what might be necessary for that goal to be realised. I fully accept the goal is technically achieveable, and agree that the idea of replacement of fossil fuel with PV is worthy of serious consideration. A section exploring of the potential for PV to replace fossil fuel, including a discussion of where we are today, and where we need to be, may help focus the mind of the right person for the job to make it so.Nick R Hill (talk) —Preceding comment was added at 22:29, 6 May 2008 (UTC)

Do you have any suggestions for a reference? The purpose of an encyclopedia is to report on subjects using reliable sources, and not to do original research. The fact that we were at 0.04% only four years ago gives me the idea that we are not very close to replacing fossil fuel, although I do like to point out the power of compound interest, which Einstein called the eighth wonder of the world. 199.125.109.57 (talk) 01:09, 7 May 2008 (UTC)

World energy usage is based on graph http://en.wikipedia.org/wiki/Image:World_Energy_consumption.png linked from article World_energy_resources_and_consumption. Energy use growth rate obtained by drawing a best-fit line through the graph for the last 10 years to 2005, differentiating, then adding 0.4% to account for the recent spurt of Chinese demand to 17% PA growth. The total figure I had proposed I have found closely matches the International Energy Agency's reference scenario: http://www.iea.org/textbase/country/graphs/weo_2007/Fig01-01.jpg . IEA figure around 17.8 Billion BBL based on Ton_of_oil_equivalent 11,630,000 watt-hours/barrel yielding IEA's estimate of 2.04E+017 watt-hours. My figure is 5.88% higher than IEA's. I am happy to base figures on either. The small difference in these long term projections is immaterial. Polysilicon required per watt is based on calculations based on current SunPower cells which appear to be a technology leader in Polysilicon base cells. A good source of clear reference is: http://www.sunpowercorp.com/Smarter-Solar/The-SunPower-Advantage/~/media/Downloads/smarter_solar/sunpower_dresden_paper.ashx which shows 7.5g/watt with further reductions possible. If you consider wastage (edge trimmings, failures) 8 grams per watt over the period appears sensible to me. The only other variable is how many watt-hours a 1 watt panel will produce in a year. This depends on irradiance. I assume panels will be fitted close to where power will be needed. I have used southern France/northern Spain as a baseline as shown in http://upload.wikimedia.org/wikipedia/commons/2/28/EU-Glob_opta_presentation.png . That is 1200 watt-hours per year per installed watt peak. I believe every variable I have used in my calculation is sourced, and correlated to within 10%. This is a 22 year projection. Events may unfold over such a period which could affect these figures substantially.Nick R Hill (talk) 22:58, 8 May 2008 (UTC)

While the numbers you use in your calculation might we well sourced, where the article is concerned your actual calculations and resulting conclusions constitute original research, which Wikipedia prohibits. Furthermore, if I were peer-reviewing your calculations there are several issues I would raise with your assumptions based on my quick reading (I don't have a lot of time to analyze/discuss this at the moment). First, I think it's a bad idea to extrapolate future growth in energy demand from historical rates of growth. What is the justification for assuming the next 25 years will be the same, plus 0.4%, as the past 10 years? You have the IEA projections, which are very well documented and far more credible than a simple extrapolation -- why not use them?

Second, electricity represents something like 15% of our total energy consumption (I'm pulling the numbers from memory, so I might be a little off here and there). Mind you, the primary energy required to generate that electricity is more like 35-40%, but the electricity itself is just 15%, and since PV burns no fuel it is this number and not the primary energy number you need to use for comparison purposes. If PV provides 25% of the world's energy use it will eliminate all of the primary energy required for electricity and leave a huge surplus of electricity to boot. Are you assuming that transportation, heating, and other non-electric uses of fossil fuel will all go electric?

Third, polysilicon required per watt has been decreasing at a rate that has only accelerated since the silicon shortage hit. While Sunpower is currently at 7.5 g/watt, they (and the rest of the PV industry) are targeting 5 g/watt in the short- to medium-term. There's no need to add anything additional for waste -- the figure reported already accounts for that (and if it didn't, a mere 0.5 g/watt wouldn't even come close to capturing the true amount of waste). To truly calculate the amount of polysilicon capacity required by 2030 you need to create a time series estimating annual PV production and the number of grams/watt of silicon required in each of those years. That would give you a year-by-year estimate of how polysilicon production needs to grow. If you do it that way, I think you'll find that the magic of compounding ensures that we have many, many years to reach the production level you assert, but that by 2030 we will need much more than you assert. Your figure is simply a 22-year average production rate, and I'm not sure how useful or informative such a figure is.

Even then, though, while this is an interesting topic of discussion it isn't something you can include in the article unless you first publish it elsewhere in a manner appropriate for Wikipedia to use as a source.--Squirmymcphee (talk) 15:49, 9 May 2008 (UTC)

I accept your overall point that information in Wikipedia needs to be well sourced. (Perhaps I should spend more time slicing positions away rather than arguing unsourced positions...?). You have raised a few questions i'll answer. 1) I had no apriori knowledge of the IEA's figures. It so happens their figures closely match mine. As noted, I am happy to drop my estimate in preference to their figure, which is better sourced than mine. 2) I am working from the principle that electrical energy can be substituted in all non-rural, grid-connected points where fossil fuel would currently be burned to produce heat. Moreover, electrical energy may generally provide a superior replacement for direct burning of fossil fuel, and such situations exceed 10% of today's fossil fuel consumption. (for thoroughness, this would need to be researched, but I don't expect many interested parties would be inclined to question it). Moreover, 25% would represent a proportion of additional demand, therefore little or no replacement of existing point-of-use equipment would be required to exploit an abundance of electrical energy in comparison to fossil fuels. 3) today's price for polysilicon is around $450/Kg vs $23/Kg for 2003. I'd suggest there is extraordinary pressure today on manufacturers of PV cells to reduce consumption of Polysilicon, even if the low-silicon design is non-optimal in other respects. Were the supply of polysilicon eased, you might expect PV cell manufacturers to direct effort towards issues other than minimising polysilicon usage. Another point, which I have not addressed, and poses some difficulty is that PV electricity supply is not available on demand, and depending on climate, may be unpredictable. Air Conditioning demand may tend to match PV production. Other demands would be unaligned with PV production, necessitating complementary power generation and/or storage. You have raised good points. Perhaps this makes a good basis for a peer reviewed article. Can you suggest suitable journals who may be interested? —Preceding unsigned comment added by Nick R Hill (talk • contribs) 20:35, 9 May 2008 (UTC)

CdTe growth possibility

PV's growth has not been projected accurately in the past and if past is prelude it won't be projected correctly any time soon. You might look into the IEA's and the EIA's track record predicting PV growth. You'll find relatively recent 2020 targets that have already been met. Alternately you can read anything from the 70s for the opposite result. You might learn a lesson from Vaclav Smil who writes convincingly about the perils of projection in Energy at the Crossroads. Or Lovins who writes descriptively about what is absolutely not going to happen in many of his books. My apologies Amory... Just kidding... Two other things: 1) Even without the current "extraordinary pressure" on silicon utilization, PV production and silicon requirements do not move proportionally. Squirmy mentioned this but there's also a report by BP you might look for that gives some numbers. These projections don't factor in CdTe which seems to be a rather disruptive technology. Just a few years ago T.J. Rogers of Sunpower was bragging about how silicon was going to "kick thin-film's butt". Check the earnings statements between Sunpower and Firstsolar and see who's kicking who... And then check back next year. 2) This is also in addition to Squirmy's thoughts on primary vs. secondary energy. A kilowatt-hour (3.6 Megajoules) can push an electric car 5 miles. Using this metric, 10 kWh (36 MJ) can push a car 50 miles. This compares to an efficient car burning a gallon of gasoline equal to 130 MJ. There are no simple linear projections to be made. Once you get out of the protective cover of your conversion tables it's a mess. Mrshaba (talk) 05:15, 10 May 2008 (UTC)

I will look for more information from those authors. There have been many announcements over the years of disruptive technology in the PV field. Yet, it appears polysilicon based cells, after decades, in terms of watt-hour produced, dominates. Until I can get a panel which has rolled off (even a small-medium scale) production line, connect a resistor and multimeter across it and wave it towards the sun, I discount the disruptive technology, and I hope anyone else will. These technologies are presented against a backdrop of polysilicon shortage. The raw material for polysilicon solar cells is fundamentally cheap, widely available and of low toxicity. The same cannot be said for Cadmium or Tellurium. Cadmium is poisonous, Tellurium is scarce. More so than Gold or Platinum. One of the 9 rarest elements on earth, the others mostly being radio isotopes. By contrast, Silicon makes 25.7% of the Earth's crust by mass. In terms of accuracy of demand projections, over 22 years, there are many unknowns. Some will lead to energy savings in some areas, others lead to increasing demand. I can't even start to take into consideration other technologies such as reverse electrodialysis which may become cost-effective once the technologies are no longer competing with pumping flexible, burnable fuel from the ground. Nick R Hill (talk) 10:31, 10 May 2008 (UTC)

I have carried out calculations on Tellurium availability which show that production of CdTe panels at current efficiency levels will not be much more than 1.5Gw(peak) per year. Using IEA estimate of 2.04e017 watt-hour global consumption for 2030, CdTe panels cannot offer more than 0.02% (or one five thousandth) of global energy demand by 2030 using my above insolation estimate. I will post the calculation on my user page if interested.--Nick R Hill (talk) 16:19, 10 May 2008 (UTC)

I agree that silicon dominates but CdTe has made a big splash this last year or so. I don't understand your reasoning for discounting CdTe. I tend to be prejudice towards Si technologies with higher efficiencies but I have to give the other technologies their due. Firstsolar is making and selling a product that works. I've heard FS is producing at nearly half the cost of their nearest competitor. It's true that Te is scarce but there are more things to consider than this. If the demand is high enough you can go after uranium in graphite or sea water. The same can be said of extracting additional Te from zinc or copper. NREL has carried out calculations for CdTe thin films and their estimates go up to 500 GW/year.[3] Mrshaba (talk) 17:11, 10 May 2008 (UTC)

I estimate 0.085g of Tellurium is needed to make every watt peak of solar panel based on 11% efficiency and 3 micron thickness of CdTe. http://seekingalpha.com/article/54614-first-solar-vulnerable-to-a-tellurium-shortage suggests 0.135g Te/watt. At my more generous figures, 500Gw/year implies access to 4.25e+10 grams Te/year. 42,500 Metric Tonnes per year. Current Tellurium production is 135Metric Tonnes/Year. According to US Geological Survey, the total world economically extractable Tellurium supply is 47,000MT. http://minerals.usgs.gov/minerals/pubs/commodity/selenium/tellumcs07.pdf . These facts imply that the 500Gw figure is not an annual panel production figure, but is a figure for total possible panel production ever. Given that high demand for Te is likely to drive prices up, CdTe would likely not remain financially competitive with PolySi. Given that there are no raw elemental material constraints for Polysilicon cells, Polysilicon may potentially supply all our needs. CdTe clearly cannot get close. --Nick R Hill (talk) 19:01, 10 May 2008 (UTC)

Hmmm...It's NREL's report not mine... They say production past 100 GW/year would face challenges but they also say 500 GW/year is hypothetically achievable.

"For silicon PV technologies, there are no availability limitations at any level of production. But for Cu(In,Ga)Se2 and CdTe, increasing production levels past 100 GW per year could be limited by indium and tellurium availability (see Figure 1). We would need to consider more aggressive extraction for zinc and copper, and more efficient refining methods for these primary ores of tellurium and indium. Developments in supply technology, such as extracting tellurium from manganese nodules on the sea floor, could also ease the potential materials gap. But improvements in PV technology would likely be the main driver: (1) technologies could use thinner layers than those used today, by a factor of 10; (2) materials lost during layer fabrication could be reclaimed and used; and (3) elements such as gallium or aluminum could be substituted for indium. We can also expect additional technological improvements over the next five decades that we cannot currently foresee and that would allow us to reach even 500 GW/yr of production from each of these technologies." Mrshaba (talk) 01:29, 11 May 2008 (UTC)

In 2004, NREL optimistically assumed a figure of 0.04665g Tellurium per watt peak. They then optimistically assumed that films of CdTe could further be reduced in thickness by a factor of 10 (bringing Te/Watt down to 4.6mg). They also optimistically assumed Te availability and refining rates 19x Global 2006 levels (USGS 2007). If (and that is a very big if) all these very optimistic assumptions are true (and I haven't seen any evidence to support a single one of them), then CdTe could really be used to make 500Gw/year between 2010 and 2030. That would account for around 5.2% of EIA projected global energy needs by 2030. I very much doubt it, like i'd doubt my neighbour will win the lottery this weekend.. --Nick R Hill (talk) 11:18, 11 May 2008 (UTC)

Based on this very sizeable debate, I think its reasonable to provide a link under See Also to a CdTe PV article SolarUSA (talk) 13:44, 24 October 2008 (UTC) Nevermind - already linked to cadmium telluride photovoltaics SolarUSA (talk) 13:59, 24 October 2008 (UTC)

Perhaps you guys know

This page and the solar energy page have a quote (see below) about PV providing .04% of the TPES. On pg. 3 of the reference provided the term "solar" is described as representing .04% of the TPES but I can't find where it says "solar" is PV only. There could be some concentrating solar or other solar contributors in there. The information as it is currently presented does not seem valid.

"Photovoltaics provided 0.04% of the world's Total Primary Energy Supply (TPES) for the year 2004, increasing by an average of 48 percent each year since 2002, at a rate of growth to reach 0.40% by 2010." [4]

The 48% growth rate quoted on the page also seems misleading. In 2007, installed PV was about 1000 MW less than the production figure quoted from the Earth Policy Institute. It seems possible that idle production capacity is being counted as production by the EPI people. Both Maycock and Solarbuzz list installation numbers that are 25% lower than this. [5]Mrshaba (talk) 17:43, 6 May 2008 (UTC)

"Idle production capacity"? With the demand for product there aren't any idle factories that I know of. The folks I have visited are producing as fast as they can. There is, however always a lead in production vs installation, which accounts for the material that is in the process of being installed and shipped. Marketbuzz quotes a 62% increase in 2007. In installations. "World solar photovoltaic (PV) market installations reached a record high of 2,826 megawatts (MW) in 2007, representing growth of 62% over the previous year." That would make the 48% number highly conservative, no? 199.125.109.57 (talk) 18:03, 6 May 2008 (UTC)

Sharp idled about half their production capacity last year due to the constrained poly supply. Many others also idled a portion of their production. As to the 62% growth rate for 2007 you have to compare it against the 19% growth rate Marketbuzz reported for 2006. To be meaninful the page should use data going back to 1997 when growth rates jumped sharply and have since averaged around 35%. The 48% number is not conservative.

Page 50 of this source lists PV energy production as 1 TWh (3.6 petajoules) in 2001 when PV installations were around 1 GW worldwide. Page 50 also lists the other solar technologies and if you add them up (206 PJ) and divide this number by worldwide energy use (approximately 471,000 PJ - 2004 number) you come up with the .04% figure from pg. 3 of the IEA ref[6]. The .04% number clearly includes all "solar" inputs and should not be used to describe a PV only contribution to the TPES.[7] Mrshaba (talk) 18:34, 6 May 2008 (UTC)

1997 is a highly artificial year to go back to. Normally people use either the last year available or the last five years to indicate rates of growth. PV has shown an on one year off the next cycle as suppliers catch up with demand. However, it isn't our job to question the accuracy of the sources as much as it is to record them. 199.125.109.57 (talk) 20:44, 6 May 2008 (UTC)

The TPES information in the intro is incorrect. The projection based upon this information is also incorrect. Please see pg. 50 of the reference I provided and decide for yourself. Mrshaba (talk) 21:13, 6 May 2008 (UTC)

<=Do you have a number for CSP in 2004? As far as I know there are not many facilities although they tend to be large. All I can account for is less than 400 MW, while 0.039% of 11,059 Mtoe represents an absurdly high number for PV, about 30,137 MWp. The source says they got their numbers from IEA Energy Statistics. 199.125.109.57 (talk) 02:24, 7 May 2008 (UTC)

This source has CSP for 2001 [8]. Page fifty. Both then and now the bulk (over 90%) of counted solar energy usage comes from hot water. Mrshaba (talk) 15:42, 7 May 2008 (UTC)

Low temperature solar heat is a separate line item, 57 GW in 2001. CSP is 0.4 GW and PV 1.1 GW in 2001. PV installed at the end of 2007 was 12.4 GW. I believe that CSP has not grown as much. I guess I wasn't that far off from 400 MW. 199.125.109.57 (talk) 21:02, 7 May 2008 (UTC)

1.1 in 2001 to 12.4 in 2007 is a 49.7% growth rate. 199.125.109.57 (talk) 21:21, 7 May 2008 (UTC)

Lists

You might consider moving the List of Research institutes and Industry associations to the List of renewable energy organizations page. Mrshaba (talk) 16:27, 9 May 2008 (UTC)

New data

Is this available for 2007? The "Produced, Installed & Total Photovoltaic Peak Power Capacity" table is looking very out of date. 199.125.109.77 (talk) 20:05, 20 May 2008 (UTC)

I see that someone put old data into the new table, that is 2006 data into the 2007 table. Even though there never was, to my memory, any 2005 data in the 2006 table. Did you want new data or not? Or is this old data, side-by-side the new, simply to emphasize the great difference in market movement (JPN down, all else up & ESP way up)? (Note: I maintained the old references within the new table so that the sum-total for 2007 = total for 2006 + the installed in 2007.) If you wanted a table showing the history of installations per annum, or the history of total installed per annum (each of which being two rather different tables, each within my ability as all of the references have already been populated into the 2006 table) then you should request those other tables of me or someone else equally dedicated, while specifying an article-section as their destination(s). I point-out at this time, that the data used for 2007 installations does not appear to be either official data or comprehensive data, as we are still waiting for the IEA's university participants to finally get around to posting their surveys. It is for this reason alone, that I will not yet delete the 2006 data from the 2007 table to make room for all of the 2007 data, as the 2007 table has yet to be comprehensively populated. BTW, the Feed-in Tariff data that I entered was adjusted for 2007 exchange rates from the reference cited, Australia and South Korea are off (the World maximum was adjusted to equal the South Korea maximum (55.84 EU¢/kW·h, not 59.3246 EU¢/kW·h as it was in 2006)), but I'll let someone else try and fix the table until we get our hands on the latest IEA data.--202.168.102.96 (talk) 08:07, 23 May 2008 (UTC)

The new table had five columns missing from the old table. In their place, until the full data is available, it was easiest to just add in the 2006 installation data. Showing three years worth of installation data would also be even better. There is definitely a limit to how many columns can be shown - when the on grid/off grid and delta on grid/off grid columns are added the historic data will have to go. 199.125.109.136 (talk) 04:58, 24 May 2008 (UTC)

We see that one hour previous to this comment, Kardrak has just made another edit to this article without giving any reasons or consultations to it's wiki-community, this time undoing the edits of many, including but not limited to those we made at the request of this talk-page-section less than 3 weeks ago. This is not the first time this user has made an edit to this article that has needed to be reverted for it's lack of just cause (Exhibit B: Our response to this user's attempt to insert unreferenced data into the table for Mexico: User talk:Kardrak#Photovoltaics.23Worldwide installed photovoltaic totals.) We will not be reverting Kardrak's latest edit, as we are still waiting for the IEA to finally get around to posting the official results for 2007. We recommend either User:Wtmitchell or User:Nigelj be requested to do the reversion, as they made recent edits to the article and seem eminently qualified to make respected changes.--202.168.102.96 (talk) 00:10, 6 June 2008 (UTC)

External links

Request for link to SustainableX.com solar portal. It has a directory of solar manufacturers http://sustainablex.com/index.php/Portal:Solar - Rufus 14/July/2008 —Preceding unsigned comment added by 82.118.72.132 (talk) 15:36, 14 July 2008 (UTC)

Merger discussion

A merger discussion has been started regarding the organisation of Photovoltaics, Photovoltaic array, Solar panel, Photovoltaic module, Photovoltaic system and Solar cell. If you would like to contribute to this discussion please click here. GG (talk) 08:20, 25 July 2008 (UTC)

Cosmic ray / Cosmovoltaic panel ?

This is an open theory question for the scientists. Is it possible to build a semiconductor material to convert cosmic rays into electrical current?

Cosmic rays seem to be mostly useless and space agencies spend much of their time building shielding to block it out. Has anyone explored the possibility of making a Cosmovoltaic panel to turn this otherwise harmful energy into useful electrical power? And if so, what would be the proper scientific search term for it, because I have never heard of anything like it. DMahalko (talk) 01:34, 4 October 2008 (UTC)

In order to do this the cosmoelectric effect should first be discovered. Further the energy of cosmic ray is so high that it will push the electron on valence band too much and blow up. The consequence of this is beta-ray-like harmful ray, not electric current. Yuletide11 (talk) 09:46, 31 January 2009 (UTC)

Worldwide installed Photovoltaic Totals

I would like to know who produced the table? I think there are some simple changes that can improve it.

1 - get rid of the colors.

2 - get rid of the first zero in the 0800-0950 notation.

3 - round all the numbers to the closest 100 kW. This would lose detail but improve comparison.

4 - To improve readability I added column widths and spacers to the table with these edits: [9][10] but they have been removed by a troublesome anon with this edit. Perhaps my method of aligning the data can be improved but the idea of aligning the data consistently should be pursued. Mrshaba (talk) 01:47, 30 October 2008 (UTC)

1 - the colours are helpful and should stay.

2 - the first zero was added so that that column will sort properly.

3 - the numbers range from tiny to large so rounding all to one particular value doesn't make any sense - Germany could be rounded to 10 MW, Finland to 10 KW, for example.

4 - the table is way too wide already to make it wider by trying to line it up.

What does need to be done to the table, though is fix the ?'s in the ref column, add many additional countries, and check all the references. Who produced the table is not important, it has been in the article for a long time, though updating it each year is a major undertaking, and I thank everyone who has taken the time to do that. 199.125.109.38 (talk) 03:25, 30 October 2008 (UTC)

What do the colors mean? There's no explanation for them that I can find. If they're just there for decoration then they need to go.--Squirmymcphee (talk) 22:56, 3 November 2008 (UTC)

The colors separate the insolation ranges and make the table much easier to read. They are not there for decoration. 199.125.109.37 (talk) 03:47, 4 December 2008 (UTC)

Photovoltaic power plants

There are many new PV power plants coming online and our List of photovoltaic power stations has gotten rather out of date. Any help with updating would be much appreciated. Also, we need some more individual articles on the larger plants listed. Thanks. Johnfos (talk) 06:04, 12 January 2009 (UTC)