Talk:Growth of photovoltaics

Misnamed

This article is not about the history of PV. It appears to be about PV system deployment. I propose renaming it to Photovoltaic system deployment. Jojalozzo 12:16, 7 July 2010 (UTC)

I agree. I was thinking this is a list. Anyway this is more about power generation capacity from solar cell technologies. Photovoltaics is a term used for study and not production. Photovoltaic is a redirect to Photovoltaic array which I find overly restrictive and imprecise for this list. So maybe something more like List of semiconductor based solar power generation capacities. No, I'm not happy with that name, but a change is needed. Vegaswikian (talk) 22:22, 15 July 2010 (UTC)

Growth Rate Wrong?

The chart of new PV production shows 77,000 MW projected capacity production in 2016, and 50,655 MW estimated capacity production in 2015, but describes this as 34% growth in new capacity (clearly not in capacity, as 0% growth rates are shown). But that's 52% growth in added capacity. — Preceding unsigned comment added by 96.95.24.246 (talk) 18:22, 7 February 2017 (UTC)

You are right. I'll change it. --Ita140188 (talk) 02:40, 8 February 2017 (UTC)

Changing page title and scope

I would say, something like: Photovoltaics_solar_power as per Concentrated_solar_power. And anyway displaying every year's results is too cumbersome. What would be if every subject, like List_of_countries_by_population kept every year's list ? --Robertiki (talk) 19:09, 15 April 2014 (UTC)

And to be merged with Photovoltaic power station --Robertiki (talk) 19:12, 15 April 2014 (UTC)

Chart caption

I suggest putting the caption of the chart below the chart and not as currently above, like the other images/pictures in the article are designed/layouted. Sadly I do not understand the template that is used here to do it myself. 78.35.203.136 (talk) 07:21, 20 June 2014 (UTC)

global electricity demand

"By the end of 2014, cumulative photovoltaic capacity reached at least 177 gigawatts (GW), sufficient to supply 1 percent of global electricity demands"

I think that this paragraph is wrong, it has no citations, how is it calculated?

the world factbook says https://www.cia.gov/library/publications/the-world-factbook/geos/xx.html

Electricity - production: 22.03 trillion kWh (2011 est.) that is 22.03 trillion kWh / year = 2500 gigawatts

Electricity - consumption: 20.45 trillion kWh (2010 est.) that is 20.45 trillion kWh / year = 2300 gigawatts

http://en.wikipedia.org/wiki/Electric_energy_consumption (cites world factbook. 20,279,640 GWh / year = 2300 gigawatts) https://en.wikipedia.org/wiki/List_of_countries_by_electricity_consumption (cites world factbook again 19,320,360,620 MWh / year = 2200 gigawatts)

According to this http://www.eia.gov/cfapps/ipdbproject/IEDIndex3.cfm?tid=2&pid=2&aid=12 Total Electricity Net Generation (Billion Kilowatthours): 21,531.709 in 2012 = 2500 gigawatts

177 gigawatts / 2500 gigawatts = 7%, not 1%

So now I am confused. The world consumption data is from 2010, 2011, 2012 did it grow so much in 2014? did I calculate something wrong?

This other paragraph has at least a citation: the eia Technology Roadmap: Solar Photovoltaic Energy 2014 edition

"By 2050, solar power is anticipated to become the world's largest source of electricity, with solar photovoltaics and concentrated solar thermal contributing 16 and 11 percent, respectively. This will require PV capacity to grow to 4,600 GW, of which more than half is forecasted to be deployed in China and India.[7]"

Can it be true? it predicts an electricity usage of 4,600GW * 100/16 = 28,750 gigawatts in 2050 if I understand it correctly. More than 10 times current electricity usage. — Preceding unsigned comment added by Argento (talk • contribs) 16:54, 5 April 2015 (UTC)

This paragraph "By the end of 2014, cumulative photovoltaic capacity increased by 38,700 MW and reached at least 177 GW, sufficient to supply 1 percent of the world's total electricity consumption of currently 18,400 TWh.[6]" has the same problem 18,400 TWh / year = 2100 gigawatts

177 gigawatts / 2100 gigawatts = 8%, not 1%, so unless I am doing something wrong, these percentages are wrong. — Preceding unsigned comment added by Argento (talk • contribs) 17:08, 5 April 2015 (UTC)

The only possible explanation is that the article is talking about nominal power (gigawatt-peak). In this case I think that every reference should be changed to watt-peak or this is confusing. A gigawatt-peak produces (depending on where the panels are installed) 1000 gigawatthour /year = 0.11 gigawatt, so the calculations will be right. — Preceding unsigned comment added by 79.35.187.239 (talk) 09:20, 6 April 2015 (UTC)

Thank you for your feedback. Here's a quick reply:

• The figures you mentioned are all sourced from IEA-PVPS snapshot report, p.6. I added the page-number to the citation in order to make it easier to find the figure (here). By the way, your comment "This other paragraph has at least a citation" is inappropriate. All figures above are fully cited. You can't expect the lead section to have a citation behind each and every figure, especially when they are repeated in more detail in the body of the article. Also see WP:LEAD.
• You cannot calculate annual power generation directly from capacity figures. Full load hours and capacity factors have to be taken into account. That's the reason why you get 7% instead of 1%.
• Yes, the article uses watt-peak, the nominal nameplate capacity for solar PV and it says so in the beginning of the first section. However, power generation always needs FLH/CF to be taken into account, irrespective of whether it's solar, wind, coal, or nuclear. It is not reasonable to change every unit from watt to watt-peak. Sometimes it makes sense to label capacities with W_p (as the article does in several places) in order to differentiate from W_AC.
• The article uses figures from the International Energy Agency (consumption of 18,400 TWh as per – Key World Energy Statistics 2013). Other sources as the domestic data you mentioned may somewhat differ.
• Hope that helps. Feel free to ask again and try to be a bit more focused in your posts and sign it with four tildes (i.e. ~~~~)

Cheers, Rfassbind -talk 16:18, 22 April 2015 (UTC)

Looks like there is some confusion between production capacity, measured in TW or 1000s of GW, and production, measured in TWh or 1000s of GWh. 1 TW capacity could generate 8,760 TWh in a year! (Although with photovoltaics, probably about 1/3 that much.) 96.95.24.246 (talk) 18:55, 7 February 2017 (UTC)

Pollution aspects

Pollution aspects

In the manufacturing process of photovoltaic cells, Silicon tetrachloride is produced as waste by product when not reused. Silicon tetrachloride can acidify the soil or water when dumped as waste material . Cadmium metal used in some PV cells (CdTe), can cause heavy metal pollution if the disposed PV cells are not recycled. PV cells manufacturing involves substantial amount of water consumption and also moderate regular requirement of water during their life cycle use for cleaning the dust deposits on the panels.

The section above [edited] was added by me explaining the pollution aspects of PV cells. The section was deleted by User:Rfassbind on 6 May 2016 saying the page is not appropriate for the pollution caused by the PV cells. It is totally inappropriate and not neutral view on solar power by concealing the pollution aspects of PV cells. The pollution generated in PV cells manufacture becomes part of pollution in solar power generation when PV cells are used. For information to the readers. 49.207.221.221 (talk) 15:38, 9 May 2015 (UTC)

I have already suggested some alternative articles (see edit comment). In addition, check out Solar power#Environmental impacts, which I forgot to mention. But I have to warn you, the article in IEEE Spectrum refers to an outdated washingtonpost article from 2008. Make sure the information you want to add is sourced to more recent events or studies. -- Rfassbind -talk 16:16, 9 May 2015 (UTC)

You need to explain first why is this article not appropriate place for indicating pollution aspects of PV cells. The cited reference is from reputed IEEE (engineering publication) published in August 2014. If the pollution aspects are no more valid, give the necessary full information with refs. here and close the topic. Being an ardent editor of Wiki articles, are you warning general readers or content enriching people without any returns. 49.207.221.221 (talk) 16:38, 9 May 2015 (UTC)

Unfortunately, accusations of me being this and that is not very helpful. The reason for the removal of section "Pollution aspects" is because of its unsuitable topic for the article. It is WP:Out of scope. The article Growth of photovoltaics specifically deals with the history, current status and future expectations of worldwide deployment of photovoltaics, with a focus on installed capacity and economic aspects. In other words, just because the article's title contains the word "photovoltaics" is nowhere near good enough to add anything related to it. Moreover, if the tone in this thread does not change, I will refrain from the conversation for good. -- Rfassbind -talk 20:25, 10 May 2015 (UTC)

Thank you for changing your tone of conversation with wiki readers and content contributors. I would be happy that the content deleted by you be added in appropriate wiki page by you (being regular editor of many pages on solar energy) as the the content is no way falsifying PV application (vis a vis to other type of electricity generation) widely but bringing out the pollution causing aspects in a subtle way. There is already lot of content which is WP:Out of scope to your scope definition. No body adds content without conviction to what he is writing. Instead of unilaterally deleting the content, express your desire to delete others content in the talk page, give 10 days (say) time for response and if proper response is not coming then delete/modify others content as you like.49.207.221.221 (talk) 21:23, 10 May 2015 (UTC)

Predictions for 2020 all wrong

Extrapolating from the table in section 5.2 "Worlwide cumulative" by 2020 there should about 1200 GW cumulative global installed capacity since there is an approximate doubling of the cumulative total every two years. Even pessimistically allowing only 1.7 times rather than double it would go from 178 GW in 2014, to 302 GW in 2016, then 514 in 2018, and 874 GW in 2020.

So all the forecasts in section 2.2 "Global short-term forecast (2020)" are way too low, the highest being 696 GW cumulative. 88.203.88.246 (talk) 17:49, 7 December 2015 (UTC)

Agree totally. The growth rate is exponential not linear as anybody can see from the "Worldwide growth of photovoltaics" chart at the top of the Article. Even at the pessimistic 1.7 exponential factor you mention then 874 GW will be installed by 2020 and 21,200 GW by 2032 which is 100% of world electricity requirement. Therefore also contradicting the statement in the intro that "By 2050, solar power is anticipated to become the world's largest source of electricity". That is completely wrong because solar will power the whole world entirely by 2032 according to the data in the "Worldwide growth of photovoltaics" chart if extrapolated correctly with the 1.7 exponential factor. Please stop misleading the public, Wikipedia, as you have been doing here for years. I pointed this out ages ago but nothing changes. 141.8.114.29 (talk) 16:03, 6 March 2017 (UTC)

How do you know that these projections for 2020 are all wrong? What makes you think that a linear extrapolation from currently installed capacity and growth rate is correct? Personally, I am also more optimistic than most of the 2020-forecasts listed in the table, but that doesn't mean anything. My opinion is a worthless as yours as long as you can't back up your claim with a reliable source (i.e. a 2020-projection by a reputable organization/company). I think you should read this guideline. In addition, there are some clear statements (e.g. the second paragraph of the lead section) about the quality of growth-projections, especially those made by the IEA... just follow the adjunct citations (currently number 6, 7 and 8); it worth a read... Rfassbind – talk 22:51, 8 December 2015 (UTC)

The "reliable source" you require is simply the "Worldwide growth of photovoltaics" chart at the top of the Article. Just look at the data and you can see the installed GW are increasing by 1.7 times or more every two years. It is quite obvious. Then just do a few multiplications by 1.7 and you get 874 GW by 2020 and around 21,200 GW by 2032 namely the entire world's electricity requirement. 141.8.114.29 (talk) 16:14, 6 March 2017 (UTC)

Without pushing a POV I am quite comfortable affirming that IEA projections are voluntarily wrong. They are mainly paid by oil companies and OPEC states so they do not want to affirm facts potentially pushing the price of oil down. Silvio1973 (talk) 11:49, 11 April 2016 (UTC)

This may be interesting: http://www.vox.com/2015/10/12/9510879/iea-underestimate-renewables --Ita140188 (talk) 06:45, 18 October 2016 (UTC)

Exponential growth does not continue for long, usually. It's all about guessing when it is going to slow down. There's no reason to believe that this rate of growth is going to be sustained until 2020, and surely it seems unreasonable to imagine it going on until 2030. --Ita140188 (talk) 10:00, 7 March 2017 (UTC)

This discussion is hilarious. You can't know objectively what it will look like. For me the best prediction is the exponential one. You may mention the underestimating article alongside with their ludicrous linear predictions. 89.103.252.191 (talk) 14:22, 22 March 2017 (UTC)

As you can see from Solar power in Germany or Solar power in Italy, growth rate are exponential up to a point, then they slow down dignificantly, resembling a Logistic function. In both countries, this happened when the share of electricity by PV reached around 7-8% of total electricity consumption. Of course these are only two examples, but if had to guess for the world capacity growth, I would think of something similar, surely not exponential at the same rate up to 100% of electricity consumption. This would make no sense whatsoever for so many reasons. --Ita140188 (talk) 05:25, 12 April 2017 (UTC)

Update needed

Hi, the whole page needs an update. There are updated data for 2015, see e.g. https://www.greentechmedia.com/articles/read/gtm-research-global-solar-pv-installations-grew-34-in-2015 Also I would remove a lot of not very useful information, for example previous and outdated previsions are useless IMO. The table "IEA – projected annual PV installations" comparing different previsions between 2013 and 2014 is also useless. The article should just talk about past data (removing all past previsions) and possibly previsions for future data.

There need to be a decision on what to do with past projections. I think it would be interesting to have an overview of how PV was expected to grow in the past compared to how it turned out to be. But surely it needs to be rewritten and it seems like a lot of work. --Ita140188 (talk) 09:30, 1 November 2016 (UTC)

Concur that an update & re-write are long overdue. 71.175.173.113 (talk) 05:39, 8 January 2017 (UTC)

Before April 2017, there probably won't be a "Snapshot of Global Photovoltaic Markets 2016". Until then, a significant update can't be done without losing consistency. In the meantime, I'll be revising the article's historic data, moving past projections (previous forecast) and annual deployment figures by country to History of photovoltaic growth. Constructive suggestions posted in this thread during my multi-edit revision are appreciated, Rfassbind – talk 14:05, 7 March 2017 (UTC)

2014 numbers are all throughout this article, often saying current but not dated. In a field changing as rapidly as this any number needs to have an associated date. Maybe we need to use "As of" again. Rmhermen (talk) 19:10, 27 October 2018 (UTC)

Forecast

There is not a single current prediction in this entire section. None of it is useful to the reader. All of it either predicts things at already past dates or has been superseded by other, likely, just as inaccurate predictions. No such section should probably exist as it requires a great deal of work to keep updated (which it has evidently not been) and solar predictions are infamously inaccurate. Rmhermen (talk) 04:18, 19 October 2018 (UTC)

I concur. This section is quite out of date and most of its content is not worth keeping. It would be great if it could be overhauled with a long-term global focus, but the past and regional forecasts are not necessary here. My suggestion would be to move the GTM forecast (through 2022) and a summary of the long-term section to a new subsection of History of Market Development. Reywas92^Talk 04:59, 19 October 2018 (UTC)

I don't disagree that a lot of information in the section is a bit old. Maybe it could be condensed and updated with newer information? I don't believe that "forecast for 2017" section should be there. Most of that information should be covered in a short term report. I do believe that there should still be a short term and long term predictions sections. Short-term meaning maybe 2018-2030 and long-term meaning present to 2050. The current long term section could definitely use some condensing and updating. I'm not too sure about that regions section. I would imagine that a long term forecast report would already mention some things about the regions with highest projected growth. I think that it's important to have some projections from reputable sources seeing as the whole article is about the growth of photovoltaics.--SeminoleNation (talk) 05:03, 19 October 2018 (UTC)

The awful track records of forecasts is perhaps the most significant thing to report. See [1] for instance. The IEA was ridiculed for the predictions and released a second set in 2017 with "new" methodology and even in its first year only continued to miss (73GW instead of actual expected 103MW). The U.S. agency a few year ago released a ten-year forecast that was lower than the actual completed in the very next year (meaning projects already under construction when the report was released exceeded their 10-year total estimate) GTM is slightly more realistic but updates their current year forecast multiple times throughout the year - which is not a good way to create a stable article. We don't have people who will update that consistently. Rmhermen (talk) 18:03, 27 October 2018 (UTC)

Given the IEA's track record, why is it the only projection cited in the intro? Even PV industry association projections are remarkably conservative, forecasting PV to "more than double over the next five years" when it's more than quintupled every five year period since 1990. The IEA forecast of 4.7 terawatts by 2050 is absurd. Prices continue to fall, so 4.7 TW is more likely by 2026 than anytime after. EllenCT (talk) 06:51, 21 November 2019 (UTC)

PV deployment growth has slowed down significantly in recent years, and is approaching a steady growth (as opposed to exponential). And the more it is deployed, the more it is difficult to deploy more (due to increasing grid integration costs, such as storage and transmission infrastructure). Of course prices are falling too, but assuming it will grow as it did in the past is not obvious. In the near future in saturated markets the dominant costs will be grid integration, not the solar panels themselves. It will need much support from countries and that is mainly a political question. Also keep in mind that while the IEA forecast has been terrible at predicting PV deployments, solar still plays a very minor role in the world energy system (even when considering electricity only it is around 2%), so its deployment is more volatile. --Ita140188 (talk) 03:40, 22 November 2019 (UTC)

@Ita140188: what is your source for approaching steady growth? I keep seeing tenders under $0.02/kWh and I'm not seeing them slow down. EllenCT (talk) 03:36, 25 November 2019 (UTC)

If you plot the cumulative growth %, the trend is quite clear. It is going down. That doesn't mean that annual deployments are decreasing, they are in fact increasing. But they are not increasing exponentially, and if this trend continues, at some point they will increase constantly. Of course this is the only sustainable outcome in the long term, since exponential growth cannot go on forever. The point is it is difficult to predict at what solar % we will have stabilized. Also note that in the long term a constant deployment means a constant installed capacity, since the lifetime of panels is not infinite (all Wiki articles assume that "cumulative installation"="current installed capacity", which is true only in early stages of deployment or with exponential growth). --Ita140188 (talk) 03:45, 25 November 2019 (UTC)

What is your source for those assertions? [2] Shows a one-year stall flat in 2018, under tariffs, in contrast to an actual decline in year-over-year figures in 2013. Would you have made the same prediction then? Do you believe year-over-year variability is more predictive than the r² of 0.95 for an exponential fit? EllenCT (talk) 04:17, 25 November 2019 (UTC)

@EllenCT: Also, I am not sure what you mean with your reference to prices. Prices and deployment are not the same. Also, as I mentioned before, for saturated markets (such as California or Germany) we are approaching the point where the grid integration costs are higher than the panel costs. Even if your panels cost zero, they are useless if they produce energy only when all others are also producing and nobody needs additional energy (value is zero). At that point, your true cost of energy becomes the cost of storage, not the cost of the panels. --Ita140188 (talk) 03:49, 25 November 2019 (UTC)

@Ita140188: Again, what are your sources for the saturation assertion? I see just the opposite: "Experience from Germany, Spain and Scandinavia shows that low-cost integration is possible, while the continued growth in operating experience, development of new markets for flexibility and emerging innovations are constantly reducing the expected costs and difficulty of integrating ever higher shares of VRE in the system."[3] If the 1,700 gas plants in North America are all producing at about $0.04/kWh it still makes sense to replace them with PV at $0.018 or lower even when all the demand is met. Do you think power company CEOs are going to forgo that opportunity to earn greater bonuses pegged to their financial performance? EllenCT (talk) 04:34, 25 November 2019 (UTC)

@EllenCT: Article talk pages are not forums, so we should maybe move this discussion to our talk page. Anyway, for my first comment, cumulative growth was constantly over 40% before 2012, and constantly below 40% after. For this year, it will be around 25%. It seems a declining trend to me. An exponential growth would need a constant % increase. Of course when you plot very long time series, such as in the figure, it is difficult to see the recent trend.

The exponential model will fit particularly well because it gives same weight to values from the 1990s as to values from today, even though we have several orders of magnitude more deployments today. As for the saturation assertion, it is well known in the literature. There are so many references that I am not sure what to reference here. To be short, as long as you have a lot of dispatchable generation and backup, as in the case of coal in Germany, you are ok. But if you want to shift to high penetration solar without subsidizing idle coal capacity, then it's just logic: you need a lot more storage and a lot more transmission capacity (as compared to a coal based power system for example). To be clear: I would be super happy if I'm wrong and solar grows to 100% in 2030. --Ita140188 (talk) 04:37, 25 November 2019 (UTC)

Perhaps it would be an improvement to the article to explain that the natural market progression to take the highest cost plants offline when solar is added leaves the more easily dispatchable second best cost gas plants remaining, thus solving the load shaping issues without storage. I stand by my assertion that leaving the IEA as the only projection in the intro without specific counterpoint is an affront to accuracy and degrades the quality of the article. EllenCT (talk) 04:42, 25 November 2019 (UTC)

For this to work, you still need gas plants and you would still produce a lot of CO2. Also, you need a lot of peaker gas plants, which are the most expensive ones. The whole system would be a very inefficient use of capital, since you would have very low capacity factors for most of your dispatchable plants (either gas or storage). Either way, I am not saying it's impossible to integrate, but the more the penetration, the more these costs cannot be ignored. There is a point where these costs exceeds generation costs. By the way, nowadays it's not only IEA that forecasts stable deployments, it's also Greentech Media (Wood Mackenzie) which are quite enthusiastic about solar: [4]. --Ita140188 (talk) 04:50, 25 November 2019 (UTC)

Here are a bunch of peer reviewed papers claiming 100% renewables is achievable in every market. I'm happy to read the countering evidence if you point me to it. EllenCT (talk) 07:11, 25 November 2019 (UTC)

@EllenCT: I know the literature well. I also know some of these authors personally. I never said it's impossible, I said it would probably very expensive and it is definitely very unlikely to happen. Also, not all literature has the same quality. In particular, some papers by Mark Z. Jacobson have very serious flaws in my opinion, see [5]. All these papers are heavily reliant on assumptions which are difficult to evaluate clearly. --Ita140188 (talk) 07:30, 25 November 2019 (UTC)

@Ita140188: I will give you my reaction to the first of the 19 points raised in that document, and then ask you a question. As for, "nuclear power produces over 60% of total US low-carbon electricity today, but in Jacobson et al. they are omitted entirely from consideration." My understanding is that the issue is one of cost, such that if you shut down a ~$0.15/kWh plant under a tariff which allows charging customers $0.25, replacing them with $0.05 renewables, that gives you $0.10/kWh extra revenue without which you would not be able to replace your fossil plants with renewables as quickly. Now, which of the 19 points do you personally find the most persuasive? EllenCT (talk) 08:13, 25 November 2019 (UTC)

All points are important. I think the most glaring absurdity in Jacobson's assumptions is that hydropower can provide 1300 GW of power, which is over 15 times the currently installed hydropower capacity in the US. This while accounting for exactly zero capacity expansion of hydropower. All the other points are also important, but this alone shows you how flawed some of these studies are and how their conclusions have limited value if any. As for your repeated point about lowest cost generation, this is actually a bad point about renewables. Of course they enter the market at zero marginal cost, so when there are too many of them they depress the value of electricity at that time until the value of generation (also for themselves) is zero. Renewables are profitable as long as there are expensive dispatchable generators that increase the marginal cost of generation in the electricity market. --Ita140188 (talk) 09:44, 25 November 2019 (UTC)

Inconsistencies in table

The two cited sources in the main table, IRENA and IEA-PVPS give very different numbers for many countries. I suspect it may be due to IRENA only considering utility scale installations (but I may be wrong). For example for the United States in 2020, IRENA gives 75 GW (in the table now), while IEA gives 93 GW ([6]). Same for many other large countries such as Japan, Germany, and India. We should use only one reference for the table to avoid inconsistencies. For example, for the United States it appears that 53,184 MW were operational in 2018, 13,300 MW were installed in 2019, and the total for 2019 is... 60,682 MW, and not ~66 GW as it should. I suggest to use IEA data (which appears to be more comprehensive) when available, and use IRENA only for countries for which IEA data is not available. --Ita140188 (talk) 02:55, 27 May 2021 (UTC)

EU data

I tried adding EU data for 2021, but as noted below, the data vastly differ between the two sources. Where are the 5-digits numbers coming from? Also, how is "EU" handled with regards to countries joining/leaving the block? Touyats (talk) 08:48, 14 May 2022 (UTC)

Consumption vs. production

@Ita140188 Many of the sources in this column appear to show statistics for production rather than consumption. This tends to be easier to calculate because it excludes imports and exports. I think that's also preferable to use because it's more straightforward in comparison and consistency. Either way, the current column title of consumption doesn't accurately capture all of the entries. Perhaps https://ourworldindata.org/grapher/share-electricity-solar should be used as it uses the same methodology for all countries. Reywas92^Talk 18:12, 6 July 2023 (UTC)

Graphics including sourced forecasts

Forecasts from BloombergNEF

@GliderMaven: Note that WP:CRYSTALBALL relates to "unverifiable speculation, rumors, or presumptions"—which does not encompass rational, evidence-based forecasts like that from BloombergNEF. Especially in climate change and related areas such as renewable energy, forecasts are critical in present policy decisions. For example, IPCC publications are replete with projections to 2100.

1. Are you arguing that Wikipedia should not have any forecasts at all? If not, where do you set the bar?

2. Do you disqualify forecasts because other forecasts have been off (quantitatively) in the past? If so, how far off must the other forecasts be, for you to justify your judgement that new forecasts should be excluded.

Please explain where you draw the line, and why. —RCraig09 (talk) 20:11, 21 September 2023 (UTC)

WP:NOTCRYSTAL says 'Wikipedia does not predict the future.'

It's pretty clear that all or virtually all quantitative predictions that have been made more than about a year ahead on this page have routinely been HORRIBLY wrong (almost always vastly underestimating).

Given that, and given that Wikipedia has a core principle that it's not supposed to be trying to predict the future, it seems that including any more dodgy graphs that try to predict the future needs to completely stop, particularly on this page.

The graph you added seems to claim that solar is going to grow much slower than it did last year for the foreseeable future. Given that there's presumably factories out there producing solar panels, unless many of these factories have done something like burnt down-something that I haven't heard of- and not rebuilt-both things seem unlikely-it seems difficult to see how that could happen. But hey, maybe it will grow more slowly, maybe these factories will run at partial output.

I don't claim to be an expert on predicting solar power, but given that it's a core principle that Wikipedia not try to see into the future, I don't have to.

Please remove the predictions from your data before reintroducing it. GliderMaven (talk) 20:47, 21 September 2023 (UTC)

— @GliderMaven: Your 20:47 post shows you project your own perceptions onto the summary, "Wikipedia does not predict the future". In fact, Wikipedia can report what reliable sources state, even if they are forecasts, even if prior forecasts have been "horrible". (Aside: viewers understand that forecasts are forecasts, not fact.)

— Pertinently, you have not answered my question: Are you arguing that Wikipedia should not have any forecasts at all? If not, where do you set the bar? —RCraig09 (talk) 22:06, 21 September 2023 (UTC)

— P.S. WP:CRYSTALBALL states more specifically: "Predictions, speculation, forecasts and theories stated by reliable, expert sources or recognized entities in a field may be included..." —RCraig09 (talk) 02:24, 22 September 2023 (UTC)

RCraig is correct here and inclusion of sourced external projections may be perfectly reasonable to include and do not violate CRYSTALBALL. We're not predicting the future, we're restating what reliable sources have predicted. Now, out-of-date content might not be particularly relevant in many cases, especially without up-to-date background to them, but it's absolutely reasonable to provide historical and recent projections along with appropriate context that the growth of photovoltaics has been a lot faster than even the experts ever thought! The graph is useful for informing readers of that and should stay in with an applicable caption indicating when the source is from and a sourced indication of any differences such as the higher-than-expected installations this year. Reywas92^Talk 03:50, 22 September 2023 (UTC)

Absent any arguments from User:GliderMaven that deal squarely with the reasoning presented above, within a day or two I'll replace the charts as suggested by User:Reywas92. —RCraig09 (talk) 12:38, 22 September 2023 (UTC)

No, by including the material, we're saying we as Wikipedia think that the source of the data is reputable and accurate. But we have ABSOLUTELY no reason to think they are.

Another problem I have with the specific graphic is the complete lack of distinction between previous real world data and future predictions; which are always half arsed for very fundamental reasons.

You're basically implying that the future is a done-deal simply by the way you present it.

You need to understand how these 'predictions' are made. They're either bottom up, or top down. In neither case can they make allowance for future events, like Putin invading or economic shocks. If they're bottom up they're highly prone to undercounting because they're only including things that have publicly already partially or completely happened; contracts that have been announced to have been signed, factories that have been built etc. but they can't easily make allowance for large governments or corporations signing new deals for example. Top down have tended to be more accurate, but reputable forecasters always try to go bottom up, and have far worse results, but top down are still subject to world shocks.

The historical accuracy of ANY of these predictions have been just ghastly. We really do need to maximally lean into WP:CRYSTAL here. GliderMaven (talk) 18:20, 22 September 2023 (UTC)

— Your arguments, User_talk:GliderMaven are your personal opinions, mischaracterizations of WP:CRYSTALBALL, and strawman arguments. No, we're not "implying that the future is a done-deal": from inception, the graphic has always distinguished past from future by stating "2023–2030 figures are estimates", and literate humans know that forecasts are susceptible to unforeseen events. And BloombergNEF probably knows as much as you, about how contracts are formed and how forecasts are made. Wikipedia content is based on content from reliable sources; there is no allowance for a single editor to supplant sources' content with his own personal opinion about prior forecasts.

— I think we've replied to each of your points, but yet again you have not replied specifically to any of our points, such as:

• Are you arguing that Wikipedia should not have any forecasts at all? If not, where do you set the bar? (objective standards are needed)
• WP:CRYSTALBALL states more specifically: "Predictions, speculation, forecasts and theories stated by reliable, expert sources or recognized entities in a field may be included..."

— Consensus is built from reasoned discussion responding to opposing arguments, and based on specifically articulated policies—not projecting personal opinion or subjective past impression. Here, I'm seeing that approach occurring on only one side. —RCraig09 (talk) 19:39, 22 September 2023 (UTC)

I'm confused by this entire statement. Bloomberg NEF is absolutely a reliable and reputable source, and their data is generally accurate. Will their predictions end up being right? No one knows, but it's still important for us to say – with charts – "here's growth in the past, there will be more growth in the future". We can also say, "historical accuracy of projections has been ghastly, here's data related to that and a qualification that the growth of photovolatics – the article's subject – consistently beats projections!" So if you want to help provide more context to the caption of the chart, that's great, but there's no reason to exclude it (unless there's a better one). Reywas92^Talk 20:38, 22 September 2023 (UTC)

None of the predictions I've seen have been remotely accurate. We just keep taking them out of the article and pretending they never happened. The last one was off by about 250% after just five years. If you claim that Bloomberf NEF is reliable for this, then find their old prediction data, and show that they've actually been reliable. I don't think they have. I don't think anyone has. GliderMaven (talk) 04:30, 24 September 2023 (UTC)

I think we should just not have any projections per WP:CRYSTAL. Failing that putting all the predictions into a separate section could work I guess. What I really don't want to see are charts implying that they are or even were accurate predictions. GliderMaven (talk) 04:30, 24 September 2023 (UTC)

Okay you can't say "per WP:CRYSTAL" because crystal does not prohibit the use of sourced projections like this, only original research. It seems pretty obvious to me that if we say "Projection of future growth of photovoltaics made in 2023 by BNEF" it's pretty obvious that people know that the future is uncertain, no one is implying a projection is anything more than that. An accurate claim that BNEF is a reliable source is NOT the same thing as saying their projections end up being perfectly accurate, and that's an appropriate thing for the article to share: "Hey, in 2015, these folks projected X growth but it ended up being Y growth" – that's valid encyclopedic information about the topic because with that the article can also discuss the learning curve, technologies, and policies that led to such unprecedented growth! Reywas92^Talk 18:39, 24 September 2023 (UTC)

Though you User:GliderMaven:

• are trying to supplant BloombergNEF forecasts with your own personal forecast that BloombergNEF's forecasts will be wrong,
• and you ignore the fact that WP:CRYSTALBALL specifically states that "Predictions, speculation, forecasts and theories stated by reliable, expert sources or recognized entities in a field may be included...",
• and you confuse reliable forecasts with reliable sources on which Wikipedia operates,
• and you wrongly claim that charts can (somehow) "claim they are accurate"

... in the spirit of compromise, I have created a Version 3 which places a gray area behind the projections and labels them as such. (You may have to by-pass your cache and when refreshing.) As we have gone well beyond WP:BRD, to BRDDD, it is clear that the chart is proper.

Aside: the chart will probably re updated or replace within a year or two, as the industry develops, but deletion is unquestionably improper. —RCraig09 (talk) 19:58, 24 September 2023 (UTC)

I notice that the community has not removed, and you have not objected to, the lead graphic, which is based on BloombergNEF data, and includes three years of "tentative" figures. —RCraig09 (talk) 20:03, 24 September 2023 (UTC)

@GliderMaven: Ahem. —RCraig09 (talk) 04:24, 8 October 2023 (UTC)

The lead graphic is trying to deal with incomplete data, and is covering events that have already happened. It seems to me you're talking out of both sides your face. You claim to be following WP:CRYSTAL while predicting the future by shoveling crystal balls into the article. This graph seems to be self-evidently likely to be inaccurate beyond the first year. We've had exponential growth for multiple decades, and while it will eventually roll off that, there's no obvious reason why it would suddenly change to linear in the next two years- but that's what this 'forecast' claims. I don't think you should get a buy on this, just because it's someone else's crystal ball. GliderMaven (talk) 15:31, 9 October 2023 (UTC)

Version 4: Years 2024- removed; retained 2023 because Bloomberg NEF undoubtedly had preliminary info for 2023 in data published in September 2023

The present lead graphic seems to be based on a January 2022 Bloomberg NEF source, so that, as it admits, at the time of its publication, it was not "covering events that have already happened" as you claim. The two-sides-of-the-mouth characterization applies to someone who accepts a January 2022 Bloomberg NEF source but rejects a September 2023 Bloomberg NEF source—all the while disparaging predictions and repudiating an explicitly quoted Wikipedia policy/guideline. Your arguments imply that the Wikipedia community should be guided by one Wikipedia editor's forecast and bury Bloomberg NEF's forecast, as to when exponential will transition to linear. These are the facts, correct? —RCraig09 (talk) 04:53, 10 October 2023 (UTC)

I mean, we could remove parts of that graph, but that's not a WP:CRYSTAL issue. GliderMaven (talk) 05:01, 10 October 2023 (UTC)

I've removed parts of my graphic pertaining to projections for 2024+, keeping 2023 because Bloomberg NEF undoubtedly had preliminary info for 2023 in data published in September 2023. The present lead graphic+table is complicated, has multiple sources with hard-to-find data, a numerical table that (apparently) repeats what's shown in the graphic, a graphic that has too much white space, and a legend at the bottom rather than adjacent the columns. It would be more concise to just use the newly uploaded graphic (adding a concise caption), especially since it's based on data that's almost two years more recent than the current assembly of stuff. —RCraig09 (talk) 06:48, 10 October 2023 (UTC)

OK. That's fine then. GliderMaven (talk) 23:33, 10 October 2023 (UTC)

Locally generated (outdated) cumulative/repetitive chart/table versus .svg

@GliderMaven and Reywas92: What is your opinion on the single purpose IP's repeated return of the lead image to the outdated image/table that predated the new chart we've been discussing? To have both image and table is repetitive and confusing. More importantly, I can't find numbers in the various references corresponding to the various numbers presented; it smells like WP:SYNTHESIS at best. —RCraig09 (talk) 07:10, 9 November 2023 (UTC)

I am repeatedly return old graphics because it is editable by anyone - and wikipedia is about cooperation, not creating graphics silos. And it is not outdated at all. The small circular graph from 2019 below main graph can be removed, but main graph is up to date much nicer as well in my personal opinion. 188.123.110.16 (talk) 17:46, 19 December 2023 (UTC)

I don't have any problem if you update current graph with better references (other people did it already). But please don't try to lock graph so it is editable only by yourself. 188.123.110.16 (talk) 17:58, 19 December 2023 (UTC)

SVG files are in fact editable by anyone - they are text files. You can see the source text of the one currently in the article if you go to https://upload.wikimedia.org/wikipedia/commons/a/a8/2007-_New_solar_installations_-_annually_by_country_or_region.svg, then right click and 'view source'. RCraig09 is not trying to lock graph so it is editable only by yourself. Edit warring like you have been is disruptive and unhelpful, but now we see that this is based on a misunderstanding, so there is no reason to continue, right? MrOllie (talk) 18:40, 19 December 2023 (UTC)

What MrOllie says is correct. The vast majority of articles have .svg or .png or .jpg charts (.svg favored), not manual charts which are easily sabotaged by passers-by. And based on my study of the IP's chart+table, it is not up to date, as the IP himself effectively admitted in this edit comment. In any event, I could not find recitations of the data in the sources and so couldn't update it as the IP "invited" me to in his edit comment. At this point, reverting to the outdated and disfavored presentation against consensus would constitute vandalism. —RCraig09 (talk) 20:01, 19 December 2023 (UTC)

If I use your logic, I should replace whole article text with a screenshot (jpg) so it will not be sabotages by passers-by, right? This would be not wikipedia which encourage collaboration. Insane. I am trying to protect the values of wikipedia. If somebody does edit-warring, it is you. 188.123.110.16 (talk) 08:35, 20 December 2023 (UTC)

I meant you can update current graph in current format with data from your data sources on which you based your SVG graph. I plan to do it as well, but not immediately due to other work. 188.123.110.16 (talk) 09:06, 20 December 2023 (UTC)

You must be joking. To edit SVG graph in text mode as a line paths and pixel counting? Insanely complicated. Wikipedia has already a standard to create graphs which is easy to edit by anyone. We don't need to learn another X-ways how to create a graphs. We use wikipedia standards. You practically create image silo only for yourself RCraig09. I invite you to update current graph if you think you have more up to date data. 188.123.110.16 (talk) 08:29, 20 December 2023 (UTC)

Using SVG is in fact a Wikipedia standard. Trying to block progress of the article like this on pure WP:IDONTLIKEIT grounds is disruptive. MrOllie (talk) 14:49, 20 December 2023 (UTC)

The Graph which needs to be updated once a year by anyone can not be SVG graphics. It is not fair to lock the graphics to single person and create silo. Btw, in old graph, you can also hover above each section to see the numbers for particular section. 188.123.110.16 (talk) 09:39, 22 December 2023 (UTC)

Locally generated charts/tables are cumulative/~duplicative space-hogs, against clear consensus here, and non-standard across Wikipedia. Single-purpose IP has had months (years actually) to update, but says that WE should do it for him!... while making strawman arguments here. I've looked at the (so-called) sources and couldn't find a clear data listing. —RCraig09 (talk) 18:45, 20 December 2023 (UTC)

If you were able create new graphics, you can also update old graphics if your interest is in the valid data and not in creating silos. 188.123.110.16 (talk) 09:40, 22 December 2023 (UTC)

You, IP, complain about updating an svg graphic once per year, but you yourself haven't updated the cumulative/outdated local chart/table yourself probably because the "sourcing" is wrong (no clear data listing). Consensus here is 100% against you. If you continue to edit war (reverting NINE times), you may be blocked. You are wasting everyone's time, including your own. —RCraig09 (talk) 15:32, 22 December 2023 (UTC)

Consensus is that you want to create graphics silo. Current graph was updated by many people already, not only me. We want to continue with that this way. 188.123.110.16 (talk) 14:45, 23 December 2023 (UTC)

Consensus is what is arrived at on this talk page. Block evasion and edit warring will not work. MrOllie (talk) 20:17, 1 January 2024 (UTC)

Wikipedia mafia has won 188.123.110.16 (talk) 18:18, 11 February 2024 (UTC)

Tables of some magnitude

There are three huge data tables in this article, and they can all go, per WP:NOTDATABASE. There needs to be graphs instead, which I'm happy to make. One of the graphs (at "Worldwide annual deployment") already duplicates the table below it.

The IEA table duplicates the IRENA one, and that table itself could be summarized in a stacked area chart, which itself would be an improvement of the aforementioned chart. The non-functioning pie chart could be replaced with another line or area chart.

And the copy of the table from Solar power by country is pretty much the same as the IRENA one. But in any case the link to that list article is already there, so no table needs to be in that section. Wizmut (talk) 14:22, 31 December 2023 (UTC)

I agree that graphical charts show information more accessibly than textual tables. I think a dutiful individual such as yourself can compress the most salient subsets of data into graphical charts. (An interim solution to reduce eyesore, is to use collapsible text using the {{collapse top |title=Click at right to show/hide ___ }} and {{collapse bottom}} template, but I agree the huge tables can be deleted, regardlesss.) —RCraig09 (talk) 18:56, 31 December 2023 (UTC)

I have removed the 3 large tables and adjusted the location of the figures near the bottom of the page. I also added the two figures I made for Solar power by country.

Next step is to refresh the old sources which likely already overlap with newer ones, as far as historical data. After that I'll try making more variations on the bar chart or stacked area chart theme, and perhaps something about capacity factor.

There is the chart in the lead, a simplified version near the bottom, and a table next to it, all describing the same trend. Probably we can get that down to just one chart (the one in the lead) and a few sentences saying which years were unusual (2011, for instance). Prose is already stating the point of the long table, in my opinion, when the lead says "From 2016-2022 it has seen an annual capacity and production growth rate of around 26%- doubling approximately every three years.". If there has to be a table down below, it could show cumulative capacity instead of add capacity, so it's not an exact repetition. Wizmut (talk) 08:12, 2 January 2024 (UTC)

If you are going to remove the tables, you must do something about the redirect from List of countries by photovoltaics production, which is no longer valid. Also, since the data range is very broad, ideally some kind of log chart would be helpful. Overall, I think that replacing the tables with graphs would be good, but currently most of the information in the table is not visible in the graphs, particularly the developments in smaller countries of a higher proportion of PV power in the energy mix (e.g. Chile). So, I think it would be preferable if the tables are not removed until after the graphs are ready. 128.23.128.23 (talk) 23:00, 3 January 2024 (UTC)

For sure, it's okay if someone adds them back for now.

As far as a log scale chart, there's currently a log scale line chart by major country[7] at History of leading countries, which includes a line for the whole world. I find log scale a little underwhelming because it turns the trend into a straight line. For me the big fact about solar is how fast it went up, which shows up better as a hockey stick. But if you want to see a variation on the chart already there, I can make one, just say which kind exactly.

I notice there is not a line graph or stacked area chart comparing solar to other sources. Out of

• solar vs renewables,
• solar vs electricity, or
• solar vs energy,

I like solar vs electricity the most. I'll do one up as a stacked area chart by the big 8 or 9 electric sources unless someone wants a line version (stacked area is easier to see as a thumbnail). Time scale 2000 or 2010 onwards, I think. (edit:found a line version here:[8])

As far as representing the smaller markets where solar is big, there's a map[9] at the top of Solar power by country that does this pretty well, albeit only for the most recent year. How else could it be done? Wizmut (talk) 23:29, 3 January 2024 (UTC)

Here's three generic charts for world electricity:

World electric generation by country and source in 2021

Yearly generation by source

Yearly generation by renewable source

Wizmut (talk) 02:12, 4 January 2024 (UTC)

I'm frankly overwhelmed by the discussion here, but FWIW I've been making an effort in the past few years to create up-to-date Renewable Energy graphics, which are presented on my Commons page, https://commons.wikimedia.org/wiki/User:RCraig09#Alternative/renewable/green_energy/transition . Maybe something there is useful. —RCraig09 (talk) 03:24, 4 January 2024 (UTC)

Separately, I think that for Verifiability, Commons graphics should have specific links to sources, not just "from Ember, released 2023". It's good practice, also, to have a full formal citation in the image caption wherever the chart is inserted. —RCraig09 (talk) 03:27, 4 January 2024 (UTC)

Appreciate the gallery link.

Roger on the citations, I'll add them everywhere. Wizmut (talk) 08:01, 4 January 2024 (UTC)