Talk:Duck curve

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Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 20:20, 17 January 2022 (UTC)

Who or what causes "the rapid increase in demand at sunset"?
Why is there a rapid increase in demand at sunset, in the USA apparently? In Germany, the demand during the day, by businesses and private households, is nicely covered by solar power (during the summer months at least), with only small peaks in the mornings and evenings that are often covered with Pumped-storage hydroelectricity. So why do US citizen need more power in the evenings? Hardly factories are to blame, or the lights in stadiums of Monday Night Football. Do people use much more eletrical power in the evening, by cooking, taking showers, watching big screen TV? Surely they don't switch on(!) the air condition after sunset, or the laundry machine? — Preceding unsigned comment added by 82.113.113.82 (talk) 13:49, 21 July 2017 (UTC)
 * In others words: Why a Duck? --2001:A62:1199:8401:989:89EF:3C56:D040 (talk) 03:12, 10 August 2017 (UTC)
 * It is not confined to USA. It also affect France and German, check https://euanmearns.com/the-california-duck-curve-isnt-confined-to-california/. The reason also described there with reason like France only has 2% of solar while California is 8% with no surplus. Regardless wikipedia is not place to talk about this. Draconins (talk) 19:15, 20 November 2018 (UTC)


 * It's because people go home, and start cooking and turn on TVs, lighting and heat. GliderMaven (talk) 15:55, 19 April 2019 (UTC)
 * The question is good, and should be answered in the article. I believe a main reason for sunset peak is that the afternoon sun keeps increasing the indoor temperature, which only goes down after the sun goes down and people come home and start the aircon.
 * Areas with summer peak demand; Texas explains that summer peak demand occurs at 17-19 (near sunset) due to aircon, and Australia says the same.
 * Areas with winter peak demand is less relevant for solar, but does show summer effect This says on page 4 (794) that peak Swiss demand is due to "electric cooling", but is vague about how common it is. US NorthEast shows the duck curve without explaining it, but NYtimes says "Much of the year, peak demand is around 5 p.m., when evening rush subways and elevators take commuters home, children turn on video games and families open refrigerator doors to start dinner. In summer, it is around 3 p.m., when air-conditioners are blasting". This source merely says "Demand peaks around 6 pm, when workers get home, make dinner, watch Netflix" without mentioning aircon. UK peak demand is in winter, but in summer it's in the morning or evening (page 21). This source says peak load in Beijing was at noon, of which half was cooling, and South China cities have peak load at night due to entertainment. Alberta also sees late afternoon summer peak.
 * TL;DR, I didn't find good sources. TGCP (talk) 19:43, 19 April 2019 (UTC)

Why this article is marked as NPOV
I am not clear why this article is NPOV, yes it might need expansion but I don't see NPOV here. Could someone clarify which one? Draconins (talk) 19:15, 20 November 2018 (UTC)


 * It's not NPOV so far as I can see, and since nobody has discussed it here on the Talk page as is required for such hatnotes, I have removed it. If that's wrong, please explain why. I also removed the "weasel words" template, which is kind of pointless, but I left the "tone" hatnote because the California section is chatty with first-person pronouns. - DavidWBrooks (talk) 15:59, 14 December 2018 (UTC)


 * In fact, that California section could probably be killed entirely - I have removed about half of it. It's sort of an essay about the effects of renewable energy on costs and deployment of power sources and IMHO doesn't belong on this article at all, above and beyond its tone. - DavidWBrooks (talk) 16:12, 14 December 2018 (UTC)

Invalid assumption in Duck Curve graph caption
The caption to the Duck Curve graph illustration states, in part, "...requiring some 5 gigawatt of generating capacity from non-renewable sources to come on line within one hour." The assumption that the additional power must come from, or comes from, non-renewable sources is not supported and is, in fact, false. A significant portion of the Duck Curve gap in California is filled by buying power on the Western Interconnection, which is fed by a number of hydro-electric sources. BC Hydro, in particular, typically buys excess solar power from the WI during the day, reserving water behind its dams to generate power in the evening when demand (and prices) rise in California. --Gep3 (talk) 23:49, 4 July 2020 (UTC)


 * Thank you for noticing this. I replaced "non-renewable" with "dispatchable" which is the accurate term in this case. --Ita140188 (talk) 10:24, 5 July 2020 (UTC)

Shark curve
According to this article, there is a more severe demand-induced problem in undeveloped nations that may be called the shark curve. Nepal is the poster child, and also includes hefty load-shedding that is unknown in most of the developed world (except where a massive cold snap or heat wave produces a media flurry of finger-pointing when a power grid or utility actually implements rolling or full blackouts). In Nepal, it's an everyday thing, as the shark begins to bite at 4 pm. I like to saw logs! (talk) 16:43, 22 July 2021 (UTC)

Common misconceptions section
What is meant by "For example, in California, solar output is low at 7pm when daily demand usually peaks. This fact leads some to believe that solar power cannot reduce the need for other power plants, as they will still be needed at 7pm when solar power output is low. However, California's annual demand peaks usually occur around 3pm-5pm" What is the difference between daily and annual demand here? — Preceding unsigned comment added by AtomicEnthusiast (talk • contribs) 22:28, 12 October 2021 (UTC)
 * The system has to be planning for the worst peak of the year (as we cannot tolerate a day yearly without the electricity). When viewed from this angle, solar in California does not contribute almost anything to the grid when the grid really needs the electricity on this particularly bad day (its capacity credit is under 10%). On average, however, situation is brighter, as the average by definition includes some better days for a variable (i. e., unreliable) source. I am not sure if this is what the author tried to say, of course - the text is indeed quite dense. --Викидим (talk) 22:17, 1 August 2022 (UTC)

Additional to the valid arguments above, 1) this section references in [20] the CAISO homepage with current daily loads and producing resources, which could not support any claims to average loads or solar output without analysis. 2) Reference [22] is an EIA article with general load shapes and general trends, not for California in particular. It does not state that California's highest loads are midday due to air conditioning as claimed in this section. 3)For planning purposes, electric vehicle charging and other changes to loads and peak load timing must be considered when adding solar or other resources to a system, highlighting that resource additions must be aligned with future demand (albeit forecasted) and not historical demand. CAISO's historical peak hour may not align to future peak hours, so historical peak analysis does not necessarily support the original argument of solar's role in resource planning. — Preceding unsigned comment added by 148.126.10.206 (talk) 19:33, 20 September 2022 (UTC)

I've removed the section, as it seemed to me to be a textbook case of synthesis. If anyone knows of some reliably sourced research that comes to the same conclusions, please feel free to add it back. --amlz (talk) 06:39, 11 February 2023 (UTC)

California
I hereby propose to reflect these items in the text. Викидим (talk) 09:23, 2 August 2022 (UTC)
 * 1) The section currently declares the 3-hour ramp-up in the springtime to be 7 GW. However, CAISO states that 13 GW are needed (and 11 GW observed), see  Fig 2. . Year 2020 that is used in our article must have been especially favorable for the duck curve problem.
 * 2) CAISO points to another problem with the duck curve: a nearing overproduction of solar electricity (same chart).