bzcat Posted April 3, 2023 Share Posted April 3, 2023 On 3/31/2023 at 8:52 AM, Rick73 said: Because 2 hours worth of storage seems pointless unless it’s there to handle power fluctuations and to provide time to bring other equipment online when solar output drops off. When solar is a very small part of total, it’s easier to essentially ignore its contribution to the total, but as it becomes a greater percentage of total grid capacity, you can’t just suddenly reduce its contribution without adverse consequences. The more solar you have, the more critical it becomes. If you are counting on solar power output and suddenly it drops off due to weather changes (clouds, storms, etc.) then battery storage can pick up the slack until conditions return to normal, or managers bring other equipment online. In my opinion renewables are great at some things, but making the grid and its operation simple isn’t one of them. Some states have codified their short duration (2 to 4 hours) storage requirements which is why most of the projects are in this time span. Almost all of this market is batteries. Short duration is designed by default to provide operational reserve like you said. Long duration (4 to 8 hours) storage are still in its infancy and is dominated by pumped hydro. But several alternatives like gravity have emerged. Time shift on renewable is in the long duration market and most states are finalizing their regulatory targets. We should see lots of developments in this area in the next couple of years. Ultra long duration (8 hours to days/weeks/months) are focused on hydrogen. This segment is actually more advanced than long duration because the needs are clear. For example, to provide power during fire season/wind advisory events in California when the powerlines are de-energized to prevent wildfire. We may need to hold this energy reserve in standby for weeks or months at a time. Hydrogen is the ideal medium. Quote Link to comment Share on other sites More sharing options...
AGR Posted April 3, 2023 Share Posted April 3, 2023 (edited) 12 hours ago, Gurgeh said: Do you have even one link from your research? I looked quite a bit online and couldn't find even one link saying that surface winds increase at night. You mean like the link in the post you originally responded to? Or how about this one: Power generation is blowing in the wind | Lawrence Livermore National Laboratory (llnl.gov) Quote The team found that wind speed and power production varied by season as well as from night to day. Wind speeds were higher at night (more power) than during the day (less power) and higher during the warm season (more power) than in the cool season (less power). For example, average power production was 43 percent of maximum generation capacity on summer days and peaked at 67 percent on summer nights. Edited April 3, 2023 by AGR Quote Link to comment Share on other sites More sharing options...
AGR Posted April 3, 2023 Share Posted April 3, 2023 (edited) 12 hours ago, Gurgeh said: Do you have even one link from your research? I looked quite a bit online and couldn't find even one link saying that surface winds increase at night. Or here, I used your Google search phraseology... Ask Tom: Why does wind speed increase from morning to afternoon? – Chicago Tribune Again, wind turbines are not ON THE SURFACE. They are several hundred feet ABOVE the surface. As the link says, the nighttime winds at that level are STRONGER. Edited April 3, 2023 by AGR Quote Link to comment Share on other sites More sharing options...
silvrsvt Posted April 4, 2023 Share Posted April 4, 2023 14 hours ago, AGR said: Or here, I used your Google search phraseology... Ask Tom: Why does wind speed increase from morning to afternoon? – Chicago Tribune Again, wind turbines are not ON THE SURFACE. They are several hundred feet ABOVE the surface. As the link says, the nighttime winds at that level are STRONGER. Founds this: ... of wind data was performed and the results showed that the annual average wind speed is 5.8 at 10m height, 6.4 m/s at 20m height and 7.2 m/s at 40m height. Table 4 shows the average wind speed for each month for Magrun site and Figure (9) shows the diurnal pattern for each month at 10 m height, which is the WECS hub height. ... https://www.researchgate.net/figure/Figure-9-Daily-Wind-speed-profile-for-each-month-at-10m-height_fig1_334597212 It works out to about 3 MPH difference from 10m to 40m height Quote Link to comment Share on other sites More sharing options...
AGR Posted April 4, 2023 Share Posted April 4, 2023 1 hour ago, silvrsvt said: Founds this: ... of wind data was performed and the results showed that the annual average wind speed is 5.8 at 10m height, 6.4 m/s at 20m height and 7.2 m/s at 40m height. Table 4 shows the average wind speed for each month for Magrun site and Figure (9) shows the diurnal pattern for each month at 10 m height, which is the WECS hub height. ... https://www.researchgate.net/figure/Figure-9-Daily-Wind-speed-profile-for-each-month-at-10m-height_fig1_334597212 It works out to about 3 MPH difference from 10m to 40m height From a city in Libya...OK What's the wind difference at 60-80 m? Those are the typical heights of modern wind turbines, excluding the blades. Quote Link to comment Share on other sites More sharing options...
silvrsvt Posted April 4, 2023 Share Posted April 4, 2023 1 hour ago, AGR said: What's the wind difference at 60-80 m? Those are the typical heights of modern wind turbines, excluding the blades. https://web.stanford.edu/group/efmh/winds/global_winds.html https://wind-data.ch/tools/profile.php?lng=en Doesn't seem like it increases all that much after 40m Quote Link to comment Share on other sites More sharing options...
akirby Posted April 4, 2023 Share Posted April 4, 2023 Can we just agree that it varies? 1 1 Quote Link to comment Share on other sites More sharing options...
AGR Posted April 4, 2023 Share Posted April 4, 2023 (edited) 1 hour ago, silvrsvt said: https://web.stanford.edu/group/efmh/winds/global_winds.html https://wind-data.ch/tools/profile.php?lng=en Doesn't seem like it increases all that much after 40m meters per second to mph - Google Search Your calcuations are a bit off. 1 m/second is equal to 2.237 mph, so in your first post, the difference from 10 m to 40 m is more like 5.4 mph. Actually mine are off, 1.4 not 2.4. From the first link, at only level 2, there is a minimum annual mean wind speed of 13 mph. Obviously, there are areas that are more conducive to wind power than others, including the Great Plains. This is no different than solar power. The Mojave desert is obviously better for that than Anchorage. But this conversation has strayed far from my original post, nice movement of the goal posts. ? Electricity needs to come from a blend of wind, solar, and natural gas, with grid storage. Nuclear is currently absurdly expensive (Google how much $$$ it is taking to add one reactor at Savannah River), coal is too dirty. Edited April 4, 2023 by AGR Quote Link to comment Share on other sites More sharing options...
silvrsvt Posted April 4, 2023 Share Posted April 4, 2023 1 hour ago, akirby said: Can we just agree that it varies? No, we must ride this into the ground LOL 4 Quote Link to comment Share on other sites More sharing options...
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