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Post by David B. Benson on May 12, 2020 11:40:34 GMT 9.5
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Post by David B. Benson on May 12, 2020 12:17:18 GMT 9.5
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Post by cyrilr on May 12, 2020 16:11:56 GMT 9.5
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Post by cyrilr on May 12, 2020 16:17:16 GMT 9.5
That seems wildly optimistic. Typical solar panel temperature coefficients are 0.2% to 0.5% per degree Celsius. So a 10 degree cooling improvement would increase power by 2 to 5%. To get 20% would require 40 to 100 degrees of cooling, which is not credible for passive surface evaporating cooling. A better option seems to integrate a cooling coil of sorts into the back of the panels, so as to generate some useful low grade heat for domestic hot water and such (perhaps as a preheater to an existing water heater).
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Post by David B. Benson on May 12, 2020 16:17:57 GMT 9.5
You couldn't have read it. The glass encapsulation protects the perovskite, of which the chemical formulations continue to improve the effective life.
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Post by cyrilr on May 12, 2020 16:28:10 GMT 9.5
You couldn't have read it. The glass encapsulation protects the perovskite, of which the chemical formulations continue to improve the effective life. You couldn't have understood the instability problems if you think a glass pane will protect it. There are intrinsic (not just extrinsic) stability problems. There's lots of ideas on how to solve them, but a long way from demonstrated to work in real applications. www.ossila.com/pages/perovskite-solar-cell-degradation-causesIndoor might be an interesting first application, but I personally expect the stability problem will limit perovskites to niche applications for a very long time (ie not a competitor to silicon or CdTe, both of which have advanced incredibly and are very stable and durable).
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Post by David B. Benson on May 12, 2020 16:28:34 GMT 9.5
cyrilr --- In the desert there is no problem producing domestic hot water. The problem is obtaining the water in the first place!
The gel obtains its water overnight. And in a desert application, I don't doubt that "up to 20%" improvement in power production when the sun is at zenith.
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Post by David B. Benson on May 12, 2020 16:36:28 GMT 9.5
cyrilr --- The indoor location plus glass encapsulation eliminates all of the environmental causes of perovskite degradation mentioned in the article you linked. So, indeed, this may well solve the pesky problem of tiny batteries which require replacement every year or three.
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Post by cyrilr on May 12, 2020 17:15:37 GMT 9.5
cyrilr --- The indoor location plus glass encapsulation eliminates all of the environmental causes of perovskite degradation mentioned in the article you linked. So, indeed, this may well solve the pesky problem of tiny batteries which require replacement every year or three. It doesn't deal with the intrinsic problems of gaps, UV, thermal, which were also mentioned but you chose to ignore or not read those. These compounds are intrinsically unstable. They would make good explosives or reagents. Not the kind of stuff you'd be looking for in a harsh desert sun with violent thermal and UV cycling. Its fun stuff, but I doubt it will ever be able to compete with silicon or CdTe.
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Post by cyrilr on May 12, 2020 17:19:50 GMT 9.5
cyrilr --- In the desert there is no problem producing domestic hot water. The problem is obtaining the water in the first place! The gel obtains its water overnight. And in a desert application, I don't doubt that "up to 20%" improvement in power production when the sun is at zenith. With a 0.5% temp coefficient a 20% improvement would suggest a 40 deg C cooling. That seems wildly optimistic for the equivalent of a wet towel. If your panel is boiling hot you have other issues of durability. In the desert you probably put up other tech such as CdTe which has lower temp coefficient. I do doubt claims made by solar researchers. A healthy attitude because most of the claims never lead to anything (or wildly overestimate potentials).
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Post by cyrilr on May 12, 2020 17:21:56 GMT 9.5
Also, I suspect that the gel would dry out quickly in a desert sun application. Water only gets you 2.5 MJ/mm per m2 of cooling energy. Not even an hour of energy in the full desert sun.
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Post by David B. Benson on May 12, 2020 17:36:34 GMT 9.5
cyrilr --- I did read the entire article regarding perovskite solar cells. It should be obvious that indoors neither UV nor temperature are a problem. It should be obvious that glass encapsulation eliminates humidity. It should be obvious that this is potentially a solution for a small market, not attempting to replace silicon where substantial power is required.
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Post by cyrilr on May 12, 2020 21:18:34 GMT 9.5
cyrilr --- I did read the entire article regarding perovskite solar cells. It should be obvious that indoors neither UV nor temperature are a problem. It should be obvious that glass encapsulation eliminates humidity. It should be obvious that this is potentially a solution for a small market, not attempting to replace silicon where substantial power is required. It should be obvious that this is a gadget. Gadgets are not helping us kick our multi billion ton a year coal oil and gas habits.
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Post by David B. Benson on May 13, 2020 15:41:00 GMT 9.5
Also, I suspect that the gel would dry out quickly in a desert sun application. Water only gets you 2.5 MJ/mm per m2 of cooling energy. Not even an hour of energy in the full desert sun. The desert where presumably the researchers tested their gel is just down the Red Sea coast from en.m.wikipedia.org/wiki/Jeddahwhich appears to have one of the most miserable of desert climates. The gel probably needs testing elsewhere as well but if it is inexpensive it may prove a worthwhile addition.
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Post by cyrilr on May 13, 2020 20:48:30 GMT 9.5
Also, I suspect that the gel would dry out quickly in a desert sun application. Water only gets you 2.5 MJ/mm per m2 of cooling energy. Not even an hour of energy in the full desert sun. The desert where presumably the researchers tested their gel is just down the Red Sea coast from en.m.wikipedia.org/wiki/Jeddahwhich appears to have one of the most miserable of desert climates. The gel probably needs testing elsewhere as well but if it is inexpensive it may prove a worthwhile addition. Desert climates are probably among the best since they are dry and tend to have reasonable humidity at night. Tropical climates with high humidity would have plenty of water but humidity would also impede evaporative cooling. Kind of like a "swamp cooler" air conditioning working well in the desert but not doing much in a tropical humid climate. Perhaps large scale application of this gel in a large desert solar farm could impact the micro climate, or impede the effectiveness of the gel (if it can't saturate because the surrounding panels' gel has already sucked out all the available moisture). Probably would be attractive to add some sort of mesh or screen and rain diverters to protect the gel, make it stick longer and to allow more gel to be applied. Re-applying may be ok in low wage countries but if labor is expensive this could become $$$ added.
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Post by David B. Benson on May 22, 2020 14:36:46 GMT 9.5
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Post by David B. Benson on May 28, 2020 18:20:48 GMT 9.5
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Post by Roger Clifton on May 29, 2020 10:23:00 GMT 9.5
No joke... Algeria plans 4 gigawatt... solar power initiative ... to export No, it's not a joke. It is barefaced fraud. On a massive scale. Despite its appeal to Green sentiment, no nation's bean counters would contemplate importing raw noise with an amplitude of 4 GW. They would require the fine print to include an agreement to buy ~12 GW of Algeria's plentiful gas to firm the storm of power. That is, for those rare events when solar is not generating at 100%. Which is most of the time. Like a sprig of parsley on a two-pound steak, the decoration of greenery is an insult to healthy living. The panels wouldn't even have to be plugged in to satisfy such dumb schmucks as would praise such a contract. Have a look at the map of North Africa. If Spain wanted pure solar generation, Morocco would best supply it. If Italy wanted pure solar generation, Tunisia would best supply it. Neither country would need it, when they can barely firm their own. Algeria has no use for solar panels except to conceal an ongoing fossil crime against the planet -- gas. Really, David. Why do you keep giving credibility to the offensive nonsense coming out of cleantechnica?
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Post by engineerpoet on May 29, 2020 17:14:11 GMT 9.5
Heh. I'm glad other people see that censorious propaganda site the same way I do.
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Post by David B. Benson on May 29, 2020 18:57:48 GMT 9.5
Roger Clifton, please refer to "authoritative sources". From en.m.wikipedia.org/wiki/Energy_in_Algeria"The program (renewables) consists of installing up to 12 GW of power generating capacity from renewable sources to meet the domestic electricity demand by 2030". The Wikipedia page points out that there are already gas pipelines via neighboring countries to Spain and Italy. Presumably HVDC could be laid along side under the assumption that Algeria intends export to Europe. But the export might well just be to Morocco; the article specified neither what proportion nor to whom. Stick to authoritative sources, yes?
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Post by David B. Benson on May 29, 2020 22:15:55 GMT 9.5
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Post by David B. Benson on May 29, 2020 22:52:36 GMT 9.5
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Post by Roger Clifton on May 30, 2020 13:29:56 GMT 9.5
please refer to "authoritative sources". From en.m.wikipedia.org/wiki/Energy_in_Algeria "The program (renewables) consists of installing up to 12 GW of power generating capacity from renewable sources to meet the domestic electricity demand by 2030" Okay then, I quote from that same source, Wikipedia: "12 GW of power generating capacity from renewable sources to meet the domestic electricity demand [of Algeria]" Now, that is clearly a blatant lie. Nowhere in the world is renewable power able to meet the on-demand electric power of any country. Yet here it is, spelt out clearly, "to meet the demand". The anonymous author must know that his statement is false. A grid with 12 GW peak amplitude of solar+wind power must include a minimum of 12 GW dispatchable power to level it, implying inefficient but fast responding gas turbines. If there is a steam component to the grid, there must be even more power on the grid seeking consumers. Hard to believe in a country that only consumed 6.5 GW in 2013. If that steam component were nuclear, the author would be proudly declaring to the world that they have nothing to do with fossil energy. The silence conceals an intention to expand their use of gas with consequent increase in fossil emissions. The same author must know that the expansion of gas around the world is doing permanent damage to the greenhouse and thereby is condemning unknown numbers of people to their deaths, indefinitely into the future. One day such people will be brought to judgement. We should not be seen to have had anything to do with them.
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Post by David B. Benson on May 30, 2020 14:33:06 GMT 9.5
Roger Clifton --- That Wikipedia article makes clear that Algeria currently uses natural gas to generate electric power. So a plan to add solar and wind lessens the country's dependency on natural gas.
You parse too fine.
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Post by Roger Clifton on May 30, 2020 19:23:21 GMT 9.5
...Algeria currently uses natural gas to generate electric power. So a plan to add solar and wind lessens the country's dependency on natural gas. Oh, but they are expanding alright. It seems their consumption increases at 5% per annum, which would turn the 6.5 GW figure of 2013 into 15 GW by 2030. The claim that they are going to power that using renewables (backed by a teeny-weeny bit of gas) is back in the category of a barefaced lie. In fact, we should call out as a barefaced lie any claim that addition of renewables is a step towards total decarbonisation. Wind means gas.
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Post by David B. Benson on May 30, 2020 20:27:37 GMT 9.5
Utility-scale solar PV: from big to biggest Dana Olsen & Brent Erik Bakken 2019 Feb DNV-GL www.dnvgl.com/feature/utility-scale-solar.htmlPredicts drop in capex to around $500/MW. Compare to the capex for open cycle gas turbines of at least $800/MW. Of course the gas turbines require fuel unlike solar PV. So the LCOE for solar power approachs but $10--15/MWh. That's 2--3 times better than even hydropower. Of course these best prices apply only to the sunniest of locations.
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Post by David B. Benson on May 31, 2020 0:29:15 GMT 9.5
California Duck Curve: en.m.wikipedia.org/wiki/Duck_curveThe result of installing a considerable portion of solar PV, both private and utility-scale farms. A solution is enough storage for the mid-day excess against the evening head-of-the-duck and the following day's tail.
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Post by thinkstoomuch on May 31, 2020 1:12:03 GMT 9.5
California Duck Curve: en.m.wikipedia.org/wiki/Duck_curveThe result of installing a considerable portion of solar PV, both private and utility-scale farms. A solution is enough storage for the mid-day excess against the evening head-of-the-duck and the following day's tail. So with 12,875 MW grid connected solar and California has 9,485.0 MW of small scale of solar, CA ISO(not all the small scale will be in CA ISO) needs how much in the way of storage?
For a hint CA ISO has already curtailed 959,716 MWH of Solar this year(more than a slight bump due to China virus stud downs) as of Thursday.
T2M
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Post by David B. Benson on May 31, 2020 1:21:02 GMT 9.5
thinkstoomuch --- Not enough data to say. However, the alternative to storage, once enough is stored, is the low-value uses: desalination and green hydrogen production come immediately to mind.
Edited to add: increasingly utility-scale solar PV projects add a 4 hour duration battery of the same power as the project maximum, i.e., nameplate.
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Post by thinkstoomuch on May 31, 2020 2:43:24 GMT 9.5
thinkstoomuch --- Not enough data to say. However, the alternative to storage, once enough is stored, is the low-value uses: desalination and green hydrogen production come immediately to mind. Edited to add: increasingly utility-scale solar PV projects add a 4 hour duration battery of the same power as the project maximum, i.e., nameplate. Four hours of storage does not seem to be enough. Especially as paired with new solar installations that are going to produce somewhere around 8 hours of power (average) in the spring. Sounds great but not going to do much. Still need something else to balance things as far as the duck curve and existing installations.
Look at Solana CSP with 6 hours of 250 MW storage.
AZPS is the other end of its PPA but Solana is not the only solar generation. Second graph of the above page shows how it is used. It is an hourly update that allows the user to display and remove various sources by clicking them on the legend. All the solar goes away except a pretty regular amount up to midnite then comes up again in the morning. The graph can be used for days back about 2 years. And even a downloadable data file. Compare that with both coal and gas generation
There is a lot more that goes into all this and unfortunately I am a poor communicator.
T2M
PS for some unknown reason I am still a Solana fanboy despite it being a poor expensive performer. <shrug>
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