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Post by cyrilr on May 3, 2020 0:49:49 GMT 9.5
The term "foibles" relates to a minor weakness.
Power that isn't there 80% of the time and can't be turned on when needed is hardly a minor weakness. It's a major physical limitation of solar power. It's physical so intrinsic - it won't go away no matter how much innovation. Similarly the large area needed is a physical limitation from the diffuse, low energy density nature.
These are not foibles. They are massive physics issues!
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Post by David B. Benson on May 5, 2020 12:50:11 GMT 9.5
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Post by Roger Clifton on May 6, 2020 19:20:21 GMT 9.5
a major physical limitation of solar power... the large area needed is a physical limitation One might say that renewable energy consumes significant non-renewable resources. That's a contradiction that the believers cannot see.
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Post by cyrilr on May 7, 2020 3:31:50 GMT 9.5
a major physical limitation of solar power... the large area needed is a physical limitation One might say that renewable energy consumes significant non-renewable resources. That's a contradiction that the believers cannot see. It's an excellent point that is rarely communicated. Sure, the sun will shine for the next billion years. Now calculate how many solar panels we'd need to power the world for the next billion years, and how much non-renewable resource that requires. Solar enthusiasts have been chiding us forever about the longevity of nuclear waste. How about the longevity of non renewable resources used to make short lived renewable generators into the same timeframe of the future? A million years from now all the nuclear waste will have decayed to harmless levels. How does that compare to the non renewable resource use and attendant, forever-toxic wastes created by the fabrication, installation, use, and recycling of renewable energy?
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Post by David B. Benson on May 14, 2020 10:43:43 GMT 9.5
US wind plants show relatively low level of performance decline as they age 2020 May 13 Phys.org techxplore.com/news/2020-05-decline-age.htmlDrops 13% over 17 years but the PTC, production tax credit, effect is noticeable. I contrast to nuclear power plants with performance growing and now up to a capacity factor of 0.935.
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Post by cyrilr on May 14, 2020 14:34:10 GMT 9.5
"only" a 13% drop? Renewables spin. How come the renewables people always make downsides look like positives?
A 1000 MWe plant that only produces 870 MWe halfway through its life is not good at all. This would be a lemon to a utility. They now need to buy 130 MWe of expensive replacement power somewhere.
It is similar tot the spin on how crap capacity factor, non-dispatchable solar and wind are "variable" yet reliable, dispatchable baseload power is "inflexible" as it cannot accomodate the "variable" renewables. Yeah, we had a reliable powerplant that didn't need unreliable fickle energy sources with no capacity, but we built those unreliables anyway and now we blame the reliable plant for inherent deficits of the fickle sources we added as a diversion to cover up how useless these things are in powering the nation. Great strategy, these people have got the nation's interest at heart clearly.
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Post by cyrilr on May 14, 2020 15:02:34 GMT 9.5
[moved to other thread]
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Post by David B. Benson on May 14, 2020 15:05:59 GMT 9.5
A typical grid has 70% of maximum demand at all times, 24/7. Traditionally the demand increases towards maximum starting about 6 am and grows to a maximum late in the day, declining abruptly at 11 pm. So the 70% so-called baseload is well met by steady nuclear power plants. It is the daytime load that was met by gas turbines that is now giving way to solar panels in sunny regions. Increasingly these have attached utility scale batteries to store the noon maximum excess against the evening demand. See: California duck curve.
All well and good but wind turbines are, in my opinion, disruptive. These require gas turbines for load balancing in regions without hydropower to perform that duty.
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Post by cyrilr on May 14, 2020 15:08:11 GMT 9.5
A typical grid has 70% of maximum demand at all times, 24/7. Traditionally the demand increases towards maximum starting about 6 am and grows to a maximum late in the day, declining abruptly at 11 pm. So the 70% so-called baseload is well met by steady nuclear power plants. It is the daytime load that was met by gas turbines that is now giving way to solar panels in sunny regions. Increasingly these have attached utility scale batteries to store the noon maximum excess against the evening demand. See: California duck curve. All well and good but wind turbines are, in my opinion, disruptive. These require gas turbines for load balancing in regions without hydropower to perform that duty. A better way to go would be to have schedulable demand so that the portion of baseload can be increased, allowing more nuclear. Electric vehicles are a primary example of this, as they'd be charged mostly at night anyway - another fact that the solar enthusiasts don't want to admit... nuclear works better with EVs than solar.
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Post by David B. Benson on May 14, 2020 15:52:13 GMT 9.5
It seems that New Zealand has a two meter system. One meter for the load which requires power whenever; the other meter only turns on when the price is sufficently low. However, this latter service is currently rarely utilized.
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Post by Roger Clifton on May 14, 2020 19:40:01 GMT 9.5
It seems that New Zealand has a two meter system. One meter for the load which requires power whenever; the other meter only turns on when the price is sufficently low. However, this latter service is currently rarely utilized. That is pretty clear evidence that there are few intermittent customers for intermittent power!
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Post by David B. Benson on May 14, 2020 21:31:00 GMT 9.5
Roger Clifton --- I know of a few commercial, even industrial, establishments which are willing to have interrupable power in exchange for lower rates. An example is the fish processing plant in Bellingham, Washington, which freezes their product. They make very cold ice, perhaps so-called dry ice, overnight when the price is lower in order to freeze fish whenever the supplier ships come in.
A more common arrangement is making ice overnight to run the air conditioners when electricity prices are higher in the afternoon. Even this is rare.
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Post by cyrilr on May 14, 2020 22:16:25 GMT 9.5
Making ice overnight works for some commercial or even a few industrial applictions, because there's a reliable excess of power every night in a typical grid with lots of baseload power. So it works well with coal or nuclear.
With wind, it would not work well. The wind is all over the place, V^3 power profile. Whipsaw armageddon. Some days you have dozens of cycles, some days no power, so weeks no power, some days and weeks too much power. Only so much you can do with a diurnal schedulable load. Very useful for nuclear power grids like France's, marginally useful for a hypothetical (that is to say theoretical) wind and solar grid.
Perhaps we can use excess solar to make ice at night... oh no wait oops there's a problem with that scheme. Forget I said anything.
A little extra solar output at noon isn't long enough to make the ice, likely needs all sorts of investments in ice making capacity. Even then there's the usual problems of cloudy weather and wintertime. Here in Holland the January capacity factor for PV is 1%. That is not a typo. Talk of excess solar PV is rather a good joke to me, and the suggestion that it could be used economically commercially reaches ROFL levels.
That said, ice making (or hot water) at night is a huge synergy for a nuclear grid. The kind of thing, together with EV charging at night, that can get you very close to a 100% nuclear powered grid.
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Post by engineerpoet on May 15, 2020 0:39:22 GMT 9.5
That said, ice making (or hot water) at night is a huge synergy for a nuclear grid. The kind of thing, together with EV charging at night, that can get you very close to a 100% nuclear powered grid. Electrofuels can get you to 100%. The waste heat can provide space heat and DHW for entire metro areas. I've run the numbers. The only unknown (to me) is the specifics of industrial process heat.
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Post by cyrilr on May 15, 2020 2:40:54 GMT 9.5
That said, ice making (or hot water) at night is a huge synergy for a nuclear grid. The kind of thing, together with EV charging at night, that can get you very close to a 100% nuclear powered grid. Electrofuels can get you to 100%. The waste heat can provide space heat and DHW for entire metro areas. I've run the numbers. The only unknown (to me) is the specifics of industrial process heat. What is your preferred method for the fuel production? HT or LT electrolysis, or electrochemical H2? Carbon source?
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Post by engineerpoet on May 15, 2020 7:31:05 GMT 9.5
I actually can't tell you that, because I'm trying to patent something. I need to find some decent drawing tools and get back to it.
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Post by David B. Benson on Jun 5, 2020 20:35:03 GMT 9.5
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Post by David B. Benson on Jun 5, 2020 20:49:12 GMT 9.5
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Post by David B. Benson on Jun 5, 2020 21:03:32 GMT 9.5
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Post by David B. Benson on Jun 5, 2020 21:16:39 GMT 9.5
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Post by David B. Benson on Jun 5, 2020 21:28:30 GMT 9.5
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Post by David B. Benson on Jun 6, 2020 20:16:27 GMT 9.5
Automated monitoring for birds in flight: Proof of concept with eagles at a wind power facility Christopher J.W. McClure et al. August 2018 Biological Conservation www.sciencedirect.com/science/article/pii/S0006320717319407Eagles are legally protected so wind turbines need to avoid eagles, somehow. h/t to Stephen Emmerson posting on Real Climate
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Post by David B. Benson on Jun 7, 2020 21:31:07 GMT 9.5
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Post by engineerpoet on Jun 10, 2020 7:39:52 GMT 9.5
One of the glaring flaws (far more than a mere foible) of "renewables" (wind and PV) is that they are unreliable. SO unreliable, as a matter of fact, that they force the adoption of much dirtier fossil-fired generators to accommodate their output swings.
Naive greenies think that "RE" can just be thrown onto the grid, but in fact an RE-heavy grid requires different generating technologies than one with little or none. You can generally follow the normal load curve using a CCGT plant, which can be up to 64% efficient (LHV). Following the bumpiness of "renewables" mostly requires simple-cycle gas turbines (the CCGT steam systems don't like rapid power variations); the best aeroderivative GT I've read about gets only 44% efficiency, and I recall that the single-shaft industrial models often get something like 38%. IOW, you're burning 60% or more fuel for the same electric output. This puts you way behind emissions-wise.
Typical capacity factors for wind are 30-40%; PV is much lower. If you're only getting 30% of your juice from "renewables", and you're burning 60% more fuel per kWh to get the rest, you're at 112% of the CCGT emissions figure. You've actually gone backwards from what you could do with all-fossil.
Now, don't let it be said that there aren't ways around this. With enough excess RE capacity you can just brute-force the issue by dumping excess power to resistance heaters in a CCGT's gas turbines, substituting electricity for fossil fuel and managing the rapid power swings on the demand side. But this is going to hit the economics, and nobody even seems to be thinking that far out of the box.
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Post by engineerpoet on Jun 10, 2020 9:05:18 GMT 9.5
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Post by David B. Benson on Jun 12, 2020 14:34:51 GMT 9.5
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Post by David B. Benson on Jun 17, 2020 3:11:15 GMT 9.5
engineerpoet --- The part you quote isn't the worst of it.
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Post by engineerpoet on Jun 17, 2020 6:09:37 GMT 9.5
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Post by engineerpoet on Jun 17, 2020 10:06:08 GMT 9.5
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Post by David B. Benson on Jun 24, 2020 4:37:33 GMT 9.5
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