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Post by David B. Benson on Feb 8, 2020 13:39:57 GMT 9.5
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Post by engineerpoet on Feb 15, 2020 11:52:06 GMT 9.5
Gas controls a lot of our thinking. The word seems to be absent from our conscience and consciousness. Speakers claiming to protect the greenhouse argue that if the world stops burning coal, global warming would stop. What they are omitting is the phrase, AND GAS. Also omitting "AND OIL", but even so they're wrong. Climate warming will continue for way, way too long even if we stop emitting fossil carbon today. The heat currently disappearing into the oceans cools the globe, and until they come to equilibrium heating will continue. Then there are the effects from things like methane from thawing permafrost. Anyone ready to consider geoengineering yet? I suspect we're going to need some megatons of SO2 in the high stratosphere shortly to prevent the phenomena of 2020 Australia being repeated world-wide.
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Post by David B. Benson on Feb 17, 2020 14:51:40 GMT 9.5
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Post by Roger Clifton on Feb 17, 2020 17:52:40 GMT 9.5
CSIRO states their opinion that SMRs will be more expensive ... Well, it isn't CSIRO engineers saying that. The GenCost 2019-20 report (currently a draft report) does not consist of peer-reviewed work by CSIRO scientists, much as the article in the renewables trade journal, RenewEconomy would have us believe, but by a group of renewables enthusiasts largely in AEMO and elsewhere. Years ago, an anti-school government required that CSIRO publish work partnered with industry. Consequently there are "CSIRO reports" on nonsense like carbon sequestration etc. On the flyleaf, as publisher, CSIRO inserts "Important disclaimer... CSIRO ... excludes all liability ... arising directly or indirectly from using this publication (in part or in whole) and any information or material contained in it." Reader beware! The GenCost report compares the costing for instantaneous renewable electricity without including the cost of firming the ragged supply for 24-hour use as electricity on demand. (Are we going for 100% non-fossil power, or not?) Costings for coal with carbon sequestration are included, despite it being purely hypothetical. The costing for SMRs is somehow set at 16 $/W, contradicting NuScale and MPower estimates of 5 $/W. They don't discuss the revolutionary drop in cost expected of the transition between FOAK and NOAK of SMRs, although they concede that their estimate of 16 $/W may decrease, but never to less than twice the cost of renewables. No mention is made of the much lower (than 16 $/W) cost for established large nuclear.
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Post by David B. Benson on Feb 20, 2020 18:44:56 GMT 9.5
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Post by David B. Benson on Feb 28, 2020 20:52:02 GMT 9.5
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Post by David B. Benson on Mar 6, 2020 6:20:19 GMT 9.5
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Post by David B. Benson on Mar 9, 2020 12:49:33 GMT 9.5
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Post by David B. Benson on Mar 21, 2020 7:43:25 GMT 9.5
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Post by engineerpoet on Mar 21, 2020 10:28:35 GMT 9.5
Organic Rankine cycles are generally aimed for low-temperature applications and have similarly low thermal efficiencies. I found nothing in the article or at the RayGen site which goes into anything close to scientific detail, so I have to consider this a half-baked scheme. Yes, it can generate some power after dark. I saw nothing to support the claim of 4 MW/50 MWh.
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Post by David B. Benson on Apr 11, 2020 5:51:53 GMT 9.5
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Post by engineerpoet on Apr 12, 2020 1:37:17 GMT 9.5
1 megawatt at 2% of final capacity. This comes to 50 megawatts when complete. This compares to the ~450 MW drop in wind-farm output which was the penultimate event in the S.A. blackout.
A Powerwall is rated at 13.5 kWh of capacity. This is enough to make a good PHEV, maybe 2 if they're small. In V2G use, PHEV batteries would make a perfectly fine VPP and decarbonize transport. Tesla's stunt is just that, a stunt.
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Post by Roger Clifton on Apr 12, 2020 11:45:55 GMT 9.5
"Tesla Virtual Power Plant In Australia Outperforms Expectations" ... This is a sizable battery. The article reports that the "Virtual power plant" was able to supply 828 kW for several minutes, about 0.1 MWh. That is big for a distributed battery and might be useful as replacement for some of the spinning reserve on the system, but it does not rank as a power station. The use of the term VPP is a clear innuendo that it does rank. A solar farm might boast of having a battery to continue supply for a few minutes when the sun goes behind a cloud. A coal-fired power station keeps a stockpile of weeks of coal in case of disruption of supply. By way of example, an Indian stockpile of 450 tonnes (of 20 GJ per tonne coal burned at 40% efficiency) represents 1000 MWh. That ten-thousand fold difference is the ballpark for storage that renewables fail to achieve. PS – That reference to 450 tonnes did not quote the size of what must be a tiny power station so its endurance is unclear. I have an old memory of three months being set for a reserve supply of coal, but it seems to predate the Internet. I did find a modern reference with a graph that indicates that US stockpiles vary between 50 and 100 days of burn. Matching that level of energy storage (again, a ballpark of 10,000 fold shortfall) for renewables seems to be an impossible pipedream.
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Post by engineerpoet on Apr 13, 2020 4:17:50 GMT 9.5
An Indian stockpile of 450 tonnes (of 20 GJ per tonne coal burned at 40% efficiency) represents 1000 MWh. That ten-thousand fold difference is the ballpark for storage that renewables fail to achieve. Indeed. Batteries provide minutes to hours, when we need weeks and months. One of the things I'm looking into is the possibility of refuse-derived fuel (char, actually) as a "renewable" solid fuel which can be stockpiled. My initial numbers suggest that it would be small compared to current use of coal, but significant. However, I'm given to understand that biochar is chemically reactive and tends to auto-ignite in large masses. It doesn't help much if you can't store it cheaply, and it's hard to get cheaper than piles on the ground outdoors.
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Post by David B. Benson on Apr 21, 2020 8:50:37 GMT 9.5
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Post by David B. Benson on Apr 29, 2020 11:45:02 GMT 9.5
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Post by David B. Benson on May 22, 2020 12:31:30 GMT 9.5
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Post by David B. Benson on Jun 7, 2020 12:27:26 GMT 9.5
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Post by engineerpoet on Jun 7, 2020 12:51:26 GMT 9.5
Y'know, it would be nice to not have to strip off the Google click-spying crap as well as the Viglink link-spying crap to go look at an article.
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Post by huon on Jun 7, 2020 16:02:18 GMT 9.5
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Post by engineerpoet on Jun 8, 2020 6:28:17 GMT 9.5
Nefarious enough. Viglink uses insecure http, and I have both Viglink and Google blocked at the name-resolution level.
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Post by David B. Benson on Jun 15, 2020 6:01:16 GMT 9.5
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Post by David B. Benson on Jun 21, 2020 13:11:25 GMT 9.5
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Post by David B. Benson on Jun 26, 2020 11:25:20 GMT 9.5
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Post by David B. Benson on Jul 7, 2020 11:05:08 GMT 9.5
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Post by David B. Benson on Jul 31, 2020 12:24:05 GMT 9.5
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Post by engineerpoet on Aug 1, 2020 6:52:56 GMT 9.5
Australia's trilemma of providing good, fast and cheap energy finally has a clear solution FTA:And as we well know, there is no defined or definable end date for the "short term".
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Post by David B. Benson on Aug 22, 2020 6:06:41 GMT 9.5
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Post by David B. Benson on Aug 31, 2020 18:27:22 GMT 9.5
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Post by David B. Benson on Sept 3, 2020 15:21:59 GMT 9.5
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