Tidal Lagoon - Energy from the Ocean, UK Gov is putting money in it - Page 1
Forum section: electronics / general

author: Zucca
author_rank: Unknown
timestamp: March 03, 2015, 09:21:39 am
content: IM(very very)HO seems interensting... and reasonable.I am wondering if you could use it in the Panama or Suez canals.

author: tggzzz
author_rank: Super Contributor
timestamp: March 03, 2015, 10:00:32 am
content: Such schemes only provide intermittent power; it is predictable when they will be generating 10%, 90%, 50%, 10% and 0% of peak power. Hence thecapacity of conventional generating plant is unchanged.Note that generating plant is most reliable when run at a constant power: thermally cycling plant reduces its operating lifetime, sometimes significantly.BTW. Also look for the Severn Barrage proposals.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: March 03, 2015, 10:01:17 am
content: They've been on about things like this for decades in different parts of the UK, with many a hugely successful trial. Shame it'll never happen, too many NIMBYs will whine about it.http://en.wikipedia.org/wiki/Pelamis_Wave_Energy_Converteris another approach I think could be more useful, less need to work out how to store the energy for later use.

author: Zero999
author_rank: Super Contributor
timestamp: March 03, 2015, 01:10:38 pm
content: Quote from: tggzzz on March 03, 2015, 10:00:32 amIt's possible to produce power most of the time and it can be stored so it should be able to take some of the load away from conventional generating plants.

author: KJDS
author_rank: Super Contributor
timestamp: March 03, 2015, 01:53:00 pm
content: I suspect that it could work well in Scotland, mostly due to the low density of population and plenty of sea lochs that would be easy to put a barrier across. There are far fewer suitable places south of Hadrian's wall.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: March 03, 2015, 02:53:33 pm
content: Quote from: KJDS on March 03, 2015, 01:53:00 pmThat's where most of the trials have been run, but like wind farms the locals and landowners don't want their views ruined. Look at where the new wind farms are turning up, on the islands where the companies can give every resident a job to get them to want it, then have underwater power lines bringing the power to the mainland.The British as a whole are terrible for this stuff. We don't want gas, coal or oil power plants, but we don't want nuclear, wind farms or solar farms or personal wind and solar power (just try to get planning permission) even more than them. FFS if we had fusion working we wouldn't want that either, and you'd have the surviving Hitchens brother whining that fission is safer :/

author: tggzzz
author_rank: Super Contributor
timestamp: March 03, 2015, 04:42:05 pm
content: Quote from: Mechanical Menace on March 03, 2015, 02:53:33 pmIf energy use keeps expanding at the historical rate of 2%/year then, however "green" the source, in 400 years the oceans boil. Simple thermodynamics of black body radiators.Seehttp://physics.ucsd.edu/do-the-math/2012/04/economist-meets-physicist/

author: malch
author_rank: Regular Contributor
timestamp: March 04, 2015, 04:19:00 am
content: Bad idea. It's a scientific fact that it will slow the rotation of the earth!

author: coppice
author_rank: Super Contributor
timestamp: March 04, 2015, 05:34:47 am
content: Quote from: Mechanical Menace on March 03, 2015, 10:01:17 amWave power is a very interesting idea, but so far results have been problematic. It has proved difficult to combine, in a single design, the efficient extraction of wave energy and tolerance the worst storms that can occur. Back in the 1970s there were some neat experimental designs which worked well until they were smashed by extreme storms.

author: EEVblog
author_rank: Unknown
timestamp: March 04, 2015, 06:12:26 am
content: Quote from: Hero999 on March 03, 2015, 01:10:38 pmThat's my understanding as well. It's not just tidal action, but regular wave action which is quite constant in many locations.We just got a grid connected one online:http://www.businessinsider.com.au/the-worlds-first-grid-connected-wave-energy-plant-in-western-australia-this-is-how-it-works-2015-2

author: tggzzz
author_rank: Super Contributor
timestamp: March 04, 2015, 04:24:43 pm
content: Quote from: Hero999 on March 03, 2015, 01:10:38 pmIt is possible to producea small proportion of the powerat all times. Unless people will accept lights going off, you need to make up the shortfall from other sources. Hence thecapacity of conventional generating plant is unchanged, even if it is used less of the time. Note that conventional plant hates being thermally cycled.I suggest you do some research to understand the various possibilities for the Severn Barrage, which could produce, IIRC 5% of UK electricity. This has been extensively studied over the past 50 years, and various schemes proposed to offset the variable power output. None are completely successful, and there are significant associated disadvantages. The last time I went to a professional seminar on the Severn and Swansea Barrages, the Swansea Barrage was shown to be comparatively unattractive.I'm glad you know how to store electricity. I trust you have patented your techniques, because they are worth billion of pounds/dollars etc. Seriously. (If, OTOH, you mean storing energy via water height, then any such advantages/disadvantageswill already have been factored in- since that's exactly what the barrage does and doesn't do!)Separate discussion: whether wind power is intermittent or not (because the "wind is always blowing somewhere"). Unequivocal answer for the UK, both theoretical and measured: wind power is intermittent. About 8% of the time the total UK wind power output is <2.5% of peak. And the UK is one of the best locations for wind power! Have a high pressure zone sat over the UK in winter, and zero wind power lasts for days or weeks. To get spatial diversity, you have to consider areas the size of Europe, and the transmission losses over those distance swould be prohibitive. Seehttp://www.jmt.org/wind-analysis-report.aspfor more details.

author: tggzzz
author_rank: Super Contributor
timestamp: March 04, 2015, 04:26:17 pm
content: Quote from: mojo-chan on March 03, 2015, 02:38:36 pmFirst sentence: irrelevant.Second sentence: simply wrong.Sorry.

author: LabSpokane
author_rank: Super Contributor
timestamp: March 04, 2015, 04:37:46 pm
content: Quote from: EEVblog on March 04, 2015, 06:12:26 amhttp://www.powerengineeringint.com/articles/2015/03/world-s-first-grid-connected-wave-power-station-activated-in-australia.htmlHere's the same system in Power Engineering. It's a pilot system at 240kW, but at least it's deployed, which is more than most wave energy systems can say for themselves. Hopefully the pumping mechanism is simple, robust, and will scale well. They are avoiding the mistake of distributing the electrical generation, which many wave energy systems try to do.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: March 04, 2015, 04:46:44 pm
content: Quote from: LabSpokane on March 04, 2015, 04:37:46 pmWorlds first? Why don't Pelamis Wave Power's 2004, 2009, and 2010 grid connected tests in the UK, Portugal, and then the UK again count?

author: coppice
author_rank: Super Contributor
timestamp: March 05, 2015, 11:04:14 am
content: Quote from: mojo-chan on March 05, 2015, 09:34:54 amYou offered no argument. You just made an assertion. Why do expect those replying to work to a higher standard than you?

author: tggzzz
author_rank: Super Contributor
timestamp: March 05, 2015, 11:08:52 am
content: Quote from: mojo-chan on March 05, 2015, 09:34:54 amContext is important, so here it is (again). Please don't snip so much that you distort the points being made.Quote from: mojo-chan on March 03, 2015, 02:38:36 pmFirstlyyouneed to explainyourmechanism that "delays the release of water for a few hours". Secondlyyouneed to define how your scheme works when the water is the same height on each side of the barrage.In doing that you should make reference tothe proposed barrage being a single-basin schemethe disadvantages of two basin schemesthe solid physics described inhttp://www.withouthotair.com/c14/page_81.shtmlandhttp://www.withouthotair.com/cG/page_311.shtmlandhttp://physics.ucsd.edu/do-the-math/2011/12/can-tides-turn-the-tide/discussion of Severn barrage and Swansea barrage schemes inhttp://www.sd-commission.org.uk/data/files/publications/TidalPowerUK1-Tidal_resource_assessment.pdfif you refer to Rance,BTW, calling someone "bro" make you look like a dilettante.

author: tggzzz
author_rank: Super Contributor
timestamp: March 05, 2015, 11:09:59 am
content: Quote from: coppice on March 05, 2015, 11:04:14 amYou offered no argument. You just made an assertion. Why do expect those replying to work to a higher standard than you?Succinctly and to the point

author: rolycat
author_rank: Super Contributor
timestamp: March 05, 2015, 12:36:06 pm
content: The video linked by the OP is a very slick bit of marketing, which generally indicates a need for skepticism.The project may or may not be technically sound, but it does appear that the unit cost of energy will be very high. The developers are reportedly demanding a strike price of £168/MWh for 35 years under the UK government's Contracts for Difference subsidy scheme. This is around four times the current wholesale price. It is also around twice the cost of onshore wind or PV solar power and will be paid for more than twice as long.Citizens Advice, a respected UK consumer organization, havedescribedthe scheme as a 'boondoggle' offering appalling value for money.

author: coppice
author_rank: Super Contributor
timestamp: March 05, 2015, 03:19:49 pm
content: Quote from: mojo-chan on March 05, 2015, 02:39:26 pmYou are still making the same assertion without backing it up. Can you refute the analysis in the links you were give?

author: tggzzz
author_rank: Super Contributor
timestamp: March 05, 2015, 06:08:10 pm
content: Quote from: mojo-chan on March 05, 2015, 04:39:06 pmIt does mean that your comments are irrelevant and/or wrong in the context in which you made them. In particular, such barrages don't reduce the capacity of conventional plant required, and they do require it to be thermally cycled in synchronism with the tides. Not good.

author: LordNobady
author_rank: Contributor
timestamp: March 06, 2015, 06:46:46 am
content: we are running one since 2008http://www.energisingdeltas.com/press-release-proefinstallatie-stromingsenergie-officieel-geopend/just updated it.

author: Zero999
author_rank: Super Contributor
timestamp: March 07, 2015, 08:30:28 pm
content: The water level at both sides is only a problem for one tidal power station.If several tidal power stations are built in different locations, with slightly different tides there will never be a time when no tidal power station is generating. It is possible for them to take some of the load off conventional power plants.

author: coppice
author_rank: Super Contributor
timestamp: March 08, 2015, 03:28:26 am
content: Quote from: mojo-chan on March 05, 2015, 04:39:06 pmIs there any possibility that if I keep asking you might eventually answer the question properly?

author: tggzzz
author_rank: Super Contributor
timestamp: March 08, 2015, 12:50:33 pm
content: Quote from: Hero999 on March 07, 2015, 08:30:28 pmThat's a completely different point. The significant operational point is that you can't reduce the required capacity of the conventional plant, even though it will be operated at below capacity forsomeof the time. The power cycling reduces the plant's lifetime thus making it more expensive.Your point has some use,but only if you add anextremely limitingcaveat. You have to very significantly reduce the total tidal power output - which makes it even more expensive.

author: tggzzz
author_rank: Super Contributor
timestamp: March 09, 2015, 11:04:00 am
content: Quote from: mojo-chan on March 09, 2015, 10:40:06 amNo, I, and others are not.QuoteThat's a different point, as I hope you are well aware (but I'm beginning to doubt). We have, infamously, 4%-5% excess capacity. Unexpectedly lose a second major plant, and everybody will notice it.Let's ask a different very important question. If you rely on a 2GW peak tidal system such as the Severn barrage, what else would you have to ensure the light stay on. To be useful your answer requiresnumericcapacities and, for intermittent sources such as wind or solar,numericprobabilities of being able to supply the capacity. If relying on wind, please make reference to themeasurementsdetailed inhttp://www.jmt.org/wind-analysis-report.aspHand-waving wishful-thinking will be publicly laughed at.

author: tggzzz
author_rank: Super Contributor
timestamp: March 09, 2015, 03:02:02 pm
content: Quote from: mojo-chan on March 09, 2015, 01:40:38 pmExactly what extraordinary claims am I making?Note that experts that are not commercially biassed make much less definitive statements - for very good reason. See Mackay's book that has been lauded by "all sides" including greens, politicians, big energy and more.http://www.withouthotair.orgWith tidal power youwilllose 100% of it on a regular basis. What will you use to cover that loss? The only industrial answer at the moment is conventional plant.If you have alternatives, let's hear them. If they do stack up, then people will shower you with riches. Seriously!Have a look at the problems currently being experienced in Hawaii, and the response of their grid. Start withhttp://www.fool.com/investing/general/2014/10/19/solar-news-watch-hawaiis-solar-dilemma-it-could-be.aspx

author: tggzzz
author_rank: Super Contributor
timestamp: March 09, 2015, 04:45:30 pm
content: Quote from: mojo-chan on March 09, 2015, 04:38:38 pmIt isn't a problemprovidedthat you have the equivalent capacity in conventional plant, and you thermally cycle that plant. That's the only current solution - if you have another solution, patent it and become a multi-billionaire. Or let me know and I'll become oneOtherwise it is a problem, as is demonstrated in Hawaii.If you don't have an alternative solution, please gracefully concede that point. I'm sure other people would respect that.

author: coppice
author_rank: Super Contributor
timestamp: March 10, 2015, 02:05:34 am
content: Quote from: mojo-chan on March 09, 2015, 04:38:38 pmOther that some cataclysmic event which destroys much of the country, can you name a random event which would take down more than one coal, oil or nuclear power station at a time? They fail so infrequently that the chances of 2 failing on the same day are down around the chances of a cataclysmic event. In the case of a cataclysmic event I expect the country would have more to worry about than the loss of power stations. since the distribution grid, and many of the consumer will probably have been taken out in the same event.

author: tggzzz
author_rank: Super Contributor
timestamp: March 10, 2015, 01:33:20 pm
content: Quote from: mojo-chan on March 10, 2015, 11:51:41 amQue?! Who mentioned anything about the number of plants. I'm having difficulty distinguising your constantly changing points from those that might be made by a troll.QuoteOf course; who said anything else? I certainly didn't. I'm having difficulty distinguising your constantly changing points from those that might be made by a troll.QuotePlease discusscapacity, and how much conventionalcapacityhas to be available when there is an intermittent (predictable or otherwise) source such as a barrage.All that has been known for years, and so far has only become a problem in Hawaii. But it will become more a problem in more locations in the future.Please try and sell your "expertise" to the Hawaii authorities - and let us know the results

author: tggzzz
author_rank: Super Contributor
timestamp: March 10, 2015, 02:50:10 pm
content: Quote from: mojo-chan on March 10, 2015, 01:55:37 pmYes. Your your ability to misread the question and to make strawman arguments does indeed make it futile.I,and others, have noticed your inability to answer the question being asked

author: coppice
author_rank: Super Contributor
timestamp: March 11, 2015, 12:07:34 am
content: Quote from: mojo-chan on March 10, 2015, 11:49:26 amExcuse me, but could you just work through the numbers for us, and show us how you draw that conclusion from the paper you cited?

author: dannyf
author_rank: Super Contributor
timestamp: March 11, 2015, 01:07:08 am
content: QuoteGoogle "prisoner's dilemma".Like in a stadium. When everyone is sitting down, your optimal strategy for a better view is to stand up.When everyone adopt's that "optimal" strategy, everyone is screwed.

author: tom66
author_rank: Super Contributor
timestamp: March 11, 2015, 11:07:40 am
content: The problem I have with an exclusive intermittent power generation grid is it's easy to conceive of a situation where all three sources (wind, solar, tidal) will be simultaneously unavailable, perhaps for hours at a time for any given day. This is not the same as being off for 24 hours a year in a few hour-long intervals. A 0.26% availability failure per year could be filled in by diesel gensets (so called "short term operating reserve") and Dinorwig storage plant in Wales. But you can't realistically do that for renewables, there isn't enough capacity as it's more like being off for 3-4 hours per day.For example, wind power, whilst predictable in the short term is very unreliable:And, we know that solar power obviously doesn't produce much at night, but it's also quite hard to rely on it for day-to-day power (typ average from installed system, hard to find data on UK average):Tides- yes, they're predictable, but again, no power during certain times.So how do you provide power during these low periods?- You can use grid storage (best option) - but very expensive, especially if you might only have tides available during low wind/solar periods. Batteries pretty much only viable option due to lack of pumped storage.- You can dynamically price for large industrial customers such as Al smelters and perhaps even retail customers charging EVs/using storage heaters/etc. to encourage usage when energy is cheap and abundant (high wind, high tide, high solar.) Not sure how much of a difference this will make but probably the direction the grid will go in anyway.- You can use a more reliable fossil fuel or biofuel plant. (Most realistic option IMHO.) Needs to be able to rapidly respond to changing load.I have a problem with enviromentalists, emphasis on the "mental" bit who seem to think 100% renewable intermittent is practical because "it'll always be windy somewhere."

author: tggzzz
author_rank: Super Contributor
timestamp: March 11, 2015, 01:09:54 pm
content: Quote from: tom66 on March 11, 2015, 11:07:40 amNaturally I agree with your post, but I'm sure mojo-chan will not address those points but will choose to "answer" points you haven't made.If you are interested in further solid evidence against the "it'll always be windy somewhere" proposition, you may care to look athttp://www.jmt.org/wind-analysis-report.aspUnsurprisingly to anyone that lives in the UK and has witnessed how long a "blocking high pressure" lasts (weeks) and the geographical area it covers (all the UK),spatial diversity for wind power is only guaranteed when you are considering the whole of Europe.

author: coppice
author_rank: Super Contributor
timestamp: March 11, 2015, 01:19:46 pm
content: Quote from: mojo-chan on March 11, 2015, 09:25:42 amSo, you don't understand what unplanned downtime means. Fair enough. Maybe you should read more.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: March 11, 2015, 01:22:42 pm
content: Quote from: tggzzz on March 11, 2015, 01:09:54 pmI totally agree that you'd either need a grid with much better conductors (maybe even room temperature superconductors) covering the entire continent (which would be terrible for energy security) and/or some amazing new grid storage tech to go 100% renewable, I don't think that's a good enough reason to not use them to at least reduce carbon output etc.It's not like we can't get away with pumping a certain amount of shit into the environment, but I don't think anyone serious would believe we can get away with not reducing it even if they think climate change is a massive international conspiracy. You only have to look back to the 80s to remember real smogs, proper acid rain, and dead waterways from lead and mercury poisoning in the UK, and while we've come an amazing way from that with pollutants you can easily see the effects of there's still a ways to go, especially on the global scale.

author: coppice
author_rank: Super Contributor
timestamp: March 11, 2015, 02:21:20 pm
content: Quote from: Mechanical Menace on March 11, 2015, 01:22:42 pmI think room temp superconductors are pretty unlikely to happen now. There was a surge in new materials which made it look like interesting things would be possible, but that ran out of steam some time ago.With all its wind farms, how much coal has the UK so far avoided burning? The figures from different sources look very different, depending on the biases of the people producing them, but none look very promising. You don't have to stop all coal burning in the near term, but if you aren't biting into it significantly you are just tinkering with things to make some people feel better about themselves.Quote from: Mechanical Menace on March 11, 2015, 01:22:42 pmThe UK didn't have serious smogs in the 80s. That was the 50s and earlier. Cleaning that up was not very hard, and didn't take very long. It just took the political will to enforce the necessary steps. A few winters with enough deaths was sufficient for that. The UK's history with water is very patchy. The Thames is an outstanding example of a river rehabilitated, but the UK has plenty of water which has seen no improvement at all. These things cost a lot, but they are now well understood, and good results are achievable. The picture isn't looking so good right now for renewables.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: March 11, 2015, 02:30:01 pm
content: Quote from: coppice on March 11, 2015, 02:21:20 pmWe did in West Yorkshire. Maybe not as bad as the Great Smog but that bad we couldn't play out during breaks at school. I think it was the EU and not local laws that fixed that. But of course we're not London so it doesn't countQuoteProblem there is how to measure that in comparison to our increased energy use. And we have nowhere near the amount or scale of wind farms that the companies wanted because of NIMBYs like that useless prat Charles Windsor. But I can say that every watt of power we get from renewables or nuclear is 1 watt less from coal, oil or gas.

author: tggzzz
author_rank: Super Contributor
timestamp: March 11, 2015, 02:35:00 pm
content: Quote from: Mechanical Menace on March 11, 2015, 01:22:42 pmBetter conductors are a pie-in-the-sky hope, and can't be used for planning.Energy storage possible and highly beneficial, but currently the technology and scope for it is limited. We should continue to invest in the R&D, and make plans for how we might be able to use it.The reduction in CO2 output is one good reason for investing in renewables (diversity and independence being the others), but they aren't a panacea and does come with disadvantages. (As I'm sure you are aware)QuoteYes, except that in the UK the last "pea souper" smogs in London were in the 1950s, and disappeared when legislation forceddomesticcity users to burn "smokeless coal", which was more-or-less coke - i.e. coal heated to drive off the volatile chemicals, which were then used for chemicals and town gas.Of course China is now experiencng "pea soupers" over a wide area, caused by industrial users.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: March 11, 2015, 02:40:17 pm
content: Quote from: tggzzz on March 11, 2015, 02:35:00 pmOh I know, I was presenting that as a problem with going 100% renewable.QuoteThe ones I can remember were definitely industrial. They stopped when companies like Microvitec had to clean up their acts and the old chemical plants finally shut down.Edit: They were rarely even the low end of "pea-soupers" in terms of visibility more like a normal fog there, but they tasted horrid and had people caughing. The asthmatics obviously got the short straw though.

author: coppice
author_rank: Super Contributor
timestamp: March 11, 2015, 03:11:03 pm
content: Quote from: tggzzz on March 11, 2015, 02:35:00 pmNo they aren't. I was a child in pea souper London, and I spend lots of time in China. The character of pollution in Beijing is nothing like we had in London. Now Delhi, that is a lot like Beijing. Damnit, I seem to be becoming a connoisseur of air pollutions.

author: zapta
author_rank: Super Contributor
timestamp: March 11, 2015, 03:52:48 pm
content: Quote from: coppice on March 11, 2015, 03:11:03 pmCan you explain the differences?

author: zapta
author_rank: Super Contributor
timestamp: March 11, 2015, 03:55:32 pm
content: Quote from: tggzzz on March 11, 2015, 02:35:00 pmThat's a very practical view of reality, which is often in short supply here.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: March 11, 2015, 04:08:24 pm
content: Quote from: zapta on March 11, 2015, 03:52:48 pmvsThe difference is one is in London and the other is outside of London, maybe even more than 50 miles away, so doesn't matter and probably really isn't thereEDIT: Or how dark the London ones were, more (relatively) large particulate matter. Don't think you could use the Beijing ones to safely filter the sun but wouldn't surprise me if they're about even on health risks etc.

author: tom66
author_rank: Super Contributor
timestamp: March 11, 2015, 04:13:39 pm
content: Quote from: mojo-chan on March 11, 2015, 03:47:32 pmhttp://www.greenpeace.org.uk/climate/low-carbon-futureEmphasis mine.QuoteThey say that fossil fuels are needed in the short term and seem to imply that we can go without them entirely eventually. I disagree, there simply aren't enough statistically distributed intermittent sources to provide high reliability power and there isn't enough grid storage to make such intermittent sources work - where we could have to rely on storage for days at a time in some cases. Nor is there sufficient biomass or waste that can be burned in converted conventional power plants. We will always have to burn fossil fuels or use nuclear power in this country, barring some kind of fusion revolution which is seemingly always 20 years away.Nuclear may have problems but it's a helluva lot better than coal or nat gas, which is another sticking point with me and Greenpeace.

author: tggzzz
author_rank: Super Contributor
timestamp: March 11, 2015, 04:20:09 pm
content: Quote from: coppice on March 11, 2015, 03:11:03 pmI bow to your superior knowledge, and I am content that you have more personal experience

author: tggzzz
author_rank: Super Contributor
timestamp: March 11, 2015, 04:23:10 pm
content: Quote from: mojo-chan on March 11, 2015, 03:52:17 pmI am content to let others judge our relative maturity.I am more than content to let others judge the solidity of your position and my position

author: coppice
author_rank: Super Contributor
timestamp: March 11, 2015, 05:22:19 pm
content: Quote from: zapta on March 11, 2015, 03:52:48 pmLondon's smogs built up when there was sustained fog. Coal particulate from domestic fires built up in the smog, making a dark choking gunge. A tissue over your mouth would go black after a couple of minutes breathing through it. Beijing's worst problems happen when dust blows in from hundred's of km away. It isn't necessarily mixed with fog. Its quite abrasive to breath, and has a much more unpleasant effect of breathing than I remember from childhood London. Put a tissue over your mouth and it goes grey as you breath through it. In the winter Delhi gets periods of a similar dusty effect to Beijing. I'm not sure where their dust comes from.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: March 11, 2015, 06:40:57 pm
content: Quote from: coppice on March 11, 2015, 05:22:19 pmMainly the Gobi. Think some of it comes from the former USSR.So there's no actual fog involved in Chinese/Indian smogs, just dust and pollution? Strange use of the word lol.

author: G7PSK
author_rank: Super Contributor
timestamp: March 11, 2015, 06:59:01 pm
content: The London pea soupers were quite something. I was born in London (1952) and when I was about 5 or 6 there was a smog that was so thick that when I held my arm out I could not see my own hand, the buses were running the only transport that was, the conductors walked in fron of the bus one foot in the gutter the other on the kerb and shone a torch backwards at the driver who followed the torch, My grand mother took us shopping on Oxford street i you had to stick your nose on the shop windows in order to see inside. The smog was full of sulfur which ate the stone work when it rained leaving streaks on the building fronts. It was that smog which made my parents move us to Cambridge.

author: tom66
author_rank: Super Contributor
timestamp: March 11, 2015, 08:12:42 pm
content: Greenpeace are strongly anti-nuclear.http://www.greenpeace.org/international/en/campaigns/nuclear/One of the reasons I cannot support them.They are campaigning for the dismantlement of fossil fuel and nuclear power and replacement of it with:- Solar, wind, tidal: intermittent- Geothermal: brilliant but limited- Biomass: ok if outside of cities and population centres, but limited

author: Galenbo
author_rank: Super Contributor
timestamp: March 11, 2015, 10:15:59 pm
content: Quote from: tggzzz on March 11, 2015, 01:09:54 pmWhat did you expect? That guy is payed by the greenscam industry.They have a scala of 'solutions' that do not work, every time for another reason. When someone points to the reason, they hop to another 'solution'. And again.

author: tom66
author_rank: Super Contributor
timestamp: March 11, 2015, 10:34:11 pm
content: I should point out I'm not opposed to renewable energy in any way. I really like the sight of wind turbines; there's one about 2 miles away from my dad's house and I have no opposition to its position (and neither does he!) But, I consider myself a realist on the issue. And the reality is, intermittent power can never form the entirety or even a significant portion of a grid, because it would be too unreliable. Which is why we must invest in good continuous power sources like nuclear and CGGT (with carbon capture) filling in the gap where wind/solar/tides cannot. Geothermal is great, let's have more of it! But it's really difficult to find places that are amenable to it working at a reasonable price and there is apparently a minor (possibly insignificant) risk of triggering earthquakes when drilling near tectonic boundaries.

author: tggzzz
author_rank: Super Contributor
timestamp: March 11, 2015, 10:38:20 pm
content: Quote from: Galenbo on March 11, 2015, 10:15:59 pmWhile I can understand someone coming to that conclusion, do you have an actualevidencefor that assertion?QuoteThat is a debating tactic they use, but it does not mean everything green is bad, nor that all points they make are false.

author: Someone
author_rank: Super Contributor
timestamp: March 11, 2015, 11:25:05 pm
content: Quote from: coppice on March 11, 2015, 01:19:46 pmYeah those numbers are bad, what follows is all rounded to a single significant figure and roughly calculated but shows a different story. If we assume a 15min planning interval and a typical scram rate of 1.5% per 7000 hours (from that same reference used) then its a scram rate of 500e-9 per 15 minute interval per reactor.9 Reactors in the UK, so the chance of any one and only one failing in a 15 minute interval is 5e-6, so a 50% chance of no scrams during a 4 year period.2 or more failing during a 15 minute interval is 500e-9, for a 50% chance of no loss of 2 or more rectors during a 40 year period.

author: Galenbo
author_rank: Super Contributor
timestamp: March 11, 2015, 11:34:22 pm
content: Quote from: tggzzz on March 11, 2015, 10:38:20 pmI am a big fan of of-the-grid stations that are powered by solar and/or wind. No more long expensive landlines just for that one station.And converting processes to reversible (replace a loss with creating energy),...Maybe, in short, with some overgeneralisation, everything that doesn't need tax money.

author: Someone
author_rank: Super Contributor
timestamp: March 11, 2015, 11:37:33 pm
content: Quote from: tom66 on March 11, 2015, 10:34:11 pmTidal (pumped or not) and pumped water storages can be a viable solution to the intermittent renewables but at the cost of reducing their sustained capacity. Its all engineering tradeoffs that can be mixed to provide all sorts of solutions, since bulk energy storage is one of the key enabling technologies for the intermittent solar, wave, wind, and water current generators it makes a lot of sense to start investing in large scale water storage if only to see how well it can integrate.Here are some real world example of the fluctuating markets faced:http://www.wattclarity.com.au/2007/01/11th-january-2007-first-spike-in-demand-above-30000mw/Hydro brought on 10% of the total grid load, and was able to balance the ramp up of each of the major peaking plants.A more recent example of pumped storage profiting:http://theconversation.com/pumped-hydro-energy-storage-making-better-use-of-wind-18565Though backed by cheap base load coal power, they can equally soak up peaky renewables.

author: tggzzz
author_rank: Super Contributor
timestamp: March 12, 2015, 12:49:19 am
content: Quote from: Galenbo on March 11, 2015, 11:34:22 pmSo you don't have any evidence to support your assertion about his finances, plus you are a neo-con liberal.You two are indistinguishable and deserve each other

author: coppice
author_rank: Super Contributor
timestamp: March 12, 2015, 01:35:01 am
content: Quote from: Mechanical Menace on March 11, 2015, 06:40:57 pmPeople usually say its the Gobi, but I think its more complex. Northern China has large areas with very fine powdery soil, which has been deeply eroding since the dawn of agriculture. In the dry parts of the year I think this is the source of a lot of the dust plaguing Beijing.Many cities in China used to have serious problems of dust in the air, due to the extreme amounts of construction work going on. These days some cities, like ShenZhen, have matured a lot, and construction rates have slowed. All cities are now subject to environmental control laws, which enforce the use of dust nets over large construction sites. People might try to evade some environmental laws, but if you are building towers without nets it stands out like a sore thumb. Hence, this is a one environmental law which is pretty strictly enforced.

author: coppice
author_rank: Super Contributor
timestamp: March 12, 2015, 02:31:10 am
content: Quote from: Someone on March 11, 2015, 11:37:33 pmTidal power can never be a major source of power, so its intermittent nature is not an inherent constraint to its use. Tidal might be a useful part of a total mix of energy sources, in certain specific places, but the planet's total tidal power is not sufficient to meet human needs.Tidal works in places like the Severn in the UK. The global tides are less than one metre, varying with the relative positions of the sun and moon. They are largely predictable, which is a really good quality for an energy source. Its wrong to say tidal is unreliable. You know when its going to be available years in advance, and you know the approximate amount of energy you are going to get. Its just intermittent. The big snag is the energy is spread over vast distances, and the water head is small. Take a place like the west coast of the UK or France, and tides are magnified by the continental shelf. Add the effects of funnelling the water into spots like the Severn, and tides can be 8m to 10m high. Now you have the kind of concentration of power which can make it useful. Its a resonant effect, though. If you want to extract energy from a resonant system, you need to work in sympathy with it. Fight it, and the energy dissipates. This is why talk of time shifting is a non starter. You can nudge the timing by a small amount, but if you try to move significantly away from the optimal timing, the total available energy rapidly drops. Some people have written as though the goal is to get a dribble of energy 24 hours a day. If you aren't getting a lot of energy you could never justify the resources needed for construction. You probably wouldn't even have a net energy benefit, after you amortise the construction energy consumption over the system's working life. Any required barrage should have a long life, but the expensive equipment won't. Mechanics doesn't life variable operation. Just compare the few thousand hour life of a diesel engine in a vehicle, with the 25 year life a diesel engine in steady 24 hour use can offer with reasonable overhaul cycles.

author: tggzzz
author_rank: Super Contributor
timestamp: March 12, 2015, 09:33:56 am
content: Quote from: coppice on March 12, 2015, 02:31:10 amOh, that's an interesting analysis!While the general populace might not understand it, people on this forum ought to.

author: tggzzz
author_rank: Super Contributor
timestamp: March 12, 2015, 09:44:10 am
content: Quote from: mojo-chan on March 12, 2015, 09:29:21 amSome of their tatics and arguments are indeed mental, and their supporters tend to be well-meaning idiots. Other organisations within the green movement are far less disreputable.I remember visiting a Greenpeace exhibition in which they attempted to demonstrate that radioactivity was nasty. The technique they chose was to have a container covered so that you couldn't see what was in it. When you put your hand in it you found something slimy, and naturally went "yuck". Their acolyte then told you that radioactivity was just as yucky.That's idiotic disreputable scaremongering, nothing less.

author: dannyf
author_rank: Super Contributor
timestamp: March 12, 2015, 11:22:23 am
content: QuoteThe fact that you failed to comprehend the demonstration doesn't mean the demonstration has failed to be understood by others.

author: SeanB
author_rank: Super Contributor
timestamp: March 12, 2015, 04:57:05 pm
content: Simple way is to install smart metering for the greens, and tie their supply to the output from any renewable resources they choose, then only connect them to the grid when said supply is actually generating power into the grid, switching on meters as the power increases to keep them from ever having to use "dirty "power. That way they get wholly green power whenever it is available. Contract is unalterable for the economic life of the generating plant of course. When the source fails they get to pay for the restoration of the area to as it was before of course. Then they can pay for the new plant that replaces it.I think that will be a good idea.

author: coppice
author_rank: Super Contributor
timestamp: March 12, 2015, 05:18:31 pm
content: Quote from: mojo-chan on March 12, 2015, 01:36:03 pmThat report does not even consider anything approaching 100% solar PV for California. It only looks at options to generate up to 16.5GW by solar PV, which it says is 30% of peak demand. It clearly explains why going higher than 30% would cause serious network problems, unless issues that current systems do not address are handled properly. That puts the peak demand at about 55GW, although I found other figures which put California's peak at over 60GW. They do not consider storage, so there is no provision for using stored solar PV energy during darkness. If solar contributes 30% during the highest output part of the day in summer, I wonder what its percentage of the total annual generated energy would be? Quite significant, sure, but not even in the ballpark of 100%.

author: mtdoc
author_rank: Super Contributor
timestamp: March 12, 2015, 05:19:59 pm
content: Physicist Tom Murphy has done an analysis of the issues of abundance and intermittency for all of the possible sources of electricity generation. He did an excellent series of blog posts on the topic. A nice summary post can be foundHERE. Here's a nice summary table:

author: dannyf
author_rank: Super Contributor
timestamp: March 12, 2015, 05:34:14 pm
content: QuoteWhat the report actually says doesn't matter.What matters is what mojo-chan says it says.Essentially, the report says whatever mojo-chan says it says, even if it doesn't say that or it says the opposite.

author: Someone
author_rank: Super Contributor
timestamp: March 12, 2015, 09:51:32 pm
content: Quote from: coppice on March 12, 2015, 02:31:10 amTake the whole quote in contextQuote from: Someone on March 11, 2015, 11:37:33 pmUsing the tidal and pumped water generators for storage a 100% renewable grid is plausible, even with the solar/wind/wave power being unreliable because you can store sufficient energy in the tidal (short term storage to match solar output for instance) and pumped storages to ride out the lulls in production from other sources. Its already done here in Australia on a substantial scale with the mountain based hydro.

author: tggzzz
author_rank: Super Contributor
timestamp: March 12, 2015, 11:42:26 pm
content: Quote from: Someone on March 12, 2015, 09:51:32 pmIn Australia maybe. The UK is much more crowded and additional pumped storage options are significantly limited by terrain.

author: Someone
author_rank: Super Contributor
timestamp: March 12, 2015, 11:49:54 pm
content: Quote from: tggzzz on March 12, 2015, 11:42:26 pmIts all trade offs, current population levels and lifestyles are probably not sustainable. All options require some sort of impact but its simply easiest (politically and short term economically) to stick with the status quo. Your claim that tidal power cannot be a major source of power is incorrect, it may not be able to be able to harvest a large percentage of the energy supply but as a demand driven supply it can deliver huge amounts of power when its needed.

author: tggzzz
author_rank: Super Contributor
timestamp: March 12, 2015, 11:53:08 pm
content: Quote from: Someone on March 12, 2015, 11:49:54 pmI have never claimed that.QuoteIt can intermittently deliver huge amounts of power at some times, which may or may not be when it is needed.

author: Someone
author_rank: Super Contributor
timestamp: March 13, 2015, 12:44:21 am
content: Quote from: tggzzz on March 12, 2015, 11:53:08 pmWhen managed as a storage resource it can deliver power when it is needed, trading off against the energy capability that it could achieve were storage not required. That it can't be a primary source of power is in disagreement with the conservative estimates for the UK in "Sustainable Energy - without the hot air"http://www.withouthotair.com

author: coppice
author_rank: Super Contributor
timestamp: March 13, 2015, 01:04:46 am
content: Quote from: Someone on March 12, 2015, 09:51:32 pmDon't conflate pumped storage with tidal power. We know all about pumped storage, as it has a long track record. If you have the right geographical features in sufficient quantity it is the only proven high capacity storage system around. If you could economically construct sufficiently big lakes you could even ride over the kind of huge lulls in output which wind farms give you. Few places have the necessary geography, though.Tidal is very different. It has value, although limited value, as an energy source. Tidal is very unsuitable as a storage scheme. As I said, its a resonant effect and you have to go with the flow, or lose most of its capacity.

author: Someone
author_rank: Super Contributor
timestamp: March 13, 2015, 01:47:47 am
content: Quote from: coppice on March 13, 2015, 01:04:46 amTidal can be looked at as a pumped storage with a trivially small head, and yes as I keep pushing its a trade between storage capacity and energy production. As per the post above there is a huge untapped potential in both and is not constrained by a lack of suitable places to build (local nimby outrage is a problem with any large development).

author: dannyf
author_rank: Super Contributor
timestamp: March 13, 2015, 01:51:21 am
content: QuoteThink about those water storage facilities and how your enemies could use them against you in a time of war.

author: coppice
author_rank: Super Contributor
timestamp: March 13, 2015, 01:53:23 am
content: Quote from: Someone on March 13, 2015, 01:47:47 amTry looking an Tom Murphy's breakdown -http://physics.ucsd.edu/do-the-math/2011/12/can-tides-turn-the-tide/- of the potential for tidal power, and see if you can find any serious flaws in his arguments.

author: coppice
author_rank: Super Contributor
timestamp: March 13, 2015, 01:55:29 am
content: Quote from: dannyf on March 13, 2015, 01:51:21 amI think most modern infrastructure is highly vulnerable in times of conflict, even to the limited kinds of attack terrorists might use. Can you really power a modern society from anything which is robust against attack?

author: Someone
author_rank: Super Contributor
timestamp: March 13, 2015, 02:28:06 am
content: Quote from: coppice on March 13, 2015, 01:53:23 amThat discussion is focusing on just the extractable energy, rather than capacity for energy storage. Using those same calculations at less than half the available tidal range the hypothetical Severn Barrage should be able to reliably release something in excess of 10GWh over the 4 hour evening peak electrical load every day of the year. With all the benefits of the fine grained and fast slewing power supplied by hydro setups.Investing in (ideally pumped) tidal and pumped hydro is the enabling storage technology to back solar/wind/wave/water flow plants.

author: coppice
author_rank: Super Contributor
timestamp: March 13, 2015, 02:49:21 am
content: Quote from: Someone on March 13, 2015, 02:28:06 amSo, you didn't actually read it.

author: Someone
author_rank: Super Contributor
timestamp: March 13, 2015, 03:02:30 am
content: Quote from: coppice on March 13, 2015, 02:49:21 amI read it and used their calculations! But they discuss energy harvesting of tidal power, which as they conclude is globally a small amount of energy available compared to other sources. But as an energy storage it has merit for the UK (along with pumped hydro), last time I looked this is a thread discussing the UK investment into tidal power, they are uniquely positioned to extract much higher than average energy from tides which:could be time shifted or pumped to cover peak requirements, at the cost of reducing its energy capabilitycan be ramped at extreme ratesis able to be scheduled with extremely high availabilty and certainty

author: coppice
author_rank: Super Contributor
timestamp: March 13, 2015, 03:14:58 am
content: Quote from: Someone on March 13, 2015, 03:02:30 amAre you sure you read it? As well as looking at capacity, and how the UK, France and a few other spots are nicely positioned to be able to harness that capacity, he looks at the horrible effects of trying to time shift. Anything more than a small time shift massively reduces capacity. Its estimated that a Severn barrier could provide 5% of the UK's electrical energy, and people hand wave about other inlets being used. They hand wave because those other inlets are much weaker propositions for development. 5% is pretty good for a single source of energy, especially one you can rely on for output you can predict years in advance. However, you only get that if you work in sympathy with the tides. You don't get 5% and be able to choose when you get it. Its either/or.

author: Someone
author_rank: Super Contributor
timestamp: March 13, 2015, 03:44:23 am
content: Quote from: coppice on March 13, 2015, 03:14:58 amI've seen suggestions of the UK having somewhere around a 60GW peak load, and suggest from the calculations I and others have done that the Severn Barrage when shifted could provide around 4% of that peak. Which when you think about it is only 0.5 to 1% of the total energy delivered to the grid.Add in some pumping to take out "excess energy" during periods of excess generation and you could probably do better than 10% of the peak load, which would reduce the energy harvesting to deliver even less than 0.5% of the total energy, but it allows those intermittent sources to be utilised with high availability and certainty.

author: coppice
author_rank: Super Contributor
timestamp: March 13, 2015, 04:18:47 am
content: Quote from: Someone on March 13, 2015, 03:44:23 amIf you only want to cope with the peak demand for a small part of the day, why not do it with gas turbines? They would be far less costly, whether you measure cost by dollars, or by how much energy you need to sink into building the system. If it only supplies 0.5% of total energy, the carbon cost is no big deal, and its not going to materially contribute to fossil fuels running out. If you are going for the huge cost of a Severn barrier surely you want some material benefit from it, like materially affecting the rate at which fossil fuels are consumed. For that you need to extract all the energy you can.

author: Someone
author_rank: Super Contributor
timestamp: March 13, 2015, 04:46:05 am
content: Quote from: coppice on March 13, 2015, 04:18:47 amThe energy produced from the tidal plant has a nominally low marginal cost, where as open cycle gas turbines for peaking can have utilisation rates of 1% or less to only make profit when the market prices reach exceptional levels. Regardless, the important point I keep pushing is:Tidal storage (and pumped hydro) is one opportunity to store energy and eliminate the intermittent issues of solar/wind/wave/water current generatorsIt fits in with a diversified generation base, alone it may seem silly but no conventional plants offer storage capability so they cannot be compared without considering the storage as part of the package. The return on investment of pumped storage is shorter than conventional plants, the UK investing in tidal power (pumped or not) is a great investment.

author: coppice
author_rank: Super Contributor
timestamp: March 13, 2015, 05:45:26 am
content: Quote from: Someone on March 13, 2015, 04:46:05 amI give up. You are conflating pumped storage with tidal power again.

author: Someone
author_rank: Super Contributor
timestamp: March 13, 2015, 07:12:26 am
content: Quote from: coppice on March 13, 2015, 05:45:26 amTidal power can store the energy until it is required (at a reduced capacity). The power delivery can be planned around the other generators due to its extremely high availability and certainty, and its able to rapidly ramp up/down to closely follow demand cycles.Or the additional costs to make it pumped are very low if its designed in when built. Then you can not only store the energy from the tidal power but also excess energy from other sources.Either way tidal energy is able to store energy and deliver it when its needed most, or it can run as a predictable but intermittent generator. Market forces will determine which of these modes it would operate in but the existing data suggest that it would be more profitable as a peaking plant, and more profitable again if pumped.

author: tom66
author_rank: Super Contributor
timestamp: March 13, 2015, 09:09:01 am
content: Quote from: coppice on March 13, 2015, 01:55:29 amExactly - at least solar and wind are distributed across a large area, so I'd actually say they're less vulnerable than say a nuclear or coal plant providing several % of grid demand.

author: rolycat
author_rank: Super Contributor
timestamp: March 13, 2015, 09:10:08 am
content: Quote from: dannyf on March 13, 2015, 01:51:21 amNo problem, we'll just send 617 Squadron to blow uptheirdamsWell, we could if it hadn't been disbanded due to lack of aircraft

author: Mechanical Menace
author_rank: Super Contributor
timestamp: March 13, 2015, 09:41:24 am
content: Quote from: rolycat on March 13, 2015, 09:10:08 amManned aircraft are a hangover of a time long gone. Drones and guided missiles, preferably launched from submarines, are the way forward. No one who would go to war with us could stop them

author: Someone
author_rank: Super Contributor
timestamp: March 13, 2015, 09:44:09 am
content: Don't worry, it's gone past talking and I'm just shouting at them

author: dannyf
author_rank: Super Contributor
timestamp: March 13, 2015, 10:55:36 am
content: QuoteThe vulnerability is different. For a power plant, you can shut it down and deal with its consequences through regulation (rolling blackouts for example).For a large dam, your choices are limited to lowering the water levels prior to an attack (presumably your attack) - your enemy can see that as a signal for a pre-emptive attack, or to live with a potential flooding by enemy attack.

author: tggzzz
author_rank: Super Contributor
timestamp: March 13, 2015, 01:40:32 pm
content: Quote from: mojo-chan on March 13, 2015, 12:31:25 pmReference please.QuoteScandalously currently at a record low of 4%-5%.Of course intermittent sources won't change that one iota, since the same capacity is required to cover their intermittancy - even though the capacity will be underutilised and thermally cycled.QuoteThe key weasel-word there is "instantly". That makes your statement true,but also makes it irrelevant and disingenuous.The probability of losing almost all of the UK wind capacity is100%, no matter how much is installed.That is not theoretical, it is measured practical reality.. Thus if you have, to pick an arbitrary figure, 30GWpeak wind power, then you must have 30GW of other idle plant ready to be ramped up. The 5% chance of losing 1GW is pretty trivial by comparison!References: the Narional Grid graphs inhttps://www.eevblog.com/forum/chat/tidal-lagoon-energy-from-the-ocean-uk-gov-is-putting-money-in-it/msg627043/#msg627043andhttp://www.jmt.org/wind-analysis-report.asp

author: tggzzz
author_rank: Super Contributor
timestamp: March 13, 2015, 01:54:53 pm
content: Note that the IEEE is a highly respectable organisation...QuoteRead and understand the full articlehttp://spectrum.ieee.org/energywise/green-tech/solar/solar-eclipse-will-test-grid-ops-in-europe?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+IeeeSpectrum+%28IEEE+Spectrum%29

author: coppice
author_rank: Super Contributor
timestamp: March 14, 2015, 09:39:14 am
content: Quote from: tggzzz on March 13, 2015, 01:54:53 pmAlthough its from the IEEE, I'm not sure how much faith to put into even that article. It read like something fair and balanced, until I got to "Since much of the U.K.‘s solar capacity is installed in Scotland...". The text then treats Scottish PV power as a substantial source of power. Scotland has a lot of installed renewable capacity, but its almost all traditional hydro power and wind. Everything I've read says they have less than 150MW of installed solar PV capacity. With Scottish levels of insolation its output during most days in spring is probably <20MW. Its insignificant

author: G7PSK
author_rank: Super Contributor
timestamp: March 14, 2015, 10:07:40 am
content: Problem in the UK is cold foggy days in winter = NO wind and no sun which adds up to No power and due to the size of the UK this can be over most of the country so how ever good the grid management is you cannot rely on solar and wind alone there has to be a big enough supply from other sources to keep the country running sometimes for several days at a time. If you have that it makes for very uneconomical running of both the renewable's and the gas,coal or nuclear plant.Martin Lorton mentioned something recently about large solar farm destabilising the grid as well due to sudden fluctuations of output which cannot be picked up fast enough by other generation means.The only way we are going to get the amount and reliability of supply is going to be from thorium reactors.

author: tggzzz
author_rank: Super Contributor
timestamp: March 14, 2015, 10:34:23 am
content: Quote from: coppice on March 14, 2015, 09:39:14 amThat's fair; it is essentially a "journalistic" article rather than a statement of record in a learned journal. I too was a little surprised about the statement about solar in Scotland - it deserves some scrutiny. I've since blundered into other articles which raise the question of what will happen, none of which are significantly more informative.I will be keeping my eye out for statements about what actually happened, and what was necessary to avert "disaster".However, the article does illustrate that intermittent sources, however predictable, are not sufficient for a reliable grid, as some (one?) on this forum seem to believe. And that's true whatever timescale is chosen for the predictability/intermittancy.

author: tggzzz
author_rank: Super Contributor
timestamp: March 14, 2015, 10:38:12 am
content: Quote from: G7PSK on March 14, 2015, 10:07:40 amBut but but "there's always wind somewhere". Isn't there? Please say there is. (Oh alright,)QuoteNah. There's no "one true way", although they are indeed beguiling.

author: Someone
author_rank: Super Contributor
timestamp: March 14, 2015, 10:47:19 am
content: Quote from: G7PSK on March 14, 2015, 10:07:40 amOr having a large percent of the peak capacity available in storage, such as water. Just having dispatchable power from hydro or tide power is a good first step to reducing the cycling of thermal plants, and as storage is added to the grid the reliability will rapidly increase. Average capacity factor will plummet but thats not a problem when the marginal cost of the generation is close to zero.

author: tom66
author_rank: Super Contributor
timestamp: March 14, 2015, 11:06:21 am
content: Average demand on the UK grid is about 40GW so we'd need around 960GWh to run us through a whole day with nil renewables. That's approx 11 milllion Tesla 85kWh packs fully cycled... Hmmm... anyone got a few trillion quid behind the sofa? (£16,000/pack)I think pumped storage would work a little better! But the problem is where to put it? There are only a few places it works really well, like Dinorwig in Wales and I think there are a few plants in the Scottish highlands.Unfortunately, England - relatively speaking - is really quite flat!

author: tggzzz
author_rank: Super Contributor
timestamp: March 14, 2015, 11:13:13 am
content: Quote from: tom66 on March 14, 2015, 11:06:21 amCruachan, which is tiny.But we do have quite a few mountains. (And for convenience we'll ignore that they are just 2000ft peaks and useless w.r.t. dams).I've often wondered if you could flood large areas of Scotland and use them as high-volume low-height storage schemes. A good way to soak up (ho ho) all the wind power in the NW

author: SeanB
author_rank: Super Contributor
timestamp: March 14, 2015, 11:14:00 am
content: The one large energy source available mostly to the UK is nuclear power from France, fed through an undersea cable and a DC interconnect. That helps with sudden grid demand as the French timing typically is different from the UK, and the French reactors provide a lot of power to most of Western Europe via assorted links.The Danish ones both pass power through and add the wind power as a small extra to it, but most power in the mainland will be French nuclear as base load.

author: coppice
author_rank: Super Contributor
timestamp: March 14, 2015, 11:54:56 am
content: Quote from: G7PSK on March 14, 2015, 10:07:40 amThe article tggzzz referenced raises the point strongly that early solar installations were poorly designed for grid stability, and that upgrades will take some time. Most people currently talking about stability refer to current problems. I haven't seen a good analysis of what is inherently hard to fix, especially if the higher levels of the grid were adapted to the changing generation patterns.The paper from California, which mojochan referenced, talks about the need to avoid distributed generation pushing energy into the higher levels of the grid. For stability, they assume energy generated in a distributed way, and pumped into a sub-station's catchment area, will be used within that catchment area. The snag is, current equipment does not enforce this. In fact, it appears a lot of current equipment might pump up the local voltage to a dangerous level, as they don't limit this properly. I've seen reference to that in several places, including the California paper. The grid was never designed to have energy pushed upstream through the major transformers. It isn't designed to stabilise itself under those circumstances. Whether is could be adapted to do so is another matter.One of the nice things about solar PV is it only outputs what you draw. As a system it can go from full output to zero to full as fast as the control loop of the inverter can react. With effective regulation of the design of inverters approved for grid connection, it seems a lot of stabilisation could be provided by this. The reason it requires regulation is that doing the right thing is not in the interests of the owners of the inverters. They want to push out every scrap of energy they can muster, and get it metered, regardless of what the grid needs at any instant. Only rules strictly enforced could help there. In this sense solar PV has the potential to provide the opposite effect from the one Martin Lorton described.In Europe it seems solar PV inverters will trip if the grid frequency appears to vary by more than 1%. In a continent with a super stable grid that probably seemed like a very sensible protection a few years ago. Now, as there is more reliance on solar output, it means a short term hiccup in the grid could turn into a full scale outage, as things trip on a huge scale. The Spectrum article raises this as one of the key concerns in Mainland Europe about what might happen in the eclipse. Its being addressed, but upgrades take time.

author: dannyf
author_rank: Super Contributor
timestamp: March 14, 2015, 12:07:18 pm
content: -early solar installations were poorly designed for grid stability, and that upgrades will take some time-Under voltage dropout. It is a fairly recent thing and depending on the panels used the upgrade could be north of 20k USD.Good luck to the early adopters and tax payers who subsidized such systems.

author: coppice
author_rank: Super Contributor
timestamp: March 14, 2015, 12:19:17 pm
content: Quote from: dannyf on March 14, 2015, 12:07:18 pmUnder voltage dropout is not one of the more serious limitations of early systems for grid stability. It wastes potential capacity, but it just drops the system off the grid is a relatively benign way.

author: Galenbo
author_rank: Super Contributor
timestamp: March 16, 2015, 12:56:23 am
content: Quote from: tggzzz on March 12, 2015, 12:49:19 amSorry, we don't use that terms here, difficult for me to know how it is interpreted exactly. The circumstances are also different because we don't live in a two-party system here.I discribe myself as a libertarian most of the time.What we know as liberal is very different from this.

author: tggzzz
author_rank: Super Contributor
timestamp: March 17, 2015, 03:35:48 pm
content: This shows that today there will bealmost zerowind power generationanywherein the UK. It will be very little better tomorrow.

author: G7PSK
author_rank: Super Contributor
timestamp: March 17, 2015, 04:04:54 pm
content: Not much solar either due to heavy cloud and rain along with virtually no wind today. It seems rather stupid to rely on French nuclear power via the cross channel link, you never know when we could have slight disagreements with them as we did in the 19th centuryBut seriously it is daft to rely on a cable that could get cut through natural or man made events.

author: coppice
author_rank: Super Contributor
timestamp: March 17, 2015, 04:08:56 pm
content: If there's not much wind, there won't be much wave power either, but the tide will still go in and out.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: March 17, 2015, 04:11:39 pm
content: Quote from: tggzzz on March 17, 2015, 03:35:48 pmI still don't understand why "this is intermittent" equates to "we shouldn't bother at all" if I'm honest. Surely it's a good excuse to diversify as much as possible? I mean I'll admit that without some new grid storage developments renewables are not perfect but 1) it would probably make people more willing to consider it and 2) would be useful even if for some miraculous reason we don't have to at least reduce fossil fuel burning plants.

author: coppice
author_rank: Super Contributor
timestamp: March 17, 2015, 04:22:20 pm
content: Quote from: Mechanical Menace on March 17, 2015, 04:11:39 pmIntermittent isn't the really big issue with wind. Unpredictability is. Try looking up estimates for how much oil and coal has been saved through the use of wind. The numbers are all over the place, due to biases, but even the most optimistic aren't very inspiring. Wind is so unpredictable that you need a large amount of backup up and running, ready to pick up the slack at short notice. Tidal power is also intermittent, but its highly predictable. At least you know in advance pretty much what you need to do to fill in the gaps. That puts it way ahead of wind as a quality energy source.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: March 17, 2015, 04:33:15 pm
content: Quote from: coppice on March 17, 2015, 04:22:20 pmIf only we couldn't flood more of Wales and Scotland

author: tggzzz
author_rank: Super Contributor
timestamp: March 17, 2015, 04:50:31 pm
content: Quote from: Mechanical Menace on March 17, 2015, 04:11:39 pmWho says that? I don't.QuoteAnd there's the problem that some people (not you) are "reluctant" to acknowledge: having xGW of intermittent sources doesn't mean that we can get rid of xGW of conventional sources.Diversification is good. Downplaying/denying/ignoring disadvantages isn't - and that's what I object to. It is a limited, albeit important point.

author: tom66
author_rank: Super Contributor
timestamp: March 18, 2015, 09:44:14 am
content: Quote from: mojo-chan on March 18, 2015, 09:34:33 am660MW of wind power, or 1.5% of current UK demand, does not a renewable grid make. That's under 10% of total capacity.To even meet the current 8GW maximum generation right now, we'd need 12x as much wind turbines... and the whole grid would need 90x as many...

author: tom66
author_rank: Super Contributor
timestamp: March 18, 2015, 10:25:27 am
content: Quote from: mojo-chan on March 18, 2015, 10:20:48 amFor power generation purposes sub 1GW may as well be zero. Granted, it's some power - but it's really nothing much compared to nuclear despite having an 8GW installed capacity (nearly 2/3rds of the installed nuclear capacity.) A grid simply wouldn't work on purely intermittent renewables unless you had either a large amount of grid storage, or a significant overhead (for example, 10x as many turbines as typically needed.)

author: Zucca
author_rank: Unknown
timestamp: March 18, 2015, 11:14:54 am
content: Thanks for all the posts, very interesting! For my side it was just a FYI only, I didn´t expect these many reactions.BTW, here it looks like there IS wind in UK:http://www.dailyrecord.co.uk/news/weird-news/watch-hilarious-video-showing-man-5342404

author: dannyf
author_rank: Super Contributor
timestamp: March 18, 2015, 11:43:40 am
content: QuoteA grid is unique in that at any given time, it is perfectly balanced: supply = demand all the time.So even if you know for sure that 100MW of power is coming on line at 10am, it is still a huge headache for the grid operator on consuming that additional power.That's why the base load operators insist on charging solar or wind generators to pull them into the grid. Intermittent power generation has negative value to a grid.The only reason we are paying them now is driven by policy and not economics.

author: tom66
author_rank: Super Contributor
timestamp: March 18, 2015, 12:31:04 pm
content: It's not entirely impossible, I suppose, to power a country with wind 99% of the time.We'd just need something like 600GW installed capacity, and turn off 90% of turbines in the heaviest wind. Short term, general area trends in wind can be predicted - so it would be possible to see when there would be insufficient wind and that's when you'd have to switch to fossil fuel or other sources, or Dinorwig/etc could fill in for shortfalls whilst the slower plants catch up.Obviously extremely costly - not just from a £/MW basis but also maintenance costs of such a large network. And those costs aren't likely to fall significantly any time soon.

author: coppice
author_rank: Super Contributor
timestamp: March 18, 2015, 01:12:18 pm
content: Quote from: tom66 on March 18, 2015, 12:31:04 pmThere are also the energy costs. Such a vast amount of excess capacity would require vast amounts of energy for its construction. I wonder what the break even time purely on energy would be?

author: tggzzz
author_rank: Super Contributor
timestamp: March 18, 2015, 03:08:43 pm
content: Quote from: mojo-chan on March 18, 2015, 10:20:48 amWhat isyourdefinition?Are you prepared to accept wind "outage" 1%, 5%, 10%, 50%, 90%, 99% of the time?

author: tggzzz
author_rank: Super Contributor
timestamp: March 18, 2015, 03:22:08 pm
content: Quote from: mojo-chan on March 18, 2015, 09:34:33 amThat's a very interesting resource; thanks; bookmarked.From that we can see on the 17thwe lost 95% of the peak wind power(~300 vs 5869) measured over the past year.From that we can see on the 17thwe lost 82% of the mean wind power(~300 vs 1705) measured over the past year.Now, what conventional plant would you use to replace that when (not if) it occurs again?

author: coppice
author_rank: Super Contributor
timestamp: March 18, 2015, 03:54:58 pm
content: Quote from: tggzzz on March 18, 2015, 03:22:08 pmThat site does seem to be an interesting source of data. Is there any way to monitor what solar PV is doing for the UK grid? From what I understand domestic UK installations are simply metered for billing purposes.

author: tom66
author_rank: Super Contributor
timestamp: March 18, 2015, 04:33:44 pm
content: AFAIK there's no direct metering for the UK grid at the moment. But you can look at France which is geographically similar. Domestic installs only show up as a reduction in demand, but the larger industrial systems are metered on the far right of this page.http://www.gridwatch.templar.co.uk/france/It's beautiful to see near 100% of power coming from clean sources. (There seems to be an error in calculating total demand, but over 55GW is from nuclear and hydro.) Nuclear may not be renewable but it's a damn sight better than coal or gas.

author: rolycat
author_rank: Super Contributor
timestamp: March 18, 2015, 05:02:13 pm
content: Quote from: tom66 on March 18, 2015, 04:33:44 pmUnfortunately for proponents of nuclear power, the Hollande government hascommittedto reduce France's nuclear generation to 50% by 2025.

author: SeanB
author_rank: Super Contributor
timestamp: March 18, 2015, 05:09:37 pm
content: A simple way to look at the grid is to take the premise of the bus in Speed. You have a bus that will go bang if it goes under 55, and will go bang again if it goes above 65. You are on a long and straight imaginary road, with some hills and dales on it. the engine provides power to the bus till it runs out of fuel. This is the grid with power stations and such with coal, gas and nuclear supplies.Now with intermittent sources you suddenly, and without warning, are going to have smaller vehicles either pushing the bus from the rear, or pramloads of cans suddenly pushed in front of it. you need to still have the bus do constant speed on the road.Now, if you have a semi truck doing the push from the rear, or you hit a whole line of prams filled with concrete you will have the bus, along with Mz Bullock and Keanu Reeves, going up in a pyre of flame. That is what happens if there is too much load change beyond the ability of the grid control to compensate.

author: SeanB
author_rank: Super Contributor
timestamp: March 18, 2015, 05:10:55 pm
content: Quote from: rolycat on March 18, 2015, 05:02:13 pm

author: dannyf
author_rank: Super Contributor
timestamp: March 18, 2015, 05:17:52 pm
content: QuoteSomething this simple, however, apparently is beyond some people's ability and willingness to comprehend.How sad.

author: mtdoc
author_rank: Super Contributor
timestamp: March 18, 2015, 07:02:11 pm
content: It's true that the current electricity generating structure cannot function without fossil fuel generating plants. In theory, with enough large scale storage (pumped hydro, molten salt?) you could create a functioning, reliable grid based solely on renewables - but reality is different. Will we ever get there? No - and here's why:The current state of the world, economically, technologically, politically is completely dependent on the energy density and portability of fossil fuels. We cannot have business as usual without them - and eventually we won't. We cannot sustain a world population of 7+ billion without them. And eventually we won't.And here's the rub - we cannot entirely replace fossil fuels- even just for electricity production - without the excess energyavailable to society that they provide. Building solar panels, windmills, tidal generating stations and nuclear plants requires oil - and lots of it - not just for the mining, refining, transportations and manufacturing of the materials required - but also for the capital to be available for the build out. The oil must be cheap for the build out - but also expensive for it to make economic sense for private industry to do it.We're in anEnergy TrapFossil fuels are a finite resource and oil, in particular, is the keystone commodity needed to keep the current state of affairs in order. It a complicated set of feedback loops that keeps the current system (including electricity production) afloat.Conventional oil production has been in a plateau since 2005. Tight oil from the US is entirely responsible for the increase in worldwide production since then. But this oil is costly to extract and has a much lower net energy yield. Shale oil wells have a short lifespan and constant (expensive) new drilling is required just to keep pace. This drilling is financed by cheap debt (thanks to central bankers) which can only be paid back if oil prices stay high.Without cheap oil the economy can't grow, but without expensive oil production cannot grow and demand stalls or declines. This has led to the current price crash. Production can't decline fast enough to keep pace (debt needs to be paid back!) - but it will and prices may rise again some but will there be the same cheap financing available the next time after the junk bond defaults from this go round?With each iteration the situation will get more dire. This is what happens when a finite resource is peaking but because it is happening with oil - THE keystone resource of our current civilization - the impact will be huge.It's not a matter of if but when. When is impossible to predict. There's anan argument to be madethat the current decline in oil prices is a harbinger of a near term collapse due to it's interdependence with the world financial system. And there'sa case to be madethat in 2012 a tipping point was reached thermodynamically whereby oil production has gone from an energy source to an energy sink.Now this is an engineering forum so I'm sure many here will insist that there is a technological solution to this problem. Perhaps there will be - (cold fusion?) I hope there is- but I don't think so. The necessary large scale technological advancement itself depends on the resources of our system as it currently exists. It would require long term thinking and political will - both of which are in short supply.I don't know when it all falls apart. Maybe not in my lifetime - but certainly within my young children lifetimes. I hope I'm wrong.That's it for your dally doom and gloom report. Carry on....

author: Someone
author_rank: Super Contributor
timestamp: March 18, 2015, 10:27:16 pm
content: Quote from: tggzzz on March 18, 2015, 03:22:08 pmIt doesn't have to be replaced with a conventional plant, a plant that can store energy and release it on demand is sufficient. Hydro and Tidal are two such plants that can provide storage of power, along with coal, gas, nuclear, etc.

author: Someone
author_rank: Super Contributor
timestamp: March 18, 2015, 10:31:01 pm
content: Quote from: dannyf on March 18, 2015, 11:43:40 amIts not an effort to absorb 100MW on the UK grid, between the 4 pumped storage installations and the ability to throttle back non pumped hydro several GW can be dispatched in either direction.

author: tggzzz
author_rank: Super Contributor
timestamp: March 18, 2015, 11:07:47 pm
content: Quote from: Someone on March 18, 2015, 10:27:16 pmThe UK pumped storage is so limited in capacity that it can only be used for two purposes: "black start" emergency reserve and for "load spikes". It cannot, emphatically, be used for peak load nor for long-term storage. I wish the UK's topology was otherwise, because it is a very good mechanism for storing power.Tidal is much more limited in (at least) two respects. Firstly it is and always will be intermittant. Secondly too many people "double-count" it for generation and for storage, quietly ignoring the disadvantages.

author: tggzzz
author_rank: Super Contributor
timestamp: March 18, 2015, 11:13:26 pm
content: Quote from: Someone on March 18, 2015, 10:31:01 pmDo the arithmetic, and tell us how long they will at full output capacity and without breaking into the vital "black start" reserve. It isn't as long as most people think.BTW, one of the things that frightens grid engineers is the requirement that you need electricity to re-start a power station. If too many are knocked offline simultaneously, or cannot connect to those that are online, then there are very serious problems getting any capacity going again. Hence the requirement for the black start reserve.Yes, such things have occurred several times, particularly in the US, Canada and Hawaii. We were lucky the earth was pointing in the wrong direction (literally) for some of those to happen in the UK.

author: Someone
author_rank: Super Contributor
timestamp: March 19, 2015, 02:08:22 am
content: Quote from: tggzzz on March 18, 2015, 11:07:47 pmIt is currently limited, but you are asking how to increase the dynamic generation capacity by adding more conventional plants, so why not add pumped storage, there are many ways to grow the grid capacity but they are intertwined. It currently has shorter payoff periods than conventional or renewable generation.

author: Someone
author_rank: Super Contributor
timestamp: March 19, 2015, 02:17:19 am
content: Quote from: tggzzz on March 18, 2015, 11:13:26 pmAny type of plant can be equipped for black start, but the smooth control of hydro is particularly suited to it. With the pumped storage schemes proposed that minimise impact on the natural environment they only plan to utilise the extent of the existing natural water height variation which would leave enormous untapped energy for emergencies. Or just have enough of it that you can keep a reserve on hand at all times, there are no difficult challenges here. Other countries (such as Australia) combine their hydro with drinking water supplies where a minimum level is maintained below which no power is generated.You were trying to make out that dissipating excess power in the grid is hard, it isn't, pumping hydro and spooling down gas (or feathering wind, or disconnecting solar) can absorb huge swings in the power balance and as more renewables come online the need for storage increases.

author: Someone
author_rank: Super Contributor
timestamp: March 19, 2015, 02:19:56 am
content: Quote from: tggzzz on March 18, 2015, 11:07:47 pmTidal power or hydro can generate and store very easily, the energy harvested will be reduced but the peak power and energy available can be increased many times over. There is no intermittency about it when it is run as storage (and the associated small amount of generation) as the power can be delivered at any time of the day or night when planned in advance.

author: zapta
author_rank: Super Contributor
timestamp: March 19, 2015, 03:24:30 am
content: Quote from: rolycat on March 18, 2015, 05:02:13 pmLet me guess, he is a socialist.

author: tggzzz
author_rank: Super Contributor
timestamp: March 19, 2015, 08:44:30 am
content: Quote from: Someone on March 19, 2015, 02:19:56 amYou'll need to explain how you can generate energy when the water level is the same on both sides of the barrage.Bear in mind that at least twice a day I look at the tide level associated with the Severn, and hence a Severn or Swansea barrage. I viscerally *know* what the tides do. I get the strong feeling that many people's understanding of tides is from books or holidays by the open sea.Q1 When the tide is high, how much surplus power from intermittent sources could be stored?A1ZeroA2 A tiny amount, provided you are prepared to flood Bristol (or presumably Swansea) city centre. That very very nearly happens naturally; I have watched buildings underwater twice in 25 years. For last year's event, search for "bristol flood", or seehttp://www.westerndailypress.co.uk/images/localworld/ugc-images/276309/Article/images/20404985/5683047-large.jpgorhttp://www.bathchronicle.co.uk/images/localworld/ugc-images/276329/Article/images/20396461/5676879-large.jpgQ2 The tide is low, so surplus energy can be stored. Twelve hours later, how muchextraenergy is available as a result of that storage?A1:zero. All that you managed to achieve was filling up the basin a little earlierthan would have occurred naturally when the tide came in. And in doing that you would have lost the energy that could have been extracted from the incoming tide.

author: tggzzz
author_rank: Super Contributor
timestamp: March 19, 2015, 08:53:43 am
content: Quote from: Someone on March 19, 2015, 02:08:22 amI'm not asking that at all. Plaese don't make strawman arguments.The people that want us to unduly rely on intermittent sources are the ones that require dynamic capability - even thought they are loathe to admit it.QuoteWhere in the UK? Seriously. If you have a good solid answer then you also know where there are serious amounts of money to be made - and I suggest you personally get in on the act.In the UK there are only a small number of sites available, and it is pretty well exploited. It is probably different in other countries, but this thread is monimally about the Swansea barrage.QuoteEconomics are a separate issue, and one that merely obfuscates the fundamental physics. I have not discussed the economics.

author: tggzzz
author_rank: Super Contributor
timestamp: March 19, 2015, 09:07:54 am
content: Quote from: Someone on March 19, 2015, 02:17:19 amPumped storage or hydro has other unique significant advantages w.r.t. black start reserve. Ask grid engineers. Tidal also has similar advantages, but to a lesser extent.QuotePlease show where I have argued that. Please stop incorrectly putting words into other people's mouths. Please stop making strawman arguments. You do a disservice to yourself and your arguments.QuoteRubbish. Since you use the word "huge", please read theuniversally acclaimedbook at http:www.withouthotair.com which the author wrote to replace adjectives with numbers:Quote

author: Someone
author_rank: Super Contributor
timestamp: March 19, 2015, 10:42:24 am
content: Quote from: tggzzz on March 19, 2015, 08:44:30 amQ1, some quantity of energy can be stored at any time if it is going to be released at a specific (and known) time in the future even at high tide in certain circumstances you might have an incentive to pump water OUT of the basin. When to produce and when to store is based on the predicted fluctuations of the market so you don't always want to harvest all the power in the tide if the storage capacity could make more money later. But you know all this and are just trolling.Q2, round trip efficiency is around 80% or higher for pumped storage. You wouldn't buy energy and store it if you weren't planning on using it so keeping it through the next high tide would be stupid.Its possible to come up with all sorts of uneconomical ways to operate any plant, you could burn an open cycle gas plant all night when the market power price is at its cheapest and turn a loss too.

author: Someone
author_rank: Super Contributor
timestamp: March 19, 2015, 10:55:40 am
content: QuoteApologies, got confused with that other person distracting the discussion with straight out lies. But you still challenged my reasoned response to those ridiculous claims with diversions into capacity which is a completely different issue. The existing capacity is not stretched by absorbing transients while other plants are brought up/down. Move to more renewables and there will be a need for more storage capacity.Quote from: tggzzz on March 19, 2015, 09:07:54 amApologies for the same collision, but I'm making the strawman? you need to check how that works when I address the original post and you come in with tangents.

author: Someone
author_rank: Super Contributor
timestamp: March 19, 2015, 11:19:45 am
content: Quote from: tggzzz on March 19, 2015, 09:07:54 amYou might want to read that book yourself, it is indeed a well balanced and in depth look at energy in the UK, I was so impressed with the work I have conversed with the author and shared some topical data with him. But as to the specifics of describing the grids ability to absorb fluctuations I had already put a number on the figure and reinforced it with colourful language, if you'd like to come up with a more accurate measure than several GW for the peak pumping capacity available in the UK it would be welcome. Losing power from the grid is easy, the slew rate of the largest thermal plants being the limiting factor but that can be partially absorbed with pumped storage. The discussion was on absorbing additional power and you wander off into the specifics of current storage capacity in pumped hydro.Quote from: tggzzz on March 19, 2015, 09:07:54 amSustainable Energy - Without the Hot Airshould have educated you on that issue, discussing the alternate locations considered when Dinorwig was constructed and then going on to suggest an easily accessible 100GWh up to 400GWh just in existing conventional water catchments in Scotland only. If you look to the published literature on pumped storage it is found to be economically viable in surprisingly small installations even in less than ideal sitings, and entirely man made reservoirs are also profitable, so there is significantly more storage possible that is not encompassed in that estimate.

author: tggzzz
author_rank: Super Contributor
timestamp: March 19, 2015, 11:25:16 am
content: Quote from: Someone on March 19, 2015, 10:42:24 amNot in the Severn without flooding Bristol city centre. That's not trolling. The pictures illustrate the extreme of a >14m high tide, but it is within 1m of that most months - have a look at the tide tables.QuoteFirst sentence is true but irrelevant. In the UK if we are to rely on intermittents as some wishful-thinkers propose, we either have to store energy for several days (not hours). I chose that question carefully to represent real conditions. The alternative os to have the equivalent conventional plant capacity standing idle and then being thermally cycled.

author: tggzzz
author_rank: Super Contributor
timestamp: March 19, 2015, 11:28:17 am
content: Quote from: Someone on March 19, 2015, 10:55:40 amApologies accepted; it happens.But, again, I haven't made those claims you are ascribing to me.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: March 19, 2015, 11:53:15 am
content: Quote from: zapta on March 19, 2015, 03:24:30 amYeah, but TBH French politics have extremes in the "mainstream" we really don't. Even the craziest of the Democrats (or Labour here) would think their left wingers go way too far and even the craziest Republicans (or Conservatives and UKIP here) would think their right wingers shouldn't be saying that in public

author: Someone
author_rank: Super Contributor
timestamp: March 19, 2015, 11:55:43 am
content: Quote from: tggzzz on March 19, 2015, 11:25:16 amYou clearly aren't the person to operate such a tidal plant, pumping water OUT of the stored basin of the hypothetical Severn barrage should avoid flooding Bristol.All sorts of specific situations can be dreamt up that make it seem illogical or silly but when operated in sympathy with the grid tidal storage can be a useful short term storage, and/or it can generate some power. If there was a known excess of cheap power you would not be stuck with zero storage, and tidal plants without elevated storage are of course illogical to carry storage through multiple tides.

author: tggzzz
author_rank: Super Contributor
timestamp: March 19, 2015, 12:14:21 pm
content: Quote from: Someone on March 19, 2015, 11:55:43 amIf you pump it out at high tide, which youwouldhave to do in the Severn, the subject of this thread, then not only have you not stored energy you have actually "wasted" it.You appear to be very reluctant to answer the question I asked about the Severn, in the UK, with UK constraints. Other locations will have different constraints and your suggestions might be relevant there - but they are not in the Severn.

author: Someone
author_rank: Super Contributor
timestamp: March 19, 2015, 11:16:19 pm
content: Quote from: tggzzz on March 19, 2015, 12:14:21 pmWhich question have I not answered? You predicate that sorting energy in a hypothetical Severn Barrage basin at high tide will flood Bristol, there are two problems with this:It assumes that every high tide is high enough to be just on the point that any more water height will flood Bristol. Tide peaks vary, so there will some times be additional storage available even at high tide when the basin is being filled in anticipation of demand more than 2-3 hours away.Which is the second part that if it is planned to generate in the time up to 2-3 hours after the high tide then the basin is ideally empty at the high tide. Further emptying it, perhaps even below the low tide, or even below the record low tide depth can store energy for release in the following several hours.These patterns of energy delivery are true of any pumped tidal plant, its not a simple decision to produce power or not as it is with elevated storage hydro, some planning is needed to have the two sides of the barrage in the right balance for the predicted generation.Quote from: tggzzz on March 19, 2015, 08:53:43 amIts all about economics, the above examples I'm providing are assuming the tidal plant operator only has access to their storage capacity and wishes to maximise their profit. If the same operator had access to sufficient conventional pumped hydro they would likely be running the tidal plant to maximise energy harvesting efficiency and using the pumped hydro to deliver that energy when its most cost effective.If you want to discuss the possible flooding of Bristol with regard to a Severn Barrage, then it is in fact able to protect them from flooding events. All off a sudden there is a huge economic value in having control of the basin depth.

author: tggzzz
author_rank: Super Contributor
timestamp: March 20, 2015, 09:51:27 am
content: Quote from: mojo-chan on March 20, 2015, 08:52:38 amStop trolling.It won't implode because there is sufficient conventional capacity to cover for its absence - and long may that continue.

author: tom66
author_rank: Super Contributor
timestamp: March 20, 2015, 10:51:23 am
content: Hmm. From what I heard, European grid operators had been planning for this event and were able to cover the shortfall of about 5GW with conventional power plant generation. The great thing is you can plan for eclipses hundreds of years in advance. Cloud cover is hard to predict more than a week ahead.

author: tggzzz
author_rank: Super Contributor
timestamp: March 20, 2015, 11:35:37 am
content: Quote from: mojo-chan on March 20, 2015, 10:45:38 amOf course we can -if and only if there are sufficient alternative sourcesavailable when needed.QuoteAll technologies have their limitations. The only crazy thing is to attempt to pretend they don't have limitations.For intermittent sources you either have to be able to store electricity (or the equivalent), or to have sufficient excess capacity to make up the shortfall.In the UK the practical storage capacity that is availableall the timeis, unfortunately, very limited. Fame and riches await the person that invents and creates practical storage technology.

author: tom66
author_rank: Super Contributor
timestamp: March 20, 2015, 12:13:15 pm
content: Quote from: mojo-chan on March 20, 2015, 11:36:54 am...so you DO agree that we need conventional power to cover shortfalls during wind and solar drop outs?

author: tggzzz
author_rank: Super Contributor
timestamp: March 20, 2015, 11:14:43 pm
content: Quote from: mojo-chan on March 20, 2015, 10:19:50 pmPutting the best possible interpretation on your previous posts, you have repeatedly and deliberately given the impression that tom66's question is very valid!Shame you can't articulate and convey your beliefs more unambiguously.

author: Someone
author_rank: Super Contributor
timestamp: March 21, 2015, 12:42:27 am
content: Quote from: mojo-chan on March 20, 2015, 10:19:50 pmWe only need conventional thermal plants for now, its possible to imagine a future where renewables and storage are able to deliver sufficient electricity. Fossil fuel is going to become uneconomic at some point in the next few decades or century, and at some point in the several centuries following fission will also come to a sharp increase in operating costs. Enjoy cheap energy while it lasts, I sure am.

author: tggzzz
author_rank: Super Contributor
timestamp: March 21, 2015, 11:46:50 am
content: Eclipse experience fromhttp://spectrum.ieee.org/energywise/energy/renewables/despite-bright-sun-its-european-grid-operators-1-solar-eclipse-0with myemphaisshowing the reason for success and other interesting pointsQuoteandQuoteandQuote

author: Zero999
author_rank: Super Contributor
timestamp: March 21, 2015, 01:51:40 pm
content: The solar eclipse was only partial for most of Europe. A the total eclipse only occurred over a small part of north-western Europe where there isn't a significant about of solar power anyway.I wonder what it would've been like if the total eclipse occurred over most of Germany?

author: tggzzz
author_rank: Super Contributor
timestamp: March 21, 2015, 02:06:20 pm
content: Quote from: mojo-chan on March 21, 2015, 01:50:43 pmSeehttps://www.eevblog.com/forum/profile/?area=showposts;u=2294

author: tom66
author_rank: Super Contributor
timestamp: March 22, 2015, 12:41:48 am
content: Renewables can work. Happy to see success for Costa Rica - 75 continuous days on renewable only. Sadly, they couldn't run the whole year, but not too bad.http://www.sciencealert.com/costa-rica-powered-with-100-renewable-energy-for-75-daysHow long until the UK can run a single day on renewables? Costa Rica's power consumption per km^2 and per capita is much smaller than the UK. I have no problem with renewables in themselves but would like to see more continuous sources such as hydro and geothermal investigated. Sadly the UK is not really that good at either.

author: tggzzz
author_rank: Super Contributor
timestamp: March 22, 2015, 10:06:12 am
content: Quote from: mojo-chan on March 21, 2015, 02:36:09 pmI deserve that. My apologies.QuoteThat is the art of asking a question: force the respondant either to address the issue or to be seen to be ignoring it. Since my points are important and relevant, I make no apologies whatsoever for doing exactly that.QuoteThat's a case of the pot calling the kettle black.

author: coppice
author_rank: Super Contributor
timestamp: March 22, 2015, 03:41:37 pm
content: Quote from: tom66 on March 22, 2015, 12:41:48 amCosta Rica is in the unusual position of being able to generate most of its electricity by hydro-electric means. That just won't work for most countries. Its also very distorted to say "Costa Rica powered with 100% renewable energy for 75 straight days ". They only got their electricity from renewable source. As well as using things like oil for transportation, a country with little industry has a lot of its overall energy usage embedded in the goods it imports. In other words quite a lot of Chinese and other countries coal was supporting Costa Rica's way of live over those 75 days.Other than some limited geothermal work, i didn't see Costa Rica doing anything innovation towards a move renewable future for the world.renewable

author: dannyf
author_rank: Super Contributor
timestamp: March 22, 2015, 03:59:42 pm
content: QuoteTo be fair, something that simple has proven too difficult for our renewable advocates to comprehend.

author: SeanB
author_rank: Super Contributor
timestamp: March 22, 2015, 05:40:41 pm
content: Yes, look at the countries that have aluminium smelters: South Africa, Mozambique ( powered from South Africa mostly, though there is a little power from Cahora Bassa) and Iceland. Only common thing is cheap electricity, all the other raw materials are imported.

author: mtdoc
author_rank: Super Contributor
timestamp: March 22, 2015, 11:47:27 pm
content: Quote from: dannyf on March 22, 2015, 03:59:42 pmTo be truthful, I've never seen anyone on this forum deny that embedded energy is an important element to be considered in the evaluation of energy resources. Quite the opposite - many times on this forum that issue has been discussed and evaluated with references cited regarding the net energy from various sources of electricity production.All sources of energy production, renewable or otherwise have energy embedded in their means of production and distribution. When it comes to electricity generation, the question in the end is, over the lifetime of production, what is the cost/benefit - with all costs accounted for - including embedded energy, consumption of finite resources, and externalities (pollution, environmental degradation, and health effects).To often the discussion strays away from discussion of these facts, as those with a political agenda seeks to steer the discussion in the direction of their ideology.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 22, 2015, 11:53:36 pm
content: How come nobody mentioned that the biggest residential energy uses - HVAC, refrigeration, and hot water - are all well suited for cheap and reliable thermal storage?

author: coppice
author_rank: Super Contributor
timestamp: March 23, 2015, 08:49:54 am
content: Quote from: mtdoc on March 22, 2015, 11:47:27 pmPeople don't deny that embedded energy is an important element, but many seem to keep forgetting it when they make an argument.

author: zapta
author_rank: Super Contributor
timestamp: March 23, 2015, 01:56:34 pm
content: Quote from: mtdoc on March 22, 2015, 11:47:27 pmIt's interesting that the externilizers choose to ignore the cost of intermittent and unreliable power.

author: rolycat
author_rank: Super Contributor
timestamp: March 23, 2015, 02:37:56 pm
content: Quote from: zapta on March 23, 2015, 01:56:34 pmIt's interesting that some people are so blinded by political prejudice that they are incapable of reading the statement "with all costs accounted for".

author: zapta
author_rank: Super Contributor
timestamp: March 23, 2015, 02:50:41 pm
content: Quote from: rolycat on March 23, 2015, 02:37:56 pmCheck the thread history here. Externalization is one sided.

author: mtdoc
author_rank: Super Contributor
timestamp: March 23, 2015, 03:15:27 pm
content: Quote from: rolycat on March 23, 2015, 02:37:56 pmYes, especially when I've repeatedly posted about the fact that intermittency is the reason why there is no way to completely replace fossil fuels for electricity production at the scale it is currently done. In fact that was a major point of my post in this thread (see post #148) just 2 days ago!.It just proves the point that "too often the discussion strays away from discussion of these facts, as those with a political agenda seek to steer the discussion in the direction of their ideology"As far as the issue of intermittency - I don't see it as a cost so much as it is a major omission from the benefit column. But regardless of how you slice it, it is the Achilles heel of most renewables (hydro being the major exception).As far as external costs go, those who try to avoid discussing them are just demonstrating their political nature.It's really too bad on an engineering forum we can't just keep the discussion focused on the facts.(BTW - one cannot be an "externalizer" and one cannot "externalize". That's just nonsense political speak. Something either has external costs or not. One can choose to ignore them or not, but they exist nevertheless)

author: zapta
author_rank: Super Contributor
timestamp: March 23, 2015, 03:22:21 pm
content: Quote from: mtdoc on March 23, 2015, 03:15:27 pmThe fact is that the abundance of reliable fossil fuel based energy enabled never imagined before life style and longevity but the haters keep demonizing it.

author: tggzzz
author_rank: Super Contributor
timestamp: March 23, 2015, 03:39:19 pm
content: I agree with your other sensible points, but I have a niggle with this:Quote from: mtdoc on March 23, 2015, 03:15:27 pm... economic agendas also play a significant part. As does ignorance and stupidity.

author: tggzzz
author_rank: Super Contributor
timestamp: March 23, 2015, 03:42:38 pm
content: Quote from: zapta on March 23, 2015, 03:22:21 pmFossile fuelsdohave significant "demons", as do all alternatives.The point is to recognise - and not to deny - the existence and magnitude of the "demons".Once that is done, progress can be made.

author: mtdoc
author_rank: Super Contributor
timestamp: March 23, 2015, 04:06:03 pm
content: Quote from: tggzzz on March 23, 2015, 03:42:38 pmAgreed. And doing a thorough cost/benefit comparison means looking these "demons" as they exist forallelectricity generation options.As far as economics goes - yes - important for sure and part of the cost/benefit analysis. Unfortunately this is where too many jump in to politicize the discussion.The difficult part when once starts to look at the economics is that it is all to easy to see only the short term economics. Also - classic economic theory does not account for finite resources nor does it pay attention to thermodynamics - so that the concept of net energy is not generally considered.

author: Someone
author_rank: Super Contributor
timestamp: March 23, 2015, 09:26:59 pm
content: Quote from: mtdoc on March 23, 2015, 03:15:27 pmAll the numbers I have looked at say that there is sufficient space/geography available in the UK and Australia to install pumped hydro storage capacity to enable 100% renewable generation for each nation respectively. Intermittency is solvable with current technology, and is economically profitable when it is operated in the current markets so it is not an external cost that needs to be added renewables, it could be counted as a profit against any generation type other than the fast gas turbine plants (with which it currently competes). The problem the UK faces with going 100% renewable is that the generating energy density per unit area of renewables isn't compatible with the limited land area.

author: tggzzz
author_rank: Super Contributor
timestamp: March 23, 2015, 10:37:17 pm
content: Quote from: Someone on March 23, 2015, 09:26:59 pmReally? Where in the UK? (I make no comment about Australia)What does yourunnamedsource know that David MacKay doesn't? Seehttp://www.withouthotair.comwhich is lauded byeverybodywithanyaxe to grind.QuoteThat must be for a definition of "solvable" that I'm not familiar with. Probably one which is similar to "the world has enough food for hunger to be a solvable problem".QuoteYou will have to point to a justification for that, which must include accounting for the increased cost of operating conventional plants since it will require them to be operated in a less economic manner. "Somebody" has to pay for conventional plants reduced efficiency, and that should be whoever" is causing the inefficiency. After all, if renewables are so efficient, their reduced cost should bemore thancapable of offsetting the inefficiency.There are good reasons for using renewable sources, but making disingenuous (at best) claims about costs and profitability makes people doubt the claimed advantages.QuoteThere are other problems.

author: coppice
author_rank: Super Contributor
timestamp: March 24, 2015, 05:54:33 am
content: Quote from: Someone on March 23, 2015, 09:26:59 pmThe continental shelf gives the UK and Ireland considerable concentrated tidal power. Only one place in the world has more. As the first land the Atlantic winds hit, the UK and Ireland receive considerably more wind than anywhere on the mainland. By the same mechanisms the UK and Ireland also get lots of wave power against their shores. They are certainly certainly weak on solar, as much from endless cloud cover as from their northern location, but compared to most of the world they are quite renewables rich. If they can't support themselves renewably, what hope is there for most of the planet?

author: Someone
author_rank: Super Contributor
timestamp: March 24, 2015, 11:38:42 pm
content: Quote from: tggzzz on March 23, 2015, 10:37:17 pmIf all you do is operate the pumped storage plant it is very profitable with the current wholesale electricity market volatility, the profitability of other generators on the network can be ignored. Further, adding pumped storage will only stabilise fluctuations in demand for conventional plants so in co-operation they could be run more efficiently.Here is a rather neutral reference on the matter for Australia:http://www.energy.unimelb.edu.au/opportunities-pumped-hydro-energy-storage-australiaQuote from: tggzzz on March 23, 2015, 10:37:17 pmYou can point to that reference all you like, it devotes substantial length to the matter and supports the realistic view that the UK has sufficient space and geography to store enough energy to cope with lulls in a largely or 100% renewable generation scenario. It trivially finds enough storage capacity in a small number of existing unutilised water bodies to store 2 hours of operational time in addition to the current estimated 30 minutes of hold up time. This is without considering the capability to build new storage capacity, increase the capacity of existing locations, tidal lagoons, etc.Quote from: tggzzz on March 23, 2015, 10:37:17 pmThere probably are, but storage is a solved problem that through pumped water can fit within economic and social constraints.

author: Someone
author_rank: Super Contributor
timestamp: March 24, 2015, 11:40:24 pm
content: Quote from: coppice on March 24, 2015, 05:54:33 amReduced population density is one answer!

author: tggzzz
author_rank: Super Contributor
timestamp: March 25, 2015, 12:43:51 am
content: Quote from: Someone on March 24, 2015, 11:38:42 pmNonsense. In each of his 5 plans for the future (see p203 onwards) he keeps pumped hydro at the same level as today - for the good reason that most of the good spaces in the UK are already fully utilised.As for the capacity, the combined capacity is 30GWh, sufficient for significantly less than 1 hours UK electricity consumption. Given the intermittancy of wind and water power in the UK, that is completely and utterly inadequate.As for referring to Mackay as a good source - of course I do. Everybody, from Greenpeace to Big Energy, regards his work as an excellent starting point for discussions.If someone makes claims that are extraordinary compared to that starting point, then that someone has to provide extraordinary proof. So far nobody has been able to provide sufficient proof that stands up to examination. If you can provide extraordinary proof for your extraordinary claims, then everybody will listen.

author: tggzzz
author_rank: Super Contributor
timestamp: March 25, 2015, 12:49:02 am
content: Quote from: Someone on March 24, 2015, 11:38:42 pmNot in the UK it can't. That's an extraordinary claim you are making, so I (and many many others in the UK) will be interested in seeing whether you extraordinary proof stands up to scrutiny. I'm not holding my breath.

author: Someone
author_rank: Super Contributor
timestamp: March 25, 2015, 02:06:12 am
content: Quote from: tggzzz on March 25, 2015, 12:43:51 amThe current UK capacity is less than 30GWh (rounded up in that reference) which is enough energy for around 30 minutes of hold up power as i said, the same document goes on to make a quick estimate that 400GWh of capacity can be found from just a small number of existing water bodies. Plan "G" from the document suggests 4000GWh or more storage and is not flagged in any way as challenging to achieve. That 4000GWh is enough energy for grid hold up of roughly 2-3 days, additional hold up can be achieved by demand management and storage by the consumer as discussed elsewhere in the same document.You are so wrong time and time again, but we await your next distraction. I'm not going to hold you to any ridiculous levels of proof but right now it would take a pretty committed geospatial analysis to prove that there isn't enough storage capacity available in the UK when so little of the well studied and proven resources are currently used.Just for reference a large version of the Severn Barrage could store 20GWh or more over the short term, pumped hydro up hills is far more effective use of surface area.

author: Someone
author_rank: Super Contributor
timestamp: March 25, 2015, 02:25:28 am
content: Quote from: tggzzz on March 25, 2015, 12:49:02 amWholesale electricity pricing over the daily cycle for the UK is seemingly tricky to get much data on but againSustainable Energy - Without the Hot Airprovides some data showing daily fluctuations of 4-5x in price and I have seen slightly less optimistic data sets that show reliable 3x daily variations in the market.Huge arbitrage potentialThe economics of pumped storage are well developed, starting with the University of Melbourne example I posted earlier. There is no extraordinary claim from any aspect. Humorously pumped storage is most profitable while there is only a limited amount of it and as larger reserve capacities are built the profit will actually drop, but that assumes the generating characteristics are as they are today and adding more intermittent generators into the grid such as solar or wind offsets that.

author: coppice
author_rank: Super Contributor
timestamp: March 25, 2015, 03:01:56 am
content: Quote from: Someone on March 25, 2015, 02:06:12 amIn the early part of Without The Hot Air the author shows scenarios that would require 1200GWh of storage to ride over the lulls in generation. He then shows what it would take to achieve 400GWh of storage, which is a substantial change to Scotland, and then says:QuoteIn plan G he says the plan would need 4000GWh of storage, which would take 100 lakes. Having already established that getting to 1200GWh would be tough he goes no further. Remember than 4000GWh from 100 lakes is an average of 40GWh per lake, and that Britain's current flagship pumped storage scheme at Dinorwig only stores 9GWh.

author: coppice
author_rank: Super Contributor
timestamp: March 25, 2015, 03:06:22 am
content: Quote from: Someone on March 25, 2015, 02:25:28 amWhat relevance does the potential for arbitrage have when the topic was having enough pumped storage to ride over long lulls in generation. Power arbitrage is basically a 24 hour cycle thing.

author: Someone
author_rank: Super Contributor
timestamp: March 25, 2015, 04:38:24 am
content: Quote from: coppice on March 25, 2015, 03:01:56 amTo me the suggested changes would not be "substantial" to Scotland, using existing water bodies within their existing natural water height variations seems like a very moderate approach. Putting in the huge quantities of storage beyond that would require substantial changes with large dams, flooding, and new reservoirs.Quote from: coppice on March 25, 2015, 03:01:56 am1200GWh would not be tough if energy storage was a priority, open up the constraints and anything is possible. When you go looking for commercially viable sites for pumped storage they come up with surprising frequency as the assessments using geospatial data in Australia have shown. Energy storage capacity has not been a priority in the grid so taking the existing fleet of storage plants is not representative of what is possible, the upper storage of Dinorwig is surprisingly small despite the large dams progressively built to increase its capacity (originally for other purposes).

author: Someone
author_rank: Super Contributor
timestamp: March 25, 2015, 04:44:55 am
content: Quote from: coppice on March 25, 2015, 03:06:22 amI'm addressing the economics of this, pumped storage is profitable, even in the UK. And then as an additional benefit it can also be used for energy storage across any timeline that the operator deems necessary (unlike the tidal examples which require more careful planning for storage/delivery timing). While it might be making money most of the year in the daily arbitrage when longer lulls arrive the capacity can be used to smooth those out too, driven purely by profit motives.

author: tggzzz
author_rank: Super Contributor
timestamp: March 25, 2015, 08:54:50 am
content: Quote from: coppice on March 25, 2015, 03:01:56 amPrecisely. One should , of course, realise that Mackay is an engineer and mathematician, and he is using the word "tough" in the engineering/mathematicial sense. "Tough" means "theoretically conceivable, but so difficult as to be impractical".

author: tggzzz
author_rank: Super Contributor
timestamp: March 25, 2015, 08:58:13 am
content: Quote from: Someone on March 25, 2015, 02:25:28 amOnce someone introduces arbitrage as an argument, it is clear that they have moved away from the world of physics and engineering and into the world of financiers such as the City of London.Students the City of London know that there is only a tenuous relationship between the City of London and the real world.

author: tggzzz
author_rank: Super Contributor
timestamp: March 25, 2015, 09:07:11 am
content: Quote from: Someone on March 25, 2015, 04:38:24 amTo rephrase that to tease out your train of thought. "It is possible in Australia, so it is possible in the UK. The largest existing scheme in the UK is 'surprisingly small' despite all the efforts to increase its capacity".Australia is large, empty, and has significant hills/mountains. The UK (even Scotland) is small, densely populated especially near water, and doesn't have many hills.

author: coppice
author_rank: Super Contributor
timestamp: March 25, 2015, 09:49:02 am
content: Quote from: tggzzz on March 25, 2015, 08:58:13 amThat's not really true. Energy arbitrage works well as a proper engineering solution over 24 hour cycles, storing during the quiet times, and releasing to soften the peaks. However, a system designed for profitable arbitrage is no bigger than the peak to trough span of the daily cycles. Its a completely different thing from providing a means to maintain supply through long unpredictable downturns in generated output, which was the topic being discussed. Its a national necessity, but its hard to imagine a system like that ever running at a profit.

author: Someone
author_rank: Super Contributor
timestamp: March 25, 2015, 10:52:46 am
content: Quote from: tggzzz on March 25, 2015, 09:07:11 amYou rephrase and completely change the result, it is a small pumped storage installation in both capacity and surface footprint. It was built up over time with successive dams but remains a very small example of pumped storage.Quote from: tggzzz on March 25, 2015, 09:07:11 amThe famously high cliffs around the UK coastline are an immediate and very cost effective location for storage, and all the estimates I can come up with show enough capacity to meet the quantities of storage being discussed here. It takes land away from other uses (as you cant store enough with tidal only) but these are the trade-offs required when trying to meet energy independence with renewables.

author: Someone
author_rank: Super Contributor
timestamp: March 25, 2015, 10:56:17 am
content: Quote from: tggzzz on March 25, 2015, 08:54:50 amWhen discussing the 5 example energy plans for the UK they are presented as such:Quote from: David JC MacKayOf which plan "G" includes the quoted 4000GWh of storage all attributed to pumped storage. Also you have misappropriated the quote inside those tags to me when they are a direct quote of the books author (taken out of context).

author: dannyf
author_rank: Super Contributor
timestamp: March 25, 2015, 11:08:48 am
content: I just cannot resist:QuoteQuote"Can not compute! can not compute! can not compute!..."

author: Someone
author_rank: Super Contributor
timestamp: March 25, 2015, 11:17:06 am
content: Quote from: coppice on March 25, 2015, 09:49:02 amWhen the grid is running with vast excesses of energy generation (as is the model where solar or wind provides large percentages of the total grid power) the prices will be pushed down, with more storage available the cheap energy can be soaked up and stored, but it may not be released within the following daily cycle if prices remain low. Further consider that once there is a large uncontrollable variance in the total generation capacity from the wind and solar intermittency that there will be fewer conventional plants competing to supply the energy during renewable generation lulls and prices will skyrocket during those periods, suddenly storage is both essential, and profitable.Unless of course you have government interference in the market forces in which case leave it to them to fund the future. The situation in this thread yes?

author: dannyf
author_rank: Super Contributor
timestamp: March 25, 2015, 11:26:10 am
content: QuoteOr simply use merchant plants: a gas turbine is the size of a house, and it can go into full power production in a matter of minutes.Sure, it is expensive but far less cheaper than the environmental costs of a pumped station.

author: coppice
author_rank: Super Contributor
timestamp: March 25, 2015, 11:47:45 am
content: Quote from: dannyf on March 25, 2015, 11:08:48 amYep. Its puzzling, isn't it. Is that a troll? Someone who has completely lost the plot? It doesn't even make sense as Disney Britain. Even that has King Arthur's Avalon only just above the sea.

author: tggzzz
author_rank: Super Contributor
timestamp: March 25, 2015, 03:34:08 pm
content: Quote from: Someone on March 25, 2015, 10:52:46 amSnort! Now you're just tossing out ideas to see who salutes them! You are clearly completely unfamiliar with the topography and size of the UK.The famous cliffs in the south reach a peak, and I mean peak-as-in-point, height of 150m/600ft, here:http://www.streetmap.co.uk/map.srf?X=337987&Y=93035&A=Y&Z=115As you can see when you look at the height and slopes, there's not much scope for hydro there! The rest of the south coast is pretty much the same. The rest of the UK's cliffs are not much better.In contrast, in the vicinity of populated areas, Australia appears to have ~30000 square miles of more-or-less unpopulated ground above 2000ft - which would be suitable for pumped storage. Repeat after me, "UK != Australia".

author: G7PSK
author_rank: Super Contributor
timestamp: March 25, 2015, 04:09:40 pm
content: Quote from: tggzzz on March 25, 2015, 03:34:08 pm

author: KJDS
author_rank: Super Contributor
timestamp: March 25, 2015, 04:14:35 pm
content: There's another small issue with building anything on top of an English cliff, most of them are collapsing into the sea on a regular basis

author: G7PSK
author_rank: Super Contributor
timestamp: March 25, 2015, 04:17:26 pm
content: The whole of the south east of the UK is slowly tipping into the sea as well but on the up side Scotland is rising,so that should help a bit.

author: tggzzz
author_rank: Super Contributor
timestamp: March 25, 2015, 04:19:29 pm
content: Quote from: KJDS on March 25, 2015, 04:14:35 pmI'll modify that just a little. Once upon a time they were hills, ripples left over from when Africa hit Europe. But the hills gradually collapsed into the sea - thereby forming the cliffs.Either way, they are useless for pumped storage.

author: tggzzz
author_rank: Super Contributor
timestamp: March 25, 2015, 04:20:45 pm
content: Quote from: G7PSK on March 25, 2015, 04:17:26 pmIt isn't rising as fast as the sea is risingOr maybe

author: zapta
author_rank: Super Contributor
timestamp: March 25, 2015, 04:27:28 pm
content: Quote from: zucca on March 03, 2015, 09:21:39 amOr the Dead Seahttp://en.wikipedia.org/wiki/Red_Sea%E2%80%93Dead_Sea_Canal

author: G7PSK
author_rank: Super Contributor
timestamp: March 25, 2015, 04:49:50 pm
content: There was once a plan to dam the straights of Gibraltar for a hydro electric scheme. The idea being the Mediterranean would evaporate at such a rate that there would be a level difference with the Atlantic. There was objections due to both cost and what it might do to the climate so it was not taken seriously.

author: coppice
author_rank: Super Contributor
timestamp: March 25, 2015, 05:03:22 pm
content: Quote from: tggzzz on March 25, 2015, 04:19:29 pmWell, the cliffs aren't entirely useless. If you step back a kilometre from the cliff edge you are far enough away that the crumble rate won't get you in trouble for a fair while, the land can probably support the weight of the damed pool, and the pipe losses aren't astronomic. The vertical displacement is certainly going to be a lot less than ideal. However, the main issues is that land is heavily populated. To build a circular dammed structure large enough to be useful, even if you make the pool inside it quite deep to minimise its width, is going to require displacing a lot of people. This is definitely a high impact project idea.

author: Someone
author_rank: Super Contributor
timestamp: March 25, 2015, 09:45:17 pm
content: Quote from: tggzzz on March 25, 2015, 03:34:08 pmDo some maths if you don't believe whats written in theSustainable Energy - without the hot airreference we have all agreed is excellent. Here are some simple starts:The total storage reservoir surface area of the UK's existing 20-30GWh of pumped storage is approximately 6 square kilometres, the total area of standing water in the UK is around 2000 square kilometres. This is before you consider the building of dams or purpose specific reservoirs.From that its believable that you could fit the above discussed 4000GWh of energy (enough to ride through several days of zero generation from other sources) into reservoirs covering 1200 square kilometres, with the UK totalling over 200,000 square kilometres this is only 0.5% of the land area of the UK.Tidal pool, thermal, and other storage techniques could contribute further without using land area.Feel free to come up with numbers or references to show how these are impossibilities, because every analysis I see on pumped storage adds up.

author: Someone
author_rank: Super Contributor
timestamp: March 25, 2015, 09:47:45 pm
content: Quote from: coppice on March 25, 2015, 05:03:22 pmYes, competing land use demands are a challenge to siting any development. But as the numbers show, when compared to alternatives for securing energy pumped storage competes exceedingly well. Unlike the wastelands around conventional power plants (look at a coal plant and its associated mines some time) pumped storage pools remain useful for recreation or aquaculture.

author: tggzzz
author_rank: Super Contributor
timestamp: March 25, 2015, 10:23:48 pm
content: Quote from: Someone on March 25, 2015, 09:45:17 pmAs you will note, I was dismissing your point about UK cliffs being suitable for pumped storage. We notice you have not repeated that claim.

author: tggzzz
author_rank: Super Contributor
timestamp: March 25, 2015, 10:27:22 pm
content: Quote from: coppice on March 25, 2015, 05:03:22 pmAnd, of course building such a circular dam structure with a hill in the middle is not exactly efficient! It would be better to build on flat land, e.g. East Anglia

author: dannyf
author_rank: Super Contributor
timestamp: March 25, 2015, 10:29:00 pm
content: QuoteEven if math is not your strong suit, you should probably do some math - it is fairly simple, btw - to do a sanity check on those numbers.I am sure the water and land in the UK are much holier, but the largest such facility in the world generates 3GW, and takes up 5 million square meters - compare with your figures.BTW, that facility was built in a remote area, in the 1980s, at a then cost of $1.6Bn.I would conservatively estimate that such a facility, if it were to be built in the UK today, would cost you well over $10Bn, assuming that you can overcome the political pressure and environmental approvals.Again, being able to think critical and not taking other peole's BS wholesale helps.

author: dannyf
author_rank: Super Contributor
timestamp: March 25, 2015, 10:31:07 pm
content: QuoteI don't know - I think s/he sounded that s/he genuinely believed in it.You know, for some people, winning a virtual argument is so important to them that they will throw anything, no matter how far fetched, as long as they stick. This could be one of those (nut) cases.

author: Someone
author_rank: Super Contributor
timestamp: March 25, 2015, 11:17:31 pm
content: Quote from: dannyf on March 25, 2015, 10:29:00 pmBath County Pumped Storage Station?It stores 45GWh of energy in the upper reservoir of 1 square kilometre, roughly 10 times more efficient per unit area of land than the existing UK pumped storage fleet. Perhaps I should revise the above estimate for the total area in the UK needed to store 4000GWh down by a factor of 10?I'm not sure how you arrive at the 5 square kilometres, but even with that estimate that counts an area larger than both reservoirs its still a factor of 2 more land area efficient than the current UK fleet.Read the papers I have linked, they look at the current costs of building storage and estimate a comparable 50,000 ML system to cost several billion dollars to build around 2 billion.For comparison a nuclear power plant with the same peak generation capacity would cost around 12 billion, a combined cycle gas plant would cost 3 billion, a coal plant interestingly has capital costs higher at around 8 billion. Multiple references come to similar numbers, these are not picking biased estimates but looking across a range of well referenced data sets.Adding in the capital costs of both pumped storage and wind or solar generation together in a system to deliver reliable and consistent power year round, the magic number is on par with coal or nuclear just for the capital costs. The lower annual operating expenses and marginal cost of the power delivering much higher returns on investment compared to the conventional plants.Having lower ongoing costs than any of those alternative generators and a marginal cost of the power orders of magnitude lower, lower capital costs for peaking plants, why is this discussion continuing?

author: Someone
author_rank: Super Contributor
timestamp: March 25, 2015, 11:20:22 pm
content: Quote from: tggzzz on March 25, 2015, 10:23:48 pmShow us how much of the UK land area is unsuitable for storage installations, perhaps with references etc. Because from the numbers I have just shown the required space to have this 4000GWh of storage is less than one percent of the total land area.

author: Someone
author_rank: Super Contributor
timestamp: March 25, 2015, 11:24:43 pm
content: Quote from: tggzzz on March 25, 2015, 10:27:22 pmWhere as a dam that includes the local topography as part of its walls reduces the construction expense (as in the example of the upper reservoir of the Dinorwig). Once again uneconomic corner cases and illogical examples can be found for any technology, this does not make them stupid or uneconomic when applied carefully.For someone accusing others of creating strawman arguments you should really be more considerate.

author: dannyf
author_rank: Super Contributor
timestamp: March 25, 2015, 11:40:25 pm
content: QuoteIf you cannot convert million square meters to square killo meters in your head - the math is really simple, I can assure you, you can still use online calculators for that.

author: Someone
author_rank: Super Contributor
timestamp: March 25, 2015, 11:44:48 pm
content: Quote from: dannyf on March 25, 2015, 11:40:25 pmWikipedia states the surface areas for the upper and lower storage reservoirs as 265 acres and 555 acres respectively, 3.3 square kilometres.I've counted the upper reservoirs above as the energy is stored there, if you want to consider the scaremongering corner case of delivering power solely from pumped storage then the lower reservoir capacity is simply another body of stored energy to be consumed.

author: Someone
author_rank: Super Contributor
timestamp: March 25, 2015, 11:53:31 pm
content: Quote from: dannyf on March 25, 2015, 11:48:31 pmQuote from: Someone on March 25, 2015, 11:17:31 pmPut in all the numbers you like, I can't come up with evidence to show that pumped storage in the UK is either uneconomic or impossible even when considering the extreme case of 4000GWh. Seems you can't either.So far it seems my maths is sound, and walking on the side of overestimating the costs.

author: dannyf
author_rank: Super Contributor
timestamp: March 25, 2015, 11:58:58 pm
content: NOTE: This message has been deleted by the forum moderator Simon for being against the forum rules and/or at the discretion of the moderator as being in the best interests of the forum community and the nature of the thread.If you believe this to be in error, please contact the moderator involved.An optional additional explanation is:

author: tggzzz
author_rank: Super Contributor
timestamp: March 26, 2015, 12:00:24 am
content: Quote from: Someone on March 25, 2015, 11:24:43 pmThat's true of course. But if you look at the topography ofyour"famous cliffs", you'll notice that they will allrequiresuch a stupid structure.It would help if you could give names to your "famous cliffs" that you feel would be suitable. Since you probably don't have Ordnance Survey maps to hand in Australia, I suggest you look athttp://www.streetmap.comfor 1:50000 and 1:25000 scale maps.

author: Someone
author_rank: Super Contributor
timestamp: March 26, 2015, 12:05:21 am
content: Quote from: dannyf on March 25, 2015, 11:58:58 pmSome cliffs will be suitable sitings for pumped storage and some won't, where it the outrageous statement in that? Its disputing the claim that the UK is dead flat and does not have enough mountainous regions to support such a scale of pumped storage Trying to claim all the seaside cliffs are impossible to site pumped storage on is the ridiculous claim, just as claiming that all the cliff tops would/should be used for pumped storage. Both ridiculous statements.But finding some sites across the UK totalling less than 1% of the land area, which are suitable for pumped storage. That sounds like something that would be trivial given the experiences in Australia leveraging geospatial data to algorithmically find candidate sites.

author: Someone
author_rank: Super Contributor
timestamp: March 26, 2015, 12:10:33 am
content: Quote from: tggzzz on March 26, 2015, 12:00:24 amStorage reservoirs come in all sorts of sizes, they can be fitted into the existing terrain.Quote from: tggzzz on March 26, 2015, 12:00:24 amSo far we've heard claims that the UK is so very flat and all the areas below sea level (incidentally a great place to have pumped storage lower reservoir), but this is against the numbers I have presented showing that less than 0.5% of the land area is needed in storage reservoirs. You can't find a tiny fraction of the total land area that is suitable?Its easy for you to continue to find the negative examples but you are doing nothing to show how there are not enough feasible locations.

author: coppice
author_rank: Super Contributor
timestamp: March 26, 2015, 12:38:46 am
content: Quote from: dannyf on March 25, 2015, 11:40:25 pmI don't know how either of you get your figures. There's 107ha of surface area in the upper pool and 255ha of surface area in the lower pool for a total of 3.62 square kilometres. Is the 5 square kilometre figure when you include the supporting area of dam walls and so on? I didn't see figures for that in the descriptions I found of the Bath County project.

author: Someone
author_rank: Super Contributor
timestamp: March 26, 2015, 12:44:16 am
content: Quote from: coppice on March 26, 2015, 12:38:46 amThat tallies with the numbers I put up for the upper reservoir, and close enough for the area of the lower reservoir. However you cut these figures its a much more effective use of space than the UK plants, though that may be at an increase in capital outlay per unit of energy stored when you consider its price.

author: dannyf
author_rank: Super Contributor
timestamp: March 26, 2015, 12:47:27 am
content: QuoteShould you be looking that total area of the "famous cliffs"? Or you have abandoned that "cliff" ideal of yours?QuoteSo in you mind, if I am unwilling to prove that your crazy ideal is crazy enough to your definition/satisfaction, it is no longer crazy?

author: dannyf
author_rank: Super Contributor
timestamp: March 26, 2015, 12:50:00 am
content: QuoteThere is a recreation area. That along pushes the number to 5 million square meters.plus areas in between the ponds - you can get a sense by watching its relative size vs. the ponds.