Monday
Nov282016
by 
Bishop Hill
Bishop Hill Decorative diesel
Nov 28, 2016 Energy: other Energy: solar From the Guardian
South Pacific island ditches fossil fuels to run entirely on solar power
Using more than 5,000 solar panels and 60 Tesla power packs the tiny island of Ta’u in American Samoa is now entirely self-sufficient for its electricity supply – though the process of converting has been tough and pitted with delays.
From the website of the government of American Samoa
The project description lists 1,410 kW of Solar panels and 6,000 kWh of battery storage. Also, three new 275KW Cummins Diesel Generators...
The latter presumably for decoration.
Reader Comments (99)
Joe Ronan, thanks for that. Had a brief flick through the pdf, and there is a promotional video on youtube. I agree that by taking moving parts out of the water, they have avoided all the inherent design flaws. The pdf mentioned things they could improve on, did they ever build a MkII?
Scottish Islands would seem ideal for this type of scheme, with exposure to the Atlantic swell. It seems that a long swell would produce more usable energy than a shorter choppy sea.
I am trying to remember a scheme from the 1970s(?) using "Ducks" that were shaped in cross-section like an elongated teardrop, and they rocked and flapped in the waves. I think they got smashed.
There was a youtube clip on Pelamis, which I seem to remember the Chinese have "recreated", however that has all the normal problems of smashability.
Halfway up the Energizer Duck's lashing
Takes a smashing and keeps on dashing
And dotting
And lotting,
Letting energy flow, force without crashing.
=======================
Right, sure, but should velcro be stored fastened or unfastened? I dare you all, climate heathens, to answer THAT question.
Real problems, require real solutions.
<Nov 30, 2016 at 11:41 AM | Unregistered CommenterACK>
Interesting. My comment was based on the reported opinion of a friend-of-a-friend who could be expected to know the subject intimately - "The engineering challenges are gigantic, we're not even considering it". It would be wrong to give any clues about his identity because I once canvassed his opinion on the long term future of wind power and the answer was "I don't want to discuss this, I enjoy my job". Following your link got me to <http://www.thejournal.co.uk/business/business-news/wave-tidal-energy-sector-critical-8392593> which seems to support his opinion.
<Nov 30, 2016 at 1:47 PM | Registered CommenterMartin A>
Following your link, my immediate reaction was that the charging cycles of L-ion and lead acid are completely different; I then noticed this at the bottom of the page "This case is valid for any type of application requiring deep discharge cycle. EV traction or autonomous systems match the same criteria. On the other hand, for UPS systems or back-up batteries, the above model can not be applied because the discharge cycles are by definition random for such systems." Apart from initial transportation costs I don't see the advantage of lighter weight.
That'll be Salter's Ducks Golf Charlie? There were many different implementations of that concept, all struggling with the issue of reliability.
From a quick web-search the Limpet OWC approach was still going in 2011 when a unit in Portugal was commissioned, but the parent closed Wavegen down in 2013 to concentrate on tidal.
Looking through the various projects it seems the costs of the OWC systems are heavy in mechanical, electrical and plant works relative to the power that's extracted. (In the Portugal case they seemed to be using 16 turbines for an overall rating of 300kW, which seems a little excessive!).
https://marineenergysystems.wordpress.com/tag/limpet/
I suspect Kim's poetry will last longer than that installation, and be more useful.
Kim
Waves may laugh at our ducks,
But are shat upon by their untethered brethren.
Eiders, however, should not laugh
They become pillows.
Gavin. I find it difficult to understand how anyone can dismiss tidal power on the basis of what a friend says or what you read when there already EXIST tidal power stations, some of which are both large and long lived. Furthermore, they use a concept that was used all around our coasts in the form of tidal mills. One still working example occurs at Woodbridge in Suffolk. There is no sandblasting there because it is sited on a mudflat.
I believe there are systems being tested in Orkney that combine tidal current and offshore wind, plus or minus wave energy.
You have to appreciate that the waves can get quite big, but you can still have fun!
Minty: you get up from the left side of a horse, but where do you get down from?
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A duck! (And, no, you do not have to kill the duck to get the down; ask an Icelander.)
Wind and solar on remote locations seems sensible - but the cost benefit needs close scrutiny.
That said - the US military aren't exactly resource constrained in most cases and the parlous state of disrepair of their windmill facility on Ascension Island must indicate that they don't see renewbables as a serious contender for incorporation into 24/7 mission critical power in remote locations...
Somewhere on BH are the results of my diggings into the BBC's wind power project on that same rather remote island - where they swerve the payback time question repeatedly.
Ravishing Rattie. What a strange 11.28am post. First I thought you were creating your own hiatus, then that our host is excising non- relevant content from WITHIN posts, but then I realized you were being so, so considerate and affording me sufficient time to dredge back to my so distant youth to seek the punchline from the antiquity of a joke so long forgotten. So considerate.
Ayla (halo be her name) until you know how to store Velcro we suggest you zip it.
ACK, loose velcro on yottie clothing during rough conditions, is a major cause of embarrassing bondage incidents between nonconsenting adults at sea.. Becoming inseparably attached to your crewmates can seriously compromise your dignity.
golfCharlie. The advice to Ayla can apply to all, on land or awash in yottie heaven. Has Velcro resulted in more permanent social attachments?
Radical Rodent, breaking waves are the scary ones. If you have ever seen someone paddling a lilo off a beach, once a breaking wave turns them side on, they roll. This applies to all boats and ships, when the height of a breaking wave is greater than the width of the boat.
http://www.yachtingworld.com/blogs/elaine-bunting/yacht-capsized-breaking-wave-294
Breaking waves are much more common in shallow water. The Bay of Biscay is on the edge of the Continental Shelf, deserves it's reputation as a shipwrecker and is best avoided.
<Dec 1, 2016 at 10:10 AM | Unregistered CommenterACK>
Don't misunderstand me, I think tidal is the only current renewable except hydro with the potential to provide dispatchable power. The friend of a friend's opinion carries weight because he is uniquely placed and qualified to comment on the subject. I realise there are tidal generation projects which have been running for a long time but they seem to be tiny and or/experimental - my question was about why there aren't more. Did you read the article?
<<http://www.thejournal.co.uk/business/business-news/wave-tidal-energy-sector-critical-8392593>>
It's almost two years old so things may have changed but I'm not aware of any rush of enthusiasm since then.
Joe Ronan, YES! Thank you, I was beginning to think I had imagined it.
https://en.m.wikipedia.org/wiki/Salter's_duck
Wikip states that they weren't developed because the oil price fell again. Oil has gone up a bit since the 70s, so I assume that their smashability has not come down.
Gavin. 240MW at La Rance is not so small, nor is the slightly larger Korean installation, but I agree the enthusiasm for larger schemes seems muted. The Cardiff Bay or the larger Seven Estuary schemes, if they ever materialize, would be mind-changing. Perhaps the in-line turbine systems to be installed in the Bay of Fundy (as a demonstation?) might change hearts and minds.
Gavin. BTW yes I did read the article. It was about in-line (=tidal stream) systems (and open-sea wave devices) rather than tidal estuary or lagoon systems that I was using to demonstrate the efficacy of tidal power. Eventually tidal stream power will be successful (because it is reliable, predictable and can be scaled up) but we don't seem to be there yet in terms of industry support or final design. The article doesn't really explain why support for this technology has recently slipped, which would have been of interest to me.
I have visited La Rance (the downflow whirlpools there are awesome) and saw the Orkney turbines before they were installed - I helped out a UEA colleague run alternative energy fieldtrips to Brittany one year and Orkney on another.
The tidal power systems do potentially have great benefit, but as others have pointed out, the physical forces involved are huge, and not as easily constrained as Hydro. The oft-mooted Severn Barrage would cause a great deal of damage to valuable wildlife sites (So the RSPB will probably support it), but if the costs are anything like the Swansea Bay scheme, the only people who will benefit are the likes of Dale Vince and others of his ilk.
Of interest to me is the project in Strangford Narrows in N Ireland where a turbine has been submerged in the 7 knot stream. I haven't heard much about it recently. The wikipedia entry hasn't been updated for several years. If turbines like this can be made a cost effective success, there are several places around the UK where they could usefully generate electricity.
Could it be that you forgot to incorporate the efficiency of a diesel engine? The efficiency of a diesel engine is less than 50%.
If the engineering problems can be overcome tidal would be the Holy Grail, providing reliable (i.e at least predictable) base load and we should all be rejoicing - I certainly would. Assuming the subsidies available to tidal schemes are comparable to wind and solar, why is Scotland disappearing under a shroud of windmills whilst no one wants to invest in tidal? Surely the only thing that would deter investors is the lack of a likely return and there must be a reason why they can't see a business in it?
Gavin, one of the advantages of wind is that it is proven technology, but unfortunately it does require the wind to blow. Small WindGens are available for yachts from about £500, off the shelf.
https://www.marlec.co.uk/wind-power/boats-and-marine/?v=79cba1185463
As Wind Turbines get bigger, they are made to order, but the basic design remains the same, whether you want to stick one in Hyde Park or on Land's End.
Wave and tidal power requires site specific designs, and the unit costs will be far greater. The bigger the scheme, the more is generated, hence ideas like Swansea Bay and the Severn Estuary (which also have some of the worlds biggest tidal ranges, ie the difference in height between high and low water.
Strangford Lough is a large inland sea, with a narrow entrance, and generates high flow rates. Small towed generators are also available for yachts, but again the ones at Strangford are not available off the shelf
http://www.yachtingworld.com/gear-reviews/wind-water-and-solar-power-65797
You need water flow of a knot, preferably more on a yacht, but finding tidal flows that produce more than 3knots for 50% of the time is not easy around the world.
Wijnand 8:25 any inaccuracies were not produced by Martin A. The figues did not add up anyway, and I miscalculated in an earlier posting. The Islands consumption of diesel probably includes uses other than electricity.
Tidal schemes: La Rance - 750m barrage; Swansea Bay - 9500m sea wall; South Korea - barrage for free after attempt to create freshwater lake failed. All fairly similar peak output. Guess which one is not economic, and why.
It doesn't add up. It sure doesn't, last time I looked the Swansea Bay project was just that, nothing built. I fail to see how a proposed project can have a peak ouput and be compared with existing facilities
Could it be that you forgot to incorporate the efficiency of a diesel engine? The efficiency of a diesel engine is less than 50%.
Dec 1, 2016 at 8:25 PM | Unregistered CommenterWijnand
Yes, you are right.
I made an incorrect assumption that "kWh" on the link that I gave was electrical output from a generator, rather than heat output from burning the stuff which is evidently what they were giving.
It seems that one gallon of diesel will generate about 10kWh of electrical energy. The link indicates 40.7kWh, presumably raw heat.
As climate enemies surrender yet again, it remains for authorities such as DiCaprio to address this serious, I dare say, critical, velcro storage controversy.
Will someone check Ayla's cave for excess methane? Alya is reading the labels on her ORCLEV food supplements backwards again, and fixating on DiCaprio worse than before.
Ayla, I don't think Trump owes his financial success to Velcro, but it may be his coiffeur's secret weapon.
American Samoa Power Authority billing details can be found here. There is a sample bill shown with details.
It is interesting. They make a fuel surcharge for the delivery costs of diesel and indicate that they expect savings to accrue to the customer as the solar power available increases. I guess that means that the consumers were not required to make any contribution to capital installation costs, otherwise they would have maintained rates at the previous level.
Friends! My recent Tweet on Hard-Right Climate Change would seem to sum things up, I hope you would agree?
https://twitter.com/SupportOurLefty/status/803967120346415104
Alec J, Strangford tidal energy turbine to be removed
From the article:
So I guess it was commercial, but not too commercial.
michael hart, I have never been to Strangford. As a yottie, I can understand why it has such high speed tidal flows.
The biggest Tidal Range (difference in height between High Tide and Low Tide) is Bay of Fundy, Nova Scotia. After that, it is the Channel Islands and Bristol Channel.
The British Isles have some of the best Tidal Ranges, and Tidal Flows in the world. If they can not be harnessed successfully here, there is little chance elsewhere.
Tide Mills were part of the UK's heritage. Whether used for milling wheat or sawing timber, the operators would have worked around the tides, ie a 23hr day, rather than 9-5. The Tide Mill at Woodbridge, Suffolk, being one of the best survivors. Emsworth Harbour still has a tidal Mill Pond, as do many other harbours and estuaries. Some of these tide mills and ponds date back 500+ years. Interestingly, sea level rise has not overwhelmed any of them.
GC, I learned to respect the power of moving water as a Merchant Navy Deck Officer but spent more time watching tides during 20-odd years rock climbing. I have been caught out by the South West's 9m tidal range more than once, including having to swim out of a cave at Baggy Point whilst trying to push a new route through behind the south facing slabs. I have spent many hours belayed above the River Wye between Chepstow and Tintern, watching the channels, patterns and debris in the silt change from one day to the next; Dealing with the silt and debris would be a task of Augean proportions and I suspect must be a major ongoing cost in any Severn scheme. I don't think large tidal lagoons will ever be built around the UK for ecological reasons anyway, so if tidal has a future it's probably in tidal stream 'farms'.
Gavin, I learned the power and force of water as a child going on canal holidays. Watching the way 70ft steel narrow boats got bobbed and shifted in a lock was educational. At school in the 70s, I learned about Hydro Electric Power and aluminium smelting (?) in Scotland, and why England has no real Hydro.
Work has taken me to river flooding events, and the power of moving water, even if it is only "welly deep".
I have never sailed around the Channel Islands, Severn Estuary, Strangford or the Corryvreckan, but I can understand why the Spanish Armada was destroyed by bad weather, tides and strong currents around waters that to them were uncharted.
The Mediterranean is non-tidal, but many people get into difficulties because they assume there are no currents.
I live not far from Portsmouth, Emsworth/Langstone and Chichester Harbours. The flows in and out are powerful. I have always appreciated that since I started sailing dinghies in the early 70s. Putting a tidal barrage across one of those would be possible, but quite rightly, there would be loads of objections. Similarly, you could dam both ends of the Solent, or why not the Straits of Dover?
It does not matter how big a scheme, it still depends on the moon, and is not maximum power whenever you want.
Even on an isolated small off grid location with huge amounts of sunny weather it is not possible to get by without dependable back up power. Very interesting.
For those interested in the challenges of operating machinery in a marine environment, a merchant vessel requires its tailshaft bearing checked every 2.5 or 5 years dependent upon type.
Turbines operating underwater will have one or two tailshafts (where the propellor/shaft enters the vessel or generator pod), will require lifting out of the water (equivalent to drydocking a vessel) for the bearings / shaft to be stripped and inspected.
If you had an underwater turbine farm, say, of 100 units, it would require one turbine to be floated/inspected every 18 days on the 5 year inspection regime if each turbine had propellor/tailshaft.
Merchant vessels achieve great engineering reliability so I do not currently see a different cost effective way of engineering the tailshaft that minimises this inspection operation.
Leakages of oil from tailshaft bearings are a big no-no in this strict environmental age.
The complete turbine would require engineering so it could be lifted easiliy and quickly which will complicate cabling to/from it.
Data:
Tailshaft with continuous corrosion resistant metallic liner or shaft of corrosion resistant material or shaft with specially approved protection arrangement: 5 years
Tailshaft with continuous corrosion resistant metallic liner or shaft of corrosion resistant material or shaft with specially approved protection arrangement: 5 years
Tailshaft with:
— non-corrosion resistant material without continuous liner subject to seawater
— oil sealing glands approved for less than 5 years survey interval: 2.5 years
From:
https://rules.dnvgl.com/docs/pdf/DNV/rulesship/2003-01/ts701.pdf
and a pic of a tailshaft:
http://marinesurveypractice.blogspot.co.uk/2013/01/surveyor-guide-note-on-tailshaft-survey.html
Having read the 'request for tender' on this solar plant I note:
The new diesel generators are to replace the old Volvo powered units and they are running a 13.2kV grid that is just over 7 miles long.
There are currently 9 main load centers on Ta’u that need to be connected to the Hybrid system. The main loads on Ta’u are the Airport, Medical Clinic, Manu’a High School, Elementary schools, and the Public Works facility.
For those interested in diesel generator costs, The three generators consume about 290 gallons of diesel per day. At $4.20 a gallon, ASPA spends $ 1,218/day to supply diesel for the Ta’u power plant, which operates at 70% of its rated capacity.
One other thing I wonder just how long the solar plant will last or will it be the white elephant like the one in an Indian Solar Village.
Thank you, Ivan. You have just proved me even more right – even righterer! With the cost of this new idea being $6.8million, my figures are even less(erer?), at less than $2.5million, leaving well over $4.3 million that the islanders could well have done something even better(er?) with! I could have taken my cut of $100,000, and the islanders would still be better off! The more this is looked at, the more stupid the entire scheme looks.
ivan & Radical Rodent, it would seem that it would have been cheaper to buy an elderly oil tanker, fill it with diesel, motor it there, drop an anchor, and use the ships engines to drive large generators, connected to the shore with a large extension lead.
It would have cost US Taxpayers less, and Mr Musk and Tesla would not have got a dime.
Green maths only makes sense when Taxpayers foot the bill. Hopefully Trump knows a few accountants who can achieve better value for money, by simply stopping some of these schemes.
Has it escaped golfcharlie's notice that while Musk's PowerWall is priced at $392 per kwh stored, the same lithium batteries are available on E-bay for $45 per kwh?
The backup generators may rust away long before they wear out.
GC Re
I am guesstimating that each 274KW Genset would use 2-3 gallons (10-15 litres) per hour.
Nov 28, 2016 at 4:51 PM | Unregistered Commentergolf charlie
You can about double the KW to get engine horsepower.
Our relatively efficient dozer at 100 hp uses about 2 (IMP) gallons per hour
So more like 11-12 gallons per hour for a gestimate
Something comparable (Wind turbines instead of Solar) has been done on the island El Hierro in Atlantic.
The project was unsuccessful and even wikipedia reports this. They use pumped-storage in a volcano caldera
instead of battery packs. The Diesel Generator at the harbour still runs day and night.
Flag that decorated diesel down.
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Yes Kim, thanks. LOL
Three new 275KW Cummins Diesel Generators has 1,410 kW of Solar panels and 6,000 kWh of battery storage for backup.
Will Judy accept appointment as Deputy Administrator of Untruth in Trump's New Model EPA, or will she defer to noted epistemologist Scottie Nell Hughes ?
https://vvattsupwiththat.blogspot.com/2016/12/whereof-we-do-not-know-thereof-we-now.html
I hope they are tornado and cyclone proof.