What, and suck what little energy they have out?Quote:
Originally Posted by BobL
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What, and suck what little energy they have out?Quote:
Originally Posted by BobL
All-in-one solar tower produces jet fuel from CO2, water and sunlight
Quote:
One hundred and sixty-nine sun-tracking reflector panels, each presenting three square meters (~32 sq ft) of surface area, redirect sunlight into a 16-cm (6.3-in) hole in the solar reactor at the top of the 15-m-tall (49-ft) central tower. This reactor receives an average of about 2,500 suns' worth of energy — about 50 kW of solar thermal power.
This heat is used to drive a two-step thermochemical redox cycle. Water and pure carbon dioxide are fed in to a ceria-based redox reaction, which converts them simultaneously into hydrogen and carbon monoxide, or syngas. Because this is all being done in a single chamber, it's possible to tweak the rates of water and CO2 to live-manage the exact composition of the syngas. This syngas is fed to a Gas-to-Liquid (GtL) unit at the bottom of the tower, which produced a liquid phase containing 16% kerosene and 40% diesel, as well as a wax phase with 7% kerosene and 40% diesel — proving that the ceria-based ceramic solar reactor definitely produced syngas pure enough for conversion into synthetic fuels....
The team says the system's overall efficiency (measured by the energy content of the syngas as a percentage of the total solar energy input) was only around 4% in this implementation, but it sees pathways to getting that up over 20% by recovering and recycling more heat, and altering the structure of the ceria structure. "We are the first to demonstrate the entire thermochemical process chain from water and CO2 to kerosene in a fully-integrated solar tower system," said ETH Professor Aldo Steinfeld, the corresponding author of the research paper. "This solar tower fuel plant was operated with a setup relevant to industrial implementation, setting a technological milestone towards the production of sustainable aviation fuels."
"The solar tower fuel plant described here represents a viable pathway to global-scale implementation of solar fuel production," reads the study.
Meltdown ???Quote:
Originally Posted by BobL
Quote:
Originally Posted by woodPixel
What is the problem? It is the other side of the world, miles away!
I chanced upon this article regarding the possibility of Nukes. Interesting and amusing at times. A no holds barred demolition of the nuclear prospect.
In particular I did take this extract as significant.
"Ziggy Switkowski appeared before O’Brien’s inquiry in 2019 and said there was no coherent business case to finance an Australian nuclear industry before adding: “I have emphasised that one of the things that has changed over the last decade or so is that nuclear power has got more expensive rather than less expensive”.
Regards
Paul
I'm sure there are a couple of companies that get rich every election/government change. There the ones doing the "feasibility studies" for nuclear power and the high speed train on the east coast to melbourne,
You are so right !!Quote:
Originally Posted by havabeer69
But don't forget, each government is looking to appease those inner city voters who think Australia should spend hundreds of billions connecting Brisbane, Sydney, Canberra, Melbourne with high speed rail -- because we're a wealthy country so should have HSR.
And those RARA voters who want the regional population boost that a HSR project might deliver.
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.
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RARA = Rural And Regional Areas
Electrify 2515 plan to adopt renewable energy, EV car lease in Illawarra suburb - ABC News
A micro grid which is the way I think things will go. I helped my dad build a house at Bawley Point and I regret the day he sold it. Post code 2515 is right next to us and I missed out there as well.
One of the disadvantages of Nuclear power was always the threat of damage by terrorists or other malcontents shouls a reactor be targeted. I had not really considered war as a potential problem before, but the Russia/Ukraine conflict has highlighted a new level of exposure.
This article identifies the breakdown of proceedural safety at the Zaporizhzhia Ukranian plant.
Rising threat of nuclear disaster at Europe's largest power plant (thenewdaily.com.au)
It is the largest in Europe at a nominal capacity of 5700MW (6 X 950MW units) and in more peaceful times supplies a fifth of Ukraine's power. It is occupied by Russia, operated by the Ukrainians and arguably may be used as a "shield." Nukes have extreme safety measure to virtually eliminate the risk of a core meltdown, but a stray shell knocking the cooling system or at least part of it could be catastrophic.
I believe two of the six units have already been shut down.
Regards
Paul
Only two units currently operational with no explanations.Quote:
Originally Posted by Bushmiller
As demonstrated at Fukushima.Quote:
Originally Posted by Bushmiller
In that case it was a stray tsunami, well an underestimated probability of a tsunami of that magnitude (9 Mw) and a seawall that was built too low for the resulting tsunmai with a wave that was up to 40m above sea level, which knocked out its cooling plant.
That makes renewables seem very cheap!
The proposition of nuclear electricity for Australia is a complete non-starter, and Voldemort knows it. He also knows that they will be condemned to likely 6 or more years of Opposition, which means that he can say or propose what he likes in these early days of Opposition and it'll be forgotten. It seems to be a last gasp at keeping the climate wars going and paying some sort of homage to previous leaders. Somewhere in this thread the lead time for nuclear power has been mentioned, and around 20 years comes to mind – maybe a little less.
Apart from the fact that we just don't have that long to sort out our power woes, renewable power will be ready at proper large scale way before that. That's before we even get to the frightening cost of setting up nuclear power, and that's before we get to the enormous political difficulties of convincing the public that it's a good idea. Then we have to find Federal members who are keen to have a Nuke plant in their electorate.....:no:
Me either. I used to be a complete NIMBY on nuclear power, but now I am also a NIYBE - Not in Your Backyard Either.Quote:
Originally Posted by Bushmiller
A single rocket or smart bomb - all conventional - hitting a reactor could be as effective as a nuclear weapon. But if you closed down the reactor due to imminent threats, then you would still have to store the uranium rods. Guess that rocket hitting the nuclear fuel storage site would be just as effective?
Thanks Woody, quite interesting.
PHOTO VOLTAIC Farms or Rooftop are certainly getting cheaper, but battery storage is still rather expensive, and their are those old fossils like me who like to turn on their lights when it is dark.
GEOTHERMAL. Have a friend who did a PhD on geothermal electricity at MIT in the early 1980's, and then worked as a consulting engineer until he retired before lockdown. It is a fascinating subject:
- The centre of the earth is molten rock - it is hot,
- Drill a hole anywhere and it will eventually get hot, very hot, the heat is near the surface in places like New Zealand and Iceland and much deeper in places like Australia, but it varies,
- Drill a hole into a heat source, pump cold water down and suck hot water or steam out, simple,
- Run the output through a heat pump to concentrate the heat,
- Use it to run a "conventional" power station.
The problems are mainly metalurgical. The solvents coming out of the well, at heat, will usually attack all/most metal fittings and corrode them. And the solvents keep changing; appparently the chemistry is extremely complex and research is ongoing. With shallow wells, the solution to corrosion is simply to monitor and replace the metal work frequently. With deeper wells this is very expensive so they are still researching better metals - but the solvents are not consistent. He still thinks that geothermal will eventually be the major energy source, but not in our lifetime. Forty years ago he thought he would be involved in the transformation.
That graph also shows that of the methods that rose in minimum price to sell, Nuclear was the runaway, at 33% increase. Next closest in rising was GeoThermal at 5% increase.
WPQuote:
Originally Posted by woodPixel
Those are interesting statistics, but I am not sure where they relate to and is it a wholesale price or a retail price? An average for world wide perhaps, but not Australia. For example, the average wholesale price for power stations in 2009 would have been $30 to $40 from memory. Coal would have been generating all the time with the other sources of power only when the price was high or they were absent.
Regards
Paul
GraemeQuote:
Originally Posted by GraemeCook
You are on the money (not an intentional pun) with the cost of storage. I believe we have reached saturation point with solar and wind until we talk of storage (battery, pumped hydro or anything else) in the same breath. I am not sure what is considered a deep well, but those that were bandied around in recent times in Australia were around four kilometers deep. I can imagine that there are technical issues associated with that depth.
As for converting existing coal fired stations as in point No.5, while I would like to believe that is possible, I am a little sceptical. Firstly the geothermal well would have to be located adjacent to the station. Secondly the heat generated may only be sufficient to produce low pressure steam at comparatively low temperature. The HRSG on the back end of a gas turbine utilises this technology. Steam in modern coal fired power stations is at a temperature of around 550°C and a pressure of 15,800KPa in drum boilers and 24,000KPa in supercritical boilers. The reheat steam, which is the exhaust gas from the HP cyclinder used in the IP and LP cylinders after first being returned to the boiler, in both types will be closer to 590°C. Geothermal steam just would not be able to deliver this.
Regards
Paul
I agree Paul, and for me the research $$ need to go into batteries (not that pumped hydro et al are unimportant). Batteries are in everything these days – the ubiquitous 18650 rechargeable cell is in Power Walls, cars, lamps, torches, tools etc etc etc. The more efficient that particular storage is, the better, and the easier it is to swap out a dud cell the better. Don't change the form factor, just improve the storage capacity and/or recharge time, then we can continue to use them in the same appliances.Quote:
Originally Posted by Bushmiller
As a side note, NCArcher has just checked 18 of my 18650 cells from two tool batteries which had refused to recharge (one with 15 cells, the other with 3), and only 3/18 were duds, meaning I have 15 spares to replace other duds as they come up. Makita and DeWalt would, of course, prefer me to just dump the two entire battery packs and unnecessarily buy new ones from them. The problem with that is the replacement cells need to be mini-welded into the "grid" which requires expertise and specialised equipment (both of which he has), when the process really needs to be as easy as it is to change AA batteries in any given appliance. One has to wonder how many millions of still-usable cells have been binned because just one cell stops the battery grid from recharging.
That was the point, I think, Paul. The depth of the hot rocks varied all over the world - from quite shallow on the Ring of Fire to very deep in geologically mature places like Australia, but even there there were variances. eg A "hot rock" zone was found in the vicinity of St Helens, NE Tasmania, at a depth of 800 - 1,000 feet. Those problems existed in wells at any depth, but it was easier to deal with them in the shallower wells. Plus costs, of course.Quote:
Originally Posted by Bushmiller
Sloppy wording by me, Paul. Power station would, of course, be a new one located on top of the geothermal field. Steam created would be used to power an existing type of conventional steam turbine. I am an economist, not an engineer, so on this I am strictly big picture and non-technical. It sounded like an "interesting project in the pipeline", but it has not arrived yet, except for some particularly favourable sites such as NZ and Iceland.Quote:
... As for converting existing coal fired stations as in point No.5, while I would like to believe that is possible, I am a little sceptical. ...
GraemeQuote:
Originally Posted by GraemeCook
The New Zealand sites are perhaps the most commonly known, although I think Italy and at least one other place has had self sustaining sites for some while. One issue is that the heat diminishes after a period of time. However, with geothermal power I am a little out of my depth ( :rolleyes: ) as it is not my area.
I realised after I had posted that you could be referring to new "conventional" power stations to take advantage of geothermal heat. I believe the temperatures are rarely above 180°C so it would certainly be low pressure. The other issue is that I have read the efficiency is low at 10% - 16% so I don't know how that would stack up against other forms of renewable power.
Regards
Paul
My brother-in-law was the consulting geophysicist (geologist-physicist) on the early hot-dry-rocks trials here in SA over twenty years ago. The primary motive behind those trials was the remote location away from any grid source of power.Quote:
Originally Posted by GraemeCook
As I understand it, two adjacent bores were drilled and cold water was pumped down the bores with the intent of the hot rock between the two bores fracturing to allow a flow between them so a circuit could be formed; colder water down one and heated water up the other.
The trials failed for one reason and another, not least a failure to create enough fractures between the base of the two bores to get the necessary water flow, if I remember that correctly. The cost of boring to the required depths is significant and perhaps recouped over time if it was always successful. However, putting aside any ongoing maintenance costs of successful bores, with an unpredictable failure rate at the depths required in our old geological zones this form of geothermal power generation may never be economically viable in those areas.
I expect with the dropping cost of solar, wind and storage (or combinations of those) over the last two decades would make those options far more favourable now for very remote locations.
PS - I enjoyed a dip in the artesian thermal springs at Moree a few years back. Good enough for a warm bathe, but not hot enough keep any lights going...:)
Neil
Thanks for the additional perspective on geothermal. As I said before, it is not my area.
Regards
Paul
Just been trying to think through a risk assessment for storage of electricity from solar and wind sources.
Best available is hydro which can ramp up and ramp down very quickly with variances in the wind and sun light. But this is very limited because you need the right topography for a hydro dam.
Otherwise you essentially have three options:
- Battery storage,
- Pumped hydro, and
- Exotics - hot sand storage, etc.
Battery storage is not yet cost effective, except in off-grid areas, so any analysis might conclude: "Good idea, but not yet - WAIT and monitor battery prices."
Pumped hydro has a very long lead time - 10 years ? from go decision to build dam and commission it. Risk is that within that period battery prices could plummet, either new technology or cheaper manufacturing - and the project could be superceded before it is completed. So any analysis might conclude: "Good idea, but not yet - WAIT and monitor battery prices."
Exotics - nothing is really out of the laboratory yet, but there can always be surprises.
As Malcolm said: "Life was not meant to be easy."
The three best things in life are a beer before and a dip in the hot springs after.:DQuote:
Originally Posted by NeilS
GraemeQuote:
Originally Posted by GraemeCook
Storage of electricity is the single most important aspect of power generation at the moment. It has easily, to my mind, surpassed the various renewable methods of generating: Solar, wind and all the others are almost old hat being able to be conceived, approved and commissioned in a very short space of time compared to almost anything else. I agree with your sumation of the storage state of play, but I would add hydrgen storage to that mix. It is a type of storage that both lends itself to renewable generation and can potentially be utilised in transport. I think more effort should be directed to the development of H2
On Malcolm's "Life was not meant to be easy" quote, while it often seems he was fundamentally right, he did plagiarise and slightly take the quote out of context from George Bernard Shaw who was the originator. I'm not sure when he said it, but Shaw died in 1950 so quite a long time before Malcolm re-gurgitated it in 1971.
The full quote is: "Life is not meant to be easy my child; but take courage: It can be delightful."
I wonder if Malcolm had a premonition about climate change. :)
Regards
Paul
Thanks, Paul, I think I now prefer Bernard Shaw's version.
I am a little more cautious on Hydrogen - possible, but not yet. Still major cost and safety hurdles to overcome.
Hydrogen has been used for 50+ years for underwater welding - just check the price of a cylinder of hydrogen vs acetylene, and you will know what sticker shock means.
Somewhere (maybe this thread) there was talk of Compressed Air storage as a battery. I'm reading efficiency rates of between 70-85% which sounds pretty good. That's comparable with Pumped Hydro isn't it?
Here's a search – take your pick of articles. CA is the preferred option for Broken Hill, as of May 2022.
Yes, CAES... I've been pumping it hard :) Nobody wants to listen. :)Quote:
Originally Posted by FenceFurniture
Its FANTASTIC. I've two investments in Ireland and Scotland, both are going gangbusters.
There are so many advantages to CAES it isn't funny.
We may need too think off others as well.
https://uploads.tapatalk-cdn.com/202...fc5250ed0a.jpg
Cheers Matt.
MattQuote:
Originally Posted by Simplicity
Hence the phrase, "Left hanging!"
Regards
Paul
Did something happen in the generation market today, around 11.30? Prices went wild, then settled again by about 1.00
Something big went offline?
Update
This advice from my retailer.. Attachment 515438
RussQuote:
Originally Posted by russ57
I wasn't on shift at that time as I am on one of my long breaks, but as far as I can make out there was an exceptional excursion in the FCAS market ( Frequency Control Ancillary Services What is Frequency Control Ancillary Services? - Australian Renewable Energy Agency (arena.gov.au)), which is another commercial feature that receivies payment separately to MWs. A brief view looks as though it was costing some generators a lot of money, as in millions of dollars an hour, and they reduced their available capacity in a vain attempt to mitigate their loses. In turn this may have been responsible for a power shortage and a consequent high spot price.
Your retailler must purchase primarily on the spot market and are not hedged against sprice spikes with contracts. I don't pretend to understand the exact sequence of events that led to this, but I have never heard of it before: Just another anomally in this tumultuous times!
Regards
Paul
It seems the Federal government are getting behind wind:
Wind turbines almost twice size of the Sydney Harbour Bridge to be built off coast of Australia (msn.com)
No problem with that, but where are they going to store it? Without a storage facility, the daytime price will be cheaper and the night price more expensive with the "night period" effectively being about three times as long.
In the late 90s ahead of the competitive market the cry was "Price, Price and Price." Today we should be substituting "Storage, Storage and Storage."
Regards
Paul
Advice from supplier is that there was an error caused by aemo, and the price is now retrospectively corrected.
My supplier amber passes on the wholesale /spot price, with an annual cap equal to the default offer.
Until April this year it was working really well for me. Not so good after then but prices are slowly looking more normal.
A battery lets me avoid the spikes.
Regards
Russell
Thanks PaulQuote:
Originally Posted by Bushmiller
With regard to delivery efficiency, much has been said about the inability of the newish remote solar and wind farms to deliver electricity efficiently. I stumbled upon this interesting paragraph when looking at HWS replacement and their inherent efficiency in the scheme of things.
For what it's worth, we replaced our gas HWS with a heat pump unit manufactured in Japan, with the water container itself manufactured in the adjoining suburb. In fact, one of my brothers works there. Before you ask, I didn't get mates rates or anything like that.
This is the second last paragraph on page two of this 2010 report.
"Electricity is considered a high-grade energy source because its generation from fossil fuels for example, is usually accomplished at an efficiency of around 30%; it gets then transmitted and distributed at a further 80% to reach end-users at a final efficiency of 30x 80 % = 24 %. Transforming electricity back into heat, at an efficiency around 50 %,makes the final transforming efficiency from heat back into heat of 24 x 50 % = 12 %.Hence, it seems reasonable to consistently engage photovoltaic systems with solar water heaters capable to supply thermal demands, in order to make sure photovoltaic electricity is being used specifically for electrical loads"
The whole of the report can be seen here:
https://eprints.usq.edu.au/8937/1/Ka...lar2010_AV.pdf
This is a further couple of paragraphs, which from a home solar powered HWS make for interesting reading.
"While grid-connected photovoltaic systems provide the ability of feeding end-users and the electrical network with solar electricity, solar water heaters provide the ability of supplying and storing thermal energy for heating and cooling purposes, otherwise produced by electricity.
Although electricity is being typically used at present for heating water during low demand periods (at night), when electricity tariffs are low, solar water heaters are offering waiving considerable part of that demand at improved efficiencies and less environmental impact. The electrical capacity relieved could be directed to supply present peak demands at improved utilization factors, reduced energy prices and enhanced reliability."
Mick.
Thanks Mick
That is all a bit demoralising. However in recent times I have become suspicious of statements that sound just a little too good or a little too bad and what aroused my suspicion this time is that although they quote a diaboloical end user efficiency, they did not seem to mention the efficiency of the panels . This leads the reader to jump to the conclusion that solar is much more efficient: It may be more efficient, but I went looking. Back in 2010 panel would have had an efficiency between 15% and 20%. Today, with improvements in technology, it could be better than 25%. This is still a worthwhile improvement on thermal generated electricity but not quite as good as the article led us to believe.
Also modern fossil fired stations since 2000 would have an efficiency of around 38%. It is only the old fossils that were back at 30%. Also that solar efficiency is under ideal conditions of sunlight, panel angle and material quality: Not all installations will meet that requirement. Some more information here:
Most Efficient Solar Panels: Solar Panel Efficiency Explained | EnergySage
Having said all that, we put in a conventional water heater quite a few years back and I kicked myself after for not going with a solar unit. What was I thinking? I wasn't . :(
Regards
Paul
Here is a bit of skookum for you.
This bad girl (Christine) is the steam turbine of France's newest nuclear reactor.
70 meters long and it can produce enough electricity to power all of Paris - 1650MW
Attachment 515514
I too installed a heat pump HWS recently reasoning that it will draw from out solar panels during the day and be switched of at night. I have changed my thinking about solar this year, don't export it, use it all and if you can't use it all the system is too big. As an aside this is the 2nd heat pump we have had, we did have a Siddons many years ago, they were the original developers of the technology but these new ones are far better.
Back in the seventies we lived in an employer supplied house that had solar thermal water heaters on the roof - Rheem, I think. We thought they were the beeze knees, but about 15-20% of my colleagues hated them - they regularly ran out of hot water. The "solution" was to add electrical resistance coils to the storage tanks. Fairly cheap solution, and it worked, but electrical usage went through the roof.Quote:
Originally Posted by Bushmiller
The engineers were all "too busy" to work out the problem so it was passed onto muggins, the economist.
At first I was baffled. But the answer was surprisingly simple. During the day the sun shined and heated the water to a maximum just before sun set, then the storage tank cooled slowly overnight but generally still very warm to a minimum just after dawn, then the sun rose and the cycle repeated. Now, the bathroom is the biggest user of hot water in most homes and most people shower just before going to bed or when getting up. In a larger household this could cool the storage tank sufficiently to trigger the thermostat on the electric heater and the tank would get heated immediately. The solution for "problem" houses was to remove the electrical booster, to put in a third roof top panel and a larger storage tank and to add more insulation around all tanks. [Remember, we are talking 1970's technology and smart meters were not available.]