Tangential to our main discussion, but in the interests of energy efficiency, this is a fascinating 12 minute vid on toroidal propellers:
https://www.youtube.com/watch?v=UzYHO4tksTc
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Tangential to our main discussion, but in the interests of energy efficiency, this is a fascinating 12 minute vid on toroidal propellers:
https://www.youtube.com/watch?v=UzYHO4tksTc
From the same guy, and back on topic, Salt Batteries:
https://www.youtube.com/watch?v=vm2hNNA4lvM
I was very suspicious when I saw the title of the video, so I went back to the source documentation. "Suspicious" is a polite word for the excretia of the species bovine. Or yet more of the Popular Science type crap.Quote:
Originally Posted by FenceFurniture
Now, I have been playing around with boats for 70 years, and am well aware of developments of various propolsion - conventional props, duo props, surface piercing props, water jets - all are optimal within specific operating ranges. Toroidal props have been around for over 100 years, but have never made an impression. Allegedly they are significantly quieter than other props, not as efficient, hyper sensitive to alignment issues including minor dings, marine growth and slime, and extremely expensive to machine. Realistically, with more research effort, one would expect incremental improvements in efficiency, not a massive 105%.
So I went back to the MIT source - and MIT is a very credible university. Their summary:
- Tests of prototype toroidal propellers on commercial quadcopters demonstrated thrust levels comparable to those of conventional propellers at similar power levels. Reduced sound levels allowed toroidal-propeller-equipped drones to operate without taxing human hearing at a distance half that of typical operation.
https://www.google.com/url?sa=t&rct=...SsUCYHGDX9BGPX
Quieter.
Comparable power.
No mention of 105%. Very cautious tone.
Oh well, at least they are quieter.
Been away for a bit and it all became vigorous!
On the Salgenx - its all basically renders, a few engineering-looking schematics and not one single installation. Ive emailed "Greg" and its not investable.
BUT the ESS inc is investable. If you want a YOLO that will either crater or go ballistic, ESS looks great. They have an actual product that ships, with real customers and an actual plan. The things can scale up the wazoo as well. Thats good.
These remind me very strongly of the Iron-Flow Rusty batteries. I'm feeling very ... positive.. about those. :D
Big heavy brutes and totally useless for transport, but for mega-bulk storage they will win. They are fabulous solutions (oh, the puns!)
On the toroidal props for drones. They are SILENT. Not "quiet" or some other term, but silent. They could fly by your head and one would feel the breeze first.
I'll find the video. See this video Amazing Invention- This Drone Will Change Everything - YouTube at the 13'50" section. It goes for about 2 minutes.
Maybe someone else is doing better research than MIT, but the MIT report definitely said "Reduced sound levels allowed toroidal-propeller-equipped drones to operate without taxing human hearing at a distance half that of typical operation...." No mention or inference of silent or SILENT - (should one shout silently?)Quote:
Originally Posted by woodPixel
My wife manages to do it when im trying to sleep after night shift and shes trying to tell the kids to "shut up your fathers sleeping"Quote:
Originally Posted by GraemeCook
My wife never quite mastered that technique. Fortunately, at some point the children left home and that was no longer an issue. :)Quote:
Originally Posted by havabeer69
Regards
Paul
I saw this for QLD:
I am sure that the media would make much of the maximum price yesterday ($14,930) , which is close to the maximum Voll (stands for "value of lost load"), which I think is $15,100, but note that the average price still remained similar to the previous days. I was not at work so I don't know what caused the price spike. Typically it would be a unit tripping at a time of high demand.
Attachment 526047
The last entry is of course a projected figure for today.
Regards
Paul
The Tasmanian pricing remains a mystery:
You can see the live data here:
AEMO | NEM data dashboard
This links to Tassie but you can click on any State. This is a quick snapshot outlining Graeme's comment a few posts earlier:
Attachment 526048
Low prices at periods of high demand (0600 and 1800hrs) are the opposite of what we would expect. At this stage Tasmania has no pumped hydro, although feasibility studies are being conducted on 14 sites I read.
Regards
Paul
Sure is a mystery, Paul. But whatever is happening, it has been incorporated into AEMO's price projection algorithm - see red arrow inserted into your graph. Someone or something is manipulating the market. The big questions are - who and why?Quote:
Originally Posted by Bushmiller
Graeme
I had seen the prediction. Even more weird! I am looking into it.
Regards
Paul
Some interesting news today.
Photoelectrochemical CO2-to-fuel conversion with simultaneous plastic reforming | Nature Synthesis
Quote:
Researchers have developed a solar-powered technology that converts carbon dioxide and water into liquid fuels that can be added directly to a car’s engine as drop-in fuel.
The researchers, from the University of Cambridge, harnessed the power of photosynthesis to convert CO2, water and sunlight into multicarbon fuels – ethanol and propanol – in a single step. These fuels have a high energy density and can be easily stored or transported.
Unlike fossil fuels, these solar fuels produce net zero carbon emissions and completely renewable, and unlike most bioethanol, they do not divert any agricultural land away from food production.
While the technology is still at laboratory scale, the researchers say their ‘artificial leaves’ are an important step in the transition away from a fossil fuel-based economy. The results are reported in the journal Nature Energy.
Bioethanol is touted as a cleaner alternative to petrol, since it is made from plants instead of fossil fuels. Most cars and trucks on the road today run on petrol containing up to 10% ethanol (E10 fuel). The United States is the world’s largest bioethanol producer: according to the U.S. Department of Agriculture, almost 45% of all corn grown in the US is used for ethanol production.
“Biofuels like ethanol are a controversial technology, not least because they take up agricultural land that could be used to grow food instead,” said Professor Erwin Reisner, who led the research.
For several years, Reisner’s research group, based in the Yusuf Hamied Department of Chemistry, has been developing sustainable, zero-carbon fuels inspired by photosynthesis – the process by which plants convert sunlight into food – using artificial leaves.
To date, these artificial leaves have only been able to make simple chemicals, such as syngas, a mixture of hydrogen and carbon monoxide that is used to produce fuels, pharmaceuticals, plastics and fertilisers. But to make the technology more practical, it would need to be able to produce more complex chemicals directly in a single solar-powered step.
Now, the artificial leaf can directly produce clean ethanol and propanol without the need for the intermediary step of producing syngas.
That sounds pretty good.Quote:
Originally Posted by woodPixel
One can also drink ethanol of course, provided it has been suitably diluted with juice of grape or Hop & Barley matter. Matter of fact, I'm consuming some right now. :;
I hear that the truly dedicated only drink it after filtering through a loaf of bread, and from a bottle wrapped in brown paper.
Quote:
Originally Posted by FenceFurniture
??? You don't like vodka?
Graeme, you are very welcome to filter your ethanol through a potato if you wish. :tequila:Quote:
Originally Posted by GraemeCook
I prefer the loaf of bread filter myself (strictly wholemeal of course)
Quote:
Originally Posted by FenceFurniture
I was thinking more in terms of extracting the ethanol from the potato, FF.
:tequila: :tequila: :tequila: :tequila:
:2tsup:
well here's another one
Scientists Devise A Way To Harvest Energy Out Of Thin Air And It Changes Everything | HotHardware
some of the quotes are from a graduate student so I guess take it with a grain of salt.Quote:
"The air contains an enormous amount of electricity," explained Jun Yao, assistant professor of electrical and computer engineering in the College of Engineering at UMass, and the paper's senior author. "Think of a cloud, which is nothing more than a mass of water droplets. Each of these droplets contains a charge, and when conditions are right, the cloud can produce a lightning bolt, but we don't know how to reliably capture electricity from lightning." He continued, "What we've done is to create a human-built, small-scale cloud that produces electricity for us predictably and continuously so that we can harvest it."
HAB
Harvesting lightning bolts etc. seems a little ambitious, but it does bring to mind some phrases from my early NSW power station days. I am sure you will be familiar with, but for those outside the industry, but nevertheless very interested:
"One flash and you're ash."
"One zap and you're crap."
Regards
Paul
A little bit small (euphemism) but interesting:
Australia's first commercial vanadium-flow battery storage completed in South Australia (msn.com)
It appears to have some benefits over Lithium-Ion including recycling, longevity and inflammability. It is however unsuitable for mobile applications.
Regards
Paul
Not a glowing report this one:
GOT GAS? Putting the pin into that Victorian coal to hydrogen plan (msn.com)
Unless renewable energy is used to create the carbon capture, more CO2 enters the atmosphere from the process and it would be better to just generate power from the gas (or coal) itself. This is quite apart from the issue should the CO2 not remain captured! There are projects around to prove CCS can be done, but clearly the integrity of the CCS is lacking for the moment.
Regards
Paul
China is really getting into it: China on course to hit wind and solar power target five years ahead of time | China | The Guardian
Imagine what we could do....
Attachment 527874
One of the big complaints of batteries is regarding the waste at the end of their life. I have previously in BobL's EV thread, mentioned how far ahead Norway is of the rest of the world. It would appear from this article that these dead batteries are not the final destination after all:
Norway's quest for 'black gold' from used car batteries (msn.com)
Regards
Paul
Norway have the economies of scale to introduce recycling but until counties reach a similar level level of BEV use other ways are most probably the best approach such as re-use of batteries not good enough for cars and apparently using them as grid storage is a good approach. The installation can be made larger as more batteries become available but eventually of course even those need to be recycled and that will happen as the need grows due to more cars on the road.
Australia most probably has not enough used batteries or so you would think but Toyota along with Nissan have been replacing batteries in cars for the best part of a decade and I wonder where all those have disappeared to. I mentioned in a post to Bob's thread that I was aware of a BYD with less than a 1000km on it being written off and I doubt that there is any sort of formal structure in Oz to deal with cars such as that so that the battery is recovered.
The big reuse: 25 MWh of ex-car batteries go on the grid in California | Ars Technica
https://www.youtube.com/watch?v=JqlOlqK_ot8&ab_channel=CanaryMedia
Thanks, PaulQuote:
Originally Posted by Bushmiller
When looking at electrical vehicles we have to be careful not to lose track of how profound the revolution will be. When IC cars became available 120 years ago, we essentially cloded a serie of industries - buggy whip makers, chaff producers, wheelwrights, stage coaches, etc - and replaced them with a series of new industries - car makers, repairers, servicers, fuel, etc. Not better, not worse, just different. (Remember, cars were greeted as non-poluting as they did not on the roads like horses!) Perspectives change.
But that Norwegian plant is a good start, but it is still only a pilot plant. "The Fredrikstad plant is a pilot project ... " Your reference. We still need the refineries to convert the "black gold" into the recoverable metals, and at an economic price. It takes time to create a new industry, and there will be false steps.
GraemeQuote:
Originally Posted by GraemeCook
That is a very good point. Also, pilot plants are sometimes built to prove that the technology is feasible: Not necessarily to prove they are economically viable!
Regards
Paul
At a time when the cost of electricity is rising by 20% or so (in NSW), I am intrigued by a conversation I had with a PV installer just a couple of weeks ago.
In addition to designing and installing PV, he is/was also involved with teaching PV and "eco energy" stuff to TAFE and high school students. He told me about a time he took a bunch of students on a tour of a local wind farm, and on an amply windy day the students noted that many of the turbines weren't generating any significant power. Whilst in the control room, one of the students asked a worker why this was the case. The worker answered that the price of power was low, so they had reduced their output "until the price goes back up". The student was bright enough to realise that given the wind is "free", this was a case of deliberately creating (or helping to create) a shortage in order to drive prices up. Apparently the faces of the students, many of whom were very keen on "saving the planet", dropped on the spot, and he could almost hear their beliefs in the publicised drivers for "green energy" come crashing down......
Speaking of electricity prices going up, I just snipped this little table out of the notification I just received in an Email from my provider:Quote:
Originally Posted by Warb
Attachment 528014
That's as close to a 50% increase that it makes little difference. Then there will be gas increase on top of that.
Doug
The wholesale price of electricity has increased a lot. I just looked up the average price for the year so far and it translates to 11.5 cents per KWhr. That is for QLD, but the other states will be in a similar ballpark. I am not surprised electricity bills are destined to increase. I am led to believe that some are even worse than your 50%. However, none of that makes the increase any easier to bear.
Those of us that have solar panels on the roof will be wondering why we are only getting paid miniscule amounts for feeding surplus power into the grid. I am not in that position so I don't know the figures, but I hear stories of 5c and less. Perhaps somebody can verify that for me.
If that is the case, it is probably time to consider a storage battery to supplement the solar panels. Put all the surplus power into the battery and use that at night. Night time wholesale prices, because they include both the morning and evening peaks, probably average 15c to 20c. By the time the power gets to the consumer the KWhr rate could be 40c. I don't know exactly what these prices are as I am only outlining a principle. I am pointing out that the nature of power generation has turned completely on its electrical head. Go back a few years and power was cheap at nightand expensive during the day. In the current climate it is the complete opposite.
Regards
Paul
The wholesale price of electricity has indeed increased, but if my PV installers story is true (and I have no reason to doubt him) then this is at least partially down to manipulation of supply and demand. It is my understanding that coal fired power stations are unable to rapidly vary their outputs, which is why in the old environment we had coal fired "base load" generation, with gas fired generators able to quickly ramp up and down to service shortfalls or oversupply. If the new generators, solar and wind, can switch on and off at will, and without cost to themselves (no wasted fuel!) then surely we must expect them (if un-monitored and unregulated) to deliberately create shortfalls in order to increase the price? Their profit will be higher if they ensure that prices are high!!Quote:
Originally Posted by Bushmiller
PV feed in payment for domestic systems is indeed very low. Before I retired last year, my farm had about 40kW of solar to run irrigation pumps, but which fed the grid when the pumps were off (most of the time for the last few years!). We got 6c/kWh, much of which the power companies clawed back through huge rises in the daily charge.
My new property has 5kW of grid interactive PV, and I'm adding a further 20kW on my new shed. Sadly it has only a tiny single phase transformer, so I'm limited to a 4kW feed to the grid. As a result, I'm also installing a 9.6kWh battery. I very much doubt that the feed-in tariff will cover the daily charge, but the system should hopefully provide the majority of my power, though not the induction cooktop in the winter!
Batteries present a bit of a conundrum for those of us who have a limited time in their home because of age and won't see the investment in batteries pay off and they are the people who really need them to lower the electricity costs. The other factor for the retirees is that they are home during the day and use more electricity warming and cooling their homes.
I'm not sure, given the cost of batteries, that they will pay off their investment for anyone. A (admittedly somewhat biased) study in the US suggested that the pay-off time for a Tesla battery was somewhere near 40 years, and Tesla only warranty their Powerwall 2 batteries (70% of initial rating) for 10 years. Tesla argued with the study, but if I remember correctly they could still only get the payoff time down to 20 something years... if the battery lasts that long!Quote:
Originally Posted by Chris Parks
In any case, the power companies are trying to recoup their "losses" to domestic PV by hiking up the daily charges. A while back there was a call to specifically increase the daily charge to those with PV, and whilst I believe that call was dropped it is only a matter of time, I suspect! The daily charge for everyone is increasing constantly, although apart from an enormous growth in "fat" (it now takes 6 vehicles, 12 men and several visits to achieve what two guys in a ute took 10 minutes to do 15 years ago) I can't really see why.....
its not the feed in tariff that should save you money... its the fact you shouldn't have an electricity bill at all.Quote:
Originally Posted by Warb
if you take doug3030's example above
if you can wipe off a $2000 electricity bill a year and a battery + panel setup is something like $15000, that's 7 years for it to pay off (assuming power prices don't increase in that time again which means its even cheap) and the rest is cream.
Sadly that isn't the case. The standing charge is about $2 per day, so at 5c/kWh for solar feed-in you need to feed in 40kWh just to cover the daily charge. With a feed in limit of 4kW, that's 10 hours of 4kW each and every day, which may be "easy" on a bright summer day, but not so much in the winter. The PV enthusiasts (and don't get me wrong, I'm one of them) will tell you that even in winter the PV system generates lots of power. That's true, except that most of that power is around mid-day, which doesn't help if you need 10 hours! The drop off in production caused by shortened hours of daylight is very real, and "lots at lunchtime" is no help if you can only feed 4kW. Equally, even for self-consumption, having lots of power at lunchtime doesn't help cook the dinner when it goes dark!Quote:
Originally Posted by havabeer69
So you get a battery. At this point the cost of the installation goes up massively. A Powerwall (no panels or inverter) costs over $15k installed (estimates vary up to $17k). That allows you to shunt power to later in the day when the light starts to fade, but with limitations. Apart from the obvious (13kWh limit), the maximum continuous output is 5kW. Having ditched the gas hob, you realise that an induction hob uses 2 to 4kW per ring/zone. So when you boil a pan of water for pasta and fry some onions for sauce, the battery can't keep up and you're using power from the grid. Then put the kettle on (2kW?) and your meter is spinning wildly. Your limited 4kW feed-in is hardly covering the daily charge, so your bill is now increasing further. You still haven't any heating, or general "through the night" usage. The result is that in winter you still will have a bill, possibly quite substantial, unless you have sufficient panels and batteries to cover 100% of your usage and also guarantee that 10 hours of 4kW feed to cover your daily charge (which is absolutely certain to increase with time!).
Now of course this doesn't apply to everyone. My previous property had two large 3 phase transformers, one with a 10kw (the standard at the time) feed in limit, and the other with quite possibly no limit at all (the transformer was huge, and I was the only connection). We could feed so much during the day that all our charges (usage and standing) were covered. But not anymore, without a vast array and several batteries.
The fact is that you need to do a lot of homework to make sure you know what you will get! I have people local to me who were told "you won't have a bill" and in fact their bill is not that much less than before installing PV, entirely due to usage patterns and low feed-in tariffs. And that's before rainy days like today when the panels do nothing......
doesn't the inverter use the solar first and export the rest?
so if you have a 20Kw system, and you're using 15Kw during the day doing the laundry etc etc, aren't you only exporting 5Kw? so you only earn feed tariff in on the 5Kw but you're not drawing in any power off the grid because its being provided by the first 15Kw from your panels? so your net bill is 0kw + 5kw of export?
Correct. I have dual qualifications in economics and accountancy and a lot of experience doing fairly sophisticated cost-benefit analyses.Quote:
Originally Posted by Warb
Two friends installed Tesla Powerwalls last calendar year and I reviewed their cost effectiveness early this year, based on the following parameters:
- Installed costs of Powerwall - $13,200 and $13,400.
- Storage capacity - 13.1 kWh (as per warranty).
- Capacity after 10 years - 9.2 kWh (70%).
- Electricity cost - 26 cents per kWh.
- Zero maintenance costs and zero downtime.
Very Rosy Glasses - Pay back period = 15 years. Assumes that the solar panels charge the batteries to 100% each and every day and that you use 100% of that power each and every night. Totally unrealistic - cloudy days, days when you do not use the aircon, etc, and when you are away on holidays.
Rosy Glasses - PBP = 20 years. Assume that the solar averages an 80% charge each day and that you use 80% of of available capacity on average each day. [A little less unrealistic]
Realistic - PBP = 30 years. Allows uniform depreciation in capacity to 70% after 10 years and continuing decline.
Real World - PBP = 40 years. Includes cost of finance. The opportunity cost of the money invested in the Powerwall - it could have been invested elsewhere.
Solar Costs - The study assumed that the cost of solar electricity was zero - totally unrealistic as there are capital costs and maintenance costs.
Electricity Price Rises - The study was done without considering future electricity price rises. If the price doubles from 26 cents used to 52 cents per kWh then the above PBP's would be effectively halved. In my real world scenario the PBP would be 20 years. Will a powerwall or me last 20 years? How many batteries are 20 years old?
Going Off Grid - I am a low electricity user averaging 11 kWh per day, but I suspect that I use 20 kWh on a high use day. Clearly the 13.1 kWh capacity is insufficient for me for one day - two needed. But we might have prolonged cloudy days so I would need more capacity - six Powerwalls for three days capacity? One of my friends above averages 21 kWh per day. If he has high use days around 40 kWh does he need 10 or 12 powerwalls? We really did not have adequate data to address those ussues, except we could see $$$$$'s.
Here is some data to show why batteries will not be charged from my 7.5kw system during two less than ideal days during winter. This same system outputs between 42kw & 45kw on a good summer day. I doubt many houses in suburbia would have any more than 10kw on the roof and most are smaller than mine being 6.5kw as a rule. Our FIT is 6 cents and there is no way I would put more panels on the roof (which I can't) to export for them to sell it back to me during the night at 30 cents+ and I would have to put a lot on to power batteries anyway.
If you enlarge the shot and then double click on it you will see the data panel on its own without the edge motif on the right. Somehow my second monitor gets included in a screen grab for some reason.
Today so far
Attachment 528057
Yesterday
Attachment 528058
YesQuote:
Originally Posted by havabeer69
Yes, sort of.Quote:
Originally Posted by havabeer69
NoQuote:
Originally Posted by havabeer69
1/ Forgive me if you know this. A kW is a unit of power, but describe the rate of energy flow. A kWh is a unit of power that has been used, so 1 kW for 1 hour is 1kWh. For a PV system to supply all your power it must be able to produce the same amount of power (kW) as you are using at any and all times. Any shortfall is drawn from the grid. The shortfall that was drawn from the grid cannot be directly "made up" by PV, only by selling enough power (feed-in) to pay the purchase price of that power drawn from the grid....... and they charge 6 or more times what they pay you! So when the sun goes behind a cloud you pay 500% interest on the power they "loan" to you, even if that "loan" only lasts a minute.
2/ PV Panels are specified for an output under a given amount of sunlight (energy) hitting them. In Australia, on a good day in summer at mid-day (from a solar point of view), we have more than the specified amount of sunlight. But that only lasts for a limited time either side of mid-day. Before and after that, there is a curve of increasing light through the morning and then decreasing through the afternoon. So 20kW of panels will produce nothing before sunrise, then increase to potentially more than 20kW at mid-day, then decrease back to nothing at sunset. To make things worse, domestic panels tend to be fixed, rather than on frames that "follow the sun". This means that they are either stuck on the roof at whatever angle and direction that happens to be facing, or adjusted to give a "best average throughout the year" result. They then gather dust, and often their output decays far quicker than the manufacturers would like us to believe. This means that the 20kW of panels, through the days and years, will only occasionally actually output 20kW. Because panels are "cheap", the solution is to install an inverter of, say, 10kW, and connect it to, say, 14kW of panels. The inverter limits the output at "best sunlight" times to 10kW, but at other times the under-performing panels can still yield 40% more than 10kW of panels. So output varies, and if you put your tumble dryer on at the wrong time, or get some clouds, then you're using power from the grid. So you have a bill.
3/ You still have a standing charge, which means you have to generate enough surplus to cover it, or you get a bill. How difficult this is depends on many things, but if (like me) the electricity company limits the amount of power you can feed in, it can become impossible even with a large PV system. So you have a bill.
4/ Without a battery, you can only use your "free" solar power when the sun is shining. As described in 2/ above, this means that in the early morning and the evening, or from mid-afternoon in winter, you struggle to produce significant power. Heating, cooking, watching TV etc. are all frequently done in those "low/no solar" times of the day. So you have a bill. Now if you have a big PV system that can export large amounts of power through the day, you'd think that would offset the grid usage. But remember that you get paid 5c for each kWh you supply to the grid, but they charge you 30c (or whatever) to buy it back - so you have to "sell" 6 times as much as you buy just to break even. So every dull day, or cloud in front of the sun, puts you further behind. And you have a bill.
5/ There are limit on how much power you can feed to the grid. For most people it used to be 10kW. For people on small transformers or long rural lines (like me!) it may be as low as 4kW. Apparently they do sometimes simply not allow any feed-in. Trying to sell 6 times as much as you use, when limited to 4kW feed-in, is very hard!
Yep, what he said. Why would I want to spend money so the electricity grid can sell it back to me at stupid prices. What I think should happen and I know this is dreamland stuff is that there should be a community battery which relies on local solar and only buys from the grid as needed. The local solar generation is kept "in house" at an agreed price until it becomes necessary to buy from the grid. My town would be a prime example of where this sort of scheme would work. How pricing would work I would have no idea but I suspect a smart meter could be utilised.Quote:
Originally Posted by Warb
The scheme in this link won't fly during winter because the communities are shaded for the greater part of the day by the local escarpment Electrify 2515 plan to adopt renewable energy, EV car lease in Illawarra suburb - ABC News
Quote:
Originally Posted by Warb
all good, did know a decent chunk of what you're saying. didn't really stop to think that you'd need to be making at least $1 a day worth of solar to cover your supply charge, which as you said comes down to your usage habbits and how much you can export.