I feel that you haven't prioritised what you want.
The original idea is to heat your house with wood, then shifting to get electricity from heat using TEGs, and finally to actively refrigerate the TEGs with ice cold water.
The final idea is completely at odds with the first idea.
I can sympathise with you as I've been through a similar thought process myself. I spent some time looking at TEGs. I realised that nobody is using them in any serious capacity. There is probably a good reason for this.
He briefly mentioned this NightHawkInLight video and commented that it really is not that impressive because the material is definitely an "ablative" (i.e. it erodes with use), and ablative heat shields are actually not that difficult to make.
Trace Oswald wrote:I was told that people used to teach not to drink from the hot water because "back in the day", lead pipes were sometimes used for water and hot water made more lead in the water.
Thank you for the link. However, there's this import part lurking at the end:
In addition, hot water dissolves copper more quickly than cold water; as a result, water to be used for drinking or cooking should not be drawn from the hot water tap.
Not sure if this statement is true in isolation. Earlier in the article it says copper pipes in new homes have not yet developed the "coating" (I assume this is copper oxide) to stop leeching into the water. The article doesn't explicitly state if hot water from old copper pipes is safe.
I was taught that the reason we don't drink the hot water from a kitchen tap is because the hot water tank is not hygienic. Maybe both are true.
Graham Chiu wrote:Also, why is copper always used? Is there better heat transfer to copper vs stainless steel?
S Bengi wrote:Yes copper is better than steel at transferring heat.
Copper has an unbelievably good thermal conductivity. Table of values here.
Copper - 401 W/(m K)
Aluminium - 205 W/(m K)
Stainless Steel - 16 W/(m K)
Copper is also very malleable so it's easy to bend into coils.
My concern with copper is that, if you look around a typical home, you rarely ever see drinking water being heated or stored in copper vessels. Washing water is often heated and stored in copper, but not drinking water. Makes me wonder if there is some health issue.
Greg Canicio wrote:what kind of solar panels are there most of out there?
I believe the only significant difference between solar panels which needs consideration is their voltage at the terminals. I believe the most common are rated at 18V.
If you are building a 12V system for car battery storage, you would normally use 18V panels. This is because when you place a load across a solar panel (or any power supply), its voltage drops. 18V panels end up being just about right for charging a 12V battery.
If you want to create an array of panels, they all need to be the same voltage. Of course, you will always need a battery management system.
I'm not an expert on this subject so you probably want to get confirmation of what I've said here.
I can't answer your question but I would like to ask - how certain are you that you know exactly what the heavy metal contaminates are, and their severity? If you do know, this will be useful information for other people here.
Furthermore, I am unable to understand exactly what the connection with the oil company is.
EDIT: Sorry ignore that last part. By the time I finished reading your post I had forgotten your title said the spill was in an oil field.
Travis Johnson wrote:The ideal place for this would be in an old quarry.
If the crane is economically viable, thousands of them would need to be built around the world. The crane makes sense because it can be built anywhere, and also built adjacent to the power plant, saving on high voltage cabling.
I believe we can both agree that GPE is economically viable at large scale (I said it twice in my first post).
I also agree that batteries are made from very finite resources, which is a major drawback.
But I am convinced that GPE is not economically viable at the scale you're proposing in your OP. Let me know when you've figured out what your idea will cost you and how long it will take to pay for itself.
Another interesting calculation to think about - the Tesla battery cost $66 million and stores 129MWh. That means it costs approx $500 per kilowatt-hour. The "Energy Vault" crane in the video is projecting $150 per kilowatt-hour. If true, that would seem extremely good.
Austin Shackles wrote:but 5000kg and 5m height would give you 25x the energy, say, and wouldn't be hard to build. Obviously, you can't carry it around like a drill, but many things don't need so much power as a drill. Take lighting, for example, if you use LEDs 10W will light a room.
5000kg at 5m = 245,000 J
10W LED light for 6 hours = 216,000 J
So you can basically illuminate 1 room for 1 evening. It's not even remotely economically viable - if it was, we would already be doing it everywhere.
Have you done an estimation on what your idea would cost? What $-per-kilowatt-hour do you expect?
Austin Shackles wrote:It might be that for small scale, batteries are still the way to go - but town-sized, they are still way too expensive.
A simple calculation will show that gravitational potential energy (GPE) is a poor store of power unless you have access to enormous amounts of storage - i.e. a lake.
Austin Shackles wrote:Gravitational potential energy though is given by mgh: so a 1 tonne weight (1000kg) lifted by only 1m has a potential energy of somewhere around 9.8KJ
Daniel Burnam wrote:His boat has a 425hp diesel caterpillar motor and he says he burns about 35 gallons of fuel/day on average. Just a quick search on the internet and some simple math says that he's using about 1 megawatt electrical equivalent in diesel fuel
I think the units you're using to analyse the problem are wrong.
Watts are a unit of power, not energy. Power is the instantaneous flow of energy. The base unit of power is Watts. The base unit of energy is Joules, which can be converted into Watt-hours.
The 425hp engine is equal to approx 317 kilowatts - this is the max instantaneous output of the engine.
The 35 U.S. gallons of diesel is approx 5128 megajoules or 1424 kilowatt-hours. See diesel-to-Joules conversion calculator here - https://www.convertunits.com/from/gallon+[U.S.]+of+diesel+oil/to/joule
So for equal performance, the boat will need a 317 kilowatt motor and a 1424 kilowatt-hour battery.
The top-of-the-line Tesla model S has a 100 kilowatt-hour battery, so they will need the equivalent of 15 Tesla model S battery packs in their boat. The estimated weight of the 85 kWh battery pack in a Tesla is 540 kg (there's no official figure that I can find in a brief search), so this boat will need about 10,000 kg (22,000 lbs) of batteries.
Here is an example 300 kilowatt electric motor. It weights 3050 kg (4500 lbs).
I'm not a scientist or an engineer so all this could be complete rubbish!
EDIT 1: link formatting
EDIT 2: I forgot to think about efficiencies!!! Internal Combustion Engine is typically 20% efficient.
Electric motor is typically (I believe) 90% efficient. Lithium Ion battery is also about 85% efficient. I guess you could get away with only 700 kilowatt-hours of batteries or approx 5,000 kg.
EDIT 3: I think you should ignore that link I gave to the 300 kilowatt motor. My instinct is now telling me you wouldn't need something as big as that. I don't know enough to give any further info.
josh ober wrote:I guess what I’m having trouble with is understanding how cob would stay cool in the heat, considering the fact that it seems it would be absorbing heat from the sun.
It does indeed absorb heat, but different materials can absorb more energy before they actually start to feel warm.
I appreciate that could be a bit hard to wrap your head around. The fundamental reason for this property is highly technical and beyond my understanding, but is explained on Wikipedia:
An example given on Wikipeida (see this table) is that water requires about 4.5x more energy (measured in Joules) to raise its temperature by 1°C compared to an equivalent mass of concrete. So in layman's terms, concrete starts to feel warm four to five times faster than water does. This means water is the better material to use as thermal mass. Of course, water has a habit of leaking out of containers and destroying stuff. On the other hand, water can also be pumped through heat exchangers which allow you to push the heat around much faster. So there are a number of factors to consider.
Here's another useful table showing heat capacity. Sandy clay requires about 1.6x more energy than concrete to raise the temperature.
An interesting (and counter-intuitive) detail to note is that air has a higher heat capacity than concrete. But of course, 1 tonne of air occupies a much larger volume than 1 tonne of concrete.
Finally I just want to point out that I am not a scientist or engineer, so I would love somebody who is to confirm what I have written above.
Jay Angler wrote:...if the goldenrod was grown in dirt with fertilizer, it might well show some of the changes for reasons other than the presence of higher levels of CO2.
There were two separate trials conducted (link to study at bottom)
1) Comparing present-day goldenrod to historic goldenrod (which does not directly address your above concern)
2) Conducting an isolated trial where the goldenrod was grown in polytunnels where atmospheric CO2 was the only variable (which does directly address your concern)
The report explains that the confidence in their conclusions from both tests is high: "...the current data do indicate a clear and unequivocal link, both historically and experimentally, between rising [atmospheric carbon dioxide] and a qualitative decline in pollen protein".
Jay Angler wrote:Who was that guy anyway?
He is a professional science communicator. He has a degree in physics engineering and a PhD in science education research.
Finally, I do also dislike how quickly he dismisses (in the video) the idea that soil health does not contribute. However I am comfortable believing the results of the study.
Apparently planning permission for offgrid homes using low-impact & sustainable techniques is easier to obtain in Wales, but I've never looked into that in detail.
You may want to look at woodlands.co.uk for finding land.
I've also heard you can put a caravan on a woodland and live there for up to 6 months of the year without any legal issues (I am not a lawyer, so do your own research).
1) How much smoke does it produce?
2) What it its long-term tolerance to heat? Will it still be working in 2 years time and hundreds of firings, or will it have been slowly but surely destroyed by the heat?
Obviously the second question can't be answered right now.
Looking forward to seeing your next videos though.
John C Daley wrote:Civil engineer who welds and sells earth block machines and plays with hot rods
Sounds like you may find the people at Open Source Ecology to be of interest to you (they designed an open-source rammed earth block machine and are working on many other machines). They are based near Kansas city, however their site is not open to the general public or to casual visitation. They do hold invitation-only events from time to time, including a new "immersion program."
I'm not affiliated with them in any way, but I think what they are doing is really cool.
My understanding is that it is a matter of UV intensity. UV sterilisation using sunlight is not possible outside equatorial regions, and even there you need to put the water into small bottles where the UV can penetrate through the entire container.
EDIT: I should add that I have never tried this myself.
Bryant RedHawk wrote:To actually get "the biggest energy-return-on-energy-invested" wouldn't you need the energy used to create the char do something else at the same time, other than heat the atmosphere?
I agree, and would love to see somebody make that. I've been tinkering with the idea myself but it is taking a long time.
Bryant RedHawk wrote:While it is great to have the new techniques and the ability to incorporate them they really can't be as necessary as the "new wave" ideology insists, otherwise there never would have been a discovery of hundreds of years old terra preta, it would not have been able to be created.
I generally agree with you, but would argue that the new techniques are necessary if you must achieve the biggest energy-return-on-energy-invested. The ancient Amazonian people probably had vast biomass resources on their doorstep and also a lower sense of economic and environmental urgency than we have today.
Can anybody here say for sure (and provide a citation) that ceramic wool is safe to handle without personal protective equipment? My current belief is that it is not.
Deb Stephens wrote:Are we more similar to predators than prey or vice versa?
If I remember correctly from "Sapiens" by Yuval Noah Harari, humans were pretty harmless creatures until we learned to control fire and tools. Before that time, we are pretty innocuous and were preyed upon by many animals. Probably not the full answer you wanted, but it's a start. If you haven't read the book, I highly recommend it.
Deb Stephens wrote:...why can't we seem to get our act together and control our own population explosion?
In 2012, the global fertility rate was 2.5 children per woman, and that number is trending downwards. Most "developed" countries are already below 2 children per woman. The continuing "explosion" is due to people just living longer. I recommend this video about population statistics:
Have you seen that technique where people hang water+bleach-filled bottles in their shed ceiling to allow light to travel through? I wonder if you could use something like that to offset the need for large windows?
pjeter schornstein wrote:...the ineffectiveness of inverting DC into AC...
This statement does not make much sense to me. Do you actually mean "inefficiencies"? You will loose maybe 10-15% of your power converting from DC to AC. That is perfectly normal and just an unavoidable fact of life.
Or instead, are you referring to the issue that "modified sine wave" inverters struggle to run some appliances properly, and you need to use "true sine wave" instead?
pjeter schornstein wrote:How would I know which machines need to be converted and do I need to convert the Volt as well?
So, instead of converting DC to AC, you want to convert all your AC appliances to DC? Am I understanding that correctly? That sounds completely impractical (much more work than just using an inverter) and also very dangerous if you don't know excatly what you're doing.
Is that an all-metal burn tunnel? The prevailing advice is: don't use metal in the burn tube and riser. It will function for a while, but eventually corrode.
Jeffrey Rush wrote:Yellow tops: These are of most interest to folks like you and me.
Thank you, that is good to know.
I see the optima batteries cost about 3x or 4x that of a budget "leisure battery". Would you say that premium is justified? Would it really give 3x the performance?
There is a company in the UK that makes fire logs using compressed waste coffee grinds. They're called "Bio Bean coffee logs". I have a bag of them (purchased on impulse), but have not yet tried them. They do appear to use some sort of waxy binder, so they're not 100% coffee grinds.
