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Posts
23864 -
Joined
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Days Won
200
Everything posted by SteamyTea
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VHS or BETAMAX the battle of two technologies relived.
SteamyTea replied to MikeSharp01's topic in Boffin's Corner
That is quite expensive. Basically means running in a second supply just for charging, and a larger local substation. More than just a socket on a wall somewhere. I have not seen any figures for the mass of suitable fuel cells and storage tanks. Mind you, current battery packs have ancillary heating/cooling fitted, so they are not as light as they seem. Yes it can, but why would you. It would still cause air pollution because most of the air we have is nitrogen. ICEs are very inefficient and mechanically complex. They also have gearboxes, which just shows the short comings of the engine. When you think about it, the modern car is really a very good compromise considering all the issues they have. I thought that it was the sampling rate that was more important than the compression. If things are sampled at a higher rate than we can hear, then in practicality, it is original sound. I am not talking about highly compressed mp3s here, just the difference between CD quality and grooved quality. But it is odd that DAB radio is a compressed format and it is considered better than traditional broadcasts. But then I only have 50 quid ears, so not really bothered. I just wish that my local DAB transmitter was reliable. -
Save the world, install an LPG tank.
SteamyTea replied to epsilonGreedy's topic in Environmental Building Politics
How does it compare to population, or GDP? That would make the government burden even smaller. -
VHS or BETAMAX the battle of two technologies relived.
SteamyTea replied to MikeSharp01's topic in Boffin's Corner
Specific energy density of liquid hydrogen is 142 MJ/kg (HHV) and for Lithium Ion batteries it is 0.875 MJ/kg. Volumetric Densities are 2,790 Wh/l for liquid hydrogen and 693 Wh/l for Lithium Ion. It does, on the face of it, look like hydrogen is a winner, but if it was that simple, we would all be using it. The problems come in when storing and converting hydrogen into electricity. This adds a lot of mass to a vehicle. As for old record players, most studio recordings, since the mid 1980's, have been recorded digitally. So anyone claiming that a grooved record is a more honest sound, it talking rubbish. Unless they like really old stuff, and the quality of that was pretty poor. -
I peeled the sidewall of one of them, was a bit scary at the time.
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Save the world, install an LPG tank.
SteamyTea replied to epsilonGreedy's topic in Environmental Building Politics
I used 5 kWh of energy yesterday to run my house, anyone lower? (not counting over self generation) -
I got one, was a nice revvy engine and a fast auto box. Like all RWD Vauxhalls, it cornered well. Would probably be horrible to drive today.
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I read something about this, and it did seem to make sense. Apparently, Toyota worked out that with their battery supply capacity, making a large number of hybrids, instead of a smaller number of EVs, reduced the total overal emissions and energy usage. Does make some sense as a stop gap.
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Hydrogen is really a dead end for personal transport. The energy density is just not that suitable for cars. It is why car manufacturers opted for batteries and not hydrogen. That is before all the other problems of using any liquid or gaseous fuels. Then add in the mass and expense of a fuel cell to drive the motors, and that they have to run pretty hot to be efficient, it was really a non starter. If it had been such a good idea, the current liquid fuel suppliers would have sorted it out and we would see hydrogen fuel everywhere, but we don't. Then look at Iceland (the country, not the 2 quid a bag for kebab meat people). They wanted to be the worlds first hydrogen economy, it failed spectacularly, though I think they have a small fishing fleet that may run on it. One of the problems of EVs is that gasoline and diesel are just so good at storing energy, are easy to move and decant, and is incredibly cheap. I like EVs, but I still want one that can do a reliable 400 miles between charges and can be bought on the second hand market for under £5000.
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Save the world, install an LPG tank.
SteamyTea replied to epsilonGreedy's topic in Environmental Building Politics
So all the computing power in public education, national health, local government etc was paid directly by the user. Is it that you perceive a high personal cost to mitigating climate change, rather than anything that the scientist come up with. You use that data just to further your argument that it will cost you personally. This phenomena has been studied. There is no need to answer that last bit as I am off out to enjoy the unseasonally low temperatures I have down my neck of the woods. -
Save the world, install an LPG tank.
SteamyTea replied to epsilonGreedy's topic in Environmental Building Politics
That is because we have a vast knowledge base now, along with better communication. I do struggle to understand where you are going with all this. Did the scientists that created your PC (or Mac, or whatever) have an agenda to corrupt information, or the scientists that developed air travel to its current level want to kill people with a software problem? -
I used to work in the health and leisure industry as a supplier/installer. If the pool is indoors, make sure that all fasteners are not affected by the chlorine, it caused the rebuild of St Albans leisure centre roof back in the 1990s.
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Save the world, install an LPG tank.
SteamyTea replied to epsilonGreedy's topic in Environmental Building Politics
Or just an old university lecturer trying hard to educate -
Probably not that different. Most of a vehicles mass will be steel for a normal car. Some EVs are made of aluminium, which has a high initial embodied energy, but low when recycled. I am not sure what the embodied energy of the batteries is, but probably not as high as people think. As an example, Aluminium has a typical EE of 155 MJ/kg, when recycled it is 29 MJ/kg. Steel is around 45 MJ/kg and 32 MJ/kg when recycled. I have seen figures of between 350 to 650 MJ/kg for lithium ion batteries. A litre of gasoline has about 45 kWh of energy in it (about 25% is usable for motion in a road car). So taking worst case, a kilo of lithium batteries is the same as 4 litre of gasoline.
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I am still amazed that I have not had to change the brakes on my C-Max after driving 90,000 miles in it. I do not know when they were changed prior to me owning it (bought it at 38,000 miles, so probably not changed). Not sure if it is my driving style, or have brakes vastly improved. Not as if it is a light car and I only drive on major A roads, it is all hilly lanes and towns down here.
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Save the world, install an LPG tank.
SteamyTea replied to epsilonGreedy's topic in Environmental Building Politics
Having been away for a while, it is interesting to see that this topic is still discussed. What does intrigue me is that some people think that shifting from fossil fuels to renewables can only harm the economy. What is this based on? "The stone age didn't end because we ran out of stones." @epsilonGreedy Do you know why CO2, or any other molecule, can trap heat? I suspect you don't. As for cars, back in 1996, I had a company Citroen that easily did 60 MPG, it was an AX 1.4 Diesel. Was dreadful. My own car was a 1991 Peugeot 309 Turbo Diesel that consistently did 50 MPG, and in those days it only had two speeds, zero and maximum. -
It is the same fib that is said about PV and wind turbines. Probably by the same people. You have to do two calculations (or at least find two datasets). The Well to Wheel emissions and the Manufacturing Embodied Energy. There may be cases where, say a hyper car that is really used, has lower environmental life cycle costs compared to the the daily Tesla S, but that will also depend on where the vehicles are geographically based.
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Dew Point - What is it and why does it matter
SteamyTea replied to Triassic's topic in Boffin's Corner
@newhomeStill at the other end of the country from you. -
Dew Point - What is it and why does it matter
SteamyTea replied to Triassic's topic in Boffin's Corner
Thanks @Dreadnaught -
It was with some waterproof MDF and a bit of ply. The MDF absorbed very little water, less than 1% by mass, the ply not so good, but the adhesive was as good as new.
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Dew Point - What is it and why does it matter
SteamyTea replied to Triassic's topic in Boffin's Corner
@Ed Daviesand @TerryE Do a statistical model, some things just cannot be sorted out with a relatively simple equation. -
Iresa have ceased trading
SteamyTea replied to Jeremy Harris's topic in General Self Build & DIY Discussion
I got a letter today from EDF about a price rice, the second in a few weeks. Generally they were good on price, but not now (though still in business). Hard knowing what to do as I agree with @Triassic, many of these smaller 'piggybacking' companies are going to go to the wall. -
The taste of my sand.
SteamyTea replied to epsilonGreedy's topic in General Self Build & DIY Discussion
Or webbed toes and fingers, like the inbreds from Helston -
The tale of the sale of our old house
SteamyTea replied to Jeremy Harris's topic in General Self Build & DIY Discussion
Just avoid Nalders as a solicitors, they are the most ineffective and useless ones I have ever had to deal with. They added an extra 3 months to my house purchase. Just dreadful. -
House Cooling ideas
SteamyTea replied to mike2016's topic in Energy Efficient & Sustainable Design Concepts
Wish my girlfriend was an ankle biting mite -
House Cooling ideas
SteamyTea replied to mike2016's topic in Energy Efficient & Sustainable Design Concepts
I use a Raspberry Pi Zero W with some DS18B20 1-wire sensors and some DHT22 sensors. Also stuck on a real time clock. Very cheap kit, around 20 quid. The chart is just knocked up in Excel, though there is software for the RPi that can do charts on the fly and publish them. The advantage of the 1-Wire stuff is that you can daisy chain many sensors to 1 input pin on the RPI. The DHT22 needs 1 pin per sensors, but there are about 20 spare pins, so that is not really a problem. The software is easy to write, or copy, just depends how sophisticated you want it really. Also pretty easy to get it to turn things on and off i.e. a fan, airco unit, heater.
