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True, at least some of the time, but you might be drawing heat out of the Parrifin reservoir at times, and that may receive heat from the compression of air, off peak power, and if you have solar panels from those to some extent. So, you may not be drawing winter heat from outside air all the time.
Done.
Last edited by Void (2023-09-28 12:50:42)
Done.
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Put the tank into a tank of sand and the heat will be retained even longer.
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If we're going into a future with less energy, then we need vehicles that require less extreme up-front energy consumption, not more. It's good to see that the idea of a low-cost / short-range vehicle (suitable for 95% of real world driving) has at least some interest within academia, because electronic vehicles that have extreme energy / labor / materials inputs are not long-term viable. If I had to guess, everyone thought that there was no upper limit to emerging battery technology, without having done their homework about how much metal is required to make the batteries and electronics, as well as where that metal could be sourced from.
The average trip duration globally is 15 minutes long. The average trip distance globally is 15 Kilometers / 9.3 miles. The average speed globally is 30 km/h (or) 18.6 mph. On average, a person spends 4.5 years in a vehicle over their lifetime.
US DoE says 59.4% of trips were 6 miles or less.
Compressed air and hot water can easily provide that kind of range.
If we're going to have gas stations every 50 feet, then why not power them with compressed air and hot water?
We're in no danger of ever running out.
Even if you have to fill the tank up once per day, if the cost of the "gas" (air or water) is limited to the cost of the machinery providing the input energy, I'm pretty sure we can swing that. It's steel that can last a human lifetime. The lubricants are limited to bearing surfaces. The tires contain more oil than anything else. Let's say we charge people $2 to "fill up" and a car can go 75 miles. This implies they're driving 27,375 miles per year, and they pay $730/year. This provides $146B in revenue per year for 200M drivers "taking a trip to the moon" every 10 years, or $1.46T over 10 years. Recall how much metal my proposed solar thermal solution required to provide equivalent energy. $1.46T was a multiple of all material costs. Which means even when we include labor / transport / maintenance costs, people who can spare $2 per day can drive anywhere they please, we don't need to bash them over the head for requiring energy, and the "fuel" costs (air and hot water vs gasoline vs electricity) are the simplest / easiest to provide and least environmentally damaging of all possible fuels. If the car and its fuel supply are cheap enough, always available, and maintainable forever, then people will buy them.
This is the most puzzling aspect of "green energy". All the machines being touted as such consume quantities of fossil fuels equivalent to driving a gasoline powered car for 4 to 6 years, but the car makers want people to buy a new car every 2 to 3 years. The only way to make that work is to make each individual vehicle very cheap in terms of energy / materials / labor. That's the exact opposite of what we've been building, though, which is why there are now tens of thousands of EVs that haven't been sold- too much cost and not enough value proposition to the buyer.
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An interesting video on the Ragged Chute air plant in Ontario.
https://m.youtube.com/watch?v=yvgNqIuz2GM&pp
The plant is a trompe air compressor, probably the largest ever made. Like all trompes, it compresses air using flowing water and has no moving parts. The device was built in the early 20th century and produced compressedair to run mine tools.
Without any moving parts, a trompe has nothing that can wear out. The Ragged Chute plant ceased operations because the local mines were depleted. But had there remained a demand for compressed air, it could have gone on operating for centuries with little maintenance.
This presents an interesting opportunity if large numbers of compressed air vehicles are to be used in the future. Compressed air can be stored at high pressure beneath the sea or in underground caverns. Trompe compressors could generate air on land or at sea, and air could be distributed through steel pipes.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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One idea that I had that I was really quite fond of, but now realise would not work well: Low pressure compressed air energy storage.
My initial idea was to store air at low pressure ~0.5 bar(g) in trenches within the ground, covered with about 2.5m of compacted soil. The weight of the soil above the trench would balance air pressure within. The trench would be charged using a compressor like a trompe and energy would be recovered by venting the compressed air through a turbine. Because the compression ratio is so low 1.5:1, the cycle would be virtually isothermal. This really does simplify the charging and recovery steps. The energy stored in the compressed air has a low volumetric energy density of about 40KJ/m3. But the trenches are easy to dig and the system should last practically forever. So energy return on investment appears reasonable.
What is the big problem with this idea? The problem is the energy recovery turbine. With a pressure ratio across the turbine of 1.5:1 max (less as the store discharges and pressure declines) the turbine must be very large for the amount of power produced. This makes the turbine a high capital cost component. Whilst the air store is cheap, provided you have the space, the energy recovery step ends up being expensive because of the low power density of the turbine. If we have a direct use for the compressed air, such as feeding a blast furnace, the low energy density isn't such a big problem. But for energy storage, this doesn't look promissing.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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