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#1 2023-01-31 22:42:19

kbd512
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Registered: 2015-01-02
Posts: 7,362

How to Squander Energy on Futile Endeavors

It's amazing how few people either understand or are willing to accept the implications of this underappreciated concept of "embodied energy".  Embodied energy is very near to the singular reason why it's not feasible to convert everything over to electric or electronic operation.  Amongst our mathematically illiterate technorati, there's a bizarre "electronics fetish" which refuses to accept the downsides to relying upon very temporary electronic devices that are very difficult to fully and efficiently recycle into new similarly capable machines.

1,000kg of Carbon steel - 50,000MJ
100kWh Lithium-ion battery - 112,500MJ
186kg of Aluminum in a Tesla EV's chassis - 37,200MJ
1kW of Monocrystalline photovoltaic panel - 15,000MJ

If we think about a "solar panel" as an energy-intensive device, like any other sophisticated machine, despite the fact that it also "gives back energy over time", like any other power plant, then there are both "poor" / "mediocre" and "good" / "excellent" solar panel devices to be had, using current technology.  If photovoltaic technology dramatically changes, then perhaps this issue is null and void.  50 plus years after photovoltaic panel commercialization, those devices still have a service life of around 25 years.  The universe is unkind to electronic devices.

Much like humans, no machine was ever spontaneously created from nothing.  In order for any sophisticated machine to be created, lots of input energy and labor is required.  If new matter and energy are never created, merely transformed, then productive service life matters greatly.  A car engine that lives for 5 seconds before requiring a tear down inspection and partial or complete rebuild, like a drag racing engine, is pretty useless for driving to work every day.  If your machine continues to function for 75 years, which is essentially a human lifetime, then each similar machine is a much greater value proposition.  If your machine only lives for 5 to 20 years at most, then it's essentially on borrowed time.

A smart phone is a fantastically capable machine that can do things that no rotary phone could ever do, like fly an entire fleet of Space Shuttles at the same time, but the rotary phone from my grandmother's house outlived her.  Unless someone tossed it in the trash, which they probably did by now, it would outlive everyone alive today.  A telephone's primary purpose is to allow you to communicate over great distances at the speed of light.  A rotary phone is no less capable than an iPhone in that regard.  I think my family has been through at least a dozen iPhones.  They all ceased to function as phones after 5 years or so, despite how useful they were when they did work.  Throughout my entire life of more than 40 years, that rotary phone never quit working.  Basically, because the rotary phone lacked electronics of any kind and was reasonably well protected from internal corrosion by the factory, it lives on.  If it ever did require repair, someone with cheap hand tools can fix it.  You can't fix a cracked smart phone display without replacing it entirely, typically with very expensive tools and training or experience.  This doesn't make them "bad" or "useless", it simply means there is nothing permanent about a smart phone.  It's a temporary utility under the best of circumstances.

Another way to look at this is owning your technology, rather than your technology owning you.  There could be excellent reasons to move on from rotary phones to smart phones, but a power plant's job is to generate heat and/or electricity.  That hasn't fundamentally changed since the time of Tesla and Edison, nor will it ever.  We don't power any piece of advanced machinery used by humanity in any other way, because no other methods provide the efficiency and speed we desire / require to live as we do.

It should go without saying that it makes the most sense to put any machine where it can do the most useful work.  Since this point is lost on so many people, it's worth repeating here.  Putting a solar farm of any type in Antarctica makes very little sense since almost nobody actually lives there and the total solar irradiance received by Antarctica is very low compared to the Sahara Desert in Africa.  Solar panels in Antarctica will still generate electrical or thermal power when struck by photons from the Sun, but "all the good they can do" is largely wasted by putting them in a frozen wasteland where almost nobody lives.  In contrast, there are far more people living in the Sahara Desert and they all require energy.  If we don't want them to burn things, then they need practical alternatives that they can afford to use and learn to operate.  Until most of them are no longer living hand-to-mouth, they won't care one little bit about the environment, because most of them don't have the time or mental bandwidth to consider such things.

That leaves us to explore the proposition of power-at-scale, because humanity requires quite a lot of energy.  1TeraWatt-hour (TWh), or 1,000,000,000,000 Watt-hours, is where scales of significance begin.  Humanity consumes approximately 384 of these "TeraWatt-hours" per day, for all uses, as-generated by all sources.  That's what we require to live as we presently do.  It's a remarkably huge number, but that's what enabled humanity to attain our current levels of prosperity.  If we want to "do more" or "become even more prosperous", then we require "even more power".  As all of our historical total global energy consumption proves, there is no such thing as "doing more with less".  You do more with more power.  You do less with less power.  There are no "two-ways" about this bit of knowledge.

The aforementioned TeraWatt-hour scale was chosen to illustrate the magnitude of the problem we're trying to solve using methods that don't involve burning something.  You don't have to worry about storing any of that energy until you can generate it in the first place.  Generation is Problem #1.  All other associated problems are downstream of that problem.  We can work on resolving storage-related issues after deciding what to do about the first problem.  The question becomes, "How on Earth can we generate 384TWh of energy per day, without burning everything within sight?"  Once we start thinking about the problem at this scale, which we have to if we're serious about finding solutions that do more than make us feel good or virtuous about ourselves, all of the electronics-based solutions become grossly unworkable, as we're about to illustrate.

A 2mm thick solar thermal reflector that weighs 1,000kg has a surface area of almost 64m^2.  If it's paired with a 50% efficient multi-stage supercritical CO2 gas turbine, which is realistic for three expansion stages including heat re-injection between stages and after-cooling, and each square meter of reflector surface area provides 500W of energy (from the 1kW received from the Sun) for 6 hours per day (in a hot and dry desert like the Sahara or Death Valley, not Antarctica), then it generates about 192kWh per day, or 70,080kWh per year.  The 2mm reflector thickness corresponds to some of the thickest sheet steel ever used in mass-produced cars, which were primarily built between the 1940s to 1960s.  Using modern metal stamping and work-hardening methods, a 2mm thick cold-rolled sheet steel panel can be exceptionally strong and stiff.  Per square meter, 2mm thick plain Carbon steel weighs about 15.7kg.  1,000kg / 15.7kg/m^2 = 63.69m^2.  A 2mm thick 6061-T6 Aluminum sheet would require about 200,000MJ of energy for every 1,000kg produced.  Although it would cover 184m^2, which would generate about 2.88X more energy, it requires 4X more energy input.  In other words, it's a bad energy trade and we need that Aluminum for other purposes.  This is why we primarily use steel for major construction projects, and why steel production dwarfs all other metals production.  Steel is about 90% to 95% of all metals production.  This is why the reflector has to be steel.  Nothing else we know how to make requires less energy input, at the scale required, whilst providing all required material properties for the intended application.  Earth-abundance and the Periodic Table limits what we can use in mass quantities.  We have Hydrogen, Oxygen, Nitrogen, and water coming out the wazoo, but it's also nearly useless for actually capturing solar energy.

If I needed to build something using steel that was capable of withstanding the test of time, then cold-rolled 2mm sheet is the sort of material I would use to make it.  Automotive manufacturers make extensive use of this type of material, albeit at less than 1mm thick these days.  If you need to make complex machines by the tens of millions per year, then cold-rolled steel is "the right stuff".  To protect plain Carbon steel from corrosion / oxidation which would reduce its reflectivity, I would hot dip that sheet in commercially pure Aluminum, which happens to be an "even more perfect reflector" than polished steel.  That is also the exact material that most modern motor vehicle exhaust systems are made of.  There are some exceptions that use more exotic materials like 304L stainless or Inconel or Titanium, but Aluminum-clad Carbon steel is the norm.  It's the lowest-cost stuff that's "good enough for the job".  Factory exhaust sytems are generally cast Iron upstream of the catalytic converters, with welded cold-rolled steel that's been hot-dipped in Aluminum to form the exhaust tubing and mufflers downstream of the exhaust headers and catalytic converters.  If lower-cost materials were available, then they'd be used instead.

Moving on from materials selection to quantities required:

To generate 1TWh per day using solar trough reflectors, 5,208,333,333kg / 5,208,333t of steel is minimally required for the "reflector part" of the machine, which implies 260,416,666,667MJ of embodied energy.  At 30MJ/kg of coal, this implies that an energy-equivalent of 8,680,555,555kg / 8,680,555t of coal must be burned to create that much steel.  The energy to make the steel has to come from somewhere and it's not presently coming from solar or nuclear or geothermal or hydro at any scale of significance, so making new steel from virgin Iron ore implies burning a LOT of coal.  Even if you did not personally witness the burning of said coal, rest assured that it was burned on your behalf to make the steel we all consume.  There are other methods to make steel that don't involve burning coal, but none are in widespread use because they all require even more energy than simply burning coal.  It's not because our engineers are dumb or don't know how.  It's "Energy Economics 101".  Engineers understand this, even if the general public does not.

How "bad" can the photovoltaic alternative possibly be?:

A 5.11m^2 photovoltaic panel (surface area of a pair of 500W panels) contains the same embodied energy as 1,000kg of plain Carbon steel.  Commercial photovoltaic panels are about 21% efficient on their first day of operation, and a 500W commercial panel generates about 2kWh per day under real world conditions.  The standard test conditions they're subjected to (1,000 lumens per square meter at 25C) give them their 500W output rating.  It's pretty safe to assume that they will make standard output at beginning-of-life, because they're tested as part of quality control- not every panel unless it's going to NASA, but enough to be statistically representative.  Each 500W panel weighs about 32kg (0.86kg / 1.89lbs per square foot of surface area).  Thus, you need about 500,000,000 of these 500W commercial grade panels to generate that same 1TWh per day.  The embodied energy is 250,000,000 (number of 1,000W "panels" or two of the 500W panels per 1kW) * 15,000MJ per 1kW panel = 3,750,000,000,000MJ.  About 16,000,000,000kg / 16,000,000t of high embodied energy materials (Aluminum, cover glass, plastic or fiberglass composite backing and insulation, Silver, power inverter solid state electronics, Copper, etc) are incorporated into each of those 500 million panels or as separately connected devices, so that dramatic increase in energy is to be expected.  16,000,000t of steel represents 800,000,000,000MJ of embodied energy, so the materials in a photovoltaic panel are inordinately energy-intensive to make.  Once again, all that energy has to come from somewhere, so that means 125,000,000,000kg / 125,000,000t of coal being burned in China for our fake environmentalists to "feel green".  Where the coal is burned and whether or not you see it being burned, is utterly irrelevant to global warming.  It still adds to the yearly total and running tally.

Globally, we burn about 8,000,000,000t of coal each year, so 125,000,000t is a very significant amount of coal.  If all 8 billion tons of coal was devoted to making solar panels, then 6 years of total global coal consumption would be devoted to making nothing but solar panels.  There would be no electricity generated, no heat provided for warmth or to make steel or other metals and industrial chemicals, nor anything else created from that coal.  25 years later, more energy has to be devoted to making a significant number of new / replacement solar panels.  It's easy to see why we haven't "gone solar" already.  We're attempting a mathematically impossible task.

It's easy to see why the entire world hasn't already "gone solar".  Our technorati's method for "going solar" requires 14.4X more energy than an existing competing method, which happens to be able to convert over 90% of the input solar radiation into heat energy without invoking any special or rare materials.  Aluminum or Aluminum coated steel is an exceptionally good mirror.  It's a miracle that wind turbines and photovoltaics and associated alternatives supplies 2% of global energy consumption after half a century of rollout.  Wind turbines are even worse in terms of embodied energy, because what they can extract is dependent upon differential heating of the Earth from sunlight, and total global wind power is estimated at 1% to 3% of the incident solar radiation received.

In any event the 125Mt of coal used to produce photovoltaic panels to provide 1TWh of power per day, would otherwise provide 14.4TWh of power per day using solar thermal, all else being equal.  That's more than 1 order of magnitude better.  Over 75 years, solar thermal is actually 42.3X better than photovoltaics.

After dealing with the primary problem photovoltaics impose on a society so-powered, they create brand new secondary problems.  Heat from solar thermal can be stored in a revolutionary new, at least back when the Earth was initially formed, technology called "crushed rock".  As a general rule, because conversion efficiency is so poor, electricity from photovoltaic panels has to be stored in even-more energy-intensive devices called batteries.  If that sounds really inefficient and potentially bad for the environment, that's because it is.  You get no omelettes without breaking some eggs.  If your broad general strategy is to get everyone off of coal and onto solar power, then you certainly don't want to force them to use photovoltaics, unless your end goal is to increase the burning of coal to wildly unsustainable levels.

This is obviously something that was never a good idea, it was simply fetishized in popular media, where group-think supersedes pragmatic choices pertaining to energy usage.

If you wish to see concrete action taken to being resolving the problem in a timely and satisfactory manner, then stop wasting your time trying to find exceptions that don't disprove the rule.  Anybody can complain about a problem.  I provide math-based solutions that are real-world applicable and achievable without invoking nonexistent new technology, materials e don't have or cannot obtain in the required quantities, or "bridges to nowhere".

We've spent the past 5 decades screwing around with electronics and batteries.  If building more photovoltaics and wind turbines was ever a workable solution, then someone should've produced very visible and dramatic results by now.  Such a thing has not happened thus far.  These grossly unworkable wind turbine and photovoltaics and electronic vehicle schemes, which have been offered up by corporations and the media as some kind of "great struggle towards a solution", are merely new ways to transfer money out of your pockets and into their pockets.  At best, it's rampant consumerism prettied up as "saving the planet".  What's that old saying about lipstick on a pig?

If you're at all serious about wanting to see a practical solution within your lifetime, then start demanding that the people making the wild claims about how "cost effective" photovoltaics are, start showing how they arrived at their answers.  In math class, the teacher would never let you write your answers on your paper without also expressing how you arrived at your answers.  Why is that an acceptable practice when a government or corporation does it?  How did we arrive at the supposition that covering the planet with electronics galore, produced almost exclusively by "burning stuff that the same people say is bad", is the least costly to humanity and the lowest environmental impact as our singular "solution"?  Is it the least bit strange that the most material-intensive and therefore expensive methods were chosen?

Assume you have to dig 100% of all the materials out of the ground, which you do, because there's not enough "existing material" in the world to make either of these schemes work, even with 100% recycling of all materials.  Photovoltaics are still 43.2X more energy-intensive than solar thermal power plants over a human lifetime.  From where I'm sitting, this looks exactly like a car that's engineered to break down immediately after its warranty period has expired.

If you had to play with your own money, which you are actually doing if you're buying energy from utility providers, as almost everyone does, then this the solution you'd choose?

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#2 2023-02-01 03:51:42

Terraformer
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From: Ceres
Registered: 2007-08-27
Posts: 3,800
Website

Re: How to Squander Energy on Futile Endeavors

I don't expect solar cells to actually have that much of a future in space. We use them now because they're solid state, but when you have direct sunlight available constantly and a 3K (theoretically; practically it might be more like 30K) heatsink, you can get far better efficiencies with simpler (to manufacture) heat engines. A lunar settlement wouldn't even need to use reflectors; during the day the surface reaches 370K, during the night it drops to 140K. That's lunar rock, no specifically designed radiators and absorbers that have the rock below them serving as a buffer.

Back to Earth, I think Solar PV has some applications where it makes sense, like an off-grid system where using a heat engine set up for electricity generation would be too much complexity for the benefits. But for bulk power generation we're better off looking at thermal systems. Not least because power storage is straightforward -- even if a system only got say 15% efficiency, being able to store heat and keep operating into the evening and through the night might make it a preferable option to a 50% more efficienct solar cell.

If you're after heat, which in a domestic context we mostly are after, solar electric vs thermal gets ridiculous. We could electrify everything, generate power during the day, have a big battery system to store it... only to use it to heat water to 40-50c. Or we could skip all that and have a big tank of water we heat directly with sunlight during the day with far higher efficiency and without needing a wall of lithium ion batteries. Hot rock/earth applies here too; if a patch of ground is insulated top and sides, we can soak it with heat and keep it maybe 20c above the rest of the earth for quite a long time. Might need a heat pump to get it from 30c to a usable 45c, but that will have quite a high CoP at least, and for space heating we shouldn't need that.


"I'm gonna die surrounded by the biggest idiots in the galaxy." - If this forum was a Mars Colony

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#3 2023-02-01 05:07:15

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 3,352

Re: How to Squander Energy on Futile Endeavors

Kbd512, congratulations on an excellent new thread.  You make a lot of very good points.  The majority of politicians and politicos are non-technical people.  They seem to think of the green transition as a moral cruisade that can be won through propaganda.  A few years back, a proffessor at one of the Scandanavian universities calculated the materials budgets needed to carry out a transition to the solar-PV, electric vehicle economy.  For most of the resource sets neccesary, the quantities needed for just one generation of 'Green' infrastructure, exceeded probable global reserves by orders of magnitude.  And batteries and PV panels are not easily recyclable.  As Terraformer points out, PV is a useful technology in applications where small amounts of power are required in an off grid setting.  Using PV to generate grid power is a misapplication of this technology.

The use of concentrated solar power for production of synfuel and electricity has merit.  One problem with the idea is that trough solar collectors have operating temperature limits of about 400°C.  This limit is driven primarily by the use of mineral oils as heat transfer fluids.  Oils are very advantageous, because they can be non-pressurised, they are non-corrosive to steel, are safe to handle and have high heat capacity.  Going hotter would require using a pressurised gas, liquid metal or molten salt.  All of these have problems.  A higher temperature woukd be economically attractive because it would allow use thermochemical water splitting for synfuel production and compact S-CO2 power generation cycles.  Producing electric power and synfuel is still possible within the temperature limit of 400°C.  But it requires generating electric power using a steam cycle.  We do at least have centuries of working knowledge in how this can be made to work.  One way of improving economics is to exploit economies of scale.  Distributed solar collectors can feed into large diameter heat mains which drive centralised multi-GW steam plants.  We now have steam power plants with generating capacity up to 1700MWe.

Storing energy as sensible heat in brick or crushed rock, is gaining popularity.  Energy density is comparable to chemical batteries and the medium is very cheap and has low energy cost.  Nothing comes for free.  Storing energy as heat requires the use of heat exchangers and sensible heat can only be released from a material across a temperature drop.  This is why latent heat storage through phase change materials are attractive, in spite of their increased cost.  If we are using oils as working fluids, then sensible heat stores could be silos containing crushed rock, with the primary oil coolant flowing directly through them, before entering a boiler.  Boilers can be constructed from carbon steels if feed water PH is carefully controlled (PH needs to be around 11).  But stainless steels allow longer service life.

Last edited by Calliban (2023-02-01 05:24:21)


"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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#4 2023-02-01 06:43:27

Terraformer
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From: Ceres
Registered: 2007-08-27
Posts: 3,800
Website

Re: How to Squander Energy on Futile Endeavors

If we're going to store heat in rock, we could also store cold. As I go on about in this thread, it's possible to achieve temperatures significantly below ambient by radiating away energy to the night sky. A cold heat sink could improve the efficiency of the generators (if they're the right type) by a fairly significant amount.

One advantage PV has over thermal, that particularly applies in Britain, is it can utilise indirect sunlight. Britain doesn't always have direct sunlight -- in August, the average recorded by a nearby weather station is ~6 hours a day. Given how long the days are in August I'm assuming that refers to the number of hours in the month where we had direct sunlight that could be utilised by solar thermal systems. That's an average, so you'll need a large buffer, but hot water tanks are fairly cheap to make and rock is cheaper.

Heating and cooling and ventilation have a significant impact on our quality of life, and Britain lags behind pretty much every developed country here. Possibly because we have a mild climate (lack of insulation usually won't kill you) and used to have cheap coal we could burn for heat, so we never integrated these things into our homes. At least we don't have large sunk costs and can use the most up to date options. I'd like to see a Britain where we affordably have well ventilated homes that can be kept at 20c year round and where people can take long hot baths every single day without worrying about the gas bill.


"I'm gonna die surrounded by the biggest idiots in the galaxy." - If this forum was a Mars Colony

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#5 2023-02-01 07:36:43

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 3,352

Re: How to Squander Energy on Futile Endeavors

For space and water heating, underground interseasonal energy storage has been used in some places.
https://en.m.wikipedia.org/wiki/Drake_L … _Community

These schemes store solar heat in boreholes some 40m deep during summer and withdraw it for heating year round.  If combined with underfloor heating, temperatures may be sufficient for space heating without heat pumps.  Though I suspect that water heating will require higher temperatures.

One of the things that might make this technology applicable to Britain is that our towns and cities have a relatively high population density.  If this heat can be efficiently injected into the ground at specific locations within cities, then a flow pattern can be established within the subsurface water table.  Heat can be removed from bore holes all over the city.  Some towns are located close to geothermal aquifers.  These could be used to charge underground heat stores.  Nuclear power plants produce a great deal of waste heat at temperatures of about 30°C.  If this heat can be delivered to regional injection points, then a single large powerplant could provide the space heating needs of a city without having to invest in a huge city wide district heating system.

The temperature of the injected water will be ~30°C and the withdrawn water 20-30°C.  This is compatible with the condenser temperatures of existing steam plants.  So standard light water reactors would produce waste heat in the temperature range needed, without specific CHP modification.  We would need to construct heat mains carrying this waste heat from power stations to injection points at urban centres.  These would be large diameter concrete pipes.  Soil will provide the insulation needed.  Small modular reactors could be located close to towns and cities for this purpose.  They could provide electricity to the grid whilst meeting all of the heat requirements of a town.

Last edited by Calliban (2023-02-01 08:00:10)


"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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#6 2023-02-01 07:58:07

Terraformer
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From: Ceres
Registered: 2007-08-27
Posts: 3,800
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Re: How to Squander Energy on Futile Endeavors

Hmm, Drake Landing isn't *too* far south of Britain. About France's latitude? We could make it work here I think. Nuclear waste heat (oh that will be a popular term...) suffers from being very difficult to build in Britain. Solar thermal doesn't, and also has the advantage it doesn't rely on foreign supplies of fuel. How long would it take us to switch to mostly using solar thermal with seasonal storage?

Another option for extracting heat would be air source heat pumps in summer. Those would work even on cloudy days, but would take electricity. Still, if we're using air at 25c to heat rocks to 40c we should get quite a high CoP. Functionally a solar collector but using the whole country to collect the heat.

We wouldn't need a heat pump to get the heat reservoir to the summer air temperature, only if we want to go above it. So getting it to 25-30c is free energy wise.

Last edited by Terraformer (2023-02-01 09:12:19)


"I'm gonna die surrounded by the biggest idiots in the galaxy." - If this forum was a Mars Colony

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#7 2023-02-01 09:14:21

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 3,352

Re: How to Squander Energy on Futile Endeavors

Terraformer wrote:

Hmm, Drake Landing isn't *too* far south of Britain. About France's latitude? We could make it work here I think. Nuclear waste heat (oh that will be a popular term...) suffers from being very difficult to build in Britain. Solar thermal doesn't, and also has the advantage it doesn't rely on foreign supplies of fuel. How long would it take us to switch to mostly using solar thermal with seasonal storage?

Another option for extracting heat would be air source heat pumps in summer. Those would work even on cloudy days, but would take electricity. Still, if we're using air at 25c to heat rocks to 40c we should get quite a high CoP. Functionally a solar collector but using the whole country to collect the heat.

In that case, the technically easiest solution would be to run plastic water pipes under roads, parks, car parks, etc, and absorb summer heat at a temperature of 15°C for injection into the ground.  There need be no specific solar collectors, as the surfaces themselves will absorb heat and conduct it into the pipes.  At the end of each street, we have a heat pumping station that extracts water from a bore hole at say 12°C and returns it at 10°C.  It then delivers warm water to houses along the street at a temperature of 30°C.  The Carnot COP would be ~15.  Real COP should be at least 10, when pumping losses and irreversabilities are accounted for.  Large heat pumps have better COP than small ones and there are system scale economies.  So it may be better having a limited heat distribution system covering individual streets or neighbourhoods, rather fitting each house with its own heat pump and borehole.

If we were clever in the design of such a system, we could use the same single length pipe to collect heat in summer and distribute heat to houses.  This would work by pulsed flooding and then draining the pipe.  When distributing heat, we drain hot water into buffer tanks in each house at a specific time.  Cold water then drains into the same pipe after it is pumped around the house and drains by gravity back to the heat pumping station for reinjection into the bore hole.  During summer, space heating is not needed, and the same pipe can be used to collect heat by filling the pipe and then draining it into the bore hole.

The heat pumping station could include thermal energy storage.  In Britain, wind power delivers most of its output in the autumn, winter and early spring.  This coincides with space heating demand.  However, wind power is variable even during peak months.  A district heat pump could be grid controlled and activated when wind power is abundant.  Several days worth of heat could be stored in tanks containing phase change materials.

In coastal towns, the sea provides a heat sink whose temperature varies no more than 5-6°C year round.
https://www.seatemperature.org/europe/united-kingdom/

In these places, a sea water main could provide the heat source for heat pumps.  The sea water main would run down main streets and heat pumping stations would be located along it.  This may be more cost effective than drilling bore holes where it is available.

Last edited by Calliban (2023-02-01 09:46:30)


"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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#8 2023-02-01 12:28:11

Terraformer
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From: Ceres
Registered: 2007-08-27
Posts: 3,800
Website

Re: How to Squander Energy on Futile Endeavors

According to the Wiki article on climate of the United Kingdom, our average high temperatures in summer are generally around 20c. That energy is gathered using the whole island as a collector. If we could store that heat, maybe we could get CoPs as high as 20... Or if we ran it through solar thermal systems, and managed to get our reservoir up to 40c, we could avoid the heat pumps entirely.

Earth has an R value around 0.25-1 an inch from what I have read. That's 10 per metre. A couple of metres thickness gives R of 20, so with a 40 degree difference the flux heat lost at the surface would only be a watt per square metre, for something that would store dozens of kWhrs. Enough that it would cool down over a few years to not much higher than the surrounding dirt, but we're talking about using it <6 months after putting the heat in.


"I'm gonna die surrounded by the biggest idiots in the galaxy." - If this forum was a Mars Colony

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#9 2023-02-01 18:01:14

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,362

Re: How to Squander Energy on Futile Endeavors

If you're qualified to be a commercial plumber, then you're also qualified to install and maintain a solar thermal power plant.  No advanced electronics are required to run a plant like this.  A mechanical Sun tracker using a pressurized CO2 line could move all the troughs to follow the Sun.  This has been proven in places like India, where "money from heaven" for expensive electronics isn't available.  Since so much of what we use is or could be low-grade heat, that is its own form of efficiency.  Better still, the technology used here directly transfers over to geothermal power plants, and some parts of it are also applicable to nuclear thermal power plants.

Frankly, all washers, dryers, water heaters, space heaters or coolers, refrigerators, and slow-cookers could be run off of district heating systems, using local heat exchanger elements at the point of use, in order to extract work from a hot flowing gas or liquid.  Whether or not someone thinks it's less efficient than using electricity, machines so-powered can be cheaper, overall more reliable since losing electric power doesn't affect your ability to use your appliances, repairable using simple hand tools so far less energy is wasted creating new ones when the electronics burn out, and as a result far less waste is created.  You don't need an electric grid or natural gas lines using this concept, reducing opportunities to get electrocuted or blown up.

This method of "powering" homes and buildings also ties into my "planned foreverance" concept, which replaces our failed "planned obsolescence" paradigm with a new "concept of operations", which takes the stance that our best bet for reducing energy consumption over the long term is to build simple but top quality machines once per lifetime, that can also be maintained by their owners using hand tools.

In the real world, heat engines are the bedrock foundation of our technologically advanced society.  We have and have had the technology to use solar thermal for quite some time now.  Newer government-sponsored scientific development projects such as NREL's supercritical CO2 gas turbines (multiple major gas turbine vendors participated in this) and supersonic CO2 compressors (primarily Dresser-Rand) are merely improvements, albeit important ones, to existing gas turbine / compressor power transfer and conversion technology.  The supersonic CO2 compressor required considerable supercomputer support to model the fluid behavior.  Whereas steam turbines in the multi-hundred MegaWatt class could be the size of buildings, the new tech is the size of an office desk, fits very neatly into an ISO shipping container, and is truck-transportable.  The ability to load major pieces of power plant equipment onto trucks is an increasingly important technology feature.

Rather than going backwards in time to before industrialization, which is exactly what will happen if we attempt to turn the world's base load energy systems into a giant computer game to satisfy the futurism dreams of our technorati, these advanced heat engines are the most promising developments for our forseeable future.  They do everything existing technology does with an extreme level of refinement, they're very long-lasting, and whatever materials are devoted to making these newer reflector troughs and power turbines and electric generators pay out much greater dividends over a human lifetime.

Given enough time, which could be measured in centuries at current rates of progress, I've no doubt that we will come up with better electronics and batteries.  Unfortunately, all of our existing electronics-based technology is very short-lived, relative to a thermal power plant exploiting the same fundamentals that made steam engines so successful.  All we're actually doing is replacing the heating source with the Sun, using hot oil / CO2 / rock / salt to transfer or store heat, and replacing more cumbersome steam turbines with exceptionally compact sCO2 gas turbines and printed circuit heat exchangers (diffusion-bonded steel labyrinth style heat exchangers).

That is enough "profound change" and technological disruption right there.  We don't need to add layer upon layer of needless complexity with microelectronics-based control systems, which is what electronic power plants require in order to function at all.  All the electronics waste and energy we don't create as a result, as previously stated, is its own form of efficiency improvement over throw-away electronics technology.

In a "power grid" based upon heat engine technology, if all customers suddenly turn on or turn up their heaters, then the line temperature dips by a few degrees at most.  Thermal inertia from the large masses of oil, CO2, rock or salt, act to buffer surges or drop-offs in demand.  There are no blackouts, no costly electrical equipment for which no available spares exist is damaged or destroyed, and life goes on, almost unaware that such an event happened.  If a nutjob with a rifle or enemy commando unit shoots a hole in a hot water pipe, then we turn off the hot water supply, weld the hole shut, and then service continues.  A gigantic solar flare or exo-atmospheric nuclear weapon detonation can't disrupt the flow of thermal power, either, because there are no long wires for the generated voltage to conduct into.  Those types of attacks will become irritations that temporarily disrupt internet or cellular service, but have no long-term ability to disrupt civil infrastructure.  If some nitwit releases a malicious AI program onto the internet, then that type of "learning machine" can't take over the infrastructure, either.  Near-instantaneous electronic control is not required if energy distribution is through heat.

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#10 2023-02-01 21:00:10

Void
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Registered: 2011-12-29
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Re: How to Squander Energy on Futile Endeavors

I respect your position on this kbd512.  For Mars also, I think getting things to work "Good Enough" with methods that are more robust and not so prone to a stupid failure, is a good way to think it out.

Very good!

Done.

But you understand they want us on our butts, they certainly don't want independent thinking.  (Whoever they are?).

Done.


Done.

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#11 2023-02-01 21:43:28

SpaceNut
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Re: How to Squander Energy on Futile Endeavors

Kbd512, I like the topic and it's got lots of facts to rumble through since they are very large posts its going to take time to get through them.

The real embedded energy is actually even higher as the finished product takes equipment for mining, fuel for the equipment a plant to make the fuel and so much more as you must count as if it needs all the startup for a true number for useful.

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#12 2023-02-02 02:58:26

Terraformer
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Posts: 3,800
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Re: How to Squander Energy on Futile Endeavors

It's pretty amazing how much of our electricity we *deliberately* turn into low grade heat. Washing machines, mostly hot water. Dryers, mostly hot air. Dishwashers, hot water. Even kettles, though given that we're trying to get small quantities of boiling water with those that's understandable. I suspect our electricity demand would come down considerably in Britain if we properly mastered heat (a fair few houses have electric showers. Instead of tapping into the homes existing and far cheaper hot water line that already runs to the room it's in. I do not understand this.) given that not all houses are on the gas network... Whilst at the same time, getting homes off gas would free up far more than we currently use for electricity generation. It's crazy how, for every two kWhrs of low grade heat we get from gas, we could have had a kWhr of electricity -- which with a ground source heat pump could have given us >10 kWhrs of space heating.

I think the problem with Britain is that our temperatures usually only get cold enough to be uncomfortable to most people (the sick the old and the very young excepted of course) rather than lethal as they are in most other places, so we never got around to properly handling the heat flows in our houses. Something we need to fix, if only because I'm sick of living in a 15c house in the winter.


"I'm gonna die surrounded by the biggest idiots in the galaxy." - If this forum was a Mars Colony

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#13 2023-02-02 06:23:19

Calliban
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From: Northern England, UK
Registered: 2019-08-18
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Re: How to Squander Energy on Futile Endeavors

It would appear that the best options for heat transfer fluids at temperatures above 400°C, are molten salts.
https://globalhtf.com/heat-transfer-flu … ure-fluid/

Nitrate salts appear to be most promissing, due to their low melting points and good compatability with stainless steel.  Calcium nitrate can be used at temperatures up to 500°C.  This temperature is high enough for S-CO2 or superheated steam production.  Going higher than 500°C, means using liquid sodium or inert gas as coolant.  Flammability during leaks is a problem.  But the biggest problem is that any oxygen getting into the sodium will yield highly abrasive sodium oxide, which will erode the pipework, pumps and heat exchangers.  So sodium probably isn't suitable for distributed pipe networks.  The problem with gas is low heat transfer coefficients and low heat capacity at achievable pressures.  Both tend to neccesitate high flow speeds, which means high pumping power.  On the plus side, nitrogen and argon both have good compatability with steels.  Carbon dioxide can also be used, but does present some corrosion problems to steel at temperatures higher than 500°C.

Another problem with high temperature operation is that low alloy steels lose about 50% of their room temperature strength between 500-550°C.  Strength decreases very rapidly as temperature gets hotter than 550°C.  It is these material limitations that tend to limit the operating temperature of real life powerplants.  It is why it took so long to develop supercritical steam powerplants.  Steam gets progressively more corrosive as temperature increases and steel loses strength.

Last edited by Calliban (2023-02-02 06:29:37)


"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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#14 2023-02-02 22:05:12

kbd512
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Re: How to Squander Energy on Futile Endeavors

SpaceNut,

To the extent that I can, I try to gather information from multiple sources to learn about what the "general case" happens to be, with respect to embodied energy.  I use median figures, rather than exceptionally high or low figures.  For example, not all processes for making steel require the same amount of energy.  However, for a typical blast furnace, that 50,000MJ per metric ton is a reasonable estimate for virgin materials.  A few years back I did quite a bit of reading about steel making (went through a couple thousand pages describing the processes, efficiencies, areas open to significant improvement, etc), simply because we use so much of it and I wanted to know more about how its made.  I did not use the embodied energy figures for recycled steel, which is much lower.  The reason I did not, is that a solar thermal plant capable of replacing fossil fuels would require "new build steel".  There's insufficient scrap steel to deploy solar thermal technology at a global scale.  The same applies to the photovoltaics.  Recycling is not even an option with photovoltaics since so few existing panels are available for recycling, relative to demand- we must extract virgin materials or there's not even close to enough to go around.  15,000MJ per 1kW of installed capacity is a likewise reasonable estimate for commercial photovoltaic panels.  Someone out there may have developed less energy-intensive processes for making steel or photovoltaic panels, but nobody is using those processes at any appreciable scale.  I have to believe that the reason is energy cost, meaning any process that is "more efficient" in one aspect of operation probably requires more energy input to accommodate some other aspect of its operation.

Ideal cases for either are not normative, thus cannot be used as a proxy for "true cost" ("true energy cost").  This is also why cast Iron was so commonly used, even after the Bessemer process for making steel was invented.  We lacked the energy required to mass produce more energy-intensive metals such as Aluminum.  Cost is a proxy for energy cost.  Money and free markets are about ensuring that someone doesn't de-facto force everyone to use some wildly inefficient process, in terms of energy cost, for any purpose.  Whether it's making energy or kitchen knives, the free market presents options and the consumer base then decides what to purchase based upon what they can afford and whether or not they need / want what's on offer.  This is why the Soviet Union could continue using vacuum tubes while the Western World moved on to transistors and then integrated circuits.  The tubes were insufficient for the purposes we in the West wanted to use them for (almost everything), but under the Soviet / communist system, computing remained a scientific curiosity.  What the Western World either "forgot", or more likely never understood to begin with, is that the constant consumption associated with "making entirely new stuff" (like electronics), demands more and more energy over time.  Whenever energy demand exceeds supply, there is catastrophe.  Absent free-market price controls through the market's proxy for energy and labor, which we call "money", we might force everyone to use kitchen knives made from Aluminum.  If we did something that silly, then we'd also be forced to replace them on a regular basis.  The market and money tells us to "stop and think about what we're actually doing" (and then invent something better or accept a more practical alternative).

Applied enough times and in enough different ways, such a course of action would prevent the use of energy for any other purpose.  This is why Titanium costs more than Iron.  It's not because Titanium is particularly "scarce", rather the energy required to make Titanium is not limitless, so fixating on making Titanium detracts from other useful things like food production, clean water, education, etc.  The free market and monetary system ultimately act to curb or entirely prevent fixation on "objects of affection" which are either luxuries or entirely unnecessary.  Oddly enough, that was also the downfall of the Soviet Union and communist systems in general.  They spent themselves into oblivion making military hardware while neglecting food production, farm tractors, and other necessary things, because the person in charge wanted more tanks than tractors.  The Soviets had those super-cool Titanium submarines, but that didn't prevent their people from starving in the streets, did it?  Totalitarian systems of governance will force people to "spend energy" on extravagance for the state, like making Titanium-hulled submarines when large swaths of the population don't get 3 meals per day, or to use wildly inefficient methods for achieving a necessary end, such as every woman in Moscow wasting all day standing in line to buy bread.  If the person at the top tells them to do it, then they do it until the state can no longer afford the energy cost of providing Aluminum kitchen knives to its citizens.  In their case, it was related to providing food.  No reasonable number of humans or animals can keep up with a John Deere combine-harvester or tractor to till the soil.  The cotton harvester effectively ended slavery here in America, regardless of what the Union and Confederacy chose to do or not do.

What we're trying to do right now, via electronic devices such as photovoltaics and batteries, is similarly silly to trying to design a supercomputer using vacuum tubes.  It might be physically possible to make and power one example, which is what the Soviet Union would do, but it's so wildly inefficient that we limit what other things we can expend energy on.  The use of electricity is "efficient" in one aspect of its operation, namely the transmission of energy / conversion back to mechanical work.  However, even that is only "true" if you utterly ignore the tonnage of materials required to generate / distribute / convert electricity, and then it starts to look pretty awful from an efficiency standpoint.

Electronic machines are not more efficient at global scale, but nobody ever zooms out that far.  They think their own little computer-controlled Espresso machine uses very little energy (to make fancy coffee), while ignoring everything else that went into making that machine.  In the end, it is not more energy-efficient than a steam kettle.  That's why we can afford to make dozens of steam kettles for the same energy cost as a single computer-controlled Espresso machine.  If you need to make coffee for hundreds of millions of people, then you're not going to do that by making $500 espresso machines for each person when a $10 steam kettle will do.  Recall that legitimate consumer products businesses make 5% to 10% profit in the real world.  That means the rest of the money you handed over for your steam kettle or electronic espresso machine was dumped into the energy and labor required to make the machine.

Needless complexity creates a "snowball effect", as it pertains to energy consumption.  Past a certain point, rules and regulations work the same way.  That is also why a "certified" aircraft instrument, which is physically identical, made on the same production line, and tested at the factory to the exact same standard is 2X to 3X more expensive than the same instrument sold for a "non-certified" / "experimental" aircraft.  One instrument has a mile-long paper trail attached to it and certain liability expectations, while the other does not.  Either way, the instrument is not "better" or "worse".  Will that certificate / sticker that comes with the "certified" instrument "save you", if the instrument fails?  Of course not.  If you altimeter is wrong, the sticker on it is meaningless.  We fixated on putting checks in blocks to the point that the quality of the instrument because a secondary consideration.  If you ask me, that's taking regulation to the point of becoming counter-productive.  If $1,000 buys a quality altimeter in the non-certified world, then $3,000 should buy one that's more or less guaranteed to never fail unless you physically damage it by, say, dropping it on concrete.  Heck, for that much you should even be able to accidentally drop it a few times without serious damage.

Per square meter of panel / trough surface area, there's not much total mass difference between 1kW of photovoltaics (12.64kg/m^2) and 2mm thick stamped steel (15.7kg/m^2).  However, the embodied energy difference versus surface area is pretty dramatic.  In the game of "let's repower the world using the Sun", surface area is a major figure of merit.  The 2mm Carbon steel is 785MJ.  The photovoltaic panel is 2,936MJ.  The. Aluminum-coated steel reflector "pays back" 500W/m^2 (it actually reflects over 900W/m^2, but that's not what you can actually get out in terms of useful work, so it makes no difference that Aluminum reflects more than 90% of the light, which is then thermalized in the heat transfer fluid tube above the trough.  The photovoltaic cells "pay back" 196W/m^2.  There's quite a difference there.

If money has any meaning, then you don't have to be very good at math to figure out which method is the "better deal".  Attempting to deploy photovoltaics at a global scale to replace fossil fuels is the energy system equivalent of walking five miles through the snow to get to school, up-hill, both ways, and then when you're within sight of the school, returning home because you forgot your backpack.  If the photovoltaic materials were easy to come by, photon conversion efficiency was a bit higher, and they lasted a lot longer without declining output, then I'd have a different opinion.

Photovoltaic panel energy requirements are so high, relative to stamped steel sheets, because making semiconductors (yes, it's a very thin Silicon wafer at the end of the day, but "any old kind of sand" will not do), extracting and refining metals (Gallium, Aluminum, Silver, Copper) or minerals (Arsenic, and sand to make glass) that are not "Earth-abundant", making glass or Aluminum- those are all incredibly energy-intensive processes.  That's how it's done in the real world, because alternatives are even more energy-intensive.  It's the same reason we don't extract Lithium from sea water.  The Lithium is there, and the total amount is a truly huge quantity, but getting it into Lithium Carbonate form to make Lithium-ion batteries would require inordinately more energy than evaporating it out of mineral pools in South America.  We don't use steel frames to make photovoltaic panels because a slew of engineers out there determined that Aluminum is the correct material to use.  They have very good reasons for doing that.  It probably has to do with stiffness-to-weight, because flexing semiconductors is bad for their health.  If you can make an Aluminum reinforcement frame twice as thick for less total weight than steel which achieves equal stiffness, then doing that makes the section of material about 8X as stiff, IIRC.  Since these things have to be transported and installed in places where the wind makes them flex or onto structures without a lot of load bearing capacity, we use Aluminum.

So, I ask all of you:
Are we getting "premium electrons" by spending more money to generate electricity?

Can your lightbulbs distinguish between "premium" and "base model" electrons?

If you can repair your washer or dryer using $50 worth of hand tools, does that sound better than getting a specially trained technician who charges more for his labor than the washer or dryer is actually worth, to come out with his fancy electronic test gizmos, only to tell you that the circuits are fried.  He'll either need to completely replace them at most of the cost of a new unit, or you can go buy another washer or dryer.  That's the entire reason why they put electronics in your washer and dryer to begin with, since that is always the end result.  The manufacturers know that with electronics, every 5 years you'll need to buy another more expensive model from them.  That's the plan.  Even if that's not the plan, that's the result, so what's the difference?

"Things they don't need with money they don't have" - George Carlin.

If we don't actually need to generate so much electricity in the first place, then we can go back to not having frequent blackouts while still having low energy prices and as much energy as we need to stay warm and have food on our plates.  How is that not a better result for those of us who are not independently wealthy?

Putting all of your eggs in a fundamentally unreliable basket is a very bad idea.  It's technology, not magic.  When you cease to control what the technology does, and instead the technology controls what you can do, then it's time to admit that you're making a mistake.  It's no great logical leap for the technology to be turned against you.  People can be evil and devious schmucks, even if most people aren't, most of the time.

I think we're going to need solar power because we'll eventually run out of oil / gas / coal, but for solar power to be sustainable the turnover rate for all required equipment needs to be about the same as the equipment at a coal-fired power plant, which means 75 years of operations.  I cannot look at any of our electronic technology and make that assertion.  It's simply not ready for such a monumental task.  That could change tomorrow, or it could change 75 years from now.  All I know is that when lives are on the line you don't willingly use anything you're not absolutely certain will work.  There are far more open questions than answers on this "energy revolution".  It's at the same stage internal combustion engines were at when the diesel engine was first built.  It could be really useful one day and shows great promise, but steam engines generated the power for ships back then because diesels were nowhere close to being ready to do that.  Even during WWII diesels were not considered generally reliable power plants.  That's why the US Army was slow to adopt them.  After technology improved, that changed, but the changeover wasn't forced by government edicts.  We have a lot of very anxious people who simply cannot be bothered to allow engineering to catch up to where their fantasies are at.

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#15 2023-02-03 17:35:35

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: How to Squander Energy on Futile Endeavors

Even with all of the energy source going to the companies that are providing the energy to the customer the prices are still going up.

One of the concepts for solar and wind is to tie them into a world crossing grid that circles the globe rather than staying just state side or being stored in batteries for the electrical systems. Of course, it's better to use gravity storage for a bulk method.

Thermal energy creation is another method but storage and use deal with conversions and at this point in time it's not capable of being a global grid system.

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#16 2023-02-04 12:35:28

kbd512
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Registered: 2015-01-02
Posts: 7,362

Re: How to Squander Energy on Futile Endeavors

Calliban,

The issue I see with using salts outside of the power plant is having the salt freeze in the lines.  At the power plant, this is less of an issue.  That's why we have to use gas or water to transfer the power.  Inside the plant, we can use oil or salt or rock for thermal power storage because the infrastructure exists to re-heat the salt.  I would assert that pulverized rock is the best option on cost grounds.  Rock can't degrade like oil or salt can, even though salt is pretty stable, rock can't become contaminated, and if pulverized rock (aka "dust") accidentally spills somewhere, then your "environmental catastrophe" can be cleaned up using a shovel, broom, and dust pan.  If you encounter a "rock spill", then you might just say "oops" and continue on about your business.

Through the power of marketing, we might also convince some stupid people that we're selling "premium rock".  To identify our market / customer base, they would most likely be the same people who think we're going to power everything with photovoltaics and wind turbines.  Those people can be convinced of pretty much anything, due to their lack of critical thinking skills and inability to do simple math.  They make great YouTube videos though, so our cadre of not-so-useful idiots awaits.  Australia has an "Electric Viking", apparently, so maybe we could have "The Rock" sell these clowns expensive "premium", ahem, rock.  You know, so they know they're "making a difference" by buying things.

Anyway, my concept involves removing both the electric power lines and gas lines.  Each home or building will have its own onsite electric generator and heat exchanger (no more electric grid or gas grid), powered by hot flowing gas or steam.  Washers / dryers / water heaters / refrigerators will be run off of the heat exchanger.  The lightbulbs / consumer electronics (cell phones / computers / television sets ) / kitchen appliances (microwaves / ovens / toasters) will be run off the electric generator, obviously.  The HVAC system will be run off the heat exchanger.  Eventually, the millions of tons of steel / Iron / Aluminum / Copper wiring can be collected from our defunct electric grids, to be used to make other machines.

There will be two kinds of lines for most homes and businesses, water and inert gas (Nitrogen or CO2).  If it's CO2, that incentivizes companies to capture CO2 for sale to the power companies.  The major appliance manufacturers are incentivized to switch to mechanical washer / dryer / water heater / HVAC appliances.  Your washer and dryer will contain no electronics or electric motors, relying instead on water and a hot flowing inert gas.  There's a very low likelihood of electrocution or explosion or fire when no electricity or natural gas is present to begin with.  Restarting a hot water heater no longer involves lighting a match or flipping a circuit breaker switch.  A mechanical valve transfers the hot gas or hot water, same as turning the water on.  All the Copper and other high-value metals can be recovered from those as well.

I realize this is very different from how most homes are powered today, but over the long term it will save money / energy on appliances and repair bills.  That money / energy / material can then be devoted to some other useful purpose.  Homes will still be wired so lights and consumer electronics still work, but they're not wired all the way back to an electric grid, because you have your own onsite electric generator.  Since we already have so many electric motors in homes today (HVAC systems, garbage disposal, washer and dryer, pool pumps), this should not be an inordinately difficult task to accomplish.

Fundamentally changing the home or building, such as completely redoing the insulation, windows, and possibly even the floors or foundation, is not required.  That's what wind turbines / photovoltaics / heat pumps require- a complete "home makeover" for every building.  The use of grid-supplied electricity and natural gas will be limited to very large structures such as skyscrapers or shopping malls or sports stadiums.

The next heat wave / winter storm / solar storm / terrorist or nutjob attack on the grid / war is not going to easily take down the power for almost everyone living in a major city, for example.  Austin, Texas, just south of where my parents live, had 400,000 homes without electricity in the middle of a winter storm.  The natural gas lines weren't affected, but since most people now use electric heaters and appliances, life had to stop for nearly half a million people.  This is the issue with "electric grids" that aren't as simple as "turning a valve" to restore the flow of power.  When conditions are ideal, which is most of the time, they work great.  When conditions are bad, they fail completely far too often.  They tend to be "all or nothing" affairs.  They don't have any "graceful failure mode", to include the so-called "smart grids", which only reduce the possibility of total failure by turning the power off.  You could say they're designed to fail because whenever local weather conditions take a turn for the worse, that's exactly what happens.

Gas lines can and do fail, but they fail from corrosion after many decades of use, or from water freezing in the line.  Whereas in the past giant electric generators would slowly be "dragged to halt" by the load placed on the grid, these days you increasingly have "zero spinning reserve".  That means if you're just a bit above the current capacity, every connected customer can lose power.  With a thermal "grid", which has a huge thermal inertia in aggregate, if too much demand is placed upon the grid then your all-mechanical clothes dryer spins a little slower and pumps a little less heat in, but it doesn't stop spinning or drying until you've extracted nearly all of the energy contained in the system, which should be almost impossible using a properly sized system.  All that intermittent energy from the Sun is immediately converted into something that is storable en-masse, because it's dumped into a giant mass of hot oil / salt / rock.  Whether or not a cloud passes overhead is largely irrelevant, because dragging down the grid would require weeks of cloudy weather.  If this (weeks of cloudy weather) is typical of your locale, then you increase the mass of materials used to store thermal power to compensate.  Since the "thermal mass" is literally "dirt" in many cases, acquiring more dirt and steel piping is not particularly problematic.  Even if some competing technology is "dirt cheap", it'll never be available in the same quantities as actual dirt.  If we ever run out of actual dirt, then we'll run out of lots of other things long before.

So, if you don't want people to use fossil fuels (coal, gas, oil) because of global warming and you restrict how much electricity they can use (California and Europe), because their electric grid can't meet demand right now- never mind when most of their customers are consuming 4X more electricity if everyone is forced by government mandate to drive an EV, then you need to present a viable alternative that's actually simpler / faster / better.

As compared to EVs, the range on compressed air powered vehicles is poor, but at least metal compressed air tanks can be easily recycled into new compressed air tanks.  If you have a solar thermal power plant providing the compressed gas, then you also have an energy storage mechanism that requires no "Complete Grid Makeover, Global Edition".  Compressed air can be transported with ease, although if "gas stations" compress and dispense air from storage tanks that they make onsite using thermal power, then they cut out the gasoline delivery truck drivers and oil companies.  If it accidentally escapes into the atmosphere, then nothing worth noting actually happened.  Air cannot catch on fire and it cannot explode, so vehicle fires are far less likely.  You cannot get Carbon Monoxide poisoning from an air powered vehicle, either.  Recharging doesn't take appreciably longer than pumping gasoline.  Since there's no fire risk associated with recharging, it truly can be charged from home, overnight, using thermal power to run the pump while dumping waste heat from compression into your hot water tank.

The best kind of grid to have is one that is stable and reliable.  This does not describe any electric grids, regardless of what powers them.  At any given time, they're seconds away from a complete shutdown if the load or supply significantly increases or decreases.  We have all manner of connected equipment intended to chase down the load.  This is clearly the wrong way to do it, even if you can make it work most of the time.  In a thermal system where inertia is quite high, even if half the customers suddenly flip on their light switches, no near-instant response is required to prevent the grid from dropping the load.

Since everyone thinks about things in terms of electricity around here, then you can think of this power system as a giant collector attached to a giant battery, although a "thermal capacitor" is a more apt description, that is essentially "hot dirt" or "hot rock".  The collector requires no fuel, it's the lowest energy structural material available that's suitable to task, and the giant battery requires very little in the way of refined materials to expand its capacity.  If there is no demand on the battery, then you get it as hot as the system will tolerate and then you maintain its capacity each day by "recharging it" from sunlight-generated heat.  If you demand energy, then flowing gas or water transfers the heat through the pipes to the point of use.  As far as "cheap" or "expensive" is concerned, the proper question is, "Cheap compared to what?"  To burning through increasingly scarce fossil fuels?  To wind turbines / photovoltaics / batteries that are pure byproducts of fossil fuel energy that are both nowhere near the required scale and are unlikely to ever come close to scaling up as required?  To using these wonky hybrids that require keeping the Methane-fueled gas turbines spinning 24/7/365, because sunlight or wind can stop at any given moment?

Sure, you have to pay for the system in terms of energy, but then the maintenance does not entail total replacement of failed components the way electrical systems work.  If supply exceeds demand for electrical systems, then you dump the current into the ground or you start blowing irreplaceable transformers and other equipment to adjust the voltage and current.  If demand exceeds supply, then you start shedding the load, which means whomever is downstream is out of power.  Constantly trying to balance a bowling ball on a see-saw is a waste of time and energy.  Size the power plant to the point that it's always over-capacity, dump any excess thermal power into a mass of material, and call it "good enough for government work".  Whatever your peak demand is, that's the capacity you build a thermal power plant to.  The rest of the time, you have excess power available for any desired use.  For the "thermal battery / capacitor", you add capacity to the point that you can go a week or so without much in the way of collector input.  We can't come close to doing that with electrochemical batteries.  In point of fact, nowhere on planet Earth, not presently powered by fossil fuels, has a week's worth of stored power.  Batteries are already mass-produced, we don't know how to make them much cheaper than they already are, and we're projected to run short of the materials required to make new ones within the next decade unless we start recycling them at near-100% rates.

Homes built since 2000 consumed the same amount of energy as one built in the 1960s, while being on average 27% larger. Of the energy used in U.S. homes in 2015, 55% of it was used for heating and cooling. Water heating, appliances, electronics, and lighting accounted for the remaining 45% of total consumption.

Air conditioning and heating: 46 percent; Water heating: 14 percent; Appliances: 13 percent; Lighting: 9 percent; TV and Media Equipment: 4 percent.

Translation:
There was no actual "energy savings" associated with "going electric".  They made the homes bigger to compensate.  The lights are left on all the time now.  The TVs and electronics became radically more efficient, so now power that can only be provided by electricity is about 13% of total demand, and less over time as all electronics or LED lights consume lower and lower fractions of the power being generated.  In a "near-future state" where personal electronics are limited to cell phones and laptops that consume maybe 50W of electricity per person, does it still make any sense to blow mad money on electric grids maintaining or expanding electric grids that are not actually "saving" any energy?

Given that most of what we're doing is turning electricity back into hot or cold air, or hot water, then why not use thermal energy directly?

If everyone is supposed to have a photovoltaic system on their rooftop and batteries for electrical storage, then having direct thermal energy for most other appliances (HVAC / refrigerator / washer / dryer / water heater), there's no longer a requirement for much in the way of grid expansion.  If the car makers were making compressed air or natural gas hybrids instead of batteries, then that pretty much takes care of daily use energy-intensive systems.  We can still make absurdly heavy powered by compressed air, but they won't cost any more than gasoline powered vehicles and won't require electricity or batteries, which means an incredibly simple and reliable vehicle can be had.  If it ever does break, then hand tools can fix it.  A compressed air vehicle would have an electric generator run off of compressed air, in order to power the lights.  Since it makes cold air during normal operation, it doesn't need an AC compressor or refrigerants.

President Biden and the Democrats are already banning a lot of this stuff (traditional lightbulbs, refrigerants, combustion engines) anyway.  Democrat Lite, which is at least a quarter of the Republican Party, is not stopping them.  If we actually had viable alternatives to fossil fuels, then nobody from the public is fighting over this issue.  Unfortunately, that's not what we have and that's not what we're doing.  Electricity is being sold as some kind of "savior" that it's not, to people who are still very much religious, albeit wackier than some of our Bible thumpers, even if they don't believe in Jesus.  That's because all electrical systems demand inordinate increases in material consumption and byzantine levels of complexity at a national or global scale.  It's naked consumerism being "prettied up" to make the ignorant think that they're "saving the planet" by buying specific and very expensive machines with low overall performance and modest efficiency improvement in energy consumption.  Well..  Saving the planet for who and for what purpose?  We're going to adjust the thermostat by turning it into a strip mine?  I don't think so.

This proposal is a more intelligent hybrid that combines the ease of transport of natural gas with the use of other kinds of non-explosive gases for delivering thermal power.  After that thermal energy is "onsite", then it can be converted into electricity, if required, or it can be used directly for heating and cooling.  Since most electric power is used for heating and cooling anyway, direct consumption without conversion is both possible and on balance more efficient after all inputs and outputs are considered.  It's the kind of in-depth analysis you don't get from people who are selling you an idea that agrees with their sensibilities.  I'm not even enamored with my own ideas, it's just that I can accept when I "thought wrong", and then take the monumental leap of changing my course of action, whereas most people can't do either.  Why can't they?  I've no idea.  I'm not emotionally invested into any of this, so maybe that's why.

Where my power comes from is irrelevant to me.  I expect it to be available at all times, but that's it.  How that is achieved is irrelevant to me.  If I lived next door to a nuclear reactor, I wouldn't care.  I would hope that being near a reliable steam kettle would mean I always have power, though.  I've never seen a nuclear reactor that failed to make heat.  Normally we have the opposite problem with those.  If it wasn't regulated out of existence, it would be my go-to.  I value reliability and simplicity over all other design considerations.  That said, we can easily "make do" with solar thermal power systems for less total cost than nuclear by immediately converting intermittent / unreliable energy into a more reliable form.  The insistence on direct conversion to electricity is trading one unreliable form of energy for another.  All electric systems are second away from shutdown the moment input power is lost.  There's less complex cleanup with solar thermal than nuclear thermal afterwards as a bonus.  The cherry on top is no obnoxious "protesters" whining and crying about having reliable power, because it was made by splitting atoms or burning something.

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#17 2023-02-04 14:26:10

SpaceNut
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From: New Hampshire
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Posts: 28,747

Re: How to Squander Energy on Futile Endeavors

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#18 2023-02-04 15:38:09

Terraformer
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From: Ceres
Registered: 2007-08-27
Posts: 3,800
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Re: How to Squander Energy on Futile Endeavors

The figure for homes built since 2000, when was it collected? Because LEDs only really became dominant (at least in Britain) sometime around... 2008 maybe? Or even a few years after, I'm sure they were still pushing CFLs on us in 2011. If a lot of people were still using incandescents, that 9% figure for lighting will be a gross overestimate for what it is today.

13% for appliances will cover toasters, fridge freezers, microwaves, washers, dryers... What fraction of their energy is heat related? I don't think I use kettles and toasters and microwaves enough for them to be a greater demand than freezers and washing machines and tumble dryers. Of course, these figures are for America... Adding up my own average daily consumption I'd say maybe 150Whr for my laptop, 5Whr for my phone (dayum), 10Whr for my tablet (basing these on charging times and battery life) -- I hardly watch TV, most of the time I'm using my tablet for streaming, I'll bear these figures in mind if there's a power cut and I'm having to rely on less powerful sources (on a clear winters day, one square metre of solar PV would keep my phone and tablet going... That's crazy efficient). 500Whr maybe for the kettle (big tea drinker). 120Whr at most for the microwave. Don't know about the toaster, I rarely eat toast. If I was fastidious about turning off lights (I am not, cheap light has made me lazy) it would probably be about 100Whr for lighting. All in all I'd say the stuff that *definitely* needs electricity (or is made significantly more convenient by it, like the kettle) takes up less than a kWhr of power a day. Hmm.

Yeah, I suspect we're still using almost all our domestic electricity to create and or move heat. Kinda insane. If we could get heat down to say 2p a kWhr @40c (and fixed our leaky uninsulated homes up), we could  seriously lower electricity demand and utility bills *whilst improving our quality of life*. I'd expect Brits to install a lot more dryers and dishwashers if that happened smile  Would help with the grid issue as well. Could be done neighborhood by neighbourhood; the gardens here aren't massive like they are in the States, but a heat network covering a couple hundred homes could work, as Calliban suggested. Our 11kV substations serve around that number, so it would tie in well with the existing electricity grid. Bring back the (couple) Hundred (households) as an infrastructure administrative unit? tongue

Last edited by Terraformer (2023-02-04 15:44:19)


"I'm gonna die surrounded by the biggest idiots in the galaxy." - If this forum was a Mars Colony

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#19 2023-02-04 20:06:11

kbd512
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Registered: 2015-01-02
Posts: 7,362

Re: How to Squander Energy on Futile Endeavors

Terraformer,

I think we're essentially noting or saying the same thing in different ways.

The data was collected before LEDs were "normal" in homes.

My point was, now that personal electronics and lighting consume so little power, on a per-person basis, almost all of the electricity used in a home is devoted to heating something up or cooling it down.  Even most industrial uses of electricity involve heating something up or cooling it down.  Since such is now the case, it makes the most sense (to me), if cost and reliability matter at all (which should matter to most people paying for something), to do that using direct thermal energy carried within a moving fluid (like water or CO2 or N2).  The things that actually need to be electric (electronics) are not directly driving energy costs up (but they are indirectly being driven up by insisting on putting a computer in things as simple as steam kettles).

Everything else is related to thermal regulation, which means it makes a lot more sense to use thermal power directly if cost and reliability and volume of energy use are properly accounted for (apples-to-apples comparison, and a photovoltaic panel with no battery is not "apples-to-apples" with coal or natural gas or nuclear or solar thermal providing thermal energy storage).  Reading off numbers on stickers is equally meaningless without context.  If a particular type of appliance is 25% more energy-efficient than the next, but it took 100X more energy and scarce materials to make it, and it's twice as heavy as what it replaced to boot, but you intend for everyone to have and use this more energy-efficient appliance, then eventually you run smack into scalability / resource constraints and energy efficiency problems trying to make those new appliances.

Fixating on a singular solution (electricity) for everything, appears superficially efficient while utterly failing to reduce energy consumption, because all those electrical devices required a lot more energy and resources to make / replace.  Electrical / electronic stuff is great because it works perfectly right up to the moment that it doesn't, and then the only cost-effective option is total replacement of the entire device.  The entire notion of recycling the scarce materials used to make electronics, "the day after tomorrow" thinking which so few people do, is never accounted for in electrical / electronic everything ideology.  Most people view electronics as "magic" because they don't understand how they work, much less how they fail.  I write software for a living and made some of my own electronics as a kid.  They're no longer "magical" to me.  Interesting and fun to work on when you have the equipment to do it, yes, but there's no magic to be had.

These people are asserting that the solution to our energy consumption problem is to buy new electronic stuff that consumes a lot more energy overall and doesn't last as long in practice as much simpler machines, are feeding into the problem.  I'm over here asserting that their ideology is wrong, because their math is wrong.  Ideology that disagrees with basic math... is wrong.

If their ideology was correct, then we'd have to be consuming less energy over time as our machines became drastically more efficient, which they did.  Unfortunately, that net energy consumption reduction hasn't happened at all or ever.  If they "for real for real" actually want to "make a difference" or "save the planet", without knowing what those things mean to them, then at some point the increase in energy consumption has to taper off.  If it doesn't, then simple entropy (creating increasingly ordered materials and machines from increasingly disordered raw ore deposits that are rapidly being depleted) mandates more emissions because it requires more energy.  That in turn creates more pollution and/or more widespread poverty as fewer and fewer people can afford to take advantage of the newer / more expensive machines that don't last as long.  That has the exact opposite effect of making energy systems cleaner.  People will default back to burning coal or wood as you make higher forms of energy unaffordably expensive.  We see that now in Germany, as well as other countries in Europe and Asia.

I don't have to be the sharpest tool in the shed to understand stuff like that, but neither does anyone else.  The information simply has to make its way past their ideological filters which have falsely convinced them to believe that there's some sort of "free lunch" to be had in electrical / electronic machines (somewhere), when there clearly isn't.  Think about all the people who have purchased a Tesla to "save money on gas".  They may not buy gas, but they paid 3X as much as they would've for a gas powered subcompact car.  How or why does that make sense to them?  It's either ideology or the "free lunch" fallacy, but it's not basic math.  There aren't any "free lunches" out there, because the known physics of this universe forbids it and nothing about the technology they're using has changed the physics involved.

You can't "save the planet" from the climate change boogeyman by buying some specific thing, or anything at all.  The climate change boogeyman feeds off of what we make and consume.  I don't subscribe to "boogeyman ideology", because emergencies don't happen over decades or centuries.  A war that lasts for 20 years is no longer a "national emergency", it's a routine part of "normal operations".  You adjust and adapt to that.  You don't spend your entire life running around like your hair is on fire, nor encourage other people to do so.

This is where my proposals come into play.  They suggest we make large and therefore meaningful improvements without completely tossing out the old systems because we don't like the fact that it's not "ideologically perfect" or "shiny and new".  The solar reflectors are "shiny and new", though, really shiny as a matter of fact, so they'll have to settle for some ideological imperfection to achieve the goals they claim they're interested in achieving.

A heat engine?  Eww...  That's "dirty old stuff", why would we ever want that?

Well...  None of your "new stuff" can keep the power on without also burning through the same amount of fossil fuels, so if you want something that's "actually new" and "actually better" for the environment, and other people if they matter at all to you, then in the realm of engineering you start making pragmatic compromises.  One such compromise is not turning heat into electricity and then back into heat.  If we have to spend mad money making electricity, only to turn it right back into heat, then maybe we could skip the entire electrical part and just use the heat directly, with all the gross simplification and energy consumption reduction that allows for, and move on to more fruitful endeavors.

I realize my posts are longer than strictly necessary.  I could just say, "all our electrical stuff ain't reducing energy consumption, so we need to go back to heat engines", but then all the nuance and detail and what I actually intended to convey is entirely lost.  Apologies if more electrons were consumed to convey more complete thoughts, but storage space is pretty cheap these days.

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#20 2023-02-04 21:03:30

kbd512
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Registered: 2015-01-02
Posts: 7,362

Re: How to Squander Energy on Futile Endeavors

SpaceNut,

If an entire engineering dream team and decades of R&D work were not spent to produce a functional sewing machine, then despite how "great" a sewing machine designed by the "dream team" might possibly be, we still arrived at the desired end result of having usable sewing machines.  The perfect is the enemy of the good.  Lifetimes can be sepnt chasing after engineering perfection.  We developed pens that wright in space, whilst the Soviets figured out that grease pencils still get the job done.  ISS has both, but most things written down are temporary in nature, so grease pencils still get used for important stuff like the frequency to reach mission control, what the current orbit is, which experiments need to be done first, and other "unimportant" little details like that.

Zip ties and duct tape get the job done until an engineer can spend unlimited time and money coming up with a "professional" solution.

GW Johnson's "gas gauge" for the Piper Pawnee Brave crop dusters was a simple mason jar.  That was a FAA-approved modification with a STC attached to it, because it works.  A mason jar doesn't cost a gazillion dollars and is available in almost unlimited quantities on farms across America, which is where those crop dusters operated at.  I've never seen a mason jar adversely affected by storing alcohol or gasoline, either, and the entire reason that mod existed was to allow the use of Alcohol-based fuels, of the type produced on farms.

Whether or not a mason jar "looks cool" or screams "aircraft part" was utterly irrelevant to how well it worked as a sight glass for judging remaining fuel quantity of corrosive Alcohol-based fuels.  The guy who used old spoons from his wife's silverware drawer as an engine cowling fastener for his aircraft determined that they did the job acceptably well, as did the FAA DAR who signed off on it.

Simple things that happen to work is a running theme with my proposals.

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#21 2023-02-04 21:13:34

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: How to Squander Energy on Futile Endeavors

The In thermodynamics and engineering, a heat engine is a system that converts heat to mechanical energy, which can then be used to do mechanical work

Heat engines are not about the Heat but about conversion to motion. It's not until you are the one feeding the engine with the fuel to generate the heat that it's an issue or cash for the fuel as all we cared about was making things move.

https://www.explainthatstuff.com/engines.html

We learned that motion was behind making electricity with coils and a magnet or more for electrical currents.
We learned that the motion of electrons would also make power in batteries long ago.

It was these things that we found from motion that allowed for life to be easier which includes human pedaling of creative devices.

what are the usable heat ranges?
https://en.wikipedia.org/wiki/Operating_temperature

Most devices are manufactured in several temperature grades. Broadly accepted grades[1] are:

Commercial: 0 ° to 70 °C
Industrial: −40 ° to 85 °C
Military: −55 ° to 125 °C

Nevertheless, each manufacturer defines its own temperature grades so designers must pay close attention to actual datasheet specifications. For example, Maxim Integrated uses five temperature grades for its products:[2]

Full Military: −55 °C to 125 °C
Automotive: −40 °C to 125 °C
AEC-Q100 Level 2: −40 °C to 105 °C
Extended Industrial: −40 °C to 85 °C
Industrial: −20 °C to 85 °C

https://en.wikipedia.org/wiki/Thermal_efficiency

This is where you get into the work to cost issue.

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#22 2023-02-04 21:37:36

kbd512
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Registered: 2015-01-02
Posts: 7,362

Re: How to Squander Energy on Futile Endeavors

SpaceNut,

Making hot water (showers, washing clothes or preparing food) or hot air (space heating, drying clothes) is a direct use of heat, but the movement of a hot flowing thermal power transfer fluid through a "district heating grid" becomes a type of heat engine if it's used onsite to spin the barrel of a clothes dryer.  Less than 10% of the power used in homes must be electricity and no other form of energy.  The HVAC system, the dishwasher, the washer and dryer, and the steam kettle or crock pot can all use direct thermal energy, with the dishwasher / clothes washer / clothes dryer converting it into rotational motion, as required.

Steel and crushed rock are so much cheaper than photovoltaics or wind turbines and batteries, in terms of the energy required to make enough input materials to create a workable energy production and storage system at a global scale, that there's no comparison between the two methods.

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#23 2023-02-04 21:53:35

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: How to Squander Energy on Futile Endeavors

Sounds like a plan to make use of a nuclear plant feeding the hot water into homes for heating at this point as it would provide a lessening of cost to do so from electricity or fuels for your "District heating grid" but it will not be free but huge in cost incurred to build the system and to maintain it. I have seen steam plants that could do a small island of 400 buildings with constant maintenance occurring.

https://www.centralstateshose.com/Satur … _62-1.html

Saturated Steam Temperatures with pressure

The warm setting on a Crock-Pot is between 145- and 170-degrees Fahrenheit. This temperature range is perfect for keeping food warm without drying it out or overcooking it.

You will need to add heat for the steam kettle as the heat is determined by pressure, ranging from 1 to 50 psi. This produces temperatures ranging from 240ºF to 280ºF.

steam conversion
http://www.legionindustries.com/product … izing.html

Steam would be too hot for direct use in a dishwasher or washing machine.

How hot is the steam that is used in a typical power plant steam turbine rotates at 1800–3600 rpm—about 100–200 times faster than the blades spin on a typical wind turbine, which needs to use a gearbox to drive a generator quickly enough to make electricity.

67c6.jpg

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#24 2023-02-04 22:17:21

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,362

Re: How to Squander Energy on Futile Endeavors

SpaceNut,

We should have a mix of solar thermal and nuclear thermal, if that's what you're getting at.  My plan has significant labor costs, but people still need jobs, and the Democrats keep bringing in people by the millions with little education, they don't speak English, and they're probably not in any danger of becoming newly minted nuclear engineers any time soon.

We can probably teach people to dig trenches, run pipes, fix leaks, and bolt solar troughs to their bases.  Since most of the construction workers I see are Hispanic, I'm going to go out on a limb and assert that we don't need to teach them much of anything.  I don't recall receiving any formal education on this.  My grandfather told me to pick up the shovel, told me where to dig, and I started digging.  I did receive some pointers on how to make sure pipes don't leak, but that didn't take too long.

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#25 2023-02-06 08:24:50

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,362

Re: How to Squander Energy on Futile Endeavors

SpaceNut,

Some of the heat from the steam can be exchanged to generate motion, using a heat exchanger with colder water flowing through it.  We're not going to run out of hot water, or rock, or steel.  We don't need to play a real-life version of "The Hunger Games".  There's plenty of these materials to go around, no matter where you live on Earth.  If you cannot afford steel and "hot rocks", then where are you getting the money for photovoltaics and batteries?

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