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#151 2023-09-05 02:02:37

kbd512
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Registered: 2015-01-02
Posts: 7,413

Re: Why the Green Energy Transition Won’t Happen

Calliban,

I can see hydraulic power being brought back, with a few modern touches.  In a world with fewer microchips, allowing for fewer and less-sophisticated electrical and electronic control systems, energy and power transfer systems that are easier to manufacture without requiring highly sophisticated equipment and specialized knowledge to maintain, will likely become the norm.  The electronic control systems we've built are not sustainable in a world with half as many people to make / install / repair / replace them, which is where we're headed during the next 30 years.  That doesn't mean the new tech is going away entirely, nor that it won't be used to manufacture tech items like cars or ventilators without requiring thousands of additional laborers, merely that it won't be applied to the energy systems powering human civilization as our population collapses.

With half as many people to feed, there's no economic benefit to the added complexity of an electronic control to, say, grind grain into flour.  The world's population was 4 billion in 1974.  The electric grids didn't use computer control back then.  The electric power grids in Australia didn't use computer control until the start of the 2000s.  That's where we're headed back to.  Computers don't go away, and in point of fact continue to increase in sophistication and computing power, but there's not point to applying them to something that sees little to no economic benefit from the application when the just-in-time demand is no longer placed on the system.  If we didn't create a requirement for perfect 60Hz 3-phase AC power with frequency control provided to within a millionth of a second, computers are largely superfluous.  We didn't use computers to control the power grid during most of the grid's existence.  Most of the time, the grid still functioned.  Using thermal and hydraulic systems, the grid continues to function even if none of the computers do.

There's a lot of talk about small modular reactors, but very little traction.  I'll believe it when the first one gets approved by the NRC and built.  I think SMRs are a great idea, but again, "if you don't build it, nobody will come".  We need action, not vague promises and platitudes.

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#152 2023-09-05 06:26:47

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 3,398

Re: Why the Green Energy Transition Won’t Happen

I share your sentiment on SMRs.  Developing a new nuclear reactor has become such a complex and drawn out process, that most firms engaged in such are likely to go bankrupt before reaching developed design stage.  The Nuscale, BWRX300 and RR SMRs are most likely to reach completion, because they built on existing fully developed designs.  But we probably won't see them online before 2030.  God only knows what state the economy will be in by then.

If mechanical power transmission can meet a lot of the loads currently met by electricity, then residual electrical needs could be met by local low-voltage DC networks.  One advantage with using DC is that skin effect is not a limitation.  This could allow the replacement of copper cabling with steel for flexible power cords.  Steel is useless for AC power transmission, but has been used for DC power transmission.  Whilst the conductivity of steel is poorer than copper or aluminium, it is far more abundant than copper and more fatigue resistant than aluminium.  Strides have been made in production of fatigue resistant, precipitation hardened aluminium alloys.  These could potentially replace some applications of copper as well.
https://www.nature.com/articles/s41467-020-19071-7

Let us take AA2024 as an example.
https://content.ndtsupply.com/media/Con … 0Chart.pdf

Resistivity of these alloys ranges from 3.6 - 5.77E-8 ohm-m.  This compares unfavourably to the value of 2.65E-8 for pure aluminium or 9.71E-8 for pure iron.
https://www.engineeringtoolbox.com/resi … d_418.html

However, a fatigue resistant aluminium alloy cable should have 1/6th the weight of an iron cable with the same conductivity and should be comparable to a copper cable, though the aluminium alloy cable will be thicker.  Fatigue resistant aluminium alloy could replace copper in flexible AC conductors.  Pure aluminium could be used for static wiring.  Iron could be used in low voltage DC systems, if the cable can be encapsulated to eliminate corrosion.  For high power density components, like motors, aluminium alloys and iron are less desirable.  But if these materials can reduce overall copper demand, then they improve the resiliance of the system overall.

These discussions lead me to wonder if we could design a more sustainable grid-scale PV powerplant?  Huge quantities of silver, copper, aluminium and steel are currently needed for each MWh of solar electricity produced.  But PV cells are encapsulated behind glass.  Could we replace silver contacts with printed aluminium with only a minor reduction in efficiency?  The aluminium cell conductors will be thicker and will block more light than the silver conductors.  But this may be an acceptable trade off.  As these are DC systems, could interpanel conductors be made from iron bars or iron fibre cables?  Instead of installing inverters on every row of panels, how about a DC motor powering a hydraulic pump, with individual hydraulic lines feeding a hydraulic main?  Instead of making panels out of aluminium and installing them on steel frames, could we make panels out of high strength, fine grain concrete?  Could frames also be made as compressive concrete structures?  Things to think about.

Last edited by Calliban (2023-09-05 06:56:32)


"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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#153 2023-09-05 08:19:11

kbd512
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Re: Why the Green Energy Transition Won’t Happen

Researchers Develop Low-Cost Solar Panels that do not Require Rare-Earth Elements

For years, scientists have been struggling to find a way to increase the efficiency of environmentally-friendly solar cells that consist of copper, zinc, tin and other abundant materials, in hopes that they will eventually replace current panels which rely on expensive rare-earth elements like indium and gallium, or highly toxic metals like cadmium.

Now, reporting in a paper published in Advanced Energy Materials, a team of researchers from the Daegu Gyeongbuk Institute of Science & Technology (DGIST) introduce a new method that could reduce both the cost and environmental footprint of most thin-film solar cells.

“Thin-film solar cells using bronze (Cu-Sn) and brass (Cu-Zn) as base materials are composed of non-toxic earth-abundant materials, and have been studied worldwide because of their low cost, high durability, and sustainability,” said project co-leader Dr. Jin-Kyu Kang.

The reason why panels consisting of these alloys fail to reach their theoretical efficiency potential is understood to be the variety of defects that form in these materials during the annealing (heating and cooling) process. These defects impede the flow of current and lead to substantial energy losses.

To manufacture the best quality CZTSSe (copper, zinc, tin, sulfur, and selenium) films possible, the research team first experimented with different annealing profiles, finding that longer durations and temperatures resulted in larger grains and therefor reduced the loss of electricity.

Next, Dr. Kang’s team used a special “liquid-assisted method” which allowed the grains of CZTSSe to grow at a fast rate even under low temperatures, thereby minimizing the material’s decomposition and attendant change of physical properties.

Project co-leader Dr. Dae-Hwan Kim concluded: “Our technology has diverse applications, including in electronic devices, household goods, buildings, and vehicles. The best part is that CZTS solar cells are free of the current drawbacks o toxic and rare metals. We can install everywhere we want!”

Can stuff like this be used to replace wildly unsustainable Silicon-based semiconductor production?

Potentially, but it requires further development, engineering manufacturing development, and grid implementation / integration.

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#154 2023-09-06 05:39:37

Terraformer
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Registered: 2007-08-27
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Re: Why the Green Energy Transition Won’t Happen

Lol. We could replace water, gas, and electricity with water (potable), water (thermal), and water (hydraulic). A system that has the advantage that you could keep it going even if Alien Space Bats yeeted your town into a different world.

Cargon transport wise, we have a lot of rivers. I've tallked before about canal and river and coaster transport using hot water engines. We could use those for intracountry movement of goods, and have large post-suezmax nuclear vessels for transoceanic shipping. Build offshore ports to transship the goods -- people can get funny about having giant nuclear vessels coming into port. Britain would be well suited to doing this. We have shallow offshore waters for the ports, our country is full of rivers (and we could always build the grand contour canal), and we have shipyards with experience building nuclear vessels for the navy. Better than having to import fuel from overseas to avoid empty supermarket shelves. We can load the ferries up with the lorry loads sans trucks and just connect them up for last (ten, fifteen) mile delivery.


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#155 2023-09-07 02:26:52

kbd512
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Posts: 7,413

Re: Why the Green Energy Transition Won’t Happen

Terraformer,

It's a matter of using what we have in extreme abundance to provide the mundane trappings of modern society.  The creative types seek novelty in all things.  It's a purpose unto itself, because it leads to new inventions, but generally not helpful when it comes to reliability.  If it works reliably, then its old and boring and why would anyone want that.  Well...  I would submit that when it comes to powering hospitals with life support equipment, factories producing foodstuffs, and energizing gadgets for people who are addicted to electronic toys, you want a boringly reliable and pervasive yet unobtrusive energy system responsible for doing that.

Water, steel, and concrete are pervasive.  I'll grant you that they're not all that interesting, but it's low environmental impact and long lasting with constant routine but simple maintenance.  This is the exact opposite of electronic systems, which function flawlessly until they don't, and then you need a brand new system.  Planned obsolescence doesn't work for energy systems.  People think routine maintenance is expensive drudgery, but everyone likes having toilets that flush.  We used to enjoy the time spent polishing the brightwork on our ship, or our leather boots.  It was quiet reflective time not spent responding to the cacophony of officers, information, and electronic equipment in radio.  You sat around with a group of your friends and talked while polishing the metal, and nobody would bother you.  The brass electrical junction box cover plates were as old as the ship, which was so old my father could've served aboard her, yet they still looked brand new when we were finished- all because someone was willing to spend a couple of hours per month to maintain what took so much labor and energy to create.

I imagine it's the same for an artist who smells the paint and feels the canvas- endless possibilities through the mind's eye while creating something that will hopefully out-live him or her by centuries.  Continuity is one of many fundamental requirements for a thriving civilization.  If society's energy supply is predicated on electronic systems functioning reliably under adverse conditions, things can get really interesting, really fast, when Earth's natural environment doesn't play nice.  Mother Nature is not known for her charity to those who are unprepared.  Continuity is lost, and what was great yesterday is unceremoniously tossed in the trash as if magic is supplying the energy and materials to replace it.  That is not the case, however, and we're bumping into limits.

We have an endless supply of water, concrete, and steel.  Technically, Aluminum should also be included in that list, but separating said metal from Oxygen requires alien space bat guano crazy amounts of energy.  Anything we could possibly use to continue generating and using the quantity of energy we've grown accustomed to using has a steep price tag attached to it if hydrocarbon fuels become scarce.  When lives are at stake, you use what you have that works well for the intended use case, not what seems like it might be better, novel, or potentially more interesting.  Novelty is something to pursue on your own time, with your own dime, when very little except a bit of money and perhaps some wounded pride are at stake.

I don't believe nuclear powered cargo ships will become economically viable unless they're mandated into existence and allowed to dock at regular port facilities.  People must learn to accept that there are only so many viable engineering solutions if they want stocked shelves.  Cargo ships that move at 20 to 25 knots run on coal, diesel, or Uranium, period.  If you don't accept the first two options, then embrace the third option.  Creating off-shore ports is a make-work project that further increases the operating costs associated with using nuclear powered ships.  To what end?

The Royal Navy operates fewer than a dozen nuclear powered submarines and no nuclear powered ships.  The ugly economic reality of merely building, not actually operating the new nuclear powered Ford class for the next 50 years, is that for the same money spent, the US Navy could've built 24 Forrestal class aircraft carriers.  They've tried to hide the spending from Congress, but the actual cost of construction ranges somewhere between $15B and $18B when you include the costs the US Navy improperly attributes to other activities, all of which support the Ford class construction efforts.  The Navy's own cost estimates indicate that each nuclear powered ship incurs a lifetime cost penalty of $3B more than operating a conventional super carrier, which also coincides with the cost of building a new Forrestal class super carrier in terms of 2023 dollars.  If the Royal Navy was unable to afford a pair of reactors for their new Queen Elizabeth class carriers, then there's no way for a nuclear powered cargo ship to operate at a profit alongside diesel powered cargo ships.  The Royal Navy was unable to afford operating an old Kitty Hawk class super carrier offered to them for free.  That should tell you everything you need to know.

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#156 2023-09-07 04:15:32

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 3,398

Re: Why the Green Energy Transition Won’t Happen

I wasn't directly involved in QE class aircraft carrier work, but knew people that were.  They discussed nuclear power and could have done it, but decided against it on cost grounds.  The US has a lot more units across which it can spread development cost.  But a carrier needs to be supplied with diesel to fuel the aircraft.  So the argument goes, why not power the the whole thing using diesel?  The US nuclear carriers do have better endurance because of their reactors.  The nuclear power is also an advantage in disaster relief.  The US carriers can generate enough electric power for a large city and can desalinate enough water to supply hundreds of thousands of people.  Back in 2003, there was a major tsunami out in Thailand, if memory serves.  I remember some French guy on tv mocking the fact that the US had sent an aircraft carrier to help out.  The guy ended up red faced when it was explained to him that that aircraft carrier could produce enough power and water for hundreds of thousands of people, had hospital facilities with enough capacity to serve tens of thousands and enough food to serve the emergency needs of tens of thousands.  That one ship probably did more than everything else the Europeans did.  Nuclear powered ships are more capable, but that capability comes at a cost.

Regarding nuclear cargo ships.  Large cargo ships are very energy efficient on a ton-mile basis.  As things stand, they can refuel in many ports along their trade routes.  Nuclear power probably would not provide a positive cost benefit ratio as things stand.  The thing that would change that conclusion would be a breakdown of global trade.  If ships could not reliably refuel where and when they needed to, then suddenly nuclear power would be important.  If coastal locations were no longer safe because of piracy, then blue water ships that can take routes that avoid the coast and follow ocean routes, will be safer.  Big ocean going cargo ships could burn coal or even biomass.  But this is more cumbersome and labour intensive than diesel.  If small modular PWRs in the 10-100MWe range are developed for land based grids, then putting them in ships coukd be a secondary application.

I agree that stored heat could be useful for short distance water based transportation.  The mass of the thermal store can serve as ballast if it is mounted along the keel.  But a stored heat engine is probably going to be a steam turbine driven system.  These have largely been displaced by diesel engines.  I would assume that is driven by operating cost burdens for steam systems.  That said, it could be made to work.  The systems involved are really quite simple.  The thermal store itself could be an insulated concrete cylinder containing lots of rock and mounted in some sort of steel sleeve, along the keel, with a steam generator tube running through it.  The steam would need to be dried, as its wetness fraction woukd increase as the thermal store cooled off.  But this isn't complicated to do.  Thermal efficiency would be 25-30% for a small system running at steam temperature of 300°C.  In some places you coukd charge the cylinder using stored solar heat, using some kind of mineral oil as heat transfer fluid.

There are lots of other ways of powering small coastal vessels.  Biomass or coal burned in boilers or gassified and burned in GTs.  Maybe some sort of compressed air powered system.  Maybe stored hot water powering some kind of subatmospheric steam engine.  There are lots of options for short range vessels.

Last edited by Calliban (2023-09-07 04:34:00)


"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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#157 2023-09-07 17:24:09

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 3,398

Re: Why the Green Energy Transition Won’t Happen

Container ships are the most energy efficient method of transporting bulk material produce over long distances.  They dominate global trade in terms of tonne-km or ton-miles.  But they are exclusively fuelled by diesel or heavy fuel oils, which will face supply constraints in the years ahead.  Could we fuel container ships with biomass, that is burned in boilers?  Biomass is available in most places, though not in infinite quantities.  Biomass fuelled ships could sustain global trade if diesel supplies run short, assuming that aggregate use of biomass is not excessive. 

Question 1: How practical is this? 

Answer:

I decided to run the numbers based upon the Triple E- Class container ship.
https://en.m.wikipedia.org/wiki/Triple_ … ainer_ship

This ship is equipped with 2x 30MW shaft power engines.  Top speed is 23knots (43km/h).  Specific fuel consumption of the engines is 0.168kg/kWh.  This would make the diesel engines some 50% efficient, which is quite impressive.  At full speed, the ship will burn some 10,080kg of fuel per hour.  Which amounts to 234.42kg/km.  Diesel fuel has density of about 850kg/m3 and an energy density of 45.6MJ/kg.  Dry wood has an energy density of 18MJ/kg.
https://en.m.wikipedia.org/wiki/Energy_density

If we burn wood in a boiler and raise steam which we then use to drive turbines, the efficiency of the propulsion system will depend upon the steam temperature, pressure and the degree of reheat that is achieved between the turbine stages.  Efficiency can range from 30-48% for steam powerplants.  I am going to assume that one third of the energy content of the wood is converted into mechanical energy.  The amount of woody biomass that would need to be burned to travel 1km, would be:

M = 234.42 x (45.6/18) x (50/33.3) = 891kg/km.  So the ship would need to burn 3.8kg of wood to get the same propulsive energy as 1kg of diesel.

How much fuel does a container ship carry?  The Explorer Class Bejamin Franklin typically carries some 4.5 million gallons, or 17 million litres, or 14,450 tonnes of fuel.
https://www.freightwaves.com/news/how-m … ship-carry

The Franklin has a 18,000TEU capacity, which is very similar to the Triple E Class and its dimensions are very similar.  However, its engine power is 80MW, rather than 60MW.  But let's see how far this takes us.  At a fuel consumption of 234.42kg/km, this much fuel would give the ship a range of 61,640km.  That is 1.5x the equatorial circumference of the Earth.  So the ship could circumnavigate the Earth.  How much wood would an equivelent biomass powered ship need to burn to get the same range?

M = 3.8 x 14,450 = 54,922 tonnes.

How much volume would the fuel take up?  This will depend upon the specifics of the biomass.  The density of wood varies greatly depending upon the species.
https://www.engineeringtoolbox.com/wood … -d_40.html

This reference gives the density of wood chips as 380kg/m2.
https://www.aqua-calc.com/page/density- … -blank-dry

Taking this value, we would need a storage volume of 144,533m3 for a range of 61,640km.  My estimate of internal hull volume for the ship are about 300,000m3, based upon the ship dimensions.  So the biomass would take up almost 50% of the internal volume of the hull.  This compares to only 17,000m3 or 5.7% hull volume for diesel.  In terms of fuel mass, we would need 14,450kg of diesel or 54,922kg of biomass.  This compares to a DWT of 196,000 tonnes for E-class ships.  So fuel only accounts for 7.4% of total dead weight of a diesel powered ship, but would account for some 28% of an equivelent biomass powered ship.

So on the face of it, it would be difficult for a biomass powered container ship to match a diesel fuelled ship in terms of range, speed and cargo volume.  What are the options?

1. Travel as slower speeds.  Reducing speed from 23 to 17.5 knots, would cut fuel consumption per km by half.  Since the GFC, most ships do that anyway.

2. Accept a shorter range, with less distance between refuelling stops.  That would be undesirable, but may be possible.  If we were to reduce range from 61,000km to 40,000, we could reduce fuel mass accordingly.

3. Increase ship size to accomodate more fuel.  This faces limitations, because berthing sizes are limited and ship capital cost is a function of size.  So I am going to reject this one.

Combining options 1 and 2, would cut the amount of biomass fuel that the ship must carry by 2/3rds.  Instead of 54,922kg, occupying 144,533m3, we would need some 18,307kg, occupying some 48,178m3.  The biomass would still weigh 26% more than the diesel and would take up almost 3x as much volume, or roughly 16% of internal hull volume.

I conclude that biomass powered container ships could work as a post oil solution.  However, compared to diesel, there are significant penalties in ship performance.  To bring fuel mass and volume to manageable levels, the ship's speed must be reduced by 25% and range by 33%, compared to a baseline diesel powered ship.

Question 2: Is there enough biomass in the world?

Answer:

Back in 2018, global sea freight was 62 trillion ton-miles or 90.5 trillion tonne-km.
https://www.epa.gov/international-coope … sportation

According to wiki, some '125 million TEU [is equivelent to] 1.19 billion tonnes worth of cargo.
https://en.m.wikipedia.org/wiki/Container_ship

So the average TEU carries 9.52 tonnes of freight.  So our Triple E Class will carry 18,270TEU, or an average of 173,930 tonnes.  We calculated fuel consumption of 891kg of biomass per km, or 5.123 grams per tonne-km.  Assuming all seaborne freight has similar energy cost, we would need 464 million tonnes of biomass each year to fuel seaborne freight transport.

Could we grow that much?  According to this reference: 'we find that the annual global production of land-based biomass is 50 billion tons, of which roughly 8 billion tons of biomass can be sustainably harvested each year. This is determined by dividing biomass into four distinct groups suitable for energy production: wood, agriculture, food waste and manure.'
https://www.mr-sustainability.com/stori … he-world-1

So powering global freight transport would consume at least 5% of the land-based energy biomass that could be globally harvested each year.  Biomass powered cargo ships would seem to be achievable from a resource perspective.


"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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#158 2023-09-08 03:47:12

Terraformer
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From: Ceres
Registered: 2007-08-27
Posts: 3,812
Website

Re: Why the Green Energy Transition Won’t Happen

4. Convert the wood to charcoal. Takes some energy, but perhaps that can be provided by solar concentrators. Opens up the possibility of using a charcoal slurry in diesel engines... maybe that would get us back to 40-50% efficiency?

Supposedly, back in the coal powered shipping days, sailing ships would be used to supply refuelling depots. The equivilent of using ion drive spacecraft to preposition supplies -- takes longer, more variability, but far cheaper and the coal doesn't go bad if it doesn't get there by next week. For a lot of freight (not refrigerated lamb from New Zealand, or apples), the tradeoff between speed and energy consumption might favour accepting the variability of wind power. There are hopes it will reduce emissions (so, fuel consumption?) by 30%. But I don't think they're planning to roll with the variability; perhaps shipping that accepts this and relies on warehouses a lot more to buffer volatility would be able to achieve far higher savings. Also wondering if sails are the best way to go about it -- some wind powered land vehicles use the wind to drive the wheels, rather than relying on the wind pushing them directly, so maybe having a turbine power a propeller, taking advantage of the far higher mass of the water, would be a workable design. You're going to want a propeller system anyway, in case there's no wind at all and you have to use the supplemental power system.


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#159 2023-09-08 12:49:51

kbd512
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Registered: 2015-01-02
Posts: 7,413

Re: Why the Green Energy Transition Won’t Happen

Calliban already noted that 3.8kg of biomass equals 1kg of diesel fuel.  All attempts to overcome this issue boil down to dramatically changing how we do things.  We can replace virtually all ocean-going transport ships, consume dramatically more fuel to accomplish the same task, or lose the economic prosperity tied to global trade.  Changes can be a good thing if what we're presently doing is incredibly wasteful, but we're entertaining the idea of burning almost 4X more fuel to obtain the same energy output.

Cutty Sark's 32,000ft^2 of sail surface area generated the equivalent of about 3,000hp, achieving a top speed of around 17.5 knots.  She could carry a cargo of 1,100t of coal.  She could cover 300 to 400 standard miles per day.  Construction was primarily East India Teak and American Rock Elm, with an English Oak rudder.  The tween deck was yellow pine.  The keel was later replaced with pitch pine.  London to New York sailing distance is 3,786 standard miles, so the trip would take about 11 days.  A standard cargo ship which travels at 25 knots will make the trip in 5.5 days.  If we intend to ship 50,000t of cargo per vessel, then we need at least 1,600,000ft^2 / 148,645m^2 of sail area.  We do get a steep reduction in power required for a larger / longer hull, though.  2.9hp/t for 27 knots from a CVN-68 super carrier vs 10hp/t for 27 knots for a FFG-7 frigate.  For a 75,000t cargo sailing vessel, our sail area can generate up to 150,000hp in a stiff breeze.  If it has the same fine hull as Cutty Sark, it should be plenty fast.

The responses thus far only reinforce the idea that there's no practical substitute for diesel fuel.  We're going to have to synthesize diesel fuel from scratch at some point, using CO2 and H2O taken from the ocean.  All the talk of "what comes after oil" is a bit like the talk about "what comes after electricity".  We have LEDs.  We're not going back to burning candles at night for light, so long as we have electricity.  The plastic insulation for the electrical wiring comes from oil, the trucks / ships / aircraft delivering the electrical and electronic gadgets use oil.  The tar paper on your roof shingles is made from oil.  If the oil comes from what we synthesize rather than what we extract, then it's never going to run out.

We need to revert back to sail power or synthesize our own fuels because cargo ships and trains as we know them are impractical without diesel fuel.  Synthesis won't do any more damage to the habitability of the planet than we've already done.  As a bonus, we can finally stop drilling for oil.  Yes, there's a lot more energy sunk into this system, but it largely stays in the system because it's maintainable.  If we get the product we can't actually live without, then we don't have to radically alter every other aspect of industry and commerce.

We can devise substitutes for relatively minor fractions of the total overall energy usage for niche applications, but if you want to maintain the lifestyle we've all grown accustomed to, that will ultimately involve synthesize of liquid hydrocarbon fuels.  All the talk about cost fails to account for what the cost of not feeding huge swaths of the population will be if the fertilizer supplies run out.  Hydrocarbon fuel energy has to be cheap and available, or people resort to silly things like burning wood to power ships, instead of diesel fuel.

Cargo ships can be sail powered if it doesn't matter when the cargo arrives.  This is the most practical solution since we're talking about radically altering what the ships burn for fuel.  I cannot fathom the notion that we're unable to make sail power work.  Burning wood chips to power a steam ship is... medieval.

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#160 2023-09-08 14:36:42

kbd512
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Re: Why the Green Energy Transition Won’t Happen

I forgot to add this to the prior post, but the other way we "make up the difference" using less diesel fuel, is by shipping cargo in lighter cargo containers.  The CONEX boxes that most non-bulk dry cargo ships in can be and are made in Aluminum vs steel.  They're much more expensive to make, but far less expensive to ship around, over and over.  The same applies to railroads and trucks.  The other benefit to ships, trains, and trucks is lowering the CG / GM, which reduces the incidence of roll-over accidents.

Sailing ships will require very strong synthetic sail cloth, as well as masts and hulls made from high-yield HSLA steels.  Construction costs shouldn't be seriously affected, but I don't know what the strength requirements are for the masts.  The operating costs should be drastically reduced, so long as transit times remain similar.  The ship needs to achieve at least 20 knots.  I think annual maintenance costs, however, will go up.  Sail cloth is expensive and there's a lot of it to maintain.  10.4 oz Dacron sail cloth is $24/yd, so $4.3M for the sails on this notional wind powered cargo ship.  Dacron lasts for 10 to 12 years.  Vectran sail cloth can last for 20 years, but is much more expensive, at $50 to $60/yd.

Either way, sail cloth is a small yearly expense compared to the salaries for the crew and fuel of a diesel powered ship.  Let's say $3,000,000/yr for the salaries for 60 crew members.  The sail cloth costs $430,000/yr.  If your operating costs are only $4M per year for a 25,000t ship carrying 50,000t of cargo, you're doing quite well for yourself.  If you carry a single 50,000t load per month, your ship's operating cost per ton is $6.67.

Say your ship costs $75M to build (in line with actual construction costs for 25,000t ships) and you have $80M in direct operating costs over 20 years.  You'll carry 12,000,000t of cargo during that 20 years, so whatever you charge your customer above $12.92 per ton is profit.  Ocean freight in 2023 ranges between $2 and $4/kg, to wherever, from wherever, on average.

You still need, four of the 800hp diesel truck engines (Caterpillar ACERT on-road diesel truck engines with a "marine camshaft" make 800hp) for electricity when the wind doesn't blow, bilge pumps, maneuvering close to port at 3 to 5 knots, and operating the anchors.  Cummins makes similar engines for the same use cases.  I'm sure MTU has something similar.  Rolls Royce?  No idea.

If the shipping rates didn't change, and you charge $1,000 per ton, forcing your competition to lower their operating costs or go out of business, this is one valid way of returning to the age of sail while roughly maintaining the existing ocean-going transportation network.  Larger ships will still be more efficient, but certain types of ships will need at least partial redesigns to support the masts, which also have to fold to stow and go under bridges.  Dry cargo would need to be RORO due to the inability to use cranes with the masts in the way.  This would increase diesel consumption at the port.  It's a problem that requires a solution for this "return to sail" concept to work, though, because RORO aside, no port in the world is set up to handle unloading of cargo container ships this way.  That said, RORO is cheaper than container shipping, so maybe we need a new invention here to load / unload containers as if they were RORO, which is easier said than done.

How about a RORO ship with CONEX boxes that are loaded / unloaded on rails, so then you don't need diesel trucks and cranes to move them, and unloading can be much faster?

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#161 2023-09-08 15:38:13

Terraformer
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Re: Why the Green Energy Transition Won’t Happen

Something similar is done, using RORO without the trucks being attached just the chassis, but I can't remember the name. The issue I see with ocean freight is that you have to use multiple decks (pretty sure we've talked about this before? I'm sure I suggested it...), whereas with a ferry you can just have one deck. Attach them in trains with guide rails and you can push then on and pull them off quite quickly.

Advantage I see is last mile shipping. No messing around moving them with crates and putting them on chassis, they're already there to hook up to the truck. Or to move onto a ferry. Or if on rails, they can go straight on.


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

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#162 2023-09-08 21:21:58

kbd512
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Re: Why the Green Energy Transition Won’t Happen

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#163 2023-09-08 23:16:03

kbd512
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Re: Why the Green Energy Transition Won’t Happen

After pondering over that chart, extra-slow steaming looks like how we should operate Navy ships in peacetime as well.  Since fuel burn is associated with engine power, it appears that 21 knots requires 100% more engine power and fuel consumption than 17 knots.  That's pretty crazy.  I knew it was an exponential function, I just didn't know it was quite that bad.  The fact that we have ships like Emma Maersk zipping along at 25 knots is... bonkers.  Her fuel burn could decrease by 200t per day.  She could probably travel between any two ports in the world at 17 knots.

The long hull version of the FFG-7 Oliver Hazard Perry class guided missile frigates weighed 4,100t at full load.  Their range was 4,200nm at 20 knots or 5,000nm at 18 knots.  That's a 19% range improvement by slowing down by a measly 2 knots.  Total fuel capacity was 185,000 gallons.  Fuel burn at 14 knots is 10,000 gallons per day, and range increases to 6,216nm.  Fuel burn at 29 knots is 72,000 gallons per day, so you're out of fuel in less than 3 days.

No 2 fuel oil, which is essentially diesel fuel, is providing 15,812,500Wh of input energy at 14 knots.  If the LM2500's thermodynamic efficiency was 36%, which it would not be unless operating at full output, then 5,692,500W / 7,624hp worth of power output.  A Cat 3616 diesel would burn 1,138.5kg of diesel per hour at that output level, or 353.5 gallons per hour, or 8,434gpd, so 21.935 days of engine power at that output level, which means it could cover 7,370nm.

4 Caterpillar 3616s would weigh as much as 6 LM2500s, but the extra 1,154nm of range is a clear winner.  With the correct pistons, they can also provide 41,600hp, matching the output of the 2 LM2500s.  The original design goal of the Speed-of-Air pistons was increasing power output by about 30% without making smoke, so our 8,000hp 3616s can produce up to 10,400hp at full output.  Actual range would be even more than simple math suggests, because LM2500 thermodynamic efficiency drops when it's operated at low output levels, as is the case for all jet engines.  The Speed-of-Air pistons would perhaps provide a 180g/kWh BSFC vs the 200g/kWh BSFC for the original equipment Cat pistons, so fuel burn drops to 7,636gpd, endurance increases to 24.227 days, with range increased to 8,140nm.  It would be very hard to justify the LM2500s at that point.  3616s are about $1.25M and can go as long as LM2500s between overhauls.  Brand new LM2500s cost $2.5M to $3.5M about 16 years ago.  Cat's recommended TBO for the 3616 is 20,000 to 25,000hrs in marine applications, with some G3616 (natural gas fueled) engines used in oilfield services exceeding 125,000hrs without overhaul.

NAVAIR - Artisans Breathe New Life into LM2500 Engines - Jul 17, 2007

NAS NORTH ISLAND, Calif. – In December 1986, Naval Air Depot North Island (now Fleet Readiness Center Southwest) here, received shipment of a General Electric-built LM2500 engine, serial number GGA 042, from the guided missile frigate USS Jarrett (FFG 33) that had 9,000 hours of usage and a high vibration problem.

“We did a typical overhaul to GGA 042. We did the gas turbine changes and we took it all the way down – everything was completely stripped on it. The rotor was completely disassembled, remanufactured to new, and rebuilt,” said LM2500 project coordinator Jim Hansen. This type of work was not unusual since LM2500s typically operate between 10,000 and 20,000 hours before a major failure, Hansen noted.

Now, 20 years and 26,000 hours of usage later, GGA 042 returned to Fleet Readiness Center Southwest in May with a v-sump oil leak (similar to a car engine’s oil pan).

With 35,000 total hours logged, the GGA 042 is a noteworthy exception to the typical maintenance interval. “If it hadn’t been for that sump leak, it’d still be out there running,” Hansen commented.

First used to power the Spruance- and Kidd-class destroyers in the 1970s, LM2500 production began in 1969. The engines proved so versatile and reliable, their use expanded in the 1980s to include Oliver Hazard Perry-class frigates, Ticonderoga-class cruisers and today’s Arleigh Burke-class destroyers. The gas turbine engine also powers oil platforms and pipeline pumping stations.

Edit (document showing the fuel consumption rates and correlation with speed for all or most US Navy ships in service back in 1996):
Naval Post-Graduate School - Predicting Ship Fuel Consumption: Update - David A. Schrady, Gordon K. Smyth, Robert B. Vassian - July 1996

Note how neatly almost all actual recorded values match with formula-based predicted values.  This seems to suggest that even for ships with hulls optimized for higher speeds, excessive power consumption beyond 15 to 20 knots is a foregone conclusion.

Edit #2:
The documentation I can find from WWII British and German sources all seems to indicate that even for ships that were purpose-built to attain even greater speeds than those typical of naval vessels of today, fuel burn rates were excessive.  Steam appears to be good at generating lots of power, but fuel burn rates were higher than for diesels producing equivalent power.  That said, there were no diesels capable of generating equivalent power for equivalent weight, so all WWII era ships that required high speed were powered by steam turbines.  78 years later a steam plant is still lighter than equivalent-output diesel engines, but now we have actually have high-output diesel engines capable of matching steam plant power output levels if the weight increase is acceptable.  For such to still be the case, there must be some fundamental engineering limits involved that no reasonable amount of computer-aided design or modern materials can overcome.

Last edited by kbd512 (2023-09-09 01:34:39)

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#164 2023-09-11 16:58:39

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 3,398

Re: Why the Green Energy Transition Won’t Happen

The biomass burning freight ship looks like a bad idea.  If port authorities are banning the use of heavy oil due to air pollution concerns, then I doubt that biomass will pass muster either.  From a logistics viewpoint, it doesn't look good either.  Sourcing, transporting, storing and loading a low density solid fuel, is going to add cost.  I think it unlikely to save money.  An even bigger problem is the low volumetric energy density of biomass.  Compared to diesel, wood chips providing the same propulsive energy would take several times the volume.  This is a significant additional space burden on a freight ship.

Maybe there are niche applications for biomass powered ships on routes between ports that happen to have local abundance of biomass.  If charcoal can be compressed into dense briquettes then it partially solves the volumetric energy density problem.  But the stuff still needs to be grown, heated to pyrolysis, transported and loaded.  Again, it may have niche applications, but doesn't look like a good general solution.  No matter.  Sometimes in reaching the right solution, we need to eliminate things that won't work along the way.  My thanks to Kbd512 and Terraformer for providing technical assessment here.

Last edited by Calliban (2023-09-11 17:03:24)


"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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#165 2023-09-11 17:18:58

Calliban
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Re: Why the Green Energy Transition Won’t Happen

The link below is to a global elevation map.
https://ian.macky.net/pat/map/world/world_etopo2v2.jpg

In the past, I have raised the idea of pipelines transporting neutrally bouyant capsules containing freight.  I wonder if the same thing could carry capsules under the sea, through flexible tubes laid on the sea bed?  In this case, there would be no pressure difference between the inside and outside of the tube.  The static pressure of seawater would be resisted by capsules that either: (1) Are reinforced by frames to resist external pressure; (2) Are pressurised with compressed air to partially counteract external pressure.

The capsules would be carried through the tubes by pumping waterinto them at a flow speed of 1-3m/s.  A pipeline from Europes to America, would follow the European continental shelf, crossing to Iceland, Greenland and then following the Canadian coast until landfall.

The advantage of transporting using an undersea capsule pipeline, is that no fuel is needed to transport in this way.  Water is pumped into pipe at one end, carrying the capsules with it.  Electricity or even direct mechanical wind power can do the pumping without burning fuel.  There are numerous disadvantages.  The need to lay an undersea pipe thousands of km long.  The need to produce watertight, neutrally bouyant capsules, capable of surviving extreme pressure.  The slow speed of pipelines transporting trans-continental distances.

In a straight line, London to New York is 5600km.  But following the European, Arctic and North American continental shelves, the undersea pipeline distance could be 10,000km.  Moving at a speed of 1m/s, a capsule would take 116 days (4 months) to make the trip.  This would be OK if the goods could afford to take their time.  But this is no faster than a sailing ship.

Of course, capsule pipelines could be built over land as well.  They could ultimately be used to transport goods to most places at very low energy cost, using local fixed energy sources like wind or direct solar for pumping.  But they would be slow.  Across the United States for example, New York to Chicago is 1146km.
https://www.distancecalculator.net/from … to-Chicago

If a capsule pipeline between these points was 1200km long and capsules travelled at an average of 2m/s, it would take 167 hours (7 days) to transport goods.  But if the energy source is direct power from the sun and wind used to pump water, then it coukd ultimately be a cheap way of transporting.  This is obviously only applicable to non-perishable goods.

Last edited by Calliban (2023-09-11 17:40:40)


"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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#166 2023-09-18 20:25:54

kbd512
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Re: Why the Green Energy Transition Won’t Happen

Since the year 2000, the world has spent somewhere between 5 and 10 trillion dollars on wind and solar.  Burning wood for energy (10% of the total, globally) still supplies more than 3 times more energy than all the wind and solar combined (3% of the total, globally).

When is everyone going to wake up and smell the coffee?

This madness is not working!

We need dramatically different approaches to reduce reliance on hydrocarbon fuels.

There is no transition, much less a rapid transition.

Burning wood in America is still 50% of the total wind and solar energy output here in America.

If you want an actual transition, it's not going to come from "hopes and dreams".  The engineering required to make an actual timely transition will never be amenable to ideology.  If the materials and money math doesn't add up, then it's not a solution that will produce a transition in a timely manner.

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#167 2023-09-19 00:56:39

Spaniard
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Re: Why the Green Energy Transition Won’t Happen

kbd512 wrote:

Since the year 2000, the world has spent somewhere between 5 and 10 trillion dollars on wind and solar.  Burning wood for energy (10% of the total, globally) still supplies more than 3 times more energy than all the wind and solar combined (3% of the total, globally).

When is everyone going to wake up and smell the coffee?

This madness is not working!

We need dramatically different approaches to reduce reliance on hydrocarbon fuels.

There is no transition, much less a rapid transition.

Burning wood in America is still 50% of the total wind and solar energy output here in America.

If you want an actual transition, it's not going to come from "hopes and dreams".  The engineering required to make an actual timely transition will never be amenable to ideology.  If the materials and money math doesn't add up, then it's not a solution that will produce a transition in a timely manner.

Mix old and new energy doesn't help to view the right picture if you don't understand the kind of curve is happening.

In 2000, solar was almost prohibitive. On 2010 was non competitive without subsidies. On 2020s solar is the cheapest source of electricity in a lot of places of the world.

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

The installation of renewable is exponential. That's the reason because old numbers seems negligible, while current numbers are really significant, and it will become even more important in the future.

Don't use median numbers with an exponential. It doesn't work that way.

The same is applicable to the consumption of raw materials. It's not the same the production/materials of 2000s technology than 2020s techonology.
In general, there is no pressure to reduce consumption if it doesn't generate too much cost impact until the price of the raw material raises.

The best example of that is silver in PV. The silver in PV has being shrinking constantly, so the cost impact in the PV has being contained while the price of the silver has gone up by a lot.
The market is big, and there was people who tried to build PV panels without silver at all. And they work to certain extend. But the market didn't buy it because not even a small  risk of raising failure make it non interesting with current prices and usage of silver.

But... what would be happen if silver will raise a lot more and/or PV with silver reach a physical limit to reduce the quantity? That kind of PV without silver would be a lot more attractive and it would be adopted.
There is a high chance that this will be happen in the future.

That's the reason because just multiply current raw usage per watt of current or past technology by the power need to power the entire civilization is a very wrong way to "predict" the failure of green energy. It won't work that way.

As soon as some raw material become expensive, the people involved start to investigate new ways to do the same things without the same bottlenecks.

Cobalt become expensive for electric vehicle batteries... They push LFP battery technology.
There is risk of lithium bottleneck... They research sodium-ion technology.

Etc. etc.

The technology of hundreds of megawatts and hundreds of terawatts would be very different in the implementation, even if it's the same idea in the core.

To believe that the green energy researchers and developers won't be able to adapt the technology to the resources available is a blind assumption of technology failure.

It's paradoxical that a forum participant about space exploration and mars colonization use technology pessimism as an argument.

Last edited by Spaniard (2023-09-19 02:30:04)

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#168 2023-09-19 08:52:50

kbd512
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Re: Why the Green Energy Transition Won’t Happen

Spaniard,

The only "cost curve" happening is that ALL prices are going up- food / electricity / photovoltaic panels / computers, basically all goods and services.  The price reductions for wind turbines, photovoltaics, and batteries happened because we had inefficient manufacturing processes.  Today, 70% of the total cost of Lithium-ion batteries, for example, is materials.  You will not see any price reductions when we're as efficient as we reasonably can be at making batteries but the materials costs are increasing.  Since the energy to make solar panels comes from coal and natural gas, not other solar panels, this is what prevents the panels from becoming significantly cheaper than they already are.  Any manufactured good can never cost less than the input materials, except through temporary price manipulations.  When we can power the Chinese photovoltaic panel, wind turbine, and battery factories using the very products they make, we can revisit the idea of costs further decreasing in a meaningful way.

My neighbor had solar panels on his home during the 1980s when I was a child.  The panels on his home were fewer in number than the panels I have on my home today, but going off of what he said they cost him and the energy provided relative to his consumption, in real terms he and I both received equal value for the panels we both purchased, about 40 years apart.  My total cost is almost identical to his total cost, after accounting for inflation (printing money / creating debt to hide the fact that energy is becoming more expensive over time).  Both sets of panels were rated to last for 25 years.  His panels lasted for about 25 years before they were removed.  This is the benefit of being old enough and having a good enough memory to know "where have we been and where are we headed".  The panel efficiency hasn't gone up at all, because it's the same basic technology, made cheaper using Chinese slave labor and abundant coal energy to make the Silicon wafers.  His panels were about 23% efficient.  I think my panels were about 25% efficient when new.  There has been no night-and-day increase in panel efficiency, only manufacturing cost.

The installation of renewable is exponential.

The total power output over 1 year, provided by all renewable sources, is definitely NOT exponential.  Wind and solar accounted for 4% of total global energy usage in 2020.  Over a period of 23 years, energy from non-renewable machines harvesting renewable energy, went from essentially 0% to 4%, after spending 10 trillion dollars.

The same is applicable to the consumption of raw materials. It's not the same the production/materials of 2000s technology than 2020s techonology.

Seriously?  The PV panels on my roof are a minor tweaking of the panels of 40 years ago (early 1980s).  They cost less per panel using better manufacturing and slave labor.  That's about it.

The best example of that is silver in PV. The silver in PV has being shrinking constantly, so the cost impact in the PV has being contained while the price of the silver has gone up by a lot.

Silver is a good example of attempting to ignore basic physics.  Silver was used because Silver makes the on-panel electrical conductors more efficient than Copper.  It's another basic physics problem that materials science and wishful thinking cannot overcome.  This is akin to asserting that we should "just accept" the fact that the F-135 engines powering the F-35, which only last 1,700 to 2,100 hours before major overhaul, whilst commercial jet engines operating at higher temperatures, routinely last 50,000 hours or more before major overhaul.  Oh, look, we "saved money" by getting more bleed air out of our fighter jet engines.  Sure you did.  The major problem with demanding so much bleed air is that we burn out the hot section long before it would otherwise require an overhaul, all to satisfy a pointless performance metric created after the engine was designed- namely its ability to cool all the electronics using bleed air.  Back in the real world, tax payers are wondering why they're paying over $19,000,000 for engines that only last as long as the piston engines that I fly behind in a Cessna before those require a major overhaul.  I fully understand "the why" behind using or not using Silver, as well as the demand for more bleed air.  I'm stating that "the why", is stupid.

We need to quit worrying about the price of Silver and start worrying a lot more about the practicality of what we're attempting to do.  Both the photovoltaic panels that don't use Silver and the F-135 engines demanding too much bleed air are attempting to flip the bird to basic physics, but basic physics always wins.  Less efficient electrical conductors produce too much heat and prematurely degrade the solar panels, just like sucking too much of the cooling air supply out of the core of a jet engine.  Can we physically make both the panel and jet engine "work" without immediately self-detructing?  Sure, but if that's your definition of "working", then I beg to differ.

That's the reason because just multiply current raw usage per watt of current or past technology by the power need to power the entire civilization is a very wrong way to "predict" the failure of green energy. It won't work that way.

This is also the wrong way to view the body of work I've written.  I have already considered all these supply bottlenecks and come to the conclusion that there is no practical way to avoid them without switching to truly abundant materials and a different way of re-powering human civilization.  Everyone is going to witness what you call "green energy" (a meaningless buzzword which describes non-recyclable / non-repairable electrical machines with short lifespans, with absurd energy and material input requirements) run into physical resource limitations over the next 10 years or so.  Only after that happens will it become entirely self-evident that different approaches are required.

The technology of hundreds of megawatts and hundreds of terawatts would be very different in the implementation, even if it's the same idea in the core.

Exactly!  It won't be the nonsense presently being pushed as "green energy".  There's nothing green about it, except the color of money.

To believe that the green energy researchers and developers won't be able to adapt the technology to the resources available is a blind assumption of technology failure.

I'm watching it happen in real-time.  So are you, but you don't wish to see what's self-evident.

It's paradoxical that a forum participant about space exploration and mars colonization use technology pessimism as an argument.

There's a difference between pessimism and realism.  A pessimist would see every new bit of technology as a failure waiting to happen.  A realist would admit when something isn't working as intended and then try something fundamentally different.  The "green energy" evangelists think the solution is to "blow harder".  That doesn't work for me, because I'm not a blowhard.  I look for general rules, not exceptions to the rule that agree with my beliefs about something.  Whenever I see something that's producing very little of the total energy supply after obscene amounts of money and decades of research have been shoveled into it, I have the good sense to try something else, because I know how basic economics applies.  I also know that there's an opportunity cost of continuing the same type of nonsense we've been attempting.  Time and money spent on something utterly impractical is time and money that could've been spent on something far more practical.

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#169 2023-09-19 12:32:57

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 3,398

Re: Why the Green Energy Transition Won’t Happen

I think Kbd512 has made most of the points already, but I will give my 2 pennies worth.

The limiting problem with the idea of solar PV replacing the energy we derive from fossil fuels, is low power density.  Gas turbines, coal fired boilers and nuclear reactors, all produce large amounts of power per unit mass of invested materials.  I keep going back to the 2015 Quadrennial energy review, produced by the US department of energy.  This is mainly because it illustrates the problem so well.
https://www.energy.gov/quadrennial-tech … eview-2015

Go to Section 10, Table 10.4 for a summary of materials inputs into several different types of powerplant in ton/TWh.  Here are some tallys per TWh:

Nuclear (PWR) = 760t concrete / cement; 3t copper; 0t glass; 160t steel; 0t aluminium.
Wind = 8000t concrete / cement; 23t copper; 92t glass; 1800t steel; 35t aluminium.
Solar PV = 4050t concrete / cement; 850t copper; 2700t glass; 7900t steel; 680t aluminium

A combined cycle gas turbine powerplant burning natural gas does even better than the PWR, requiring 400t concrete and 170t steel per TWh.

The high materials budgets for PV and wind are unavoidable, because the power density of wind and sunlight are not parameters that we can control.  You could in principle, eliminate silver from production of PV panels.  But if this does result in a decline in efficiency or increase in resistance losses, then it will increase the amount of steel, concrete, glass, copper, silicon, aluminium, etc, that must be invested per TWh.  In terms of embodied energy, these will be big hitters, because they are already used in such huge quantities.  Developing a balanced design is always a balancing act of competing requirements.

Another problem with intermittent renewables is that they do not replace fossil fuels.  Combined cycle gas turbines are used to provide backup power.  Yes we could use storage of some sort instead.  But an energy store is really just another kind of powerplant, that absorbs energy and then spits it out again.

Between 2008 and 2020, several factors converged to reduce the apparent cost of Solar PV in dollars per installed watt.

1. The Chinese began to approach peak coal production in their population heartlands.  The CCP announced that it would develop PV as a key national industry.  A lot of western Greens hailed the growth of Chinese solar industry as the vanguard of a new age.  In the real world, PV allowed the Chinese to access otherwise stranded coal deposits in the Xinjiang region.  By using Uiyger forced labour in the coal mines and building powerplants at the minehead, Chinese poly-silicon and module manufacturers had access to some of the cheapest electricity in the world.

2. Forced Uiyger labour in the poly-silicon and module factories meant that labour costs in PV manufacturing declined between 2008 and 2020.

3. The Chinese PV industry also benefited from zero interest loans.  This made capital almost free.

4. The Chinese PV industry had cheap energy, almost free labour and cheap capital.  As it increasingly displaced western producers that didn't have these advantages, it gained economies of scale, which pushed down costs even further.

5. In western markets, 2008 - 2021, were a period of almost zero interest rates and in some places, rates were even negative.  If you were an institutional investor, you could borrow almost for free.  For an industry in which the bulk of costs were capital costs, this was clearly very important at keeping cost per kWh down.

In summary, we have an industry that was established using free money, powered by cheap coal based electricity, manned by forced labour and selling into western markets with close to zero interest rates.  How could it not be cheap under those conditions?  Whilst the Chinese did take steps to undercut their western rivals, the majority of their PV was used domestically.  By integrating PV into the grid in their industrial heartlands, their stagnating coal production could be stretched to provide more electricity.  This worked by using the coal plants for backup.  The solar PV cannot replace the coal plants, but it can reduce their fuel consumption at the expense of lowering their capacity factor.  Solar PV made some sense to the Chinese, but it must also be viewed as an act of desperation.  Domestic coal production can no longer keep up with power demand.  And the Chinese nuclear industry will take time to grow.  All of this went over the heads of western Greens, who swallowed the narrative of a green energy revolution power by cheap PV, because it is was what they wanted to believe in.

The problem is that all of the factors that led to declining PV costs between 2008 and 2021, have now gone into reverse.  The Chinese labour force is shrinking and their economy is beginning to collapse.  People have taken to calling this 'supply chain disruption'.  In reality, everything that relies on manufactured components produced in China has a short life expectancy.  The trajectory is terminal because their working age population is collapsing faster than any population in human history.  The Chinese state already has the highest debt / GDP ratio of any large economy.  Further cheap credit will only push them into collapse faster.  At the western end, low interest rates are a thing of the past.

I do not consider PV to be a waste of time.  If you need a modest amount of power supplied offgrid, then in most places it will be the most practical option.  But expecting it to provide the terrawatts of power needed to meet the bulk energy needs of human civilisation, is not realistic.  The same is true of wind power.  It poweredtransportation and milling for millenia.  But it has limitations that limit its applicability.  The problem we face now is that political ideology is being used to force a solution that just isn't suitable for what the political idealists are pushing it for.

Last edited by Calliban (2023-09-19 13:35:46)


"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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#170 2023-09-19 13:28:27

kbd512
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Registered: 2015-01-02
Posts: 7,413

Re: Why the Green Energy Transition Won’t Happen

Calliban,

My goal here was to pursue some "green energy" concepts that could feasibly work at the scale required.  I see nuclear thermal and solar thermal as the only serious contenders that are globally applicable.  The waste products from nuclear power plants are so small relative to coal / oil / gas / photovoltaics / wind turbines / batteries, that we can almost ignore it.  100% of the "nuclear waste" from all US nuclear power produced from the 1950s to the present day would fit on a single football field, stacked 40ft high.  If we can't contend with that amount of waste product from generating energy, then the entire notion of effectively dealing with the literal mountains of toxic electronic waste produced by photovoltaics / wind turbines / batteries is pure lunacy.  Anyone who says 1 lousy football field of nuclear waste can't be properly cared for is a liar, full stop.  These same people have no answer to the vast quantities of toxic wastes produced by defunct photovoltaics / wind turbines / batteries.  Worse still, almost all of the so-called "nuclear waste" is actually fissile "nuclear fuel" containing 97% of its original energy content.  We don't want to spend the money to recycle the fuel, even though we can get almost all of the energy out if we keep recycling it and adding minor quantities of virgin Uranium or Thorium.  Solar thermal and some forms of geothermal are different, being long-lasting and completely recyclable if we stick to simple materials and don't chase after every last percentage point of efficiency, oblivious to the fact that the result will not be sustainable or practical or cost-effective.

In places without a lot of sunlight, you'd be silly to try to operate solar anything.  That's where nuclear reactors come into play.  In places that are scorching hot deserts, you'd be silly to try to operate a reactor there, even if you technically could.  In places with low population but strong and nearly-constant wind, it makes sense to use wind turbines there.  It makes no sense at all to incessantly attempt to jam square pegs into round holes because of religious or political beliefs about X energy system being better than Y.  That is what we're presently doing, and it's rapidly depleting scarce material and energy resources for little real environmental or economic benefit.  In short, energy systems don't operate according to imagination, but to well-understood scientific principles reducible to repeatable engineering practices.  An energy production system cannot consume inordinate amounts of input energy, capital, labor, or materials relative to what it produces, either.  A globally scalable energy production system must have modest material and labor inputs over time, while producing enough energy to both replace it with the next generation of technology, as well as provide significant surplus energy output for all other uses.

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#171 2023-09-19 13:59:24

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 3,398

Re: Why the Green Energy Transition Won’t Happen

Agreed regarding solar thermal electric.  (1) Power density won't be any better than PV, but the power systems can at least be constructed from structural grade steels that can be recycled almost endlessly.  That will keep costs down in the long term.  (2) The systems are also relatively simple steam plants, with steam raised in boilers.  We have been building this sort of technology for over a century and most nations have the expertise to make it work.  Technological simplicity is a major selling point here.  (3) Heat can be stored quite easily in hot rock, phase change materials, or even in steam drums.  This is far cheaper and easier than trying to store electric charge in chemical batteries.

The significant downside is that this technology will not work year round in most of the developed world which is concentrated in the northern hemisphere.  The US is the country most capable of developing this technology at scale.  The southern US gets a lot more insolation than Europe, Japan, China, Russia or any other developed country except Australia.  The US also has a grid capable of distributing that power.  In Northern Europe, solar power may still be applicable in producing the low grade heat needed for space heating.  This is substantially greater than our electricity demand.

Last edited by Calliban (2023-09-19 14:07:14)


"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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#172 2023-09-21 07:22:30

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 3,398

Re: Why the Green Energy Transition Won’t Happen

This man built a water powered sawmill based on Leonardo Da Vinci's sketches.
https://m.youtube.com/watch?v=hmWPlLp1qAw

This is an example of direct mechanical power.  Presumably, directly harvested mechanical wind power could be used to power devices like this, in areas away from water sources.  The work rate would vary according to the power available on any particular day.  Whilst working in this way is not ideal, the machinery is technically easy to build.  Hydraulic power transmission would make it easier from a factory layout perspective.  Renewable energy falls down when people attempt to use it to make electricity and supply large grids.  Large power grids require instantaneous balance of supply and demand.  They are fossil fuel optimised systems, because they require supply to adjust to demand.  This doesn't work for renewable energy, because nature controls the supply and we do not.

Last edited by Calliban (2023-09-21 07:38:04)


"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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#173 2023-09-25 11:01:54

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 3,398

Re: Why the Green Energy Transition Won’t Happen

A wind powered sawmill in The Netherlands.
https://m.youtube.com/watch?v=Q6FxG3ll-lw&pp

This is another example of direct mechanical power, with a windmill raising and lowering the saw blades by turning a crank.  The speed of cutting is proportional to wind speed.  The operators of the mill adjust the number of saws that are operating as wind speed changes.

In places where the wind is strong and dependable, it could be used to generate direct mechanical power that could fulfil many functions.  These functions can reduce the amount of electrical or diesel power needed by a society, by displacing it.  Using direct mechanical power is more resource efficient than generating electricity for the grid, as it avoids the embodied energy and materials associated with electric power generation, transmission and conversion back into mechanical energy.  Instead, the mechanical power is used at source.

These Persian windmills have been grinding grain for over 1000 years.
https://m.youtube.com/watch?v=3ugw7-BwsmI&pp

The panemone is a relatively inefficient device.  However, it is easy to build.  The sails turn a shaft that is directly connected to the mill stone, without even gearing.  Whilst the device is inefficient, its slow speed and low operational stresses allow longevity.  The materials used to build these grains mills were also energy cheap.  The long life and low embodied energy, allow these devices to achieve a good overall energy return on investment.  The materials involved are wood, plant based twine, mud and stone.  Whilst these mills would be unsuitable for generation of electricity, they avoid the need for using electricity, by raising mechanical power where it is needed.

It would be interesting to consider how we might improve upon these Persian windmills with more modern technology, without sacrificing their advantages.  One innovation that would improve their efficiency is Gorlov type wind motors.
https://en.m.wikipedia.org/wiki/Gorlov_helical_turbine

The windmill itself could still be made from wood, but adopting the Gorlov geometry would allow much more wind energy to be captured for grinding the grain.  Another possible innovation would be to use the wind mills to drive hydraulic pumps.  The flour mills would then be drived by hydraulic motors.  This would allow the speed of the mill stones to be precisely controlled and also allows the work rate to be more precisely balanced to the wind energy available, making use of it even at low wind speed.  But the hydraulic transmission introduces a lot of complexity over a simple coupled shaft.
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Additional:

Windspeed follows a gradient close to ground, as friction results in drag.
https://en.m.wikipedia.org/wiki/Wind_gradient

The extractable power from the wind increases with the third power of velocity:

W = 0.5 x n x rho x v^3

Where n is efficiency and rho is air density.

It follows that the power output of a wind machine per unit swept area, is a strong function of wind velocity.  Large wind turbines not only produce more power, they have superior power density.  This is the case regardless of whether the machine is producing mechanical power or electricity.  Large machines are more efficient and all else being equal, more cost effective.

This means that wind machines should be located in favourable geography (i.e on a hill top) and constructed as large as possible, with users of the mechanical power clustered around them.  Power distribution under this arrangement could be either electrical or mechanical (hydraulic or line shaft).  Instead of individual houses owning freezers, a town, village or city district, could have a large underground community freezer, like a giant root cellar, for storage of food.  If it is accessible to everyone 24/7, then it would provide the same flexibiluty as a home freezer, provided one can tolerate a short walk.

Instead of wash facilities in every house, there could be a community bath house, using a mixture of solar, geothermal and wind pumped heat to warm up the water.  This is close to the concept of a Roman bath.  Heat for cooking could be generated by compressing air to high pressure without intercooling.  In this way, ovens and hobs could be hydraulically powered.  Restaurants could be clustered near a large mechanical windmill, perhaps around a thermal store which stores heat for cooking.  A community scale laundry could use stored solar heated water from a large tank, with mechanical wind power driving the laundry machines.

In all cases, the work rate is a function of wind velocity.  When wind speed is high, all functions can run simultaneously.  At reduced wind speed, work rate drops and ultimately, one must prioritise which functions remain active as windspeed drops.  This is easier to do on a relatively small scale.  Heat can be stored economically, so hot water, cooking and freezing, can function as dump loads that are switched on and off as wind rises and falls.

Generally, the more functions we can divert away from electricity and onto direct heat and mechanical power, the easier it is to power functions using renewable energy.

Last edited by Calliban (2023-09-25 19:05:20)


"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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#174 2023-09-26 09:59:51

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 3,398

Re: Why the Green Energy Transition Won’t Happen

This Dutch windmill was built in 1874 and used to drain water from the land, which is beneath sea level.  It is a simple low head pump, raising water through a head of 2 - 3 metres.
https://m.youtube.com/watch?v=3STOY9DEi2s

It still works today.  It is a smock mill, with a masonry construction up to a certain level, with the wooden upper tower able to move on bearings as it tracks the wind.  One advantage of these traditional machines was that the tower itself was a useful building.  It would be home to someone who would work the mill.  For flour mills or saw mills, the tower was part of the factory.  The fantail was an English invention in the 18th century.  This allowed windmills to track the wind without human intervention.  It appears not to have been replicated on this mill, despite it having been built relatively late.

These older mills have simple reaction blades that do not generate lift.  This makes them less efficient per unit swept area than a modern wind turbine, whose blades are designed to maximise lift whilst minimising drag.  However, we could apply aerodynamics to the design of windmill blades making them more efficient.  The Dutch did this in the 1930s, with a great deal of success.  But by that point, widely available coal, diesel, petrol and electricity, were making direct mechanical wind mills less cost effective.  In the early 2000s, we entered an era of more expensive fuel and electricity.  The mechanical windmill may be worth revisiting.  In situations where people are running home businesses and can vary their working hours according to wind conditions, this could provide power to mechanical loads.

Hydraulic power transmission only really took off towards the end of the 19th century.  But it would greatly extend the application of mechanical wind power, as it allows easy flexibility of factory layout.  In this way, it provides many of the benefits of electricity, without the complexity and demand for exotic metals.

Last edited by Calliban (2023-09-26 10:08:23)


"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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#175 2023-09-26 12:04:39

Void
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Registered: 2011-12-29
Posts: 7,070

Re: Why the Green Energy Transition Won’t Happen

You made me think of using a humanoid robot to work in your electric free windmill environment.  Of course the robot would need a bit of electricity.  But if it could do a useful task, it might not matter if it works at a faster or slower speed, or even ceases to operate for a time.  It would depend on the work that the mill + Robot was doing.

Done


Done.

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