Geothermal and Geothermal Battery (Changed Title 12/21/23)

kbd512 · 2023-08-26 22:16:31

I would think that whatever you put on the surface of the moon will eventually equilibrate to 120C in direct sunlight, or -130C at night or in shadow.

This is sort of how I envisioned this working:

1. The molten salt tank dumps the collected / stored heat energy into a working fluid like Helium or Argon, and that gas is used to power an electric turbo-generator of some kind.
2. The radiator array / cold sink can be kept behind something casting a shadow for improved performance (maybe a piece of mylar), realizing that we can only produce power by re-radiating heat extracted from the salt into space. It's rate-limited with radiation as the sole heat rejection mechanism, or you need a larger radiator array, and the fact that the operating temperatures involved will be rather modest. Let's say 400C is your "hot side" and -100C is your "cold side". That's high enough, and with a sufficient temperature delta, to keep the radiator size in check.
3. The salt tank can be double-walled and use vacuum as its insulator. I probably wouldn't bother with bore holes on the moon, but it makes a lot more sense on Mars.
4. The solar thermal mirror collectors reflecting photons onto the concentrator tubing can be made from Aluminized Mylar, which is light and cheap.
5. The concentrator tubing can be a flexible ceramic. It contains no pressure and supports very little weight, so the fact that it's not all that strong is not a major issue. The ceramic will conduct heat well, but won't crack or corrode from impurities in the salts. Salt remains solid or liquid, so it's not going to escape into space if the seals aren't perfect. It's not quite as flexible as PVC piping, but still bendable without immediately cracking- a very useful feature.
6. The turbo-generator will have to use Helium or Argon and be very well-sealed, but it's the same tech that NASA has continuously run for 15 years on end without stopping, as well as the same turbo-generator tech used by KiloPower.
7. This same collector setup won't work quite as well on Mars. You need a much harder material than mylar, or it will craze as the wind blows the abrasive dust across the surface. There's not much wind on the moon. The concentrator, radiator, turbo-generator, and salt tank technology can remain the same.
8. This kind of heat engine tech is pretty close to the last word in ultimate reliability where turbo-generators are involved. TEG devices like those used aboard RTG-powered spacecraft are the only longer continuously running zero-maintenance power generating systems, but unsuitable for the level of output a base requires. Even a diesel engine requires periodic oil changes. NASA-level photovoltaics are also highly reliable, but very expensive. The batteries they require are heavy, degrade rather quickly, and cannot be made from local materials until we start our own Lithium mine. All it takes is one battery cell with a manufacturing defect to ruin an entire pack. Batteries remain very useful for portable electronics and power tools, but relying on them to power entire bases will put us in a bind as the power requirements grow.

I think bore holes will be far more useful on Mars, especially if we can use ice deposits as our cold sink. Geothermal combined with solar thermal could be a way to both extract liquid water while making energy. It's a bespoke heat engine solution. Maybe it would also work on the moon, but I think Calliban already indicated why it may not work as well.

Void · 2023-08-27 08:40:52

If I might be permitted to, I will suggest compressed soil bricks with tubing in them to make heat exchanger fins to set on the ground on Mars.

https://www.newsweek.com/mars-soil-bric … 20concrete.
Image Quote: martianbrick.webp?w=790&f=1e00e38200d5e5831ae4db98aae73850
Image Quote: martianbrick.webp?w=790&f=8fe58dbf3557b49a39d5b25db1e66c26

It might look a bit like a maze, with walls set on the ground.

If a "Pigment" were available the albedo could be adjusted.

Just a possible option to try, the manufacture and durability of such would need some work.

And similar to what you said you might have some kind of shade, maybe a movable one to block sunlight a bit?

Maybe CO2 as the working fluid?

Done.

Last edited by Void (2023-08-27 08:46:23)

SpaceNut · 2023-08-27 17:55:13

The temperature is a bit misleading as the soils are reflective and we want the heat to be obsorbed and that means black as black can be.

SpaceNut · 2023-08-27 17:56:10

The temperature is a bit misleading as the soils are reflective and we want the heat to be obsorbed and that means black as black can be.

Void · 2023-08-27 20:22:44

Well, that is a good point, but really, I was considering radiator fins, that would be like walls standing on a solid foundation. But per your post, perhaps something for the hot side could be done as well.

I think there will be trouble crushing the soil into brick and not squashing the embedded tubing, but I suppose some solution can be found.

But I also have now considered embedding wire mesh into the brick to be compressed and perhaps even glass fibers / basalt fibers. Just for more strength.

As for exterior color and shades such as kdb512 mentioned, those are options to be worked on as well.

If you did do the "Hot Wall" option then perhaps Heliostats might be employed to up the temperature, but a concern on the durability of the materials would need investigation.

Done.

Last edited by Void (2023-08-27 20:23:56)

Void · 2023-08-31 09:49:33

I am having a look at this today as I stumbled on to it.

https://antoraenergy.com/

https://www.youtube.com/watch?v=hXB5bwYFYv4

Yet another example why Carbon is wonderful. Let's hope it will work and also expand.

Done

Last edited by Void (2023-08-31 09:56:03)

Terraformer · 2023-08-31 10:27:00

There are now kits available for underfloor heating. Screedless low profile plates you lay on the floor to run the pipes through and conduct the heat. Makes low temperature heating far quicker and cheaper to install.

Britain could cut maybe 30% of its gas consumption if we transition homes over to this, powered by heat pumps, and that's with air source and relying on gas for electricity. Given that 60% of our gas is imported, this would make the country significantly less dependent on foreign markets. We could do that and then connect up ground networks as and when, eventually maybe even dispensing with the heat pump part if the stored heat is high enough.

The focus on using heat pumps as a drop in replacement for boilers severely limits their use in Britain. Keep the gas boilers for now for hot water, we'll move to heat pumps once we have lukewarm sources to draw from.

Void · 2023-08-31 10:58:57

It is good if a region can find its way in all of this. Prosperity beats the heck out of being poor

Done.

Last edited by Void (2023-08-31 13:24:17)

Calliban · 2023-08-31 11:38:15

Air source heat pumps are a weak solution that is indicative of poor planning. Heat demand is highest precisely when air temperatures are coldest and COP is poorest. And air is diffuse and heat transfer coefficients from gas to solid heat exchanger tubes are inherently poor. A high flowrate fan is therefore needed to blast air across the heat exchanger tubes. That eats a lot of power on top of the power consumed by the heat pump itself. It is also noisy, prone to vibration and really isn't something you want a lot of in a dense urban environment. The high power consumption of the fan and the inverse correlation of air temperature with heating load, is why COP for air source heat pumps is no greater than 2, which makes them not much better than resistance heaters. The need for pumping power is one of the reasons that real heat pumps never get close to their theoretical COP.

The problem with Britain is that most houses are in densely populated urban areas with no space around them. This makes ground source heat pumps problematic. You either need to dig a very deep borehole, which is expensive, or get heat from somewhere other than the ground. One possibility is cold district heating. Under this arrangement, cold water at around 10°C is delivered by a pipe main to heat pumps in individual houses. This is close to year round average ground temperature in the UK, so heat at this temperature is not difficult to source and the pipes do not need to be heavily insulated, the soil itself being sufficient. A heat pump drawing heat from a source at 10°C and providing heat at 30°C, would have a theoretical COP of 14. Practical COP might only be half of that. But a COP of 7 beats a COP of 2.

The cold water main would run year round. During spring and winter months, it would such heat out of local rock bodies, reducing their temperature to single digit °C. For the restof the year, the heat flow would go into reverse, with ambient heat soaking into the roads above the main, warming the water and allowing the thermal storage volumes to recharge. As the pipes are not pressurised or heavily heated, concrete or polypropylene could be used.

Last edited by Calliban (2023-08-31 11:46:19)

Void · 2023-08-31 13:19:49

While heat pumps may well apply to some situations, I feel that this may also have a place: http://newmars.com/forums/viewtopic.php … 56#p213156

https://antoraenergy.com/

https://www.youtube.com/watch?v=hXB5bwYFYv4

And this: https://www.youtube.com/watch?v=rY3n7hhe6EM&t=36s

Thermovoltaics, using cooling water may shed heat for some heating processes.

These systems may provide industrial heating and electricity.

Done.

Last edited by Void (2023-08-31 13:23:46)

kbd512 · 2023-09-01 02:17:55

Terraformer,

Unless these heat pumps are attached to a geothermal well providing district heating, I don't think they'll save any money. In-floor heat pump systems are seriously expensive hardware. There are about 24,800,000 homes in England and Wales. If an average-sized home in the UK is 1,000ft^2, and a 1,000ft^2 heat pump system costs about £15,768, then that equates to about £392B to replace residential gas heaters with heat pump systems.

Edit:
How much does it cost to fit a heat pump in the UK?

Fitting an air source heat pump usually costs between £7,000 and £15,000, while a ground source heat pump installation typically costs £17,000 to £35,000.

72B m^3 of gas is what the UK consumed in 2022. You're stating that 30% could be saved, so 21.6B m^3 of gas per year. At £1.35 / m^3, that's £29.16B / year. This heat pump system has to last for 13.4 years before spending on gas overtakes spending on the new heat pump system, ignoring the fact that all of this stuff still consumes electricity from the grid unless there's a geothermal well nearby.

How long should your heat pump last?

Heat pumps normally last an average of 15 years, though some can wear out after a decade. Some of the newer units being manufactured today can last a bit longer. The factor most important in determining the lifespan of your heat pump is maintenance.

I think you're setting yourself up for disappointment. The math doesn't work.

Edit #2 (major caveat):
I assume this is about money rather than ideology. If it's about ideology, everyone can go broke chasing after that.

Last edited by kbd512 (2023-09-01 02:23:50)

Terraformer · 2023-09-01 06:48:22

The math does work, you're just not doing it. You're making the argument essentially that food is super expensive, based on the tastes of the wealthiest 10%. Very few people are installing heat pumps in Britain, so of course the figures are skewed by who is installing them (rich people getting government grants).

Norwegians, OTOH, pay ~£2100 for a heat pump. Because unlike Britain, they don't insist that it provides 60c hot water as well as space heating. Our costs are high because we're going about it in a supremely idiotic way. And before you go on about the cost of plumbing... are you really going to insist that connecting a heat pump to pipes is a £5k job at a minimum? (EDIT: wait no you picked the highest number deliberately, because your argument is a lot weaker otherwise. LOL.) Really? But even if it did, the 15 year figure is for the heat pump replacement only, the plumbing and underfloor heating panels are going to last a lot longer than that. You're not ripping out the whole system every 15 years, so the replacement cost is maybe £3k, or £200 a year budgeted for replacement.

Calliban, water source is also an option. Guaranteed 0c source no matter the outside temperature, since you're drawing down the latent heat. Though in most places in Britain the air only gets colder than that for a few days of the year, so there's not that big an advantage over using the air.

EDIT2: a paper analysing heat pump usage in Norway.. Purchase + installation costs for air to water there are £4.5k-£10k, significantly better than Britain manages. (Anglo cost disease strikes again. Sigh.)

Last edited by Terraformer (2023-09-01 07:09:22)

tahanson43206 · 2023-09-01 09:03:31

For Terraformer re Norwegian company ...

This question is just coming from curiosity, but it is inspired by what appears to be a market opportunity in Britain ...

Does the Norwegian company that installs heat pump systems for so much less have a branch in Great Britain?

If not, you're a natural to become the UK branch manager pro tem.

(th)

Terraformer · 2023-09-01 09:43:36

UK climate averages

We don't have that many days when the air is below zero, even in December and January. Winters here are pretty mild.

I'm thinking about air source, because the difference between that and cold district heating is just the source. Ideally we'd separate the heat pump from the heat exchanger fan, so we can simply plug in a different source when it becomes available... not sure they sell systems like that though.

Even if we go all in on nuclear, we should still build district heating systems. *Especially* if we go all in on nuclear. No point wasting all that lukewarm water. It's hard to think of a situation where they'd become stranded assets. We should definitely future proof (read: insulate) them though.

With underfloor heating, I think it's better to *not* insulate it from the concrete floor? The temperature of the ground beneath a house should approximate its annual temperature -- metres of earth are still an effective insulator. I don't think stopping a small amount of heat loss is worth losing the benefit of thermal mass from the concrete.

kbd512 · 2023-09-01 10:08:07

Terraformer,

The first article you linked to states that burning wood is less expensive than running a heat pump in Norway in the dead of winter, which is why they're still burning wood, which is dirtier than burning coal.

The Eco Experts UK - Heat Pump Costs UK 2023

From the article:

An air source heat pump usually costs around £10,000
A horizontally installed ground source heat pump costs £24,000, on average
The Boiler Upgrade Scheme can cut £5,000 or £6,000 off the total cost
Heat pumps are an efficient, renewable way of replacing gas and oil boilers in most homes – provided you prepare properly – so it makes sense that the government's encouraging homeowners to buy them with subsidies.
...
How much does a heat pump cost?
2-bedroom air source, 5kW: £7,000
2-bedroom ground source, 4kW: £17,000
3-bedroom air source, 10kW: £10,000
3-bedroom ground source, 8kW: £24,000
4-bedroom air source, 13kW: £13,000
4-bedroom ground source, 11kW: £30,000
...
An air source heat pump costs £10,000 for a three-bedroom house, on average.
You’ll pay more to draw heat from the earth – a ground source heat pump typically costs £24,000 for a horizontal installation, or £49,000 for a vertical installation with boreholes.
However, you can buy either one for much less at the moment.
The Boiler Upgrade Scheme can reduce the cost of an air source heat pump by £5,000, and the cost of a ground source heat pump by £6,000.
Also, the current price war between British Gas and Octopus means you can currently get an air source heat pump for as little as £2,500.
Considering an air source heat pump will now typically save you £1,442 more than a gas boiler over 20 years, the maths is now decisively in favour of air source heat pumps.

The second article you linked to, doesn't seem to support your assertions very well.

AAHP = Airt-to-Air Heat Pump
ASHP = Air-Source Heat Pump
GSHP = Ground-Source Heat Pump
Startup + Installation Costs; Maintenance Costs; Payback Time; Service Lifespan
AAHP: £1,110 - £2,220; £125.8 - £185; not listed; not listed
ASHP: £4,440 - £9,620; greater than £185; 6-10 years; 12 - 15 years
GSHP: £12,580 - £18,500; greater than £185; 8 - 10 years; 20 years
The cost of drilling boreholes with depths of 100–300 m in Norway is £2,960 to £7,400.
...
The only additional cost for the energy geostructures is embedding high-density polyethylene (HDPE) pipes inside the concrete and the heat carrier fluid within them. While ASHP simply consists only of indoor and outdoor units, with no need for drilling or additional long pipes, making it much more affordable than GSHP. The advantage of GSHP systems is that they can operate for 20–30 years with almost no significant maintenance, while ASHP requires a lot of maintenance and hence has a higher operating cost.
It is crucial to evaluate the economic viability of different types of heat pumps (ASHP and GSHP) by calculating the installation and product costs. In order to fairly calculate the payback period, the incentives and subsidies are not considered, the COP was estimated under similar environmental conditions, and the average electricity tariffs in 2021–2022 were used. For the GSHP, the cost is calculated for both scenarios where energy piles and borehole heat exchangers are used, since in the case of using boreholes, we have drilling expenses, but in energy piles, there is no drilling cost, and the only additional cost is for installation of HDPE pipes.
As stated earlier, COP is affected by the temperature difference between the source and destination environments. Hence, it is vital to know more about the air and ground temperature variations in Norway. Figure 13 shows the average daily air temperature in two cities of Trondheim and Oslo in Norway between July 2021 and June 2022. Oslo is the capital city of Norway, located in the south, and Trondheim is the third largest city in Norway, located relatively in the northern part. Figure 14 shows the ground temperature over the depth in two sites in Trondheim and Oslo. The ground temperature is stable from seasonal changes below a depth of 8 m from the ground surface and is approximately 6 °C for Trondheim and 8 °C for Oslo.

This article from a financial analyst does a good job of breaking the issue down in detail:
Why has the UK seen so little uptake of heat pumps compared to our neighbours in the last 10 years? by Ben Whittle, Senior Analyst at Energy Saving Trust, Mar 12, 2022

I can guess at why Sweden and Norway have much more reasonable product and installation costs without knowing anything more about the issue than how British versus Scandinavian homes and buildings are insulated, relative to each other. The Scandinavian homes are much better insulated than British homes, thus they require less energy to keep warm or cool, even though it gets colder in Scandinavia than it does in Britain. That seems like a fairly easy to guess reason behind the cost differential.

In order for these systems to make sense for the majority of the British people, by achieving installation and operating prices similar to those seen in Scandinavia, they'd need to spend many more hundreds of billions of pounds on home insulation, erasing any possible cost and environmental benefit over the next 20 years or so.

How Much Does it Cost to Insulate a Home and What Options Do You Have?

You'll either need to alter the exterior of the building or lose precious space internally. For a typical 3-bed semi-detached home, expect to pay £8500-£15000 for external insulation and render. For internal insulation and plaster, expect the price to be lower at around £5000 – £7000.

I'm going to ask that you devise a better argument for the costs than calling your fellow countrymen "stupid", especially when we have cost data available from people in the UK who did the very thing you want them to do, namely installing heat pumps. The costs presented are reflective of what it actually costs in the UK vs Norway. In Norway, according to the first article you linked to in Post #337, many Norwegians are still burning wood during the winter because electricity costs, even with the benefit of their heat pumps, is still too expensive for many of them to afford. There are normally other explanations for dramatic costs differentials that don't resolve to, "everyone but me is stupid".

Terraformer · 2023-09-01 14:23:35

Oh I'm sure the government giving people £5000 towards their heat pumps won't have any effect at all on reported costs. Governments giving people money have never had such inflationary effects.

Calliban · 2023-09-01 16:11:47

A £24k capital cost for a horizontal heat pump is a lot of upfront cash. And it won't be an option anyway unless the house has a sizable garden. Even with gas at 15p/kWh, that is still a 12 year payback time based upon an average annual gas use of 12,000kWh. There is clearly a lot to consider here. A cold water main would dramatically simplify the heat pump, as the heat source would be water circulated through a compact heat exchanger. Capital cost in this case would be comparable to the air source heat pump. But the cost of a district water main will be additive to this, albeit spread across a huge number of town properties. Then again, a gas main has capital cost as well.

Water has a very high specific heat and this allows it to carry an impressive amount of energy. Consider the case for a 1m internal diameter concrete water pipe. Flowrate through the pipe is 10m/s. Specific heat is 4.2KJ/kg.K. Let's say the water starts at 10°C and is cooled to 5°C. The total heat delivered by the pipe would be:

Q = pi x r^2 x V x density x 4200 x 5

Q = pi x 0.5^2 x 10 x 1000 x 4200 x 5 = 165MW.

That is enough thermal energy to heat a town of 40,000 homes in the UK under peak winter heat loads of 90kWh/day. Coastal towns and cities could have seawater mains. Even Edinburgh in the coldest months (Jan - Mar) has seawater temperature of 7-8°C. If this could be piped around the city, individual buildings could have dedicated heat pumps with seawater heat exchangers. A flowrate of 10m/s represents a dynamic head pressure of 0.5 bar (5m static head). This is easily achievable using single stage centrifugal pumps.

If Britain were to do the sensible thing and build a new generation of small modular reactors, then waste heat could be used to heat cities. Condenser temperatures for LWRs are about 30°C. In some cases, water at this temperature could be used as a direct heat source. Or it could function as the cold source for high COP heat pumps. A heat pump with an inlet temperature of 300K and outlet of 310K, would have a theoretical COP of 30. Real system COP will be lower, but even so, using warm waste water from nuclear powerplants would dramatically reduce the amount of electricity consumed by a heat pump.

Last edited by Calliban (2023-09-01 17:14:51)

tahanson43206 · 2023-09-01 17:13:36

For Calliban re #342

Thanks for the insight that a nearby ocean might be useful for providing heat pump thermal energy.

Two questions came to mind after reading your post ...

1) How far inland might this concept extend?
and
2) How well would this concept work for a river? For example, the Thames river is on the large side when it passes London... could it provide thermal energy for an entire city, or would it freeze due to loss of thermal energy?

(th)

Calliban · 2023-09-01 17:39:28

The average flowrate of the Thames is 65.8m3/s. If we were to cool it by 5°C, it would provide an average of 1.38GW of heat. That is enough to heat 350,000 homes at peak winter heating rate. That is about 10% of London housing stock. So yes, the Thames could meet a sizable fraction of the city's heat load. But 1.38GW is less than one half of the waste heat output of one of the EPR reactors being built at Hinkley C. The new RR SMRs will produce some 900MW each of waste heat. A dozen of them would produce all of the heat and electricity needed by the city.

Last edited by Calliban (2023-09-01 17:45:02)

Terraformer · 2023-09-02 04:00:19

Guess it depends on how much heat we can take from the estuary? And how far it can be pumped without losing too much heat in zero c weather.

One advantage that pipes for heat networks have is that they're not dangerous. You could run them above ground if you wanted, though you probably don't want to because damage is still a hassle to sort out, even if it's not a threat to life and property as a gas main would be. But a shallow trench with plenty of insulation should do it. Perhaps beneath or alongside canal towpaths (no, Councillor, the canal itself is not a good source for heat pumps...). We have an extensive network of canals in England.

Going back to geostored energy, how tricky is it to drill into limestone compared to clay? We have a lot of outcroppings up here. I'm guessing harder to drill but without the expense of stopping the hole from collapsing in on itself?

I wonder what the temperature profile of mudflats is like...

kbd512 · 2023-09-02 16:03:25

Above-ground operation is one of the major benefits of district heating pipelines. Placing the pipeline above-ground allows for much easier inspection and replacement of piping. There are cases where placing the pipeline in the ground will prevent certain types of damage, such as impact from motor vehicles, but subjects the pipeline to other types of damage at the same time, all of which are much more difficult, expensive, and time-consuming to repair. Long-distance oil pipelines are typically above-ground for this reason.

If you commit to switching to a true thermal system, with onsite generation of electrical power only when electricity is actually required, then you secure the following benefits:

1. The power distribution equipment can be entirely mechanical. Most appliances can also be mechanical. This means they do not require any wiring, microchips, highly conditioned electrical power with a stable voltage / amperage / frequency, and can be repaired using hand tools, rather than thrown away because they're not economically repairable. Home lighting can be accomplished using fiber optics, so even that system only requires electrical power for a single LED light source. That leaves electric ovens, ranges, microwaves, kettles, cell phones, laptops, and televisions as devices that absolutely require electrical power. 75% of residential power consumption is low grade heat. This holds true everywhere on the planet.

2. You do not need massive amounts of Aluminum, Copper, and rare Earth metals to transmit electrical power. Since there is not an adequate supply of these metals to make everything electrical, point-of-consumption thermal energy supply is the lowest cost and most reliable alternative. It requires more volume of flow than electricity, but consider the cost of your electric bill vs your water bill.

Consider 20,000 gallons of hot water heated to 99C. The City of Houston charges $25 for 20,000 gallons. $12.50 is the minimum charge, regardless of usage, up to 10,000 gallons.

20,000 gallons of water = 75,600kg
20°C is used because the ocean "cold sink" is colder than 20°C in the UK
99°C - 20°C * 4182 J/kg°C = 322,014J/kg
322,014J/kg * 75,600kg = 24,344,258,400J
24,344,258,400J / 3,600J/Wh = 6,762,294Wh
If you recover 33% of the energy by turning it into electricity, that's 2,254,098Wh.
90,163.92Wh per $1, or 901.6392Wh per 1¢ (almost a full kWh of electrical power per penny)

A British company developed a heat pump improvement for HVAC systems that operates over a similar temperature range, but it's 60% efficient at converting electrical power into pumping and heat removal power. The piston in the refrigerant fluid exchanges heat using radiator fins attached directly to the piston.

Use the waste heat from the reactors. Almost all of it is being uselessly thrown away, but it's still real power. Use the waste heat from the Earth through geothermal if you don't want nuclear. Either way, modern energy systems of all varieties don't work without enormous quantities of heat energy provided 24/7/365. In places with extreme heat / sunlight, you can use the Sun to cut the peak off the power consumption. In places with extreme cold, you use the temperature gradients between the ocean and atmospheric temperature, or nuclear and geothermal heat sources.

3. A power distribution scheme based upon hot and cold water is inherently recyclable, maintainable, and reliable. Nearly every major storm here manages to knock out the power. I can count on one hand the number of times water pressure has been lost, and all of those incidents were directly attributable to loss of electrical power at the pump stations. Electrical power is only reliable when all connected systems are not subject to adverse weather events and regular maintenance is undertaken. A lightning strike on a hot water pipe or mechanical pump is a non-event, because it will have no effect whatsoever on the thermal energy that the hot water pipe is carrying.

For the prior part, the average lasting of transformers is about 35 years. But, when operated under ideal conditions, including temperature, weather patterns and setting, the expectancy can be 30-40 years. However, this decreases a bit for industrial transformers making it 20-25 years.

The typical lifespan of an oil-filled transformer is around 20-30 years, but some high-voltage models that are kept in pristine conditions can last 50 or 60 years! Most of the time, these transformers will outlast the career of the person who ordered or installed them.

The average life span of general purpose dry type transformers are more than 25 years. If an air cooled dry type transformer operated in dust free, well ventilated avoiding direct hit, dust, wet and humidity with rated parameters, it may last more than 35 years even 50+ years
...
The normal life span of indoor 100kVA enclosed air cooled transformer is more than 60 years if they are well maintained and operated with rated parameters and installed in locked electrical rooms.

Powering the nation: how to fix the transformer shortage

A 2020 report from the Department of Commerce found that the average transformer is 30 to 40 years old — far beyond the intended lifespan of 25 years. The age of our current stock suggests that active transformers may be more vulnerable to mechanical breakdowns and failure

Transformative Times: Update on the U.S. Transformer Supply Chain

Large electric transformers are inconvenient machines. They are large and heavy, which means they usually need to be delivered by sea freight, not air freight, which would be faster. They must be designed by specially trained engineers and assembled by experienced technicians. They require expensive and often rare materials, like copper, specifically milled steel, high-cellulose paper and other hard to come by components. They have extremely exacting technical specifications, which limits production and keeps new producers out of the market. They must be built to exacting standards for safety and reliability, which requires extensive testing and often customized manufacture.

Over 30 to 40 years, which power companies get to adjust the weather and temperature to ideal values for power transformer longevity?

Has anyone else noticed that the long list of caveats does not actually describe any outdoor environment located on planet Earth, which also happens to be where most of these devices are located?

The amount of money spent trying to to flip the bird to basic physics is staggering.

Who here thinks replacing some bent or broken steel pipes after a major storm would be easier than much of the electrical power infrastructure?

Assume that both could and would be damaged. A transformer explodes, the steel pipe gets bent and broken by a giant tree falling on it. Either way, bad weather took out both systems. Think it'll be easier to fabricate new steel pipe or replace giant transformers that have manufacturing lead times measured in months?

Resiliency is at least equally important as longevity. Electrical power systems don't have much of that. They can be replaced, but not easily repaired. Repair of an exploded transformer usually involves melting down whatever is left, back into the base metals, and then fabricating a new one. As that last article indicated, 82% of the components (very different from raw materials, which can be stockpiled) are imported into the US. Relying on China to deliver them is madness. A mechanical power grid, based upon steel / concrete / hot and cold water, is something nearly every industrialized nation can make themselves. It cannot be affected by lightning strikes, high-altitude EMP / nuclear weapons detonations, solar flares, or any other electrical or magnetic anomalies.

Calliban · 2023-09-04 03:28:18

Kbd512, that is a novel idea. Ultimately, all densely populated towns and cities are going to have to transition to some sort of district heat distribution. In Europe, this would seem to be an urgent necessity. For Europe and East Asia, natural gas is something that must be imported in liquefied form from thousands of miles away. Burning it to produce low grade heat is wasteful and doesn't generate enough economic value to be affordable as a long term strategy. A heat distribution network will be expensive and time consuming to build. However, it can be constructed from relatively abundant materials like concrete, cast iron and polymers. Once built, it should last for decades if not centuries. So the high upfront cost is spread over many years of operation.

Most of power demand of a home can be met using thermal or mechanical energy. Refrigeration could produce both cold for a fridge-freezer and hot wash water. The same heat pump can do both. The cooling coils on a fridge are warm to touch. So the district heat network does not need to reach washwater temperature. Cookers are a relatively small energy consumer, but require high quality heat. Bottled gas could do that. Washers and dryers need mechanical power and hot water. Some limited electrical supply would be advantageous for control purposes and valve actuation. But we could design systems that are spring operated.

Mechanical power could be delivered by pressurised water. Tap water actually has enough pressure to do this, but wouldn't be affordable if delivered potable water ran to waste. Instead, we need closed cycles with a return pipe. A small powerplant could produce pressurised water for a town, with any waste heat supplying the district heat network. Pressurised water at a pressure of say 10 bar, could be produced using centrifugal pumps. Simple wind turbines could be used to drive positive displacement pumps.

Where we need electrical power is lighting, computing, appliances like an iron, a kettle (this could be gas), microwave, television, etc. For these much smaller electrical loads, a home solar system would be more affordable. Or perhaps a small DC generator producing power from the pressurised water network.

Last edited by Calliban (2023-09-04 03:46:50)

kbd512 · 2023-09-04 15:18:41

Calliban,

I think thermal power distribution systems will become a hard requirement for all of humanity. Nothing else is any cheaper and simpler to operate, more resilient to both supply and demand fluctuations, nor more fault-tolerant of anomalous operating conditions such as weather and temperature changes.

Direct thermal charging cell for converting low-grade heat to electricity

Efficient low-grade heat recovery can help to reduce greenhouse gas emission as over 70% of primary energy input is wasted as heat, but current technologies to fulfill the heat-to-electricity conversion are still far from optimum.
...
Energy conversion from primary energy carriers to the final energy of use is subject to considerable losses equivalent to ~72% of the global primary energy consumption. The major loss is identified as waste heat, and specifically 63% of which occurs as low-grade heat below 100°C.

Someone needs to tell these geniuses to stop attempting to do thermal-to-electric and then electric-to-thermal energy conversions if they care at all about efficiency. Energy conversions are the absolute best way to incur dramatic energy losses. If there's no reason to do it, apart from the one you artificially created by trying to force everything to use electricity, then you don't have to deal with the losses.

If 72% of energy consumption is low grade heat, then you design an energy system that primarily produces and consumes low grade heat, while minimizing energy conversions. If the overwhelming majority of the energy systems were intentionally designed to use low grade heat, then we can optimize our power distribution and mass transport infrastructure. I would argue the true value could be as high as 85% of all energy consumption. This is a solvable problem.

Imagine "not losing" 63% of the energy which is 85% supplied by hydrocarbon fuels, merely by foregoing the creation of high grade heat in favor of a low-grade heat energy systems that run off of collected thermal energy. What do we suppose not losing that amount of energy would be worth, in terms of CO2 emissions? Would it probably be worth more than if every car and truck was an EV? Recall that if every vehicle was an EV, it would eliminate 8% to 10% of the hydrocarbon fuel consumption. If you're intent on fixating on solving a specific problem, then fixate on something that dwarfs all other possible changes to energy consumption.

Calliban · 2023-09-05 04:09:01

Fossil fuel trade between countries is already seeing significant constraints.
https://ourfiniteworld.com/2023/08/31/f … nstrained/

Oil exports appear to have hit a plateau around 2005, which was the peak year for conventional oil production. Until that point, exports were growing strongly. Since 2005, the regions that have increased exports are Russia and Middle East. These appear to stopped growing in 2016 and are now declining. Africa has seen strong decline in exports, as has Mexico. North America has been able to achieve a high level of self-sufficiency in oil and gas, thanks to tight oil from fracking and heavy oil from Canada.

The problem going forward is that we now live in a world with much more capital restraint. The boomer generation is retiring and most are taking their money out of the investment space. Interest rates are climbing. This will make new investment in new hydrocarbon infrastructure more difficult.

Mars_B4_Moon · 2023-09-05 12:08:56

On Earth

Recent Developments in Geothermal Energy
https://www.azocleantech.com/article.as … cleID=1717

Singapore expands study nationwide to assess geothermal energy as potential power source
https://www.channelnewsasia.com/singapo … ma-3744691

Hot Spots found on the Lunar Far-Side and Hot Sun Baked Dust and Rock creating steam to power turbines, fumarolic activity on the Lunar surface support to the validity of the concepts of utilizing geothermal fluids as a source of Moon basepower?

challenges you base hit by micro meteorites, no atmosphere to block radiation on your crew, other risks are moonquakes and the lack of water in the ground, very long days and very long nights.

Exploration of energy storage system

Energy Storage for Lunar Surface Exploration
https://ntrs.nasa.gov/api/citations/201 … 000472.pdf

University Teams Forge Forward in NASA Moon Metal Production Challenge
https://www.nasa.gov/directorates/space … _Challenge

Last edited by Mars_B4_Moon (2023-09-05 12:10:42)

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