New Mars Forums

Official discussion forum of The Mars Society and MarsNews.com

You are not logged in.

Announcement

Announcement: This forum is accepting new registrations by emailing newmarsmember * gmail.com become a registered member. Read the Recruiting expertise for NewMars Forum topic in Meta New Mars for other information for this process.

#51 2021-12-23 14:53:25

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 18,189

Re: Thermal Energy Storage

For SpaceNut re #49

Thank you for helping with the question of getting from 200 Joules per gram to power to operate a tool at 20 Amps/125 VAC for an hour.

Your calculation (as I understand it) gives 2400 watts for an hour.  I'm guessing ??? this is 2.4 kilowatt hours. ???

8,640,000 joules

The MIT reported research indicates their tests indicate the material they are trying can hold 200 Joules in a gram.

Assuming that is the case, and no other mass is involved (which is surely NOT the case) then 8,640,000 / 200 >> 43200 grams

The energy storage material in a container would then weigh 43.2 Kg, or 95 pounds (and change).  The container and any mass needed to convert energy from the stored thermal form to active electricity flow would be extra.

This gives me an idea of what a cart might weigh.  A utility cart able to carry 500 pounds is available from a local vendor for about $100 (US).  The same device is available from the manufacturer in another country for half that, but shipping costs would add to that.

The point I am trying to make here is that it is possible to imagine a thermal energy device might be practical, if the goal is to power a machine that takes under 20 Amps at 125 VAC for an hour.  However, I suspect the efficiency of conversion back to electric flow would be considerably less than 100%.

The post you gave us recently showed Zeolite as an energy storage material, but I have not yet seen any figures for energy storage capability for that material, other than the round number of four times the capacity of water, and I don't know what that might be referring to.

If Zeolite were heated until it is white hot, according to the sources I found and reported above, the material would still be cool enough at the surface to touch, because (again according to the source) the heat energy is stored in the chemical structure of Zeolite.

I'm unsure of what that wording means.  My impression is that the molecules of Zeolite are agitated by thermal energy, but that they hold position inside the material and do not melt or vaporize or otherwise lose structure.

There must be an upper limit to how much energy can be stored in Zeolite, but I'm wondering if whatever the upper limit may be, if it compares favorably (or at all) to the material the MIT researchers were investigating.

In any case, whatever the energy storage capacity of Zeolite may be, the only way that I can see (at the moment) to get it out is to feed water into a mass of Zeolite so that the water becomes steam, which can then be harnessed to produce electricity.

I would expect **that** process to be no better than 10% efficient. 

If we start with the figure of 8,640,000 joules to be fed to the machine, and if the entire mechanism is only 10% efficient, then we would need 86,400,000 joules, or 950 pounds (more or less)

Taking the mass of the cart and machinery for energy conversion into account, we would then be looking at 1500 pounds as a ball park estimate.

Even lead acid batteries would weigh less than that, but the cost of those would total up in to multiple thousands of dollars.

The weak point in my analysis here seems to be the lack of knowledge of the thermal energy carrying capacity of Zerolite.

The text suggesting 4 times the capacity of water doesn't help much, or at least, doesn't help ** me ** much!

(th)

Offline

#52 2021-12-23 14:56:45

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 18,189

Re: Thermal Energy Storage

For SpaceNut .... I decided to show this next quote from Google in a separate post ... I'm not sure what to make of it ...

Zeolite heat storages are chemical storages that promise to reach energy densities of 150–200 kWh m−3 and almost lossless seasonal heat storage 6.
Sep 29, 2020

Zeolite Heat Storage: Key Parameters from Experimental Results ...
onlinelibrary.wiley.com › doi › full › ceat.202000342

About Featured Snippets
People also ask
What is thermal storage capacity?
Does zeolite absorb heat?
Which material has the highest heat storage capacity?
What is thermal energy retention?

Water/Ethanol and 13X Zeolite Pairs for Long-Term Thermal Energy ...
www.frontiersin.org › articles › fenrg.2019.00148 › full
Dec 18, 2019 · Sensible heat storage is the most common and simple method, and relies on the capacity of a storage medium—e.g., solid or liquid—to store ...
Introduction · Materials and Methods · Results · Discussion

Sorption Heat Storage - an overview | ScienceDirect Topics
www.sciencedirect.com › topics › engineering › sorption-heat-storage

19.14). The storage consists of 7000 kg of zeolite 13X. During the heat release phase, the power can reach up to 13 kW. The storage capacity ...
Investigation of a household-scale open sorption energy storage ...
www.sciencedirect.com › science › article › pii

Jul 5, 2018 · The expected theoretical energy storage capacity of the reactor segments is 12.5 kWh, based on the energy density of zeolite. From the results ...
Zeolite thermal storage retains heat indefinitely, absorbs four times ...
www.extremetech.com › extreme › 130523-zeolite-thermal-storage-retains-...

Jun 6, 2012 · When heat is applied to the zeolite, the process is reversed and the water is released. Because the heat is locked up in the chemical structure ...
Improving the thermal conductivity of zeolite materials for thermal ...
www.innovationnewsnetwork.com › improving-thermal-conductivity-zeoli...

Oct 4, 2021 · Thermal storage utilising zeolite material permits heat to be accumulated for extended periods of time without any being lost. Researchers at ...

Note the 2018 entry: 12.5 kWh for a "reactor segment" but I don't know either the mass nor the physical volume of a "reactor segment"

Per Google, 125 kWh is 45,000,000 joules

Per your calculation, the power requirement of the tool is 8,640,000 joules.

So one "reactor segment" would comfortably sustain the tool, but (at this point) I have no idea what a "reactor segment" would weigh or how much volume it would consume. I also do not know how efficient the conversion from stored state (without water) to empty state (with water) might be.

I'm getting the vague impression that allowing water to enter the Zeolite causes heat to be released, but in what form I have no idea. If the water is retained by the Zeolite, then it can't be available as steam.

(th)

Offline

#53 2021-12-23 18:23:19

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,314

Re: Thermal Energy Storage

kbd512 wrote:

SpaceNut,

In your Post #44, we're missing the number of cubic feet of molten Silicon for equivalent thermal energy storage.


The post 28 had the molten silicon values of which I have not looked at the volume but from what I remember 1 liter is 0.001 m cube or equals 1 kg

kbd512 gave Molten Silicon: 528Wh/kg and 4.3MJ/L @ 1414C

1992 w / 528 w = 3.8 kg to achieve 6,912,000 joules for the hour


In that same post 44
I had the conversion of dc watt Ac factor which I missed in post 49 so the tool will run longer that is all.

edit posts 21 through 30 talk about the cell type to capture the photons where we got caught up in color versus black  from pumping it into a tube that glowed versus not pumping.

The TEGS-MPV system would be built with two heavily-insulated tanks, each made of graphite and measuring 33 ft (10 m) wide.
These are heavily insulated and filled with liquid silicon. One tank stores silicon at a temperature of 1926°C. The “cold” tank is connected via a bank of tubes and heating elements to a “hot” tank in which liquid silicon at a temperature of 2370°C is stored.

When electricity is needed, the molten white-glowing liquid silicon is pumped through an array of tubes that emit light. The tubes are routed past high-efficiency solar cells, called multi-junction photovoltaics, with the light from the molten silicon then being turned back into electricity. Through that process the silicon cools down and flows back into the “cold” tank, to be used again.

"At such high temperatures, silicon intensely shines in the same way that the Sun does, thus photovoltaic cells, thermophotovoltaic cells in this case, can be used to convert this incandescent radiation into electricity. The use of thermophotovoltaic cells is key in this system, since any other type of generator would hardly work at extreme temperatures.

In addition, these cells can produce 100 times more electric power per unit area than conventional solar cells. These thermophotovoltaic cells are able to reach higher conversion efficiencies, even over 50%.

Thermal Energy Grid Storage-Multi-Junction Photovoltaics (TEGS-MPV), is based on the molten salt batteries that sit at the heart of grid-scale energy storage systems like concentrated solar. Salt tops out at about 1,000° F (538° C), after which its damaging effects become too problematic.

https://www.nextbigfuture.com/2017/02/m … orage.html

energystoragegap-1.png

Offline

#54 2021-12-23 19:31:26

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 18,189

Re: Thermal Energy Storage

For SpaceNut re #53

Molten Silicon sure looks as though it is a candidate thermal storage material.

The heat of 1414 C could be achieved by slow heating over 24 hours or more with a simple electric resistance heater.

I may have missed how your design would produce electricity from the hot material?

What I'm working on is a mobile power supply that could be pulled (wagon) or pushed (cart) to provide power for the tool away from utility outlets.

One difference between Silicon and Zerolite is that (apparently) Zeolite can be heated by then touched without hurting the toucher.  That would not be the case for molten Silicon   Molten Silicon would need to be kept in a secure insulated container.

In both cases, water might be used as a working fluid to pull heat out of the store.

I'm not clear on how Zeolite works however.  There ** seems ** to be heat released when water is admitted into the Zerolite store, but how that heat is used is not clear (to me for sure).

(th)

Offline

#55 2021-12-24 19:56:28

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 18,189

Re: Thermal Energy Storage

This post is offered to try to advance the vision of a machine to provide 20 Amps at 120 VAC for 1 hour using thermal energy.

A Google search for the equivalent horsepower to 2400 watts gave:

2400 watts =
3.218 british horsepowers
Convert 2400 Watt to Horsepower (W to hp) - Power Conversion
www.theunitconverter.com › watt-to-horsepower-metric-conversion › 240...
Result : 2400 Watt = 3.26309 Horsepower (metric). How to convert Watt to Horsepower ? 1 watt (W) is equal to 0.00136 horsepower (hp). 1W = 0.00136hp.
Convert 2,400 Watts to Horsepower - CalculateMe.com
www.calculateme.com › power › watts › to-horsepower › 2400

The 2400 watts comes from the post by SpaceNut earlier in this series...

Next, I asked Google if there is a steam engine that can produce 3 horsepower,,,

Here is a web site for a company that (apparently) offers steam engines of 1, 3 or 20 horsepower

https://mikebrownsolutions.com/steam-engines/

Mike Brown Steam Engines
Mike Brown Solutions offers 1, 3 & 20 horsepower steam engines.
Our 1-horsepower Steam Engine:
(1-cylinder)

Our 3-horsepower Steam Engine:
(2-cylinder)

Efficiency of a steam engine is low ... I'm guessing the best that can be hoped for is 30% ...

Here is a snippet that indicates 40% is possible for a turbine system:

What is the average efficiency of a steam engine?
Steam engines and turbines operate on the Rankine cycle which has a maximum Carnot efficiency of 63% for practical engines, with steam turbine power plants able to achieve efficiency in the mid 40% range. In earliest steam engines the boiler was considered part of the engine.
Engine efficiency - Wikipedia
en.wikipedia.org › wiki › Engine_efficiency

An ideal solution would be one that delivers electric power directly from heat, but the only mechanism I am aware of for that is the Seebeck effect.

A thermoelectric generator (TEG), also called a Seebeck generator, is a solid state device that converts heat flux (temperature differences) directly into electrical energy through a phenomenon called the Seebeck effect(a form of thermoelectric effect).
Thermoelectric generator - Wikipedia
en.wikipedia.org › wiki › Thermoelectric_generator
About Featured Snippets

Someone asked:

What is the most efficient way to convert heat to electricity?
A specially engineered photovoltaic cell captures that radiation and converts it to electricity. To get high efficiencies, thermophotovoltaic systems made so far have had to incorporate expensive materials. Most infrared radiation from thermal emitters is low energy.
Oct 2, 2020
Device converts heat into electricity more efficiently - C&EN
cen.acs.org › Device-converts-heat-electricity-efficiently › web › 2020/10
About Featured Snippets

I hope these notes inspire a forum member to think about the problem posed, and offer suggestions for possible solutions that cost less than an off-the-shelf package of Lithium batteries and electronics to deliver 120 VAC at 20 Amps for an hour.

(th)

Offline

#56 2021-12-24 20:52:53

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,314

Re: Thermal Energy Storage

Typically when you start to talk BTU's we are talking about heated air as what we see for a home.

https://www.ehow.com/how_6027485_calculate-btus.html

Thanks for the steam engine as the exhaust heat could be send through a rock bed for later air heating in addition to being able to create power.

As for the MIT molten silicon I am not sure it can be down sized as you need a given volume of material to create the glow in the tubes for the panels to be able to create the power.


So far we have about 3 technologies going on in the topic.

Offline

#57 2021-12-24 21:33:13

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,314

Re: Thermal Energy Storage

Kbd512 molten quantity for the 1414 temperature is in this article

https://www.nextbigfuture.com/2017/02/m … orage.html

1414 Degrees’ process can store 500 kilowatt hours of energy in a 70-centimeter cube of molten silicon

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

Offline

#58 2021-12-24 21:34:01

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 18,189

Re: Thermal Energy Storage

For SpaceNut re #56

If you have a moment, please add to this list ... all I can remember are:

1) Zeolite (a material able to store heat in the "chemical structure")
2) Molten Silicon .... Would require a container able to hold the material while thermal energy is drained

In neither case am I aware of a practical way of converting stored thermal energy into electrical power: 20 Amps 125 VAC for 1 hour.

(th)

Offline

#59 2021-12-24 21:39:01

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,314

Re: Thermal Energy Storage

Rocks, water and other forms of absorbing methods for heat energy.

In all we are neglecting the mass of the system that creates the heat to store.

edit
I think the intent is to have a wiki page by th to be only one type of
Portable Power Electrical Best Solution Compare Discuss Evaluate

Offline

#60 2021-12-24 22:31:06

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 18,189

Re: Thermal Energy Storage

For SpaceNut re #59

Thanks for reminding me of the other thermal heat sinks that might come into play.

I've been trying to use this topic to work on a mobile/portable/practical energy storage system able to deliver 20 Amps at 125 VAC for one hour.  This topic is so generic, my attempt to focus upon a specific product/application is getting lost.  It is like trying to float a raft on the Mississippi River.  The raft is (of course) going to get run over by barges, tug boats, excursion liners and miscellaneous other craft.

It might be time to consider opening a topic that would be limited to a specific application of thermal energy storage that a  ** real ** person (on Earth or Mars) might actually buy and use for a "real Universe" purpose.

What I see at the moment is that while ** storing ** thermal energy is simple and can be achieved with close to 100% efficiency, it is the recovery of that energy as electricity that is the challenge, and where efficiency drops like a lead weight in the Mississippi we were just considering.

Heat store >> steam engine (40% max) >> Electric generator (80% ? ) means 32% for the system.

That means the heat store has to be three times larger than the expected load, due to inefficiency.

That means the mass of molten Silicon must be three times larger, and of course, the container with insulation must be correspondingly more  massive.

I don't know enough about Zerolite to know if it might be a practical alternative, but even if it is more practical than molten Silicon, the mass and volume of the Zerolite might well turn out to be too great for a small cart that would be pulled or pushed to the job site.

(th)

Offline

#61 2021-12-25 02:49:48

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,612

Re: Thermal Energy Storage

SpaceNut,

These are stationary energy storage systems.  A thermal power plant should last for 5+ decades.  The thermal storage materials (rock / water / salt / metal) do not require any "recycling" per se, so the energy expended to move the thermal storage material is inconsequential when compared to the amount of thermal energy that will continually be stored and released over the power plant's lifetime.  The same applies to the materials used to construct solar and nuclear thermal power plants.  Few of the major components are entirely replaced over the service life of the power plant.  Think about the number of times a nuclear reactor's pressure vessel is replaced over the service life of the power plant.  That number is always equal to zero.

In contrast, photovoltaics / batteries / wind turbine blades / control electronics are continually replaced, every 5 to 25 years, assuming no power surges or other destructive transient events kill them before their projected service life ends.  The amount of energy and labor expended on planned obsolescence is extreme, relative to competing alternatives, which is why the associated cost keeps going up, up, and away.  Civilization level power plants can't be replaced every 10 to 25 years.

Yes, you absolutely get "more for your money" from a microchip made today versus one made in the 1970s, but in terms of energy expenditure, the only net result from increased efficiency (more circuits per chip), has been more and more energy / labor / capital spent on making new microchips, with no end in sight.  If you have sufficient surplus energy, then that may not be a problem, but we're running low on surplus energy.  The constant rolling blackouts in China are "Exhibit A" for us running out of cheap and abundant surplus energy provided by coal / gas / oil.  We're producing far more coal / oil / gas than we ever did back in the 1970s, but since consumption continues to rise, all increased efficiency has been more than completely offset by increased demand.  You can't operate a technologically advanced civilization on a planned obsolescence / limitless growth model on a finite planet.  Nuclear energy doesn't change that paradigm, either.  None of the "more energy efficient" methods we've discovered to generate light / heat / electricity since the 1970s have reduced total energy consumption one iota.  The end result of our current situation is that we need a drastically less consumptive model for generating and storing energy, which starts with heat engines and includes more appropriate materials selections for storing energy than batteries.

Offline

#62 2021-12-25 17:38:14

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,314

Re: Thermal Energy Storage

Yes you are correct as always that For naval reactors but due to there costs maybe getting extended for use.

They have long core lives, so that refuelling is needed only after 10 or more years, and new cores are designed to last 50 years in carriers and 30-40 years (over 1.5 million kilometres) in most submarines, albeit with much lower capacity factors than a nuclear power plant (<30%).

I am looking to do a solar concentrated box of rocks that are on top of a wood heat generating support under the box for direct convection from the top of the wood stove section with the exhaust piped zig zag through the rock box sealed from the air flow that would go between the rocks which would have a blower to push the heated air into the house. Of course the return air is from another part of the home where it will enter the box cold.

The insulation would be similar to the electric stove oven type and rated for the heat of the wood stove to isolate it from the external air.
The solar portion would have similarities to the solar ovens with the box being the focal point for the heat collection. A cover for the top can be moved into place for inclement weather or for when there is no sun.

Offline

#63 2021-12-26 21:53:15

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,314

Re: Thermal Energy Storage

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

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

Thermal energy storage in Zeolite material allows heat to be stored for long periods of time without losing any. When water comes into contact with zeolite it is bound to its surface by means of a chemical reaction which generates heat. Reversely, when heat is applied the water is removed from the surface, generating large amounts of steam.

In Germany, 55 percent of final energy consumption goes towards heating and coolingthermal-storage-for-th.jpg


Zeolite Heat Storage: Key Parameters from Experimental Results with Binder-Free NaY


Adsorption Heat Storage: State-of-the-Art and Future Perspectives

Potential Ability of Zeolite to Generate High-temperature Vapor Using Waste Heat

Offline

#64 2022-04-17 12:22:46

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,314

Re: Thermal Energy Storage

Heat-driven photovoltaic device hits 40% efficiency
https://arstechnica.com/science/2022/04 … sing-heat/

Offline

#65 2022-04-17 13:49:29

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,612

Re: Thermal Energy Storage

SpaceNut,

Their device has to get hot enough to melt Rhodium, then it can achieve 40% efficiency?

BTW, that link doesn't link to the article, so here's one that does:

Heat-driven photovoltaic device hits 40 percent efficiency

Offline

#66 2022-04-17 18:37:26

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,314

Re: Thermal Energy Storage

Article

So the researchers plan to use a relatively high temperature (in the area of 2,000° C) to boost the number of higher-energy photons near the edge of the visible spectrum. This will allow them to use a semiconductor with a higher bandgap, which corresponds to a larger output voltage.

To boost the efficiency further, the cell combines two different materials that absorb different areas of the spectrum in what's called a two-junction configuration. The team tried two different two-junction setups, one using aluminum/gallium/indium/arsenic and gallium/indium/arsenic and a second that's gallium/arsenic and gallium/indium/arsenic. The two have slightly different properties in what they absorb most efficiently, which we'll come back to shortly.

Since this configuration is entirely controllable, the researchers essentially wrap the whole device, which includes both the heating element that produces photons and the thermophotovoltaic cell that converts them to electricity, in highly reflective material. Any photon that emits in the wrong direction gets reflected to either strike the thermophotovoltaic device or be absorbed by the heating element, thus helping maintain its high temperature. The same is true for any photons that reach the thermophotovoltaic material but aren't absorbed by it.

This describes the pellitier device junctions of image in post 36 of topic

Offline

#67 2022-05-15 17:30:32

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 18,189

Re: Thermal Energy Storage

Here is a link to a "Just Have a Think" talk about the MIT TPV system...

https://www.youtube.com/watch?v=Gn7pfYKB7DA

The presentation includes the entire plant design.

There are a number of serious technical problems that have been addressed.

The goal appears to be to strive for an overall efficiency of 50%.

Renewable/intermittent power goes in, and reliable power comes out, on demand.

(th)

Offline

#68 2022-05-15 19:00:06

kbd512
Administrator
Registered: 2015-01-02
Posts: 7,612

Re: Thermal Energy Storage

tahanson43206,

I watched about half this video before I "just had a think" over the number of energy transformations and specialized high-cost / low-availability materials before I'd heard enough.

Offline

#69 2022-08-13 19:22:06

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 18,189

Re: Thermal Energy Storage

For SpaceNut ... the article at the link below is an overview of air conditioning and summary of possible technologies that might be developed.

There may have been (or be) a better topic for this, because this article is not "storage" so much as moving thermal energy around, but the subtopic of heat pumps is included.

https://www.vox.com/recode/2022/8/10/23 … heat-pumps

The search for an AC that doesn’t destroy the planet

The AC is about a century old. What comes next?

By Rebecca Heilweil Aug 10, 2022, 1:30pm EDT
Share this story

A growing number of startups are tinkering with the science behind cooling. Hildegarde/Getty Images

Amid a growing number of heat waves, air conditioners have become a lifeline. Because these appliances are critical to keeping people cool — and protecting them from dangerously hot weather — the International Energy Agency (IEA) estimates that there may be more than 5 billion air conditioners across the planet by 2050. The problem is that while air conditioners do keep people safe, they’re also a major contributor to climate change.

So why not rethink the AC entirely?

The basic science of air conditioners hasn’t changed much since they were first invented about a century ago, but these appliances have become a bigger and bigger threat to life on Earth. Most modern air conditioners consume a massive amount of energy, strain the electrical grid during sweltering summer days, and use harmful chemicals, called refrigerants, that trap heat in the atmosphere. That’s why, along with a vast number of other structural changes the world will need to make to fight climate change, some experts say it’s time to change how we cool our homes.
      
      
“We need to design our buildings in a way that consumes less energy. We need to insulate them better. We need to ventilate them better,” explained Ankit Kalanki, a manager at Third Derivative, a climate tech accelerator co-founded by the sustainability research organization RMI. “These strategies are very important. We can reduce the air conditioning demand in the first place, but we cannot eliminate that.”

The race to redesign the AC is already on. The IEA predicts that within the next three decades, two-thirds of the world’s homes could have air conditioners. About half of these units will be installed in just three countries: India, China, and Indonesia. The extent to which these new air conditioners will exacerbate climate change hinges on replacing the cooling tech we currently use with something better. Right now, ideas range from retrofitting our windows to more far-out concepts, like rooftop panels that reflect sunlight and emit heat into space. To succeed, however, the world will need to boost the efficiency of the appliances we already have — as quickly as possible — and invest in new tech that could avoid some of AC’s primary problems.

The AC’s noxious environmental impact stems from its core technology: vapor compression. This tech involves several components, but it generally works by converting a refrigerant that’s stored inside an AC from a liquid to a gas, which allows it to absorb heat, removing it from a room. Vapor compression uses an immense amount of electricity on the hottest days, and there are growing concerns that the technology might eventually overwhelm the grid’s capacity to provide power. And hydrofluorocarbons, the chemical refrigerants that many ACs use to soak up heat, are greenhouse gases that trap lots of heat in our atmosphere when leaked into the air. The challenge is that, for now, vapor compression ACs are still a critical tool during deadly heat waves, especially for high-risk populations, young children, older adults, and people with certain health conditions.

Related
The air conditioning paradox

Technology to build cleaner, more efficient air conditioners does exist. Two major AC manufacturers, Daikin and Gree Electric Appliances, shared the top award at last year’s Global Cooling Prize, an international competition focused on designing climate-friendly AC tech. Both companies created ACs with higher internal performance that used less environmentally damaging refrigerants; the new units could reduce their impact on the climate by five times. These models aren’t yet on the market — Gree plans to start selling its prototype in 2025, and Daikin told Recode that it hopes to use the new technology in future products — but the IEA estimates that using more efficient ACs could cut cooling’s environmental impact by half.

Another strategy is to double down on heat pumps, which are air conditioners that also work in reverse, using vapor compression to absorb and move heat into a home, instead of releasing it outside. Heat pumps usually cost several thousand dollars, though the Inflation Reduction Act includes a proposal for a significant heat pump rebate, and President Joe Biden has invoked the Defense Production Act to ramp up production. Experts have argued installing heat pumps is critical to another important climate goal: transitioning away from fossil fuel-powered furnaces, which are an even bigger source of emissions than cooling. The holy grail of HVAC would be a heat pump that could provide both heating and cooling but isn’t dependent on vapor compression.

“Heat pumps are a critical technology in reducing our energy consumption, enhancing grid reliability and the utilization of renewable power, reducing emissions, reducing our reliance on foreign sources of energy, and lowering utility bills for US families and businesses,” Antonio Bouza, a technology manager at the Department of Energy, told Recode. The next step, he said, is reducing emissions even further by designing heat pumps that don’t rely on refrigerants, as current vapor compression systems do.

Another challenge, though, is that heat pumps are not the easiest appliance to install, especially for renters, who don’t necessarily have the money or ability to invest in bulky HVAC systems. To address this problem, a company called Gradient has designed a heat pump that easily slides over a windowsill — it doesn’t block light — and currently uses a refrigerant called R32, which is supposed to have a (comparatively) low global warming potential. Gradient recently won a contract to install its units in New York City public housing.

A fleet of new companies want to make even bigger changes to how we cool our homes. One of these startups is Blue Frontier, which is backed by Bill Gates’s investment fund, Breakthrough Energy Ventures, and plans to start selling its futuristic AC units in 2025. The company’s technology uses a specialized salt solution that can release water into the air — or draw it out — which allows the AC to control its temperature. This approach, Blue Frontier claims, can save up to 90 percent of the energy used by a traditional AC and avoids draining electricity from the grid during peak hours.

“By eliminating air conditioning that’s a problem for the grid, it allows the grid to actually reduce the costs of power production [and] utilize renewable energies in a more effective manner,” Daniel Betts, the CEO of the company, told Recode. “So not only do we save energy, but we are saving energy at the moments that are most critical.”

Scientists and startups are playing with other concepts, too. One path, which the company Transaera is taking, is to develop new materials that efficiently soak up moisture from the air, almost like a sponge, so that air conditioners can work more efficiently. A similar concept is to take advantage of solid-state technology. This idea would use solid materials to absorb heat, and some research on it has support from the US Department of Energy. The British firm Barocal is developing a type of plastic crystal that could do this and also help control temperature. One company, Phononic, has developed a solid-state core that could be integrated into existing HVAC systems. The company says its first commercial installation will be next year.

While many of these technological breakthroughs are promising, the movement to revolutionize air conditioning still faces some major challenges. Right now, AC manufacturers primarily focus on meeting minimum performance standards, rather than competing for higher levels of efficiency. Consumers also tend to buy air conditioners based on their sticker price, not an AC’s overall impact on their energy bills. And even though there are a growing number of AC-focused startups, the industry is still dominated by a small handful of large companies, all of which primarily focus on far-from-ideal vapor compression tech.

“We don’t install more efficient technologies unless we really need to, or it’s mandated by a government or another organization,” said Eli Goldstein, the co-founder and CEO of SkyCool, a startup developing tech that could be used to send heat from buildings and ACs into space. “Ultimately, the key is going to be dollar investments from both private and public enterprises to deploy the technologies.”

Related
It’s time to rethink air conditioning

Other changes, like better insulating our homes and installing batteries throughout the grid, are still critical in the fight against climate change. However, all signs indicate that humans will continue to buy air conditioners, not just to feel comfortable but to survive increasingly devastating weather brought on by climate change. This is especially true as temperatures and incomes rise in some of the world’s largest countries and fastest-growing economies. In India alone, demand for cooling tech was already growing between 15 and 20 percent every year, as of 2020.

This surging demand creates a promising, but incredibly risky, situation. There’s the possibility that the growing need for cooling spurs a race to build the best AC technology and, ideally, tech that could also displace fossil fuel-based heating. But if better, more affordable AC doesn’t come to market fast enough — especially for the vast number of people in developing countries who will buy these appliances in the coming decades — significantly worse air conditioners will take their place, warming the planet even faster.

This story was first published in the Recode newsletter. Sign up here so you don’t miss the next one!

(th)

Offline

#70 2022-12-04 11:03:50

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 18,189

Re: Thermal Energy Storage

Here is a recent post by Calliban that seems well suited for this topic:

Calliban wrote:

Regarding thermal energy storage: Sensible heat storage may provide a reduced cost option at the expense of more bulk.  By this I mean silos filled with crushed rock.  Rock will be crushed into pieces no larger than a few inches in diameter.  Heat will be introduced into the silo via an oil-air heat exchanger.  A fan will blow across the heat exchanger tubes and transfer heat into the crushed rock.  The air would return through an inner tube into an air-steam heat exchanger, which would generate the steam needed for power generation.  The silo would be a double skinned, thin shell of low alloy steel with I-beams to maintain a cylindrical shape.  Insulation would be provided the sand between the two skins.

The amount of energy stored in the rock is a function of the temperature difference between the hot oil and the steam.  If a 10K temperature difference is sustained, then the energy stored per cubic metre will be:

Q= 3000kg/m3 x 1KJ/Kg.K x 10K = 30,000KJ (8kWh).

To generate 100MWe for 8 hours (night) at 33% efficiency, requires 2400MWh of stored heat.  This would require some 300,000 cubic metres of rock.  A cylindrical steel silo some 73m in diameter and 73m tall would be sufficient.

(th)

Offline

#71 2022-12-04 11:55:24

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,314

Re: Thermal Energy Storage

I am reminded about this post for a construction method but using the stone rather than a liquid

Since in my area there were dug wells that can be dug down to a depth if not hitting rock quite easily to 30 ft and at a diameter of 3 of 4 ft of which one can use precast concrete section to make a sealed well from the bottom to the top to give a reservoir for the heat to go into from any source type.

Concrete-ring-well-step-by-step-construction-1.jpg

Concrete-ring-well-step-by-step-construction-3.jpg


Concrete-ring-well-step-by-step-construction-4.jpg

In looking at the issue of storage there is no reason not to do a horizontal storage if you have the property to do so with and it can still be a combination of plastics for a liner and prefab concrete tub in whatever diameter that is reasonable.

There is also no reason to keep it round at all if you are good at foundation style pouring

Build a 6500-gallon concrete water tank for $1500

ainsworth101-03.jpg

Of course, which ever method you will need to insulate the outer wall from the ground to keep it from sinking into the ground's natural cooler temperature.


All of this is based on volumes and money available to achieve any sort of goal.

Offline

#73 2023-01-23 15:08:04

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 18,189

Re: Thermal Energy Storage

The article at the link below includes mention of making ice with solar power to cool buildings ...

That's the reverse of the heating phase that has been the focus of much of this topic ...l

https://www.yahoo.com/news/5-reasons-wh … 00563.html

Canary Media
5 reasons why thermal storage may finally be set to take off

Julian Spector
Mon, January 23, 2023 at 3:30 AM EST
You don’t need a battery to store energy. A class of technologies known as thermal storage can do the job too, and it even has some potential advantages over lithium-ion batteries.

The long-overlooked thermal-storage category could play a critical role in easing the strain on the grid brought on when too many people use their air conditioning or heaters at the same time — an occurrence that is becoming frighteningly common in the face of increasingly extreme weather.

A number of thermal-storage companies already tackle that challenge by tapping cheap midday solar power to freeze blocks of ice and then using those blocks to cool buildings later in the day, when solar power stops producing, thereby reducing carbon emissions and making the grid more efficient at the same time.

Calmac (now part of HVAC giant Trane) has been commercially active for decades freezing tanks of liquid to help cool large commercial buildings.

Thule Energy Storage has some 1,500 “Ice Bear” units freezing ice to cool down houses and small businesses. (It picked up the IP from startup Ice Energy, which went bankrupt in 2020.)

Viking Cold Solutions does the same for cold-storage warehouses, making them more energy efficient while improving the quality of frozen foods.

Five-year-old startup Nostromo Energy has operated its IceBrick product for commercial buildings in Israel for more than two years; now it’s in the running for a $189 million loan guarantee from the U.S. Department of Energy to install it at 120 buildings in Southern California and beyond.

- ADVERTISEMENT -

Other thermal-storage products store heat in insulated containers, offsetting the need for electric heating that exacerbates peak winter power demand in cold places. (A different up-and-coming cohort aims to use thermal storage for long-duration grid storage, as Canary Media has reported.)

Thermal storage can also be far more cost-effective than relatively expensive lithium-ion batteries that store electrons to run heating and cooling processes (while losing some of that power in the process, since batteries aren’t perfectly efficient). And while fire risks make it hard to install lithium-ion batteries inside densely packed buildings, blocks of ice don’t catch fire.

Nevertheless, as lithium-ion batteries go mainstream, thermal storage has struggled to take off. Building owners just haven’t felt compelled to shift their heating and cooling loads, even if they theoretically could save some money on their energy bills. Analyses of the thermal-storage industry from a few years ago concluded it was a good idea in search of a receptive audience.

That search may be over, thanks to significant federal policy changes, technological advancements and a growing urgency to decarbonize the building sector. As 2023 gets rolling, here are five reasons why thermal storage might finally be about to take off.

1. Thermal storage now has a dedicated tax credit
Few statements make a customer’s eyes light up like “It’s now 40 percent off!” Thermal-storage companies can proffer this enticement thanks to their first-ever federal investment tax credit.

Last year’s Inflation Reduction Act created a new federal tax credit for stand-alone storage. The mature battery-storage market will benefit from this, but thermal-storage advocates worked with legislators to make sure the law specified that thermal-storage systems qualify, too.

The baseline tax credit is now 30 percent for projects that meet labor standards recently defined by the IRS. The credit jumps to 40 percent for projects that use domestic content (though the rules for that one are still being written).

Thermal storage is a strong contender to make use of the domestic-content bonus. Lithium-ion manufacturing remains largely clustered in East Asia; it takes huge capital investment and workforce development to spin up a high-grade lithium-battery plant out of nowhere. But the assembly process for thermal storage is not as complicated and costs less to set up.

For example, Nostromo’s “IceBrick,” a modular block that freezes ice to help commercial air-conditioning systems, is already being assembled in Anaheim, California. Factoring in the new tax credits, Nostromo advertises a five-year payback for building owners who buy the system.

2. Thermal-storage products are getting smaller and easier to install
A key challenge for any marketable storage product is how to deliver benefits without taking up too much space, because space comes at a premium in commercial real estate. Large tanks of water are great at storing thermal energy, but they take up valuable square footage and are quite heavy, limiting where they can sit in a building.

Today there are a small but growing array of compact thermal-storage options that fit more flexibly into unused space. By spreading out the liquid among a bunch of small containers, startups have engineered a version of thermal storage with fewer limitations on where it can go.

Companies like Nostromo and Viking Cold Solutions can slip thermal batteries into nooks and crannies that are otherwise unused. Thule designed its Ice Bear product to fit in smaller commercial spaces and offers a residential product that connects with home-cooling systems. And Calmac, an early mover in large commercial thermal storage, has updated its ice tanks to take up less space and be more flexible to install.

3. The need to cut peak power usage is growing more urgent
As time goes on, more programs are springing up to reward people for shifting their electricity consumption out of peak hours as a way to relieve stress on the grid.

Thule has installed 1,500 thermal-storage units in part by partnering with several different utilities on demand management. Many of those are located in California, where air-conditioning needs during heat waves have nearly broken the grid many times over in recent years. But extreme weather is hitting all across the U.S., and each near miss drives home the imperative to reduce peak load.

A huge reason why building owners haven’t bothered with thermal storage is that they don’t see enough of a financial incentive to shift when they use energy to times that are easier on the grid. But more utilities are adopting time-based rates that send stronger price signals.

The new electric rates in Hawaii, for instance, charge customers three times more for electricity during peak hours than during the sunny hours when solar power floods the grid. As more jurisdictions adopt such “smart” rates, building owners will see a clearer financial payoff for thermal storage.

4. Building owners are feeling pressure to cut their carbon emissions

These days, incremental energy-bill savings may not even be the main draw for thermal storage. Instead, building owners are demonstrating unprecedented interest in measurably reducing their carbon emissions — both for their own sake and to help their customers deliver on climate commitments.

Let’s say a large business has publicly committed to a net-zero goal, including reductions in Scope 3 emissions, which come from the supply chain that supports the company’s operations. Now this company needs to ask its vendors questions about their carbon emissions. Hotels where employees stay, event venues that companies book, office buildings that companies occupy — all of those are under new pressure to show they won’t hurt a customer’s progress toward fulfilling their carbon-reduction pledges.

In fact, many building owners now describe carbon reductions as their primary motivation for exploring thermal storage, said Nostromo CEO Yoram Ashery.

“The payback financially makes sense, but they see a strategic benefit, not just cost reduction,” he explained.

5. The broader building-decarbonization movement creates new demand for thermal storage
Thermal storage stands to gain from the newfound momentum on decarbonizing the building sector, which is being driven both by corporate climate promises and by increasingly assertive building policies in places such as California, New York and Washington state.

The movement to “electrify everything” focuses on the switch from fossil-fueled heating to high-efficiency electric heat pumps. Air conditioning doesn’t get as much attention, because it already runs on electricity. But playing out this scenario, if the building sector en masse switches from fossil-fueled heating to electric heating, it will put a huge new strain on the grid during moments of peak heating demand.

Indeed, as buildings in some places push toward being 100 percent carbon-free, they may find this goal practically impossible without help from thermal storage.

“Thermal storage is a must-have to decarbonize buildings and the grid,” Ashery said.

As larger buildings electrify, they could use thermal storage to reduce the size and cost of the heat pumps they need to install for space and water heating, said Brett Bridgeland, principal in the Carbon-Free Buildings program at climate think tank RMI. (Canary Media is an independent affiliate of RMI.)

Shifting heat-pump use to warmer daytime hours allows the heat pumps to work more efficiently, so buildings could store heat while the sun is shining for use in the cold night, Bridgeland pointed out. In aggregate, using thermal storage to reduce peak electricity demand lowers the grid investment needed to meet the power needs of electrified city buildings; that could lower the societal cost of decarbonizing the building sector.

Building decarbonization is still in its early stages. But as more buildings have to eliminate carbon emissions — New York state calls for its buildings to be carbon-neutral by 2050, for instance — thermal storage could emerge as a crucial enabling technology.

(th)

Offline

#74 2023-01-23 15:40:05

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,314

Re: Thermal Energy Storage

Yes a little ice can go a long way towards that summer heat in a glass works with that smooth drink.

But I am fighting a power outage and cold. Plus it's still snowing.

Offline

#75 2023-01-23 18:14:32

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 18,189

Re: Thermal Energy Storage

For SpaceNut re #74 and how nice wood fired heating would be ....

About 32,800,000 results (0.75 seconds)
Known as hypocaust, this heating system, more common in public baths, used a furnace to force heat into a series of hollow chambers between the ground and the floor, and up pipes in the wall, heating the rooms. It is considered the world's first central heating.Jan 19, 2021

Keeping Warm the Roman Way - Getty Center

All snippets are from Google...

People also ask
How were public baths heated in ancient Rome?
They were also built to strict specifications, so that their 'hypocaust heating' would work properly. This system used water, heated in fiery furnaces under the raised floors of the baths. The resulting steam was channeled through special chambers under the floors and in the walls.

in the First Century. The Roman Empire. Life In Roman Times. Baths
https://www.pbs.org › empires › romans › empire › baths

Search for: How were public baths heated in ancient Rome?
How did the Romans make under floor heating?
Image result for roman architecture heating of public baths with pipes under floor
The Hypocaust system of the Romans worked using the principle of heated hot air which was generated by burning fires. A system of hollow chambers was constructed between the ground and the bottom of the rooms to be heated. Hot air that rose from the fires would flow through these chambers and heat up the rooms above.

Hypocaust - Underfloor Heating Invented by Romans - QS Supplies

Search for: How did the Romans make under floor heating?
How were the Roman Baths in bath heated?
Image result for roman architecture heating of public baths with pipes under floor
Early baths were heated using natural hot water springs or braziers, but from the 1st century BCE more sophisticated heating systems were used such as under-floor (hypocaust) heating fuelled by wood-burning furnaces (prafurniae).May 2, 2013

Roman Baths - World History Encyclopedia
https://www.worldhistory.org › Roman_Baths

What year did the Romans invent underfloor heating?
Image result
80 BC. Its invention improved the hygiene and living conditions of citizens, and was a forerunner of modern central heating.

The technology to heat a home (or a business) to a comfort level suitable for a Roman Citizen was invented over 2000 years ago.

(th)

Offline

Board footer

Powered by FluxBB