Heat battery invention could make millions of homes gas-free | Hacker News Reader

Heat battery invention could make millions of homes gas-free

independent.co.uk

10 pointsmdp20218 comments

They envision charging container-sized units at heat sources such as industry, data centres and horticulture and transporting them to places where heat is needed.

This doesn’t need very high temperatures, so heat that currently is typically wasted can be taken to where it’s needed.

They claim a m³ can store 361kWh (https://cellcius.com/en/warmtebatterijen-vol-zout-kunnen-mil...). I don’t dare say whether they can store it, or estimate whether that’s good enough.

According to Wikipedia potassium carbonate has a density of 2.4 tons per cubic meter(1). So ten cbm will fit on a full size truck (eu). That is 3610kWh of heat energy.

Let’s assume a price point of 0,1€/kWh heat(2), a truck load would carry heat with a cargo worth of 361€.

I wonder how far it can be transported unless it’s more expensive than traditional heat sources.

Could they somehow double the heat per weight, this would be a thing.

(1) https://en.m.wikipedia.org/wiki/Potassium_carbonate

(2) https://partner.toshiba-klima.at/heat_output/index.php?l=2

Researchers from Eindhoven University of Technology have developed a "heat battery" based on the heat produced by mixing salt and water; the project started 12 years ago and the first deployments of four pre-production prototypes are expected this year in Europe. Storing the heat is achieved by drying the salt: the heat that causes evaporation of water is stored in the salt and released by adding water. [Not literal abridgement owing to time constraints.]

> The heat source to store in the salt can be taken from industrial by-products, such as the residual “heat waste” in factories or surplus heat from data centers

> The system is made up of a heat exchanger, fan, evaporator/ condenser and a boiler with salt particles. [... A] protoype around the size of a large cabinet [...] could heat a home for up to two months

> [According to Professor Olaf Adan, ] «In the Netherlands we have about 150 PetaJoule of residual heat from industry per year... That would enable you to take almost 3.5 million homes off the gas»

A more in-depth article is at TechXplore, https://techxplore.com/news/2022-04-battery-quickly-millions...

The selected salt, potassium carbonate, was chosen also since well resistant to the physical stress of enlarging and shrinking during the process.

> The prototype looks like a sort of large cabinet with dozens of lockers [...] each duo of small "lockers" represents a heat battery that matches the entire, original [7 kWh 2019] demonstrator in terms of storage capacity. The whole device contains some 30 "lockers" with a total storage capacity of over 200 kWh [...] equivalent to two fully charged Tesla. [...] Most applications do not require such a large battery[: it is] deliberately... a modular system

> With a consortium... Adan is therefore now preparing a real-world test trial to use the heat battery for the reuse of industrial residual heat. Residual heat from the Chemelot Campus in Sittard-Geleen will be transported [by truck to a sort of 'transformer house' in the residential area] to about fifty homes in the neighborhood in the same municipality

@Dang, if you happen to read this: the TechXplore linked page is much better than the original one provided. I cannot change the link through the editing field. In case you would like to replace it...

Sodium sulfate (aka Glauber's salt, melts at about 32°C) heat-storage has been around a long time. [https://en.wikipedia.org/wiki/Sodium_sulfate#Thermal_storage] It's already in wide use - the article hasn't enough detail to clarify any 'game-changing' advantages of their system.

Transport and storage costs would very likely negate most of the advantages. For commercial, in-factory use, they probably would be suitable. For domestic use, not so much.

People do buy wooden pellets and logs for domestic heating.

And on the other hand, of fixed infrastructure (pipeline) distribution: how much does one pay in the bill for infrastructural costs (maintenance, administration etc.) and how much for the combustion material itself? The infrastructural costs can be an important component of the total - sometimes overwhelming.

So: you really need the numbers to crunch a balance - energy does not reach your heat exchange terminals for free anyway.

The weight and size of the batteries described pretty much means that only one, maybe two, batteries could be transported on a truck from the factory where the excess heat is being produced to the house where the battery will be used temporarily. That battery then needs to be collected and transported all the way back to the factory for 'reheating'.

That's not a cheap process. One battery: four factory-house trips involved. ( = 2 return trips from the factory to a house for a largish haulage truck)

That's why I said that it probably would not be cost-effective for use in a domestic situation.

On the other hand, the industrial use of these batteries would be efficient and cheap. The only transport required would be short-distance, in-house, and could be further cheapened by the use of rails and being pulled by electric haulers round and round the factory.

With further scaling of the batteries, more possibilities may open.

They could be used for the heating of transport vehicles - which is not trivial, because it is easy to heat a running vehicle but not fully practical to heat a stationary one, because of the pollutants produced in close proximity.

They could become portable heaters.

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