Comment by Xylakant | Hacker News Reader

Comment by Xylakant | Hacker News Reader

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> It sounds disingenuous to call one-way energy sinks 'heat storage’

One-way conversation of energy to heat is a very common use-case: Warm water, heating are all things a lot of people use. Currently, most of that conversion happens on-demand, when someone turns on the tap. Heat is a form of energy that is fairly easy to store. Have a large bucket of water, well insulated and you’re mostly set. It’s dead cheap. There are similar concepts that use a generator to provide electricity for buildings on demand and store the waste heat for warm water and heating.

> Calling such a one-way sink a battery is even worse.

The article does not. They are a replacement for batteries in some use cases. The article may overstate how often that’s the case but it does not pretend you could regain the energy stored as electricity.

The article headline is “BATTERY KILLER”

Yeah. It replaces batteries. It’s not a battery.

It's far less useful than a battery, though, because heat is only good for heating things, which means you also need to provide fuel to convert it into electrical or motive applications. like computers and cars.

It may be more efficient to time shift heating loads than to time shift electrical availability with batteries.

If heating loads are a significant amount of the total load, then this would help reduce the need for peaker plants or battery energy storage. And, if done properly, it provides a cost savings to the utility user too.

It’s far less useful in the general case, but substantially cheaper and more efficient in a special case that consumes a substantial chunk of the primary energy used. It’s not as if battery storage is lossless. Currently, heat generation is often done using primary energy, but that too, needs to be reduced if we want to tackle CO2 production levels.

You can also use the same principle to store cold in summer: Cool down a vat of coolant (though water likely won’t do) at times when you have electricity surplus and use it later.

Certainly, that not solving all problems, but it can kill battery usage for some cases.

It doesn’t though. It serves a different purpose than a grid-battery at my house. I would avoid using my household battery UPS to ever heat water at all costs. This system just tinkers with my water heating to help the utility. The Battery Killer theme of the article is misleading.

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