Finland has inaugurated an industrial-scale sand battery this week in the southern town of Pornainen, where it'll take over heating duties from an old woodchip power plant for the municipality. It's set to reduce carbon emissions from the local heating network by as much as 70%, and is the largest…
Yes, and the basic principle of thermal batteries has been quite common here in Finland for some time.
All Finnish cities have district heating networks, so there is some heating plant that generates heat, which is distributed to homes using water as medium. It is closed system where hot water goes in, colder water comes out, which is heated back up. This energy is used to heat the home and heat the cold usage water (faucet/shower etc)
Because the network is lots of water, there is already quite a lot of energy storage in the heat grid itself, so itself works as a battery. In last five years almost all big networks have created water based thermal batteries. Those are 7-8 stories high insulated water containers. These make sense because you just start taking the already heated water from the container to the grid when ever you need.
So the tech itself is quite standard here, just the medium of using sand is new. Sand brings you bit longer storage time, but adds bit of complexity to the process.
Source: I work in a company that owns these kind of networks
I’m not knocking the tech, I’m criticising the article for getting the terminology completely wrong. Moreso, the manufacturer has even fewer excuses.
Maybe there’s a language thing here, but in English battery is not the appropriate term for this. “Battery” really refers to just a bank of some multiple of something. Originally it was naval weapons and then in electrics it was multiple cells of electrolyte. An electric battery is a specific type of energy storage, this is a different type: thermal energy storage or TES.
Hell, on the grid you don’t even refer to battery electric storage as batteries that much, the common term is BESS - Battery Energy Storage System.
Yes, I totally agree, when talking about these thermal batteries, it should always be made clear.
When Converting heat MWh(t) to electricity MWh(e) is pretty much 2/3 loss in the process, i.e. turbine, and it must be super heated vapor meaning like 800C°.
Edit: But to be clear, they are called heat batteries, even in English.
They’re called batteries, but they’re not batteries, by definition. They’re called batteries mainly for marketing, I imagine.
However on the grid in English speaking countries they will refer to them differently. Probably TES or TESS, as it goes nicely with BESS (Battery Energy Storage System), which is the common industry name for grid scale electric batteries. Furthermore, in that sector it’s necessary to have clear distinction, as different types of generation have different characteristics.
Source: am HV electrical engineer.