Finnish City Inaugurates 1 MW/100 MWh Sand Battery

Finland is still 25% oil for electric generation [1] (and almost 40% fossil fuel). That means a lot of the electricity to heat the sand still comes from oil. It makes me wonder if this is more efficient than just using oil heating. Or some hybrid approach that uses oil to heat the sand.

Of course there are other benefits: it's still a good way to level electric generation, which is important for e.g. nuclear plants and wind power.

[1]: https://ourworldindata.org/grapher/energy-consumption-by-sou...

> Finland is still 25% oil for electric generation [1] (and almost 40% fossil fuel). That means a lot of the electricity to heat the sand still comes from oil.

This is not a valid conclusion. Battery projects like this are gonna charge/heat up when the electricity price is low, electricity price is low when supply/demand ratio is high and this often happens when renewable electricity is most available and makes up a disproportionate share of the electricity mix.

Edit: Your graph is not what you say it is, this shows primary energy (i.e. includes fuel/heating/...), not "electric generation". Electricity in Finland is mostly nuclear, wind, hydro and certainly not "40% fossil fuel".