[dinkblam]

a Blast furnace needs closer to 2000° than 400°

in any case, how would you transport high temperatures to the industrial sites? water boils at 100° and few liquids boil above 400°. most liquids will be impractical due to cost or safety (combustibility, toxicity…).

[happosai]

Of course you can't do blast furnace with a sand battery. But there is still a sizable market for industrial heat in between 100c <> 400c.

[rsynnott]

Pump water through, producing steam to drive a turbine, use turbine to generate electricity, use electricity for industrial process.

Now, in practice you _probably_ don't want to do this, because, in this case, you have district heating demand, which is a far more efficient use of the power.

[fulafel]

Steam?