[Retric]

It requires full sun to hit steal melting temperatures which is unreliable in many industrial areas. So you need a backup.

You can also easily move electrical power long distances but parabolic mirrors are hard to integrate into existing industrial processes and locations. PV electricity is competitive with fossil fuels even if you ultimately just want heat.

Solar thermal is far more viable for low grade heat. Especially as energy storage is fairly trivial.

[s1artibartfast]

This comment isnt about the industrial processing applications of this technology, but energy storage.

[Retric]

How exactly are you going to CHEAPLY collect and store energy for a 1400+C process using solar thermal?

It seems like an huge advantage to use an 80% thermal setup vs a 22% efficient panel, but we gave up on solar power towers for a bunch of reasons. With PV things are a lot more straightforward because you can reach nearly any temperature at equal efficiency.

[s1artibartfast]

Maybe I dont understand. If your primary goal is thermal storage, why do you care about the peak temperature?

If we are talking primarily about storage, what are the advantages of a PV field + 1400 C brick storage vs parabolic + 500C storage?

[Retric]

> If your primary goal is thermal storage

The goal isn’t thermal storage the goal is to do something that needs extreme temperature.

You can’t melt steel at 500C, you can melt it in bricks at 1500C that then cool to 1400C. Use electricity to heat a brick to 1500C and you get 100C worth of energy storage. Use solar thermal to get to 1400C and you get zero energy storage.

[s1artibartfast]

I think that is kinda my point. These comments are all in reference to the idea of using these bricks for electrical storage, as an alternative of offset to other technologies like molten salts, batteries, or pumped hydro.

Im skeptical that they would be improvement on other forms of grid power storage.

This is independent of the question if they are good for melting steel.

I guess I dont understand the point you are advocating for.

[Retric]

The energy never gets turned back to electricity. It’s electricity > melting iron for steel (or whatever) and we’re inserting an energy storage in the middle because it’s effectively free.

The total energy storage is also unlikely to be huge so it’s more like load management not really grid storage. https://en.wikipedia.org/wiki/Load_management IE: Because we have energy storage and other users don’t we can cut demand when prices spike. Utilities will cut special rates for companies that allow the utility to load shed them first.

The same basic concept is common in other areas. Get enough storage for ~free such as with an EV and you can simply wait until prices get cheap before charging.

[yetihehe]

Higher temperaure = more energy stored in the same material. Simple as that. When you have a process requiring 400C for reasonable effiency, your storage actually starts to count from above 400C, so if you have 500C storage, you only have effectively 100C of usable tmperature difference stored in your bricks.

[s1artibartfast]

If it is cheaper to store at 1400 than 500, then that is an argument for doing so. Higher temperature is not a justification in its own right, absent economic benefit. It is also the case that conduction losses are proportional to heat, and it brings many other challenges as well.

[Retric]

Chemical processes don’t occur at any temperature. So the ideal storage temperature depends on the goal temperature and a bunch of other factors.

The argument for storing at 1500C could be 500C is useless not just worse economically.

[neltnerb]

The parent correctly notes that you can't use solar thermal directly for industrial processes because it won't get hot enough and that it's easier to retrofit electric infrastructure than a bunch of mirrors and optics.

Grandparent:

> These are unique it seems because they're durable electric heating elements that can hit industrial process temperatures and might be cheaper then alternatives?

Storage usually makes less sense, but depends on capital cost per kW-hr right? No idea on the economics of that, but an electric heater can get hotter than solar thermal and use much less space at the point of use.

They are durable electric heating elements that can get hotter than solar thermal and hit industrial temperatures without using fossil fuels to heat locally with fire.

[s1artibartfast]

I understand what they are. I am skeptical that they more economical than other forms of grid power storage.

IF you just want to go electricity>heat>electricity Industrial Arc furnaces can go to 2000 C (and much higher but they have no industrial need).

I would love to be wrong.

[danans]

> IF you just want to go electricity>heat>electricity

I think the idea here is to go electricity->heat-storage->heat-usage, using the heat storage to take advantage of cheap renewables that might be otherwise curtailed and to buffer the heat to provide reliability for whatever process it is used for.

Almost any form of energy storage other than heat (i.e. batteries, hydrogen, gravity) would be far more expensive in that use case. By comparison, bricks are an incredibly cheap way to store heat.

If packaged correctly this could also be useful for uses like ovens at industrial bakeries, which have highly predictable energy use patterns.

[s1artibartfast]

Thanks, I understand better. I'm sure there are some applications for pre-heating to time shift demand, but I do think it is limited.

[danans]

> I'm sure there are some applications for pre-heating to time shift demand, but I do think it is limited.

Another example of a big application for time-shifted heating is domestic hot water heating with heat pump water heaters (or even resistance water heaters if the electricity is cheap enough). At least one company (https://www.harvest-thermal.com/) is taking this further to also provide space heating by time-shifting heat, again using water as the energy storage technology.