Are Liquid Metals Green?

To pick one example, liquid sodium has a very high specific heat; thus it takes a relatively small amount to store or transmit heat energy. In large bulk, it costs about 10 Euros/kg.

As to its greenness, I don't know if it gives off problematical gases when in the molten state, what the process is for producing it, and how abundant it is. Container and piping components must be properly selected to avoid corrosion.

The label "green" tends to be attached to all sorts of things without necessarily considering the whole picture. As in electric cars; green on the final end, but where did the electricity come from?

Tornado:

I think the liquid metal use specified is as a componenet of an electric battery, not for storing thermal energy.

I feel like i am missing something here, so help me out. why would anyone use sodium to store thermal energy, when water has a higher specific heat, lower cost, and more managable corrosion characteristics. i know sodium was use in some early nuclear reactors, but i believe this had more to do with cross section for neutron absorption than for specific heat.

Benbenben

I read into the question an idea of generalizing this to a "thermal battery" rather than just electrical--probably departing too far from the original intent.

Liquid metals come in all sorts of colors, and generally change color depending on their temperatures...I have never personally seen a green-colored liquid metal, but that is no indication of whether one exists or not. Is liquid sodium yellow, as it is in it's solid form? At what temperature does it turn white?

Brine solution is now used for heat storage. It is geen. No pollution.

Concentrated Brine is one of the most commonly regulated pollutants. Concentrated Salt water solutions severely impact the habitats that they enter, and the beneficial uses of any water source they may be discharged into. Salt contamination is one of the most common causes of drinking water degradation. Discharges of Brine even to the oceans can cause localized dead zones iof not properly and expensively discharged in a manner that allows mixing and dilution before reaching the habitat. So No Brine is not necessarily green and is definitely a well defined pollutant.

The biggest limitation on more use of electric cars is storage.

Flow batteries show some promise here.

One which is working is the Br/Zn battery.

Both materials are readily obtainable in quantity and, as they are not consumed, the result may be regarded as "green" (whatever that means these days).

http://www.electricitystorage.org/site/technologies/znbr_batteries/ is one site, but there are several.

The thought of bromine leaking everywhere in the event of a crash is somewhat scary.