World's First Molten-Salt Solar Plant Opens

An anonymous reader writes "Sicily has just announced the opening of the world's first concentrated solar power (CSP) facility that uses molten salt as a heat collection medium. Since molten salt is able to reach very high temperatures (over 1000 degrees Fahrenheit) and can hold more heat than the synthetic oil used in other CSP plants, the plant is able to continue to produce electricity long after the sun has gone down. The Archimede plant has a capacity of 5 megawatts with a field of 30,000 square meters of mirrors and more than 3 miles of heat collecting piping for the molten salt. The cost for this initial plant was around 60 million Euros."

Comments

Should improve efficency!

[Antony T Curtis]

This is big news!

The larger the temperature difference, the more efficiently we can turn the heat into electricity. Superheated steam is just too difficult to manage over distances so this would make a great first step of collecting the solar energy and transporting it to a single location to make superheated steam.

The best part is that NaCl is non-toxic and doesn't need to be kept under pressure. If you have a natural gas Bunsen burner and good test tubes handy, it is just about possible to melt salt and prove to yourself how stable it is. Just be careful about spilling it because it is hot enough to get things like wood and paper to auto-ignite on contact. The hottest temperature you can expect to achieve with natural gas is around 700 degrees Celsius, if I remember correctly.

(as a side note, this is why low pressure nuclear power plants have such poor efficiency - because the water is only at 100 degrees Celsius after being heated by the nuclear fuel).

"Salt" != "NaCl"

[billstewart]

The article isn't specific about *what* salts they're using, but says "molten salts solidify at around 425 degrees F" - NaCl's melting point is about 800 C.
One of the articles they reference refers to another project that uses a mixture of sodium and potassium nitrates.

Re:Already done?

[Bemopolis]

Theoretical maximum efficiency for any kind of solar plant (on the equator) is less than 200 Watts per square meter

BZZZT. The solar constant is 1360 W/m2 (minus atmospheric effects). With this, the efficiency is a reasonable 12%.

I suspect the number you have quoted there is the TMI of solar cells. This plant depends on thermal conversion, not liberating electrons across a silicon band-gap. I do respect your effort, and so will not request that you turn in your geek card.