Gallery: World’s First Molten Salt Solar Plant Produces Power at Night


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 even after the sun has gone down.

While photovoltaic solar panels work by directly producing electricity from sunlight, CSP plants use mirrors to concentrate sunlight and produce high temperatures in order to drive a turbine to generate electricity. CSP plants have been in existence for many years, but the Archimede plant is the first instance of a facility that uses molten salt as the collection medium.

Heat from the molten salt is used to boil water and drive the turbines, just like other fossil fuel plants. CSP plants use the same kind of steam turbines as typical fossil fueled power plants. This makes it possible to supplement existing power plants with CSP or even to retrofit plants to change over to clean energy producing technology. Some existing CSP plants have used molten salt storage in order to extend their operation, but the collectors have relied on oil as the heat collection medium. This has necessitated two heat transfer systems (one for oil-to-molten-salt, and the other for molten-salt-to-steam) which increases the complexity and decreases the efficiency of the system. The salts used in the system are also environmentally benign, unlike the synthetic oils used in other CSP systems.

Since molten salts solidify at around 425 degrees F, the system needs to maintain sufficient heat to keep from seizing up during periods of reduced sunlight. The receiver tubes in the Archimede facility are designed to maximize energy collection and minimize emissions with a vacuum casing that enables the system to work at very high temperatures required with molten salts. By using the higher temperatures of molten salts, instead of oil, which has been used in other CSP plants until this point, the plant is able to maintain capacity well after the sun sets, allowing it to continue generating power through the night.

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.

Via Guardian UK

Images via: Angelantoni, The Engineer UK, Siemens


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  1. Geoff Crack August 22, 2014 at 6:26 am

    425 degrees F = 218.333 Celsius

  2. ibromaka August 7, 2014 at 11:17 pm

    Wow!!! this is interesting i’m glad i could the net to this point, but i guess i got stocked at a point which is very vital “how is the heat stored in the molten salt converted into electricity?”. please i need a response it’s quite urgent and important. Thank you.

  3. Beth Hansen February 10, 2013 at 7:30 pm


  4. GreEngineering November 19, 2011 at 5:44 pm

    The Sicilian one is the first of its type. Look at the technological specifications first!

  5. RZL October 14, 2011 at 6:41 pm

    In the 1990s in the USA molten salt power tower technology was fully demonstrated at Solar Two. Salt temperatures reached 1050F, 10 MWe peak power was produced and connected to the SC Edison grid, and continuous day and night operation was demonstrated.

  6. sarvesh October 14, 2010 at 3:41 am

    it is really a briliant technology

  7. Sharkonwheels July 31, 2010 at 10:40 am

    Hey genius – I was commenting on the ARTICLE, not pvdg.
    Someone REALLY needs to teach you how to COMPREHEND reading…

    He and I say basically the SAME THING.


  8. cjcrp July 30, 2010 at 8:07 pm

    Someone should REALLY teach to sharkonwheels to read. Pvdg didn’t says never that Andasol were the first molten salt solar plant. He only says that the Sicilian one wasn’t the first.

  9. sharkonwheels July 26, 2010 at 12:08 am


    Someone should REALLY tell Spain, that their Andasol 1 solar plant, which went online in March of 2009, and stores energy in molten salt for night-time turbine driving, was not the first one, 14mos ago.

  10. pvdg July 23, 2010 at 5:42 am

    The “first molten salt power plant”, really?
    And what about Andasol, in Guadix, Spain? 50 MW.
    It has been working for one year and more, now… 
    Your text explains what is really new: that the molten salt, for the first time, is used to collect heat from the sun, and not just to store it (heat).
    But your title is misleading. Especialy when you consider the end of it: “…Produces Power at Night”. Andasol, for one, already produces power at night!

  11. punch_md July 23, 2010 at 3:39 am

    World’s first?

    What about the Thémis solar plant in France, or the Solar-1 plant in the US (Barstow), both of which operated in the 80s using a field of orieltable mirrors concentrating on a solar tower with a molten salt circuit?

  12. Ale July 23, 2010 at 2:45 am

    °F, meters and miles mixed in the same article !… Please, make everything imperial or everything SI. Do not mix the units, the result is just like in this case, poor.

  13. SolarHappy July 22, 2010 at 9:41 pm

    I would hate to be the technician that has to free up the solidified salt after a long spell without sun. Blow torches anyone?

    I wonder what the plan it for that!

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