Solar storage plant Gemasolar sets 36-day record for 24/7 output | RenewEconomy

Solar storage plant Gemasolar sets 36-day record for 24/7 output

The Gemasolar power plant with molten salt storage marks 2nd anniversary with a record-breaking 36 consecutive days of 24/7 output from solar.


The ground-breaking Gemasolar Concentrated Solar Power (CSP) plant with storage near Seville, Spain, has marked its second anniversary with another breakthrough – producing round the clock power for a record breaking 36 consecutive days.

The power plant, owned by Torresol Energy, has been producing energy for two years since its official opening on October 4, 2011.  It was the first large scale solar tower power plant to use molten salt, which captures heat during the day so that the plant can still produce energy at night.

Torresol said in a statement marking the anniversary that the plant has exceeded the expected results and has demonstrated the sturdiness of the design. Producing energy 24/7 for 36 consecutive days from solar energy “is something that no other plant has performed so far.”


Molten salt is used in solar power tower systems because it provides a low-cost medium to store thermal energy and operates at temperatures that are compatible with steam turbines as well as being non-toxic and non-flammable.

According to Torresol, the Gemasolar 19.9 MW plant is capable of producing more than 110 GWh per year as well as being able to run for up to 15 hours without any solar feed.

The power plant continuously supplies power to around 27,000 homes, avoiding the release of 30,000 tones of carbon dioxide emissions into the atmosphere. Torresol says the notable increase in the plant’s power efficiency guarantees electrical production for 6,500 hours a year, 1.5 to 3 times more than other renewable energies.

This breakthrough in CSP technology comes just after the announcement of that the 375MW Ivanpah CSP solar power plant has synced its first energy to the local grid.

The Ivanpah plant is set to be the biggest solar thermal plant in the world, although it will not have storage. However, another solar tower plant is being built with molten salt storage.

The 110MW Crescent Dunes project being constructed by Solar Reserve in Nevada will provide a block of electricity between the hours of midday and midnight for the Las Vegas utility.

These developments will come as good news for CSP as recent reports have stated that the market has grown slower than expected – due to the rapid decline of PV prices.

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  1. Sean 7 years ago

    Cost per Kwh?

    • Giles 7 years ago

      Bloody expensive. But it was the first of its kind. The Crescent Dunes facility being built in Nevada has signed a PPA at $135/MWh. So it will be downwards from there – considering they will be competing with gas leakers, that will make them competitive quite quickly

      • Sean 7 years ago

        expected reduction if the plant size was say 800MW?
        comparison to PV? (price wise)

        • Giles 7 years ago

          Not sure they would go that big. They made in 110MW modules. Developers see sub $100/MWh after a few projects, it is chasing PV down the cost curve. May not catch up for a while, if ever, but dispatchability is the winner (and the value add).

          • Sean 7 years ago

            The two coal plants in Port Augusta total 760MW…
            Dispachable solar thermal with a HVDC link to QLD would provide a huge boost to the area, and provide an additional export market for Wind.

    • sunoba 7 years ago

      My estimate is EUR 300 /MWhr. See original post at, Cost of Solar Power (16), 1 July 2011. The original estimate was EUR 326/MWhr, but I later adjusted the methodology to give EUR 300.

  2. Zvyozdochka 7 years ago

    Great to see these plants proving the concept. It is after-all pretty low-tech stuff however so we shouldn’t be terribly surprised that it works!

    CLFRs should be cheaper to build and much more modular.

  3. Miles Harding 7 years ago

    Great news.

    Being a thermal power station, there will be a lot of reject heat that presents many possibilities for co-located industries.
    Where the sea is nearby, something like forward osmosis desalination
    (see here: ) could make use of that waste heat, adding another product to the power station.

  4. Biff 7 years ago

    Good to see that the technology works, pretty vital if we’re going to build more of them. Australia also benefits from being an east-west country – our best solar resources are in the north-west of WA. If we could link up to the NEM via new HVDC lines (I know it’s expensive but worth it) we should have good direct solar power for the densely-populated eastern seaboard well into the summer evening.

  5. TonyfromOz 7 years ago

    This is really exciting news.

    At last, now we finally have a plant that can in fact take the place of large scale coal fired power plants.

    Let’s actually do a comparison for a large scale coal fired plant here in Australia, say the Bayswater Plant of 2640MW.

    This Gemasolar plant has a Nameplate Capacity of 19.9MW, and despite having 15 hours of thermal storage, it still only supplies 110GWH of power over a full year giving it a Capacity Factor of only 63%, which (on average) is around 15 hours a day, so if can supply 36 days at 24 hours in Mid Summer, then there must be times when it in fact supplies very little.

    So then, with that 36 consecutive days at full rated power for the full 24 hours, what sort of comparison are we in fact looking at?

    Bayswater delivered that same amount of power in 6.5 hours.

    Bayswater delivers the yearly total from this plant in 41 hours.

    This Spanish Gemasolar cost around $AUD500 Million, (in 2010 dollars) so just to replace the Nameplate Capacity of Bayswater, you would need 133 of these plants at a cost of $66.5 BILLION, and still get considerably less power delivered to the grids than what Bayswater delivers.

    36 consecutive days of 24 hour power delivery.

    Who cares.

    It’s only 20MW.

    • A Real Libertarian 7 years ago


      And those Wright brothers contraption only flew for 12 seconds! What use is that?

    • MorinMoss 6 years ago

      You’re overlooking economies of scale.
      Crescent Dunes cost only 2x of this but has a nameplate capacity of 5.5x and yearly output 4.5x that of Gemasolar.

      A 500 MW system incl storage with 2200 GWh yearly output would cost ~$AU 2.7 billion, assuming capacity factor of 50%.
      Since Bayswater has an annual output of 17000 GWh, you’d need 8 of these which would give a nameplate capacity of 4GW and the same annual output at a cost of ~ AU$ 22 billion
      Bayswater burns 8,000,000 metric tonnes yearly and during the past 5 yrs the price per tonne ranged from $80 – 143 AUD, and most of that time, judging from the graph below was around $100.

      So the annual cost of just buying fuel ranged from $640 million – $1.1 billion AUD, with an average cost of $800 million AUD.
      What are the annual running costs of Bayswater? What does it cost for waste disposal, flue gas cleaning, etc?

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