"Baseload" solar at 5c/kWh? How solar + storage can be cheaper than coal | RenewEconomy

“Baseload” solar at 5c/kWh? How solar + storage can be cheaper than coal

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German CSP developer says its molten salt storage technology can get cost of utility-scale electricity down to between 5-7 cents (US) per kilowatt-hour.

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A German – and formerly majority Australian owned – developer of concentrated solar power plants with molten salt storage says it can get the cost of electricity from a utility-scale version of its technology, with 15 hours of thermal energy storage, down to between 5 and 7 cents (US) per kilowatt-hour.

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The claims were made in a white paper published this week by FRENELL, an outfit established by Novatec Solar – a Germany-based company that was formerly majority-owned by Australia’s Transfield – to develop and commercialise cost efficient CSP technology.

Its Direct Molten Salt (DMS) technology has been used at the 110MW Crescent Dunes power tower in Nevada US.

According to the paper, the DMS CSP technology can, at a scale of 50MW with 14-hour energy storage, deliver electricity prices of 9.3-12.2 US¢/kWh – a cost “already below today ́s average cost of fossil power generation.”

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But as the chart above shows, the larger the plant’s capacity, the lower the cost of electricity falls. So a 100MW DMS plant with around 15 hours storage could deliver electricity price levels of 6.4-8.5 US¢/kWh – “lower even than (new) coal,” the paper says. And with its large and scalable molten salt energy storage systems, the use of expensive diesel generators to cover late-night demand peaks would also be mitigated.

The White Paper includes case studies from around the world, showcasing the most suitable applications of FRENELL’s DMS technology and the cost advantages over carbon-based power plants. Below is a chart modelling the generation and storage profile of the technology, both as a baseload and dispatchable service.

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While there is no case study based in Australia, the paper does note that the DMS multi-tank energy storage system is particularly suited to countries like Australia, which have high shares of intermittent renewables, high electricity price variability, and significant coal-fired generation capacity expected to retire soon “due to economic pressure from competition with renewable energies and compliance with greenhouse-gas reduction goals.”

In the chart below (figure 56), the paper compares the DMS with 2015 electricity cost estimates by the California Energy Commission and finds it to be “the cheapest dispatchable energy technology at sun-rich locations in southwestern US.”

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“Even at a relatively small-scale,” the paper says, “a FRENELL DMS plant of 30MW capacity already delivers cheaper electricity than other CSP technologies at larger scale and is comfortably cost competitive with far larger Combined Cycle power plants fired by natural gas.”

Another chart – below – compares the cost of electricity from FRENELL DMS CSP to the power purchase price for phase II of Morocco’s Noor CSP plant, at which the 160MW phase 1 was recently completed. As you can see, the DMS plant in both scenarios comes in lower than Noor II, and in one instance at lower than a coal-fired plant of the same size.

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This is interesting because Noor 1 – currently the largest CSP plant in the world – has been criticised for its high cost of electricity, currently at around $0.18/kWh, although the World Bank has argued its development has already served to bring this cost down.

The main concern is that projects like Noor – which has so far cost nearly $US1 billion and could total $9 billion once phases II, III and IV are completed – will not be able to compete on cost with large-scale PV projects with battery storage.

But the report notes that CSP, in comparison with other renewables like wind and solar PV – which it concedes currently offer the lowest costs per unit electricity – cannot entirely cover the power demand curve.

“DMS CSP plants are able to deliver power on demand but at lower costs than using gas or coal fired power plants. This offers sunny countries the opportunity of a 100 per cent renewable energy power supply at the lowest cost option”, says FRENELL CEO Martin Selig.Screen Shot 2016-05-12 at 11.30.33 AM

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  1. Petra Liverani 4 years ago

    This is super exciting. I take it when comparing the cost of fossil fuels against renewables, the current and future re-location costs (and so many other types of climate-change costs) are not included. How about $48 million to re-locate 100 members of a Native American tribe as sea levels rise on the Louisiana coast. http://www.reuters.com/article/us-climatechange-usa-displacement-idUSKCN0WJ34D?

    • 807gt 4 years ago

      Get those engineers to build a plant here.

  2. solarguy 4 years ago

    What are we waiting for! Oh, yes a change of government, as it won’t have chance till then, Will it!

  3. Alastair Leith 4 years ago

    there seems to be some contradictory or at least confusing information in this article. on the one hand it’s said that the Direct Molten Salt (DMS) made by FRENELL is currently being used in the Crescent Dunes (110 MW CST power tower plant) and the graph says Crescent Dunes has a LCOE of 13.5c/kWh (not sure if that includes subsidies or excluding). But then on the same graph it says FRENELL 30 MW and 100 MW both come in with substantially cheaper LCOE rankings at 10.7 and 8.3 c/kWh respectively.

    maybe a link to the white paper will clear things up for me but I’m left wonder what is their technology exactly (the molten salt storage and heat exchange part?) and if it was used in Crescent Dunes what’s the difference of it used some other way in FRENELL’s own virtual plant that makes it undercut the Crescent Dunes plant so drastically… they aren’t using PVs to electrically heat the DMS system are they? very confusing write up with dubious claims to a price breakthrough as reported.

    • Alastair Leith 4 years ago

      Seems that the FRENNEL system is, as the name might imply, a parabolic trough system, considered by some to be generally less efficient to power towers because it has to transport the heating conduit through the entire reflective trough network and not lose heat while it does it. FRENELL are not adverse to the fossil fuels industry though, check out this proposed application in the oil extraction business to “lessen the fossil fuel footprint of oil” recovery where the equivalent of 20% of the energy extracted can be used burning gas to make steam.

      • Anton Hoffmann 4 years ago

        FRENELL uses a Linear Fresnel Collector design. Instead of curved mirrors commonly used for parabolic trough collectors, a Fresnel collector uses flat mirrors relatively close to the ground that concentrate sunlight onto a fixed absorber tube mounted on a support structure.

        • Alastair Leith 4 years ago

          ah thanks that makes sense. previous troughs have used some kind of oil as the heat conduit, right?

    • Anton Hoffmann 4 years ago

      I think the statement “Its Direct Molten Salt (DMS) technology has been used at the 110MW Crescent Dunes power tower in Nevada US.” is a misunderstanding. FRENELL uses a Linear Fresnel-type collector with molten salts directly as heat transfer medium being pumped through the absorber tubes to collect heat. The innovation here is, that it is the first commercially available linear focusing technology that uses molten salts as heat transfer and storage medium.
      The similarity to Crescent Dunes is that they both use molten salts as the heat transfer and storage medium, but Crescent Dunes is a Tower/Central Receiver type of plant.

  4. Giles Parkinson 4 years ago


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