It's time to shine for 24-hour solar power | RenewEconomy

It’s time to shine for 24-hour solar power

With nuclear ruled out as way too expensive, it may finally be time to turn to solar tower and storage technology. The technology is proven, dispatchable and cheaper than most people think.


gemasolar sunny
“It is the way to see the future”.

So says the sign at the entrance of Gemasolar, the world’s first commercial-scale solar tower and storage facility, in southern Spain. And the future is so impressive that the glow from the 140-metre solar tower at the heart of this unique plant can be seen from the city of Cordoba, some 80kms away.

The 19.9MW Gemasolar power plant first began producing electricity in May 2011, just two months after the Fukushima nuclear melt-down, and for nearly five years it has been the sole standard bearer for a technology many are convinced will play a major force in future electricity systems, including Australia’s.

The conservative International Energy Agency, for instance, says solar thermal (which includes solar tower and storage) could account for 12 per cent of all electricity generation by 2040. It would not be so indiscreet as to say how much Australia should have, but the implications are obvious.

Gemasolar was the first solar plant in the world to operate non-stop for 24 hours, and in June/July 2012 it set a record of 36 days providing non-stop power. That record was nearly broken in May/June last year –when it ran for 35 days non stop. In winter it has operated 12 days non-stop on several occasions.

Those records are expected to be handsomely beaten when the new generation of solar towers – bigger and more efficient – are finally brought into service in the next few years. These plants will be able to bring non-stop power to its customers all year round, answering the criticisms of fluctuating power from solar and wind energy.

“We have proved that this technology works,” says Raul Mendoza, the Germasolar plant manager as he guides RenewEconomy on a tour of the facility in early January.

Other similar plants had been expected to follow quickly on the heals of Gemasolar, including two 100MW plants in Spain using the same technology. But in the past five years, plans solar towers and other solar thermal technologies have been mostly sidelined by the plunging cost of solar PV and by changing energy market rules in Spain.

But now, as the value of storage becomes more apparent, solar towers may be about to have their day in the sun, with new projects planned in the solar rich regions of north and south America, and northern and southern Africa.

Sener, the Bilbao-based Spanish manufacturing giant that built the Gemasolar facility, through it partly owned subsidiary Torresol Energy, has now started construction of a 150MW solar tower with molten salt project at the huge Noor solar facility in Morocco.

Mendoza says that plant will benefit from some of the key learnings of the Gemasolar facility – including the optimisation of output during cloudy periods, faster ramp up times (35 minutes versus 90 minutes when it first came on line), maximizing storage efficiency and improved calibration.

The Noor tower will stand 250m tall, and its molten salt storage facility will be seven times bigger than Gemasolar’s. With Morocco’s superior solar resource, and an optimized array, the plant is expected to provide electricity 24/7 every day of the year.

Elsewhere, the US company Solar Reserve is putting the finishing touches to its 110MW Crescent Dunes facility in Nevada, is building another similar-sized plant in South Africa, and has a 260MW facility planned for Chile. Another Spanish group Abengoa is scheduled to build two 110MW solar tower and storage plants in Chile – presuming it gets over its current debt problems.

All companies have expressed interest in the Australian market, although this has proven difficult because of the lack of firm policy, and the massive excess of baseload capacity from its surplus coal plants.

Gemasolar, near the town of Fuentes de Andalucía in the predominatly flat farming lands in pretty much the mid-point between Cordoba and Seville, is truly an impressive sight.

Fittingly flanked on one side by fields of sunflowers, the central tower is surrounded by 2,650 heliostats (mirrors) – some up to 1km from the tower – that reflect the heat of the sun on a collector near the top of the tower. Each heliostat has 35 mirrors totalling 120sq meters of reflective surface.

gemasolar 2

This heats molten salt to temperatures of around 565C, which are then sent straight to a heat exchanger to create steam and drive a conventional turbine, or to be stored in tanks below for later use.

This means that the electricity can be dispatched when the market operators want it. Mendoza says Gemasolar has to inform the market operator of its dispatch capabilities by 10am the previous day. Predictability is key.

During the tour, Mendoza dispels some of the myths that often plague solar towers and storage.

The Gemasolar plant does not need gas back-up. It used to have a 17MW gas-fired generator but dismantled it when energy market rules were changed. It is no longer needed and the non-stop production records were set without gas.

It does not kill birds. Mendoza is confused by reports that the Ivanpah solar tower facility in California has become a “killing field” for bird-life. At Gemasolar, he says, the bird life has actually increased, according to surveys by the environment department, because birds have found a haven from the guns of hunters. Rabbits too.

And the facility does not blind pilots. Seville’s airport is just over 40kms away. There are no issues with airport authorities, Mendoza says.

Gemasolar was a pilot facility and the “full-scale” plants planned for the US, Chile and Africa are expected to run without interruption. Crescent Dunes has a contract to supply the city of Las Vegas with electricity from noon to midnight, to keep the lights during the afternoon and evening.

Mendoza says that when Gemasolar started “everything was new in this plant” – that included the design, development, construction, even operation and maintenance.

The rapid learning curve – in design, efficiency and production – means that the technology costs have decreased significantly.

“In these four years of operation, Gemasolar’s continual production has exceeded all expectations,” he says.

Gemasolar is coy about the costs of the technology, although technical press reports at the time that the Noor contract was signed two years ago suggest a price of around $US140/MWh.

That equates to the price of the Crescent Dunes tower in Nevada, although the South African version is expected to come in at around $US115/MWh. In Chile, Abengoa bid a price of less than $US100/MWh for the 250MW solar tower and storage and PV facility. That beat all bids from coal and gas generation.

Indeed, ACWA Power, which is building both the Noor plant for Sener, and the South Africa plant for Solar Reserve, says “baseload” solar will beat coal and other fossil fuels on price.

CEO Paddy Padmanathan told RenewEconomy last year that “base load” solar power – a combination of solar tower and storage and solar PV, would beat thermal energy in Africa and the Middle East.

In Abu Dhabi last month, he told RenewEconomy that he expected solar tower and storage prices to settle around $US80/MWh. We will have more of that interview later this week.

Many would like to see solar towers with storage in Australia. There has been a major push for a facility to replace the coal-fired generator about to be shut down permanently in Port Augusta in South Australia, and there was disappointment when an auction for next generations solar technology from the ACT government chose household and business battery storage rather than proposals from Solar Reserve and others.

Now that the nuclear royal commission has finally acknowledged that nuclear is an absurdly expensive generation technology that could not even fit into the South Australian grid, there may well be a greater push for such technology to be built in South Australia.

A solar tower plant is actually being built near Port Augusta, but only to generate heat and desalinated water for an innovative greenhouse technology that will grow tomatoes.

Pilots have been run with competing technology from solar in NSW, including by Vast Solar, and Abengoa has been involved in a possible 20MW solar and storage project in Western Australia.

A Sener spokeswoman says Australia has excellent radiation figures and both Sener and Germasolar plant operator Torresol Energy are looking for opportunities to develop new solar power plants.

“Our aim is to work with the countries in their process to implement renewable energies, especially in those sectors in which we have a significant technology advantage, and solar thermal is one of them.”

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  1. phred01 5 years ago

    If the Moroccan’s can do it we should be able to romp it in

    • solarguy 5 years ago

      Yep, we have some of the best brains for solar CST, but they had to go to the States to further their careers. What the hell is wrong with this country. We get an opportunity to be world leaders and make a fortune and nothing happens.
      I’m voting Labor next election. Damn these idiots.

      • Alastair Leith 5 years ago

        Don’t forget preferential voting, you can vote greens for RE policy advancement, followed by labor.

      • Richie 5 years ago

        Alistair is right. Don’t forget Labor still support export of thermal coal. Vote Greens and have two goes at getting a better election result.

  2. david_fta 5 years ago

    Kill birds? Blind pilots? They’d have to be flying within the cone described by lines of site from farthest heliostats to receiver at top of tower.

  3. david_fta 5 years ago

    “All companies have expressed interest in the Australian market, although this has proven difficult because of the lack of firm policy, and the massive excess of baseload capacity from its surplus coal plants.”

    If Australia needs tax reform, how about cutting Company Tax by loading up a Fossil Carbon Consumption Tax? Coal-burners would be paying the FCCT, while everyone else gets a tax holiday.

    That’ll see Australian coal-fired generator owners interested in soft CEFC loans so they can build solar thermal plants. At Callide and Collinsville, both in Queensland, they might even be able to just install a solar collector at the front end to raise the steam and retain the generators.

    • solarguy 5 years ago

      Yes, David it’s obvious and the bastards now it. Guess why they won’t?

      • david_fta 5 years ago

        With due respect, I’d prefer not to get into conspiracy theories.

        • Webber Depor 5 years ago

          its conspiracy but not a theory.

          yes, late answer.

  4. Colin Nicholson 5 years ago

    Australia is a complete disaster area for thermal solar – domestic and commercial – Some aspects were handled poorly in the past, but its current situation is difficult to explain and painful to think about

  5. MaxG 5 years ago

    Land down under = the home of the stupid people. Remember, if people would have brains, they would never vote for an LNP government… what more do I need to say?! I am ashamed for being an Australian… taking part in the destruction of the environment, ruining it for my children and grand children and beyond.

    • solarguy 5 years ago

      Max, don’t be ashamed to be Australian, but you can be ashamed of the flat earther’s, who in their mindlessness continue to screw as much as they can out of fossil fuel interests and that includes some pollies.

  6. George Michaelson 5 years ago

    Given that we were willing to forego strategic interest and buy spanish navel vessels, why can’t we just buy Spanish solar technology? I don’t particularly want this outcome, but it feels like a no-brainer to say to some venture-capital, this is both doable, and affordable. Proven technology: whats not to like?

    • Coley 5 years ago

      Or licence the technology and build it using your existing infrastructure , given your wind and solar resources it’s a no brainer,oh aye, forgot there are no brains in Canberra.

  7. Mike Dill 5 years ago

    CSP works great. The issue is then the cost, at $US100/MWh. Wind is getting down to $US60/MWh and solar is not far behind. Yes, CSP can act as baseload, and there is some value there. Distributed storage is looking to make more sense in the future.
    One issue for the CSP plants is water, which in many places would need to be treated before use, if it was available.

    • Alastair Leith 5 years ago

      self cleaning glass and closed cycle steam turbines will help with that.

    • Chris B 5 years ago

      The principle use of CSP is as a gapfiller around PV generation to bridge the peak mismatch between 5pm and 8pm. Currently we’re using natural gas peaking and the Snowy scheme for that.

  8. ardvarc 5 years ago

    At night or on a cloudy day, such will not generate power. Solar has a 24% capacity factor. It’s unreliable. Storage? We are still 10X short of requirement. You want to build this? Fine. Get ready for blackouts. You want to do a smart grid? Fine. One for the US will cost two trillion. You need baseload power? Great, let’s build more coal and gas plants. You want me to pay for it? Well, OK…..Hold on, let me check my balance.

    • solarguy 5 years ago

      No solar works at night of course not. On complete cloudy days CST fails to produce sure, however PV will still produce some power. Now back to CST, 24% capacity factor is BS, in the real world, more like 75%. And molten salt storage is only going to get better. Wind works 24/7 as there is always wind some where in the country and of course there is storage. Lots of different types.
      In essence, anyone who believes that 100% RENEWABLE is not possible are ignorant.

  9. david_fta 5 years ago

    Dear moderator, please delete this spam that purports to be from someone calling themselves Jeanne Roberts.

  10. Jesse Cane 5 years ago

    Yeah, try that here where there can be a week of overcast skies. Try it where the Winter sun is too weak for this due to its angle. Even the EIA says that solar thermal power plants operate at a minimum during the Winter. What’s sad is that a solar power plants maximum is all ready pretty pathetic. I will take nuclear power thank you very much.

  11. Gary Rowbottom 5 years ago

    The campaign for CST with storage in Port Augusta is over 4 years old now, the tide is swinging in favour of realising that project – it will help if the steady murmurings of support rise to levels that can’t be ignored. I like the idea of joint CST and storage combined with PV “inside the fence” as per the Copiapo development in Chile and others – lowers the overall cost per MWh, and finance risk and therefore finance cost. Not sure if a first utility Australian build would use that model but I am sure it has benefits for early builds. I also like CST because, as a mechanical tech Officer at the soon to be out of business Northern/Playford Power stations, I like things that go whizz, whir, spin and hum. Apart from being more interesting, that translates to good jobs in operation and maintenance. Oh and the main reason for the relatively high LCOE is the high cost to build, which is of course largely jobs, direct and in material manufacture and supply, a lot of it domestic sourced. I thank all the Repower Port Augusta Alliance partners for continuing this campaign for so long – we will continue until it is built.

  12. Beat Odermatt 5 years ago

    Has anybody ever seen a bird in Spain? In a country with a lot of corruption you may be able to find that you can “find evidence” for anything you want.

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