中文  |  ENGLISH

Why thinking small could help reignite the concentrated solar power sector

2020.02.18     From: power-technology

Concentrated solar power accounts for only a fraction of the overall green energy market, but recent research suggests smaller-scale designs could help revitalise interest in the sector. We talk to Luis Crespo, president of Protermosolar, Spain’s solar thermal electricity association.

With demand for clean, affordable energy spiking around the world, it may seem counterintuitive to suggest that scaling down concentrated solar power (CSP) operations could help revive the industry.

However, despite the CAPEX costs of building new concentrating solar power plants having fallen by almost 50% between 2013 and 2018, the scale and complexity of such projects remains prohibitively expensive compared with alternatives such as solar thermal towers with storage, solar photovoltaic (PV) or wind projects.

As a result, CSP continues to account for only a fraction of the green energy market and emphasising plant storage value is now seen as key to attracting the investment required to kick-start the sector.

“CSP generation increased by an estimated 8% in 2018,” says the International Energy Agency (IEA). “Nevertheless, CSP is not on track with the Sustainable Development Scenario, which requires annual average growth of almost 26% through 2030.

“Policy design that emphasises CSP plant storage value will be key to attract additional investment.”

It is a view that is shared by Luis Crespo, president of Protermosolar, Spain’s solar thermal electricity association and author of a recent research paper entitled ‘Lateral Thinking on Storage: Getting the Most When it is Empty’.

“The electrical sector is undergoing a period of rapid transition, and planners are only looking at the short-term on how to manage the penetration of competitive but non-dispatchable technologies such as wind and PV,” he states. “CSP is the most competitive renewable technology to replace PV after sunset in sunny countries – the main factor preventing its wide-scale deployment is simply the lack of long-term planning criteria.”

Storage space: optimising CSP night-time storage capabilities

Spain has for decades been at the forefront of efforts to propel solar thermal technology into the mainstream, both domestically and worldwide. The nation’s installed capacity stands at around 2,300MW, while the contribution of Spanish companies in international markets is around 75%.

Crespo agrees with the IEA that optimising CSP’s proven storage capabilities – whereby the solar collector system within the solar power tower, trough or solar dish/engine heats an energy storage unit during the day, and the heat from the storage system is then used to generate electricity in the evening or during cloudy weather – is the way forward for CSP operators and the sector as a whole.

“It makes no sense to generate from CSP plants when the sun shines, as PV is much cheaper,” he explains. “After the sun sets – and the whole night through – there are important demand requirements and there is no other renewable technology that can satisfy this type of demand at lower prices.

“Extending PV production with batteries with 2–3 hours of life will not solve the problem and will end up costing more than double the price of PV systems without batteries during daytime.”

Small wonder: the benefits of modular heliostat fields

One of the most popular CSP technologies, solar power towers, use a large field of flat, sun-tracking mirrors called heliostats to reflect and concentrate sunlight onto a receiver on the top of a tower.

A heat-transfer fluid is then heated and circulated in the receiver and used to produce steam, which is converted into mechanical energy in a turbine, which powers a generator to produce electricity.

However, recent research by Crespo and Francisco Ramos, PhD Physics, director at Nevada Software, concludes that many large-scale power tower plants are inefficient, since the reflected light begins to disperse as it travels across the large distance between the CSP receiver and the heliostat field.

The solution, Crespo and Ramos argue in their research paper ‘Making Central Receiver Plants Modular, More Efficient and Scalable’, is to think small. By dividing a heliostat field into several smaller polar field units that share a single big power block and storage system, developers could potentially realise significant plant efficiency gains.

“Currently, the main issues concerning CSP tower plants are scalability limits, lack of standardisation and single critical path failures,” Crespo explains. “Our research demonstrated that by splitting large surrounded heliostat fields into smaller fields with polar design, the efficiency can be increased close to 25%, and single storage and power blocks of larger commercial units can be used.

“In addition, field designs and receivers can be standardised, reliability can be increased and, at the end of the day, better-performing and cheaper CSP tower plants can be deployed.

“In the future, towers and troughs will share the market depending on the latitude of the site,” he continues. “In latitudes above 30º, I think that the multi-tower concept – but still of a large size, equivalent to around 30MW per unit – will be the preferred solution.”

Expense account: making CSP technologies cost competitive

The precipitous drop in the CAPEX costs of building new CSP plants has been accompanied by a spate of promising new-build projects in emerging markets such as the Middle East and China.

The latter connected its first 100MW large-scale parabolic trough plant to the grid in January and currently has eight large-scale CSP projects with a total capacity of 500MW in operation, while in Dubai the first stage of a $3.9bn, 700MW parabolic trough CSP plant – part of the Mohammed bin Rashid Al Maktoum Solar Park – is due to be commissioned in the fourth quarter of 2020.

However, Greentech Media notes that, according to recent analysis from Lazard, the unsubsidised levelised cost of energy from a new solar thermal tower with on-site storage is $126–156/MWh, making CSP pricier than geothermal energy and much more costly than utility-scale solar or wind.

However, CSP is the cheapest technology after sunset, and the future role of CSP and PV will be to complement each other, Crespo says.

He takes issue with the view that cost is an unsurmountable hurdle to widespread adoption of CSP, noting that the Dubai CSP project was won with a record bid of $0.073/KWh, without subsidies.

“That was cheaper than the price of gas combined cycles,” he says. “In addition, total cost system studies have demonstrated that the total electrical generation cost in a given country will be lower with CSP plants than without, as the captured price of PV plants – and correspondently the reduction of the necessary financial incentives – will be higher.

“Therefore, CSP plants – with their current costs – will make systems cheaper, and hopefully CSP cost will continue go down as there is room for cost reduction; for example, by reducing the size of large heliostat fields, as discussed.

“There are no proven examples yet, but there are neither technical barriers nor uncertainties preventing CSP plants such as these becoming a reality in the future.”

Upcoming CSP events:

5th CSP Focus MENA 2020(June.23-24,Dubai, UAE)

10th CSP Focus China 2020 (Beijing China) 

More CSP news and reports please visit www.cspfocus.cn 

or CSP Focus social media on LinkedInTwitterFacebook.

Leave your thoughts here

Free Reports

See more+
  • Dubai 950MW NOOR Energy 1 CSP+PV Project

    The $4.4 billion Noor Energy 1 solar thermal project will be the world’s largest CSP plant and includes a 100 MW CSP tower plant, three 200 MW parabolic trough CSP systems, 250 MW of PV capacity and 15 hours of molten salt CSP storage capacity.

  • China Large-scale CSP Projects Update

    Updating--Jan., 2020 Edition24 pagesPart 1: Background and Fact Sheet (P1-11) · Implementation and adjustment of 1st batch of CSP demonstrations· FiT policy update and prediction· Sum-up on the 20 projects technology, location, ownership and key participants Part 2: Milestones of Ch

  • Suppliers List of China Key CSP Projects (Updating)

    13 key concentrated solar power projects in China undergoing:Shouhang Dunhuang 100MW Molten Salt Parabolic Trough ProjectRoyal Tech Yumen 50MW Parabolic Trough ProjectDCTC Dunhuang 50MW MS CLFR ProjectRayspower Yumen 50MW Trough ProjectCNNC Royal Tech Urad 100MW Parabolic Trough ProjectSupcon Delingha 50MW Molten Salt Tower ProjectLuNeng Haixi 50 MW Solar Thermal Tower Plant ProjectPower C

  • Construction and Operation of SUPCON SOLAR Delingha 50MW Tower CSP Project

    40 pages in totalCompany Profile (P3-4)Construction of Delingha 50MW Tower CSP Project (P6-17)Operation of Delingha 50MW Tower CSP Project (P18-30)Issues during Commissioning and Operation (P31-39)

Upcoming Events

See more+

Project Updates

See more+


Tex:+86-21-6111 0177



Wechat public platform

Follow CSP Focus for more news