EU-SOLARIS Folleto revision imagenes fileEU-SOLARIS Solar Concentrating Systems Solar thermal plants for electricity generation, or chemical applications, always involve concentrating

EU-SOLARIS

Solar Concentrating Systems

Solar thermal plants for electricity generation, or chemical applications, always involve concentrating system designs that are tending to larger geometries approximating those of the ideal parabolic concentrator under real operating conditions.

Usually these are reflection solar concentrators that reach the temperatures required to operate thermodynamic cycles or chemical processes. The four most widely used solar concentrating concepts are:

1. Parabolic-trough concentrators: These are line-focusing concentrators with tracking on only one axis, concentrating radiation from 30 to 80 times and

having a nominal capacity per field unit of 30 to 80 MWe. 2. Tower or Central Receiver Systems: These consist of a field of heliostats that

track the sun’s position at all times (elevation and azimuth) and redirect the reflected rays toward the focus located at the top of a tower. Concentration ranges from 200 to 1000 times and the unit capacity is from 10 to 200 MWe.

The four configurations of concentrating solar systems used in Solar Thermal Power Plants.

Heliostats

Parabolic trough

Parabolic dish

Receiver/Engine

Reflector

Central receiver

Central receiver

Linear Fresnel

Absorber tube

Heat transfer fluid pipe

Mirror

NEW EXPERIMENTAL FACILITIES

3. Parabolic dishes: These are small independent units with a parabolic reflector, usually connected to a Stirling engine located at the focus. The concentration is relatively high (1000-4000 times) and unit capacity is from 5 to 25 kWe.

4. Linear Fresnel reflector systems are conceptually simple, using inexpensive, compact optics that can produce saturated steam at 150-360ºC with less than 1 ha/MW-1 land use.

In the past we have witnessed successful solar electricity production operations; such as the 354-MWe Solar Energy Generating Systems (SEGS) plant in California, which for 25 years has been supplying 90% of the

commercial solar electricity produced worldwide. Nevertheless, it is only now that major breakthroughs are being achieved and solar thermal power plants are becoming widely accepted and commercially developed. For this reason the proposed new Research Infrastructure (RI), to push forward this technology, presents itself at a critical moment.

EU-SOLARIS

The ANDASOL-1 CSP Power Plant near Granada (Spain)

The ‘solar cluster’ CTAER / PSA

The EU─SOLARIS project addresses the need for a high-powered European research infrastructure within Concentrating Solar Power (CSP). This target can be achieved by upgrading existing CSP research infrastructures, developing new unique laboratories and strengthening networks between European CSP laboratories. A consolidated European RI can ensure the competitiveness and leadership of European scientists, research centres and industries in the field of

concentrating solar energy.

EU-SOLARIS will consist of several distributed sites, all of them devoted to world-class, cutting-edge research on CSP. The CTAER/PSA cluster in Almería (Spain), shown in the picture below, is currently considered the most important CSP lab in the world; at present there are 50 senior researches, 15 doctoral students and 25 auxiliary staff working on solar technologies. These CTAER/PSA

facilities will have a core role within the EU─SOLARIS initiative.

CTAER, which stands for Centro Tecnológico Avanzado de Energías Renovables1, is a non-profit foundation. It is composed of various leading Spanish companies in the field of solar energy, together with two Andalusian Government agencies dealing with the promotion of innovation and development of renewable energies. The Plataforma Solar de Almería2 (PSA) belongs to the

Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas3

1Advanced Technology Centre for Renewable Energies

2 The Almeria Solar Platform 3 Centre for Energy, Environment and Technology Research

NEW EXPERIMENTAL FACILITIES

(CIEMAT), which is one of the founding members of CTAER. At the same time, CIEMAT belongs to the Spanish Ministry of Science and Innovation, which fully supports the EU-SOLARIS project.

The picture above shows the PSA and CTAER sites. Both are of the same size, approximately 100 hectares each.

CTAER will also provide a large space for the rapid implementation of highly innovative industrial demonstration projects. This site (2.2º W, 37.0º N, 600 m high) is located in a highly insolated area of flat land, with water for cooling

purposes and access to the grid easily available. The surface could be enlarged in the future, if needed.

Additionally, some complementary sites at several leading European labs – representing those European countries with largest solar potential (Portugal, Greece, Turkey, etc.), Germany (one of the main technological providers in the world) and others – could become an integral part of the new RI, offering their

own facilities to create a real networking atmosphere, and contributing to jointly encourage the implementation of these technologies in Europe.

The new and existing EU─SOLARIS facilities, as a part of the ESFRI Roadmap, will be a foundation for real and fruitful Research and Development (R&D) co-operation between a core group of countries, on the basis of integrated funding, joint management and collective use policy, EU-SOLARIS will

continue developing this multilateral approach for the project.

EU-SOLARIS

In summary, the main objective of the project is to start up a process where current research challenges in CSP may be overcome by a pan-European work team through a major upgrade of existing facilities in Europe. The initiative focuses on the high-level target of establishing a strong, distributed infrastructure

for developing new solar technologies.

This proposal is supported by the Spanish Government (Ministry of Science and Innovation) and the Andalusia Government (Department of Science, Innovation and Business) along with the two most relevant industrial associations in this field, PROTERMOSOLAR (Spanish) and ESTELA (European).

Introduction to Plataforma Solar de Almeria (PSA)

The PSA belongs to CIEMAT, a public research centre, dependent on the

Spanish Ministry of Science and Innovation. The PSA is, without doubt, the largest concentrating solar radiation research, development and test centre in the world. Only two other facilities, the Weizmann Institute of Science in Israel and Sandia

Laboratories in Albuquerque, New Mexico (USA), have similar capacities in some of the concentrating solar technologies, but neither has the variety or features of the PSA. Thus Spain, and in particular, the PSA as the centre of excellence, receives visitors and researchers in such systems from all over the world.

The unique character of the PSA is the consequence of a combination of historical coincidences and the opportunity presented by its absolutely privileged

site at 37º05’27.8’’ latitude North and 2º21’19’’ longitude West in the Desert of Tabernas, province of Almería in south-eastern Spain. It has a direct annual insolation above 1900 kWh/m2 and the average annual temperature is around 17°C.

The PSA offers researchers a location with climatic and insolation characteristics similar to those of developing Sun Belt countries (where the solar

energy potential is the greatest), but with all the advantages of the large scientific facilities of developed European countries, making it a privileged site for the evaluation, demonstration and transfer of solar technologies.

As mentioned, in addition to its location in the Desert of Tabernas, its historical background has also contributed to placing the PSA in the privileged position it now occupies.

NEW EXPERIMENTAL FACILITIES

The PSA took root in the late seventies with the construction of two demonstration projects to prove the technical feasibility of

generating electricity by concentrating solar thermal systems. (These have come down to us as “First generation solar thermal power plant systems.”) The first of these two projects was called the

SSPS (Small Solar Power Systems), and was sponsored by the International Energy Agency (IEA) with the participation of nine countries (Germany, Austria, Belgium, Spain, the United States,

Greece, Italy, Sweden and Switzerland).

It consisted of the design, construction and testing of two 500-kW solar thermal power plants,

the first of which was based on the tower, or central receiver, technology and the second on the parabolic-trough collector technology. The second project, known as the Central Electrosolar de Almería-I4 (CESA-I), was sponsored by the Spanish Ministry of Industry, Commerce

4 The Almeria Solar Thermal Power plant

Aerial view of the Plataforma Solar de Almería

The PSA CESA-1 central receiver facility

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and Tourism and was of entirely Spanish design and technology. It consisted of the design, construction and testing of a 1-MW rated power central receiver solar thermal power plant. Evaluation of both projects was completed in 1984.

From 1985 to 1987, the CESA-I project served as a test bed for an ambitious

technology program called the GAST, or GAsgekültes SonnenTurm5, a Spanish-German project for the design, construction and testing of components for a second-generation air-cooled plant. During that same period, Spain negotiated with the International Energy Agency the transfer to Spain of all the SSPS project capital, and with Germany the signature of a bilateral collaboration agreement for the joint use of the PSA as a centre of concentrating solar thermal technology

research, development and demonstration. The two centres that partook in the agreement were CIEMAT for Spain and the DLR (German Aerospace Agency) for Germany.

The Spanish-German Agreement became effective in 1987 and continues to be active to date. In the first phase, from 1987 to 1998, CIEMAT and DLR shared the basic PSA operating and maintenance budget and its joint management

equally. Since January 1999, by mutual agreement of both parties, the scientific management of the PSA is now wholly the responsibility of CIEMAT and the framework of collaboration with DLR is based on specific projects. Collaboration with DLR continues as strong and as fruitful as ever.

In the international sphere, the PSA participates in the International Energy Agency’s Solar PACES program Tasks I, II and III, where information is exchanged

and project costs are shared with similar centres in the USA, Germany, Switzerland, Australia, Israel, France, etc. At the present time, this is the only network of experts in solar thermal concentrating systems and technology (www.solarpaces.org).

Another recent initiative in international collaboration at the PSA was the creation of the Alliance of European Laboratories on Solar Thermal Concentrating

Systems (Slab). This virtual laboratory is made up of the main European concentrated solar energy research institutions, that is, the PROMES-CNRS (France), DLR Solar Energy Div. (Germany) the Federal Institute of Technology of Zurich Renewable Energies Laboratory (Switzerland), the Paul Scherrer Institut (Switzerland) and the CIEMAT itself

(www.promes.cnrs.fr/ACTIONS/Sollab/presentation.htm).

Furthermore, continuous intense collaboration with the University of Almería (UAL) has been consolidated with the creation of a mixed centre for joint research in solar energy applications called CIESOL. This collaboration is physically located in a new laboratory building on the UAL campus, partly financed by the ERDF6, which was inaugurated in 2005 (www.ciesol.es).

5 Air-cooled Solar Power Tower plant 6 European Regional Development Fund

NEW EXPERIMENTAL FACILITIES

PSA Facilities and Capacities

The scientific and technical commitments of the PSA and the associated workload this involves are undertaken by a team of 100. To this staff is added the stream of visiting researchers and students from different countries managed by the Training and Access program. On a normal day, active personnel at the PSA

usually exceed one hundred and fifty.

Location of the main PSA test facilities

Of the 100 persons who work daily at the PSA, a significant portion is made up of auxiliary services and operation and maintenance contracts for the various facilities (45 persons). The remaining personnel are made up of CIEMAT staff (43 persons) and the DLR permanent delegation (12) who are involved in activities

resulting from current commitments under the German-Spanish Agreement.

At present, the main test facilities available at the PSA are:

• The 7-MWt CESA-1 and the 2.7-MWt SSPS-CRS central receiver systems. • The 1.2-MWt SSPS-DCS parabolic-trough collector system, with

associated thermal storage system and water desalination plant. • The 1.8-MWt DISS test loop, an excellent experimental system for

research in two-phase flow and direct steam generation for electricity production.

• The HTF test loop, with a complete oil circuit for evaluation of new parabolic-trough collector components.

• The 6-unit DISTAL dish/Stirling facility. • The 60-kWt solar furnace for thermal treatment of materials.

• The versatile solar detoxification facility: a two-axis-tracking parabolic-trough loop and three CPC photoreactors for different types of trials.

• The Laboratorio de Ensayo Energético de Componentes de la Edificación7 (LECE).

• A meteorological station, member of the international BSRNi network.

7 Laboratory for Energy Testing of Building Components 8 Baseline Surface Radiation Network

EU-SOLARIS

1.8-MWt DISS test loop for direct steam generation research. The two rows in the loop total 13 collectors. It is 665 m long with a solar collecting surface of 3838 m2. The facility has the instrumentation and equipment necessary to generate 1 kg/s of 100-bar, 400ºC steam.

1.2-MWt DCS solar field of 40 ACUREX 3001 parabolic-trough collectors with a total solar collecting surface of 2672 m2. The thermal transfer fluid employed is Santotherm 55. It also has a 140-m3 thermal oil storage system, a 500-kWe electricity generating system and an MED (multiple effect distillation) desalination system with a nominal production of 72 m3 distillate per day.

In the 7-MWt CESA-1 central receiver, or tower, facility, direct solar radiation is collected by a field of 300 heliostats, each of which has a surface area of 39.6 m2. 99% of the power is collected in a 4-m-diameter circle. The concrete tower is 80 m high and can support a 100-ton load. The tower has three test levels, specially conditioned for receiver, or solar boiler, and materials testing. The system is complete with two storage tanks and a 1.2-MWe turbine.

The PSA DISTAL facility is made up of 6 parabolic dish/Stirling systems. The unit capacity is 9-10 kW. There is one 7.5-m-diameter DISTAL-I stretched membrane dish and three 8.5-m-diameter DISTAL-II dishes, which are also stretched membrane, and two EURODISH dishes with fibreglass support structure. DISTAL is the most complete dish/Stirling facility in the world and has accumulated nearly 60,000 hours of solar operation.

NEW EXPERIMENTAL FACILITIES

The PSA solar furnace is a very high concentrating solar system with fields of application mainly in materials testing and solar chemistry experiments that use receivers associated with chemical reactors. The furnace consists of 4 flat heliostats that continuously redirect the solar radiation onto the surface of a static parabolic concentrator composed of 89 spherical facets having a total surface of 98.5 m2 and 92% reflectivity. The facility is complete with attenuator, test table and concentrated solar radiation flux measurement system.

The HTF test loop was installed in 1997 to evaluate components, such as mirrors, absorber tubes, solar tracking systems, etc. under real operating conditions. The facility consists of a closed-loop thermal oil circuit connected to two solar collectors, one LS-3 and the other a Eurotrough, mounted in parallel. It has a total reflective surface of 685 m2 and a thermal power of 350 kW.

General view of the Solar Photochemistry CPC (Compound Parabolic Concentrator) collector facility for water detoxification and disinfection. The 3 collector rows at lower left. Tanks for mixing and storing test effluents and chemical solutions in the centre.

Envisaged R&D Activities at EU-SOLARIS

The physical principle of solar concentrating technology consists of

tracking the sun by reflectors (parabolic troughs, heliostats, parabolic dishes or linear Fresnel mirrors) that concentrate the sun’s rays into a linear or a point focus called ‘receiver’. The thermal power at the receiver is further converted into

EU-SOLARIS

electricity by more or less conventional power cycles, or into solar fuels inside specific chemical reactors.

The relevant disciplines concerned are: optics, thermodynamics, materials science, heat transfer and storage, thermo-chemistry, automatic control,

industrial design, process optimization, photo-catalysis, electronics, etc.

New scientific and technological developments require the experimental demonstration of the suitability, durability, reproducibility, efficiency and competitiveness of this concept, as they are intended to be deployed on a large scale. The EU─SOLARIS facility will fill the gap from the theory or the lab scale test to a demonstration plant of almost commercial size.

There is still a wide range of scientific and technological open questions that public research centres and private industries are willing to jointly answer. In particular, the upgraded and new facilities considered within the EU-SOLARIS project will enable more advanced levels of research in:

Aerial view of the commercial PS10 & PS20 plants in Sanlúcar La Mayor (Seville)

Solar Fields and Receivers:

Issues on concentration optics (σ, aberration and tracking accuracies) and corresponding impact on the land requirements, optical behaviour of long distance heliostats, achievable working fluid temperature depending on the type of technology and the concentration ratio, optimum working temperature

considering fluid and receiver material properties, thermal losses, fluid mechanisms effects, etc., matching between fluids and concentration technology, features of the control systems, combined reflection a refraction techniques, etc.

NEW EXPERIMENTAL FACILITIES

Storage:

Storage principles (thermal, chemical reversible reactions, …), use of the same or different storage medium than the collector fluid, use of sensible or latent heat or a combination of both, use of single or dual media, mass and volume

requirements per unit of energy stored, achievable charge and discharge rates, safety issues, etc.

Cooling systems:

Reduction of water needs in wet cooling systems, combined dry and wet approaches, passive night cooling systems, exhaust heat uses, etc.

Hybridization:

Conceptual approaches (response to cloud passing or enhancing the conversion cycle efficiency), use of fossil fuels or biomass (direct burning or gasified), partial or full load capabilities, complement or alternative to storage...

System Design:

Preferred conversion cycles (combined cycles, steam Rankine, organic Rankine, Stirling, …), capacity factor (base load, picking power, …), advanced

multi-tower approaches, reduction of heat exchanger requirements, dual electricity and desalting water products, process heat for industrial application, chemical solar fuels or synthesis products, etc.

The development of the next generation CSP lab (EU─SOLARIS) and enhanced integrated network for European research on CSP is intended to facilitate a comprehensive approach to all these issues. This should be considered

not only from a technical point of view, but also from an economic one (the cost of these technologies during their whole life span). Individual researchers and research teams will be able to work on the most auspicious solutions.

CPC-type solar collector field for water desalination purposes

EU-SOLARIS

It is envisaged that a wide user community from all countries that have significant interests in CSP (not only European countries, but also developing countries having association agreements with the EU) will obtain access to the EU─SOLARIS facilities. For each particular case, open access to the most

appropriate EU─SOLARIS infrastructure will be given to international researchers from public research institutes, academia and companies with interests in CSP and solar technologies. Thus, EU─SOLARIS will be operated as a proposal-driven open laboratory, with a selected group of experts chosen to perform and guarantee a transparent prioritisation of proposals, according to a programme of support for researchers that will be both internationally and nationally managed.

The selected researchers will have the opportunity to work on cutting-edge experiments that are a part of the essential CSP-activities described above.

Proposed New Experimental Facilities

To tackle all the challenges listed above, the following needs for new EU─SOLARIS infrastructures have been identified in the first phase:

• Multipurpose functional tower (70 m high with three apertures)

• Solar field with 180 heliostats, 120 m2 each (around 20 MWth)

The ‘HYDROSOL-II’ receiver plant at the PSA

NEW EXPERIMENTAL FACILITIES

• Beam down facility up to 0.5 MWth

• This facility would yield 1 MW power on the “on-ground” receiver aperture. A hyperbolic mirror of 300 m2 attached to the tower and 10 heliostats with reflective surface of 120 m2 each would make the sun tracking

• Test beds for parabolic trough modules and complete loops

• Test beds for Fresnel linear mirror collectors and complete loops

• Test beds for Stirling motors and micro turbines with special attention on hybridization techniques

• Test beds for storage systems

• Test beds and auxiliary installations for micro-STE and thermal applications

• Test beds for dry cooling systems

• 1 MW hybrid solar-biomass test facility, including solar field, biomass gasification plant and power cycle plus a hybrid systems laboratory, oriented to the development of specific components for solar-gas hybrid plants.

• A controlled-atmosphere chamber with 2m-diameter quartz window and

all necessary instrumentation for testing of innovative materials (ceramic, nano-structural materials, composites, etc.) under severe conditions (high flux, temperature gradients, heating rate) as an example the aerospace materials that requires testing temperatures close to 2.000ºC

• Solar Hydrogen and Solar Chemistry Test Facility, capable to achieve temperatures close to 2000 ºC and high radiant flux

Apart from these facilities, which could be regarded as the core of the EU─SOLARIS ESFRI scheme, other complementary (distributed) infrastructures in other leading centres are needed.

It is envisaged that these core and distributed infrastructures will altogether offer, after the necessary enlargements and improvements, a full range of

facilities across the partner countries.

CONTACT

Contact Us

CTAER

Paraje los Retamares S/N 04200 Tabernas (Almería)

Spain

Phone (switchboard): (+34) 950 104546 Fax: (+34) 950 214361 e-mail: [email protected] Website: www.ctaer.com

Plataforma Solar de Almería P.O. Box 22

04200 Tabernas (Almería)

Spain

Phone (switchboard): (+34) 950 387900 Fax: (+34) 950 365300 e-mail: [email protected] Website: www.psa.es