FACILITIES

Type and Name of Facility

Brief Description

A) Parabolic Trough Collectors (PTC)

A1.- DISS

A Direct Steam Generation (DSG) test loop (North-South oriented) of parabolic trough collectors (PTC) for experimenting with DSG at high-pressure and temperature steam (up to 100 bar/500°C, flow rate of 1 kg/s, 2.5 MWth) in the PTC absorber tubes. It consists of two subsystems, the solar PTC field (5,400 m2 and 1,000-m long) and the balance of plant (BOP). The solar field can be configured for: a) Recirculation (perfectly differentiated evaporation and superheating zones), b) Once-Through (the intermediate water-steam separator and the recirculation pump located in the solar field are not used) and c) Injection mode (feed water is injected at different points along the solar collector loop).

A2.- HTF

Large-size PTC test loop (East-West oriented) with 3 PTC units (up to 275 kWth each) for characterization of solar components: new PTC designs, mirrors, absorber tubes, ball-joints, flex-hoses, solar tracking systems, etc. Thermal oil Syltherm 800® is used in this facility (max. working temp. of 400°C and a freezing point of -40°C). Main activities at the HTF test loop are related to study the optical and thermal performance of complete parabolic-trough collectors (optical efficiency, IAM coefficient, and global efficiency/heat losses) and receiver tubes.

A3.- PROMETEO

East-West oriented test loop that allows the qualification of all collector components and complete collectors of a length of up to 100 m, i.e. structures, reflectors, 70 to 90 mm diameter receivers and rotary/flexible joints. It enables sun tracking covering all solar radiation incidence angles in one day thanks to its orientation. The collector modules are connected to the balance of plant (BOP) in parallel or in series configuration using the ad hoc set valve. A pump circulates silicone heat transfer fluid (SHTF) with a mass flow similar to that of PTC commercial power plants.

A4.- PTTL

Large test facility implemented in a 420m x180m plot of the PSA and composed of two solar fields: a) the North one (E-W orientation) is designed to install complete PTCs with a maximum unit length of 180 m; it has an oil pump (75 m3/h) provided with speed control and a 1.5 MWth oil cooler refrigerated by air; b) the South field (N-S orientation) is designed to install complete loops of PTCs (i.e. several collectors connected in series), with a maximum length of 640 m; additionally, it has an oil pump (125 m3/h) provided with speed control and a 4 MWth oil cooler refrigerated by air. Up to four complete loops can be installed in parallel. The facility is also suitable to install big-size PTC prototypes.

A5.- TCP100

A 2.3 MWth PTC facility with a thermocline storage tank with 115 m3 of Santotherm-55 oil specially designed to perform studies related to control systems for parabolic trough solar fields. The facility is composed of six TCP 100 PTCs, installed in three parallel loops with two collectors in series within each loop (N-S oriented). Two collector loops are provided with a solar tracking system developed by PSA, while the third loop is provided with a commercial solar tracking system for comparison. Each collector is composed of eight PT modules with a total length of 100 m and a parabola width of 5.77 m (545 m2 of total solar collecting surface).

A6.- IFL

Innovative Fluids Test Loop (pressurized gases) in PTCs (E-W orientation) to study the use of pressurized gases as heat transfer fluid in PTCs, evaluating their behaviour under a diversity of real operating conditions, and designed to work at conditions up to 100 bar and 500°C. It is composed by: a) Two East-West-oriented Euro-Trough PTC, each 50 m long with a 274.2 m2 collector surface, connected in series; b) A 400 kW air-cooler with two 4 kW motorized fans to thermal energy removal from the fluid; c) A 15 kW blower to provide the needed gas flow rate at the receiver tubes.

A7.- NEP

A 125 kW test loop of small-sized PTC collectors (Polytrough 1200). It has a production of 15.8 kW per module (0.55 kW/m2) under nominal conditions, with an average collector temperature of 200ºC, and an efficiency over 55% in the range of 120-220ºC (for 1000 W/m2 of direct normal irradiance). The field is configured in 8 collectors placed in 4 parallel rows (two collectors in series each row). Thermal oil can reach 220ºC, being possible the evaluation of different polygeneration schemes using thermal energy.

A8.- LAVEC

Test facility designed for evaluating and qualifying small line-focus solar collectors using pressurised water as working fluid within the temperature range of 100-250°C, which is very suitable for industrial process heat applications. Expected size of the solar collectors tested: up to 25 m2 per collector unit. Field length: up to 40 m, in both orientations: East‒West and North‒South. Hot water storage tank of 3 m3. The test facility fulfils the current standards for solar thermal collectors testing: ASTM E905-87:2013, SRCC 600 2014-17:2015 and ISO 9806:2017.

B) Other Line-Focus Solar Concentrators Facilities

B1.- KONTAS

Rotary test bench for parabolic trough collectors and components, under a constant normal incidence angle of the solar radiation. It allows the qualification of complete modules of a length of up to 20 m (structures, reflectors, receivers and flexible joints). It enables for two-axis tracking (test bench platform over a circular rail) at any desired angle of incidence of the solar radiation. It is equipped with high precision instrumentation and controls for precise, quick and automated measurements. The collector module is also connected to a heating and cooling unit on the platform.

B2.- REPAs

Accelerated full lifecycle tests of Rotation and Expansion Performing Assemblies for PTC systems. This test bench is divided into two functional sections, the kinematic unit (to hold and move the REPAs to be tested), and the balance of plant unit (for supplying the conditioned heat transfer fluid). The balance of plant unit is composed of a variable speed pump that circulates the HTF through with adapted collar type electrical heaters. The kinematic unit can accommodate test samples (ball joints and flexible hoses) with adjustable geometries and for different PTC designs.

C) Thermal Energy Storage

C1.- MOSA

Molten Salt Test Loop for Thermal Energy Systems. This facility is composed by two installations: an outdoor test loop, with a two-tank configuration filled with 40 tons of molten solar salt, and an indoor test bench, named BES-II, which can be used for testing small hydraulic components (valves, pressure transducers, etc.) in different molten salt mixtures. MOSA is the largest facility worldwide, which is a reduced scale replica of a commercial CSP thermal storage system so everything related to this type of systems can be tested in a relevant and extrapolated scale.

C2.- ALTAYR

Insulated storage tank of around 0.1 m3 where different packed bed configurations and materials can be tested using atmospheric air as heat transfer fluid. Provided with a maximum electric power of 15 kW, a charge process with air up to 850 °C is possible. Thermocouples along its length and at different radial positions give an accurate map of the packed-bed temperature

D) Central Receiver Systems (CRS)

D1.- CESA-1

6 MWth CRS. Solar field: 330 x 250 m south-facing field of 300 39.6 m2 heliostats distributed in 16 rows; tower: 84 m high with four different levels to accommodate receivers and a big with target square to heliostat canting and adjustment. Typical peak flux of 3.3 MW/m2 with an irradiance of 950 W/m2 (99% of the power is focused on a 4 m diameter circle and 90% in a 2.8 m circle). It is a very flexible facility for testing components such as heliostats, solar receivers, thermal storage, solarized gas turbines, control systems and concentrated high flux solar radiation measurement instrumentation. It can be also used for other applications requiring high photon concentrations on relatively large surfaces, such as in chemical or high-temperature processes, surface treatment of materials or astrophysics experiments.

D2.- SSPS-CRS

2.5 MWth CRS facility. South part of the solar field is composed by 91 (39.3 m2) heliostats and the North part of the solar field has 20 (52 m2 and 65 m2) heliostats with an average nominal reflectivity of 90%. The solar tracking error is 1.2 mrad per axis and the optical reflected beam quality is 3 mrad. Under 950 W/m2 of solar irradiation, total field power is 2.5 MWth with 2.5 MW/m2 of peak flux. 99% of the power is collected in a 2.5 m diameter circumference and 90% in a 1.8 m circumference. Tower: 43 m high metal structure with 3 test platforms (at 26 and 28 m and for testing new receivers for thermochemical applications and a calorimetric test bed with crane at the top of the tower for small atmospheric-pressure volumetric receivers evaluation).

E) Solar Furnaces (SF)

E1.- SF-60

Composed by a 130 m2 flat heliostat that reflects the solar beam onto a 108 m2 parabolic concentrator, which in turn concentrates the incoming rays on the focus of the parabola. A louvered shutter placed between the heliostat and the concentrator regulates the incoming light. Finally, a test table movable on three axes is used to place the element to be tested in the focus. The parabolic concentrator is the main feature of this solar furnace; it is made of spherically curved facets, each with a curvature that varies based on its distance from the focal point. It concentrates the incident sunlight from the heliostat, multiplying the radiant energy in the focus. The characteristics of the focus with 100% aperture and 1000 W/m2 solar radiation are: peak flux, 670 W/cm2, total power, 80 kW, and focal diameter, 22 cm.

E2.- SF-40

This SF consists mainly of an 8.5 m diameter parabolic-dish (56.5 m2 concentrator parabolic area), with a focal distance of 4.5 m coupled to a 100 m2 reflecting surface flat heliostat, a, slats attenuator, and test table with three axis movement. The concentrator surface is made of 12 curved fiberglass petals or sectors covered with 0.8 mm adhesive mirrors on the front. The parabola thus formed is held at the back by a ring spatial structure to give it rigidity and keep it vertical. The facility reaches a peak concentration of 5,000 suns and has a power of 40 kW, its focus size is 12 cm diameter and rim angle a= 50.3°. Its optical axis is horizontal, and it is of the “on-axis” type that is parabolic concentrator, focus and heliostat are aligned on the optical axis of the parabola.

E3.- SF-5

5 kW SF power, reach concentrations above 7,000 suns. It consists of an 8.7 m2 concentrator mirror, placed upside-down on an 18 m high metallic tower and with the reflecting surface facing the floor; in the centre of the base of the tower there is a 25 m2 flat heliostat, whose rotation centre is aligned with the optical axis of the concentrator. At the top of the tower, and 2 m below the vertex of the concentrator, there is a test table. Finally, under the test table and at floor level of the test room, a louver attenuator is placed. SF-5 focus diameter is 2.5 cm, and is mainly devoted to heat treatment of materials at high temperature, under vacuum and controlled atmosphere conditions. The main advantage is that the focus is arranged in a horizontal plane, so that the samples may be treated on a horizontal surface.

F) Parabolic Dishes

F1.- AGEING TEST BED

DISTAL-I concentrator formed by a 7.5 m diameter parabolic dish with 40 kW thermal power and one-axis polar solar tracking system in which the Stirling motor was removed and replaced by different test platforms to perform accelerated temperature cycling of materials or small-scale prototypes of high concentration receivers. With fast focusing and defocusing cycles, the probes placed in the concentrator focus stand a large number of thermal cycles in a short time interval, allowing an accelerated ageing of the material. These platforms can be used testing: materials, air-cooled volumetric receivers (metal or ceramic), small-size receivers prototypes with or without heat transfer fluid, etc.

G) Materials

G1.- OPAC

Optical Characterization and Durability Testing of Solar Components facility. This facility is the largest one worldwide devoted to the complete study of the materials used in the optical components of concentrating solar thermal systems (reflectors, receivers, transparent covers, etc.), allowing the determination of characteristic optical parameters, their possible deterioration along the time, as well as different O&M aspects, such as soiling evaluation and mitigation (including cleaning strategies). It is composed by several unique outdoor facilities to assess the possible degradation mechanisms affecting these optical component (including a high number of test benches that simulate different operating conditions) and four full-equipped laboratories to reproduce such degradation mechanisms under accelerated aging conditions in weathering chambers.

H) Solar Desalination facilities

H1.- MED

Pilot plant based on multi-effect distillation (MED). It has 14 stages or effects arranged vertically in a forward feed configuration. The maximum temperature that the saline water reaches inside the plant (top brine temperature) is about 70ºC, a limit set to avoid precipitation of salts and the consequent formation of scaling on the heat exchange surfaces inside the plant. The minimum temperature of the last effect is set by the final condenser, which condensates the last vapor generated in the MED process and is usually cooled using the same saline water that feeds the process. At design conditions, about 200 kWth are required to produce 3 m3/h of desalinated water with recovery ratio (ratio of produced to feed water) of 37.5%. The energy supply is a solar field of flat plate static collectors or small aperture parabolic trough collectors, in case of operating the MED coupled with a double effect (LiBr-H2O) absorption heat pump.

H2.- NF-RO-FO

Facility for combinations of Forward Osmosis (FO), Reverse Osmosis (RO) and Nanofiltration (NF). 12 Aquaporin HFF02 hollow fibre FO modules with 2.3 m2 total membrane area each in a flexible rack for series or parallel combination of all, nominal flow rate 3.6 m3/h. One 8” and two 4” pressure vessels that can be connected in series or parallel, each of which able to host four membranes, nominal flow rate 3 m3/h, max. pressure 80 bar (RO)/16 bar (NF). All units fully monitored, working with separate water containers and flexibility for interconnection between them, including microfiltration (3 m3/h nominal) pre-treatment.

H3.- MDTF

Membrane Desalination (MD) Test Facilities operated with different solar fields of flat-plate collectors with thermal storage and controlled heat supply temperature. The facility has also several chillers to dissipate heat and can work with real seawater (300 m3 stored from a beach well). It includes several MD pilot plants with spiral-wound commercial modules operating in permeate-gap, air-gap and vacuum-assisted air-gap configurations, as well as multi-effect plate and frame modules operating in vacuum configuration. Feed recirculation for brine concentration is possible in all cases. There are also innovative multi-effect modules without membranes (CEVAP technology).

I) Water Treatment

I1.- SOLWATER

Water Treatment and regeneration test facility composed by: a) 300 L PTC photo-reactor with two axes solar tracking system; b) multiple solar decontamination and disinfection pilot photo-reactors based on Compound Parabolic Collectors (CPCs, from 32-75 mm of tube diameters, 0.5-15 m2 of irradiated surface and total volume from 10 to 300 L) equipped with heating and cooling systems for temperature control, pH and dissolved oxygen monitoring, and coupled with other treatment technologies (electro-oxidation, ozonation, etc.); c) 2 m2 solar disinfection reactor with different reflector shape (CPC and U mirror type) equipped with a solar water heating panel; d) a 5 L multi-step photocatalytic pilot reactor and 2 raceway pond pilot scale photoreactors (10-90L); e) Ultraviolet pilot plant equipped with a reagents dosing system; e) micro- and nano-membranes pilot plants, including pH automatic control; g) wet air oxidation pilot plant prepared to operate under 200 bar and a maximum temperature of 300°C; h) electro-oxidation pilot plant (four electrochemical cells); i) two ozonation pilot plants coupled with a CPC; j) Biological pilot plant reactors with a double depuration system (fluidized biomass systems and sequencing batch reactors); k) 30 m2 Culture crop chamber used for wastewater reclamation testing (4 individual areas with cooling and heating system).

I2.- HYWATOX

Solar facility to the production of photofuels (H2 and other hydrocarbon fuels directly from sunlight) composed by: a) Pilot plant 1 specifically designed for photocatalytic production of photofuels and other photoproducts. It consists of a stainless-steel tank coupled to a CPC photo-reactor (2.10 m2). Mass flow controllers for gas stream used to remove oxygen from the system as well as to eject the photofuel produced from the system and carry it to an on-line MicroGC analyser (evaluation of H2, CO2, O2, etc); b) Pilot plant 2 also designed for photocatalytic photofuels production and for testing cutting edge photocatalysts. It is provided with a sedimentation/ separation tank for photocatalyst recovery, mass flow controllers and on-line MicroGC analyser.

J) Solar Radiation Characterization

J1.- METAS

The METAS station instruments provides information on solar radiation and more general atmospheric variables that can be used for spectral models validation as well as all other PSA research activities. Some key specific available data: a) measurement of the terrestrial radiation balance; b) incoming and outgoing shortwave and long-wave radiation is measured at 30 m; c) solar radiation component characterization: (global, direct and diffuse); d) UV and PAR spectral bands; e) spectroradiometer (200 to 2500 nm); f) vertical wind profile: wind speed and direction at 2, 10 and 30 m; g) vertical temperature and humidity profile at 2 and 10 m; g) miscellaneous weather information: rain gauge, barometer and psychrometer. Since 2005 METAS follows Baseline Surface Radiation Network quality requirements.

K) Energy Efficiency

K1.- LECE

The Building Component Energy Test Laboratory (LECE) is an outdoor facility devoted to the research of energy analysis of buildings, integrating passive and active solar thermal systems to reduce the heating and cooling demand. It is composed by: a) five test cells, each of them made up of a high-thermal-insulation test room and an auxiliary room to the experimental characterisation of building envelopes; b) PASLINK test cell incorporating a Pseudo-Adiabatic Shell concept; c) CETeB test cell for roof testing; d) Solar Chimney; e) Single-zone building for in-depth energy evaluation methodologies for experimental buildings.

K2.- ARFRISOL Building

Fully instrumented and continuously monitored operative Office Building Prototype of around 1000 m2 built area. It is designed to minimize heating and air-conditioning energy consumption whilst maintaining optimal comfort levels by including passive and active (mainly solar) energy saving strategies based on architectural and construction design.

M) Cooling

M1.- WASCOP

This facility is composed of different cooling systems: an Air Cooled Heat Exchanger (200 kWth), a Wet Cooling tower (200 kWth) and an Air Cooled Condenser (335 kWth). All of them connected to a steam generator (80 kWth) driven by solar thermal energy, which produces saturated steam (120-300 kg/h) at different temperatures (42-60°C), simulating the exhaust steam from a turbine in a power cycle. The cooling systems can be evaluated either separately, or combined, having two options within the latter: 1) a conventional combined cooling system composed by an Air Cooled Condenser in parallel with a Wet Cooling Tower plus a Surface Condenser; 2) an innovative combined cooling system composed by an Air Cooled Heat Exchanger and a Wet Cooling Tower, both sharing a Surface Condenser. In the last case, the hydraulic circuit allows to evaluate series and parallel configurations, and different flow rate percentages in the parallel ones.

N) Flat-Plate Collectors (FPC)

N1.- AQUASOL

A field of stationary flat plate collectors with 323 kWth thermal power output under nominal conditions (59 % eff. for 900 W/m2 and 75°C), 40 m3 thermal storage (two water tanks) and an air-cooler. It is divided in 4 loops with 14 large-aperture collectors (Wagner & Co.’s LBM 10HTF with 10.1 m2 area) each (2 rows in series with 7 collectors in parallel), and one additional smaller loop with 4 collectors in parallel. Collectors are tilted 35° with S orientation and have moving flat mirrors tracking the Sun to increase the collection area. It is connected to a centralized heat exchanger and also individual ones in each loop to couple with low-temperature thermal energy-consuming devices for testing purposes.