The NACIR Project: New Applications for CPV'S: A fast way to improve reliability and Technology progress

The main goal of this proposal is to join together the owners of the most advanced CPV technology, with respect to the state of the art, in order to research from its leading position new applications for CPV systems. In addition to opening up new markets, it will unveil possible sources of failure in new environments outside Europe, in order to assure component reliability. The proposed project will also try to improve the current technology of the industrial partners (ISOFOTON and CONCENTRIX) by accelerating the learning curve that CPV must follow in order to reach the competitive market, and lowering the cost under the current flat panel PV significantly within 3-4 years. The use of CPV systems in remote areas, together with harsher radiation, ambient and infrastructure conditions will help to increase the rate of progress of this technology. In addition, the ISFOC s contribution, which brings together seven power plants from seven CPV technologies up to 3 MWpeak, will allow creating the most complete database of components and systems performance to be generated as well as the effects of radiation and meteorology on systems operations. Finally, regarding the new applications for CPV subject, the project will use a CPV system sized 25 kWp in a stand-alone station in Egypt (NWRC) for the first time for water pumping and irrigation purposes. In a similar way ISOFOTON will connect up to 25 kWp CPV to the Moroccan ONE utility grid. From the research content point of view of this project, which is directly addressed by the scope of the call, the cooperative research between UPM, FhG-ISE and the two companies will be favoured by the fact that all are progressing in similar directions: developing two-stage optics CPV systems. In addition to these technology improvements the UPM is very interested in developing a new concept of module, recently patented, which will fulfil all required characteristics of a good CPV with less components and reducing cost

Atmospheric parameters, spectral indexes and their relation to CPV spectral performance

Air Mass and atmosphere components (basically aerosol (AOD) and precipitable water (PW)) define the absorption of the sunlight that arrive to Earth. Radiative models such as SMARTS or MODTRAN use these parameters to generate an equivalent spectrum. However, complex and expensive instruments (as AERONET network devices) are needed to obtain AOD and PW. On the other hand, the use of isotype cells is a convenient way to characterize spectrally a place for CPV considering that they provide the photocurrent of the different internal subcells individually. Crossing data from AERONET station and a Tri-band Spectroheliometer, a model that correlates Spectral Mismatch Ratios and atmospheric parameters is proposed. Considering the amount of stations of AERONET network, this model may be used to estimate the spectral influence on energy performance of CPV systems close to all the stations worldwide

Spectral classification of worldwide locations using SMR indexes

Spectral variation of solar irradiance can be analyzed by the means of component cells, being useful for multi junction (MJ) and concentrator photovoltaics (CPV) characterization by the use of component cells derived spectral indexes, namely, spectral matching ratios (SMRs). When enough spectral data is available, a location can be also characterized and a MJ solar cell can be locally tuned. The AERONET network of ground-based sun photometers is employed to obtain the atmosphere parameters for 34 sites worldwide. To conclude, the SMR indexes are obtained for every location, and a comparative analysis is completed for four architectures of MJ solar cells technologies (two lattice match and two metamorphic). Based on this information, some cluster of locations that share similar spectral features arise

Evaluation of misalignments within a concentrator photovoltaic module by the module optical analyzer: a case of study concerning temperature effects on the module performance

Instituto de Energía Solar, Universidad Politécnica de Madrid (IES-UPM) has developed a method [referred to as the luminescence inverse (LI) method] and equipment [called module optical analyzer (MOA)] to fast measure the optical-angular properties of a CPV module without illumination system nor module movement. This paper presents how the MOA can investigate the optical performance of concentrator photovoltaic (CPV) modules optical-angular performance (in particular, misalignments between the optical components comprising the module) at different temperature conditions

Development of a full hybrid lighting-CPV prototype and savings in a real case operation

A full Hybrid lighting-CPV prototype has been assembled. This new concept mixes a classical CPV module with the production of light for illumination without a double conversion (solar energy to electricity and electricity to light) allowing a higher efficiency to the whole system. The present prototype is based on a commercial CPV module that has been adapted in order to be hybrid, adjusting the receivers to pass the fibers into the module, inserting a holder to adjust x,y and z position of the fibers and changing the original parquet of lenses by a bifocal one composed most of the original lenses and the inclusion of other lenses in the position of the corners. Results show that with a minimal loss in the CPV part, a luminous flux is obtained that can be used to illuminate. Adding an additional electrical lamp and a light sensor that enables this lamp when no light from the sun is received, a 38% saving on lighting electricity is expected in Madrid during a year

Characterization of CPV arrays based on differences on their thermal resistances

Thermal characterization of Concentrating Photovoltaics (CPV) modules and Arrays is needed to determine their performance and modelling of energy forecast. Module-ambient thermal resistance is easily obtained from its definition but the cell-module thermal resistant needs to be estimated from indirect procedures, two of them are presented in this paper. In addition, an equivalent parameter is defined, the Concentrator Nominal Operating Module/Cell Temperature (CNOMT/CNOCT), the temperature at Concentrator Standard Operating Conditions (CSOC). Definitions and expression to relate (CNOMT/CNOCT) to thermal resistances are presented, plus several examples of estimations from real operating arrays

A novel achromatic Fresnel lens for high concentrating photovoltaic systems

In this paper we present a novel manufacturing method to produce achromatic Fresnel lenses for photovoltaic application. These achromatic lenses are capable of reaching a concentration factor three times higher than that attained by a conventional Silicone-on-Glass (SOG) Fresnel lens. The manufacturing method presented to fabricate the achromatic lens, which we refer to as Achromatic Doublet on Glass (ADG) Fresnel lens, is simple, cost-effective and highly scalable. A comprehensive ray-tracing analysis and its comparison with experimental results is presented in this work

Spectrum Controlled Solar Simulation for Factory Testing of CPV modules

The validity of a solar simulator for concentrator PV modules is assessed through a comprehensive characterization of its illumination system: irradiance level and uniformity at the receiver, light collimation and spectral distribution. Methods for adjusting and characterizing the spectrum are described and applied, and a more meaningful way of comparing it with the reference spectrum is proposed, by means of the measurement of component (‘isotype’) solar cells

Experiences with European Low-Concentration PV

Esta Conferencia se impartió en el "5th ICSC5 International Conference" celebrado en Palm Desert en Noviembre del 2008. Su objetivo es realizar una revisión de todas las experiencias que se han llevado a cabo en Europa con Sistemas fotovoltaicos de baja y media concentración

Experimental analysis of a photovoltaic concentrator based on a single reflective stage immersed in an optical fluid

This article reviews all the experimental tests carried out to analyze the performance of a FluidReflex photovoltaic concentrator. This novel concentrator concept consists of a single reflective stage immersed in an optical fluid. The presence of the fluid entails significant advantages. It not only allows a high system optical efficiency and increases the attainable concentration but also enhances the heat dissipation from the cell. In addition, the electrical insulation is improved, and the problem of water vapor condensation inside the module is avoided. A complete characterization is addressed in this paper. Among the experimental results, a measured optical efficiency of 83.5% for a concentration of 1035× stands ou