For decades, solar-cell efficiencies have remained below the thermodynamic limits. However, new approaches to light management that systematically minimize thermodynamic losses will enable ultrahigh efficiencies previously considered impossible.

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Photonic design principles for ultrahigh-efficiency photovoltaics

The use of solar energy in recent years has reached a remarkable edge. The continuous research for an alternative power source due to the perceived scarcity of fuel fossils is its driving force. It has become even more popular as the cost of fossil fuel continues to rise. The earth receives in just 1 h, more energy from the sun than what we consume in the whole world for 1 year. Its application was proven to be most economical, as most systems in individual uses requires but a few kilowatt of power. This paper reviews the present day solar thermal technologies. Performance analyses of existing designs (study), mathematical simulation (design) and fabrication of innovative designs with suggested improvements (development) have been discussed in this paper.

A review of solar thermal technologies

Global energy demand and environmental concerns are the driving force for use of alternative, sustainable, and clean energy sources. Solar energy is the inexhaustible and CO2-emission-free energy source worldwide. The Sun provides 1.4 � 10 5 TW power as received on the surface of the Earth and about 3.6 � 10 4 TW of this power is usable. In 2012, world power consumption was 17 TW, which is less than 3.6 � 10 4 TW. Photovoltaic (PV) cells are the basic element for converting solar energy into electricity. PV cell technologies, energy conversion efficiency, economic analysis, energy policies, environmental impact, various applications, prospects, and progress have been comprehensively reviewed and presented in this paper. This work compiles the latest literature (i.e. journal articles, conference proceedings, and reports, among others) on PV power generation, economic analysis, environmental impact, and policies to increase public awareness. From the review, it was found that PV is an easy way to capture solar energy where PV based power generation has also rapidly increased.

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Global Prospects, Progress, Policies and Environmental Impact of Solar Photovoltaic Power Generation

With the aim of utilizing the infrared region of solar radiation to improve solar cell performance, significant progress, including theoretical analysis and experimental achievement, has been made in the field of up-conversion for photovoltaic applications. This Research News article reviews recent progress in the development of rear-earth (RE) ion doped up-conversion materials for solar cell applications. In addition, new trends for RE-ion-doped phosphors are briefly discussed, among them trivalent RE-ion-doped up-conversion materials for organic solar cell applications.

Rare-earth ion doped up-conversion materials for photovoltaic applications.

Performance of a concentrating photovoltaic/thermal solar collector

In this work, the temperature sensitivities of field-aged multicrystalline silicon PV modules affected by microcracks are investigated. It is found that the temperature coefficient of efficiency of all modules has increased more than 10 times over the 20 years period, mainly due to a degradation in the temperature coefficients of fill factor. Temperature coefficient of efficiency of PV modules affected by microcracks changed from -0.44 %/ °C to -1.51 %/°C under solar irradiance conditions at 1010 - 1030 W/m2. Inconsistent values for the Evans–Floschuetz efficiency ratio versus temperature plots for the microcrack affected modules were also observed.

Temperature profiles of field-aged multicrystalline silicon photovoltaic modules affected by microcracks

The National Solar Energy Centre (NSEC), located at the CSIRO Energy Technology headquarters in Newcastle, features the largest concentrating central receiver system in the Southern Hemisphere. This paper discusses simulation and optimisation efforts associated with optical aspects of the solar tower system, and show by example how these efforts have been used as a design and research tool at the NSEC. Results from ray tracing simulations are compared with measured flux density data achieved as part of a collaborative project with the German Aerospace Centre (DLR). The flux measurement system is an important contribution to the centre’s research capabilities, providing reliable and accurate solar radiation data as a basis for the scientific evaluation of solar conversion materials and processes being investigated for solar gas and hydrogen production at the NSEC.

Ray Tracing and Flux Mapping as a Design and Research Tool at the National Solar Energy Centre

In Smart Village Skarpnes in southern Norway, five detached houses are designed as zero energy homes. This work reports on the photovoltaic (PV) power production and energy consumption behavior of these homes and discusses whether an annual zero energy budget may be achieved. Results so far indicate that the extremely low annual energy consumption assumed for these types of homes may be difficult to achieve, and also point at a need for better matching between production and consumption power profiles. Performance results are based on monitoring data combined with estimated performances from PVsyst simulations. The work is part of a larger research project that investigates how the introduction of low-energy buildings equipped with PV systems is expected to change the power flow to and from the grid, which will require new models for efficient operation and investment in the future electric distribution grid.

Performance of zero energy homes in smart village skarpnes

The present invention provides a method of fabricating a receiver for radiation. The method comprises the step of determining a distribution of the radiation from at least one radiation concentrator that in use illuminates a receiving surface of the receiver. The method also comprises the step of selecting a shape for the receiving surface so that in use the receiving surface is more evenly illuminated by the or each radiation concentrator than a flat receiving surface. The present invention also provides a receiver for radiation that is in use substantially evenly illuminated.

A receiver for radiation

Aerial inspection of solar modules is becoming increasingly popular in automatizing operations and maintenance in large-scale photovoltaic power plants. Current practices are typically time-consuming as they make use of manual acquisitions and analysis of thousands of images to scan for faults and anomalies in the modules. In this paper, we explore and evaluate the use of computer vision and deep learning methods for automating the analysis of fault detection and classification in large scale photovoltaic module installations. We use convolutional neural networks to analyze thermal and visible color images acquired by cameras mounted on unmanned aerial vehicles. We generate composite images by overlaying the thermal and visible images to investigate improvements in detection accuracy of faint features related to faults on modules. Our main goal is to evaluate whether image processing with multi-wavelength composite images can improve both the detection and the classification performance compared to using thermal images alone. The hypothesis is that fusion of images acquired at different wavelengths (i.e., thermal infrared, red, green, and blue visible ranges) would enhance the multi-wavelength representation of faults and thus their histogram feature signatures. The results showed a successful detection and localization of faint fault features using composite images. However, the classification of the fault categories did not show significant improvements and needs continued investigation. This research represents a step towards the design of robust automated methods to improve fault detection from airborne images. Further work is still necessary to reach a classification accuracy comparable with the performance of human experts.

Anne Gerd Imenes

Papers

Temperature profiles of field-aged multicrystalline silicon photovoltaic modules affected by microcracks

Ray Tracing and Flux Mapping as a Design and Research Tool at the National Solar Energy Centre

Performance of zero energy homes in smart village skarpnes

A receiver for radiation

A Deep Learning Approach for Automated Fault Detection on Solar Modules Using Image Composites