Greenhouse Solar Thermal Application

This chapter includes brief description of different solar thermal applications of greenhouse structure based on the different research work done in this area. It provides the basic knowledge of the use of solar energy to increase the production of different agricultural products using greenhouse system, e.g., crop production and drying of agricultural products. The chapter includes the introduction of greenhouse system, the definition, the concept, and the importance of greenhouse technology. The uses of various solar thermal applications in different greenhouse systems such as flat plate collector in greenhouse fish pond system and application of photovoltaic system in greenhouse drying are covered in this chapter.

Artificial Intelligence Techniques for Solar Energy and Photovoltaic Applications

Artificial intelligence (AI) techniques play an important role in modeling, analysis, and prediction of the performance and control of renewable energy. The algorithms employed to model, control, or to predict performances of the energy systems are complicated involving differential equations, large computer power, and time requirements. Instead of complex rules and mathematical routines, AI techniques are able to learn the key information patterns within a multidimensional information domain. Design, control, and operation of solar energy systems require long-term series of meteorological data such as solar radiation, temperature, or wind data. Such long-term measurements are often non-existent for most of the interest locations or, wherever they are available, they suffer of a number of shortcomings (e.g. poor quality of data, insufficient long series, etc.). To overcome these problems AI techniques appear to be one of the strongest candidates. The chapter provides an overview of commonly used AI methodologies in solar energy, with a special emphasis on neural networks, fuzzy logic, and genetic algorithms. Selected AI applications to solar energy are outlined in this chapter. In particular, methods using the AI approach for the following applications are discussed: prediction and modeling of solar radiation, seizing, performances, and controls of the solar photovoltaic (PV) systems.

Image Processing for Solar Cell Analysis, Diagnostics and Quality Assurance Inspection

Image capturing, processing, and analysis have numerous uses in solar cell research, device and process development and characterization, process control, and quality assurance and inspection. Solar cell image processing is expanding due to the increasing performance (resolution, sensitivity, spectral range) and low-cost of commercial CCD and infrared cameras. Methods and applications are discussed, with primary focus on monocrystalline and polycrystalline silicon solar cells using visible and infrared (thermography) wavelengths. The most prominent applications relate to mapping of minority carrier lifetime, shunts, and defects in solar cell wafers, in various stages of the manufacturing process. Other applications include measurements of surface texture and reflectivity, surface cleanliness, integrity of metallization lines, uniformity of coatings, and crystallographic texture and grain size. Image processing offers the capability to assess large-areas (> 100 cm2) with a non-contact, fast (~ 1 second), and modest cost. The challenge is to quantify and interpret the image data in order to better inform device design, process engineering, and quality control. Many promising solar cell technologies fail in the transition from laboratory to factory due to issues related to scale-up in area and manufacturing throughput. Image analysis provides an effective method to assess areal uniformity, device-to-device reproducibility, and defect densities. More integration of image analysis from research devices to field testing of modules will continue as the photovoltaics industry matures.

Materials Characterization Techniques for Solar Cell Devices

Characterization of an issue provides the required information to determine the root cause of a problem and direct the researcher towards the appropriate solution. Through the explosion of nanotechnology in the past few years, the use of sophisticated analytical equipment has become mandatory. There is no one analytical technique that can provide all the answers a researcher is looking for. Therefore, a large number of very different instruments exist, and knowing which one is best to employ for a specific problem is key to success.

Nanotechnology and Polymer Solar Cells

In response to environmental concerns there is a drive towards developing renewable, and cleaner, energy technologies. Solar cells, which harvest energy directly from sunlight, may satisfy future energy requirements, but photovoltaic devices are currently too expensive to compete with existing fossil fuel based technologies. Polymer solar cells, on the other hand, are cheaper to produce than conventional inorganic solar cells and can be processed at relatively low temperatures. Furthermore, polymer solar cells can be fabricated on surfaces of arbitrary shape and flexibility, paving the way to a range of novel applications. Therefore, polymer solar cells are likely to play an important role in addressing, at least in some small part, man’s future energy needs. Here, the physics of polymer photovoltaics are reviewed, with particular emphasis on the computational tools which can be used to investigate these systems. In particular, the authors discuss the application of nanotechnology in self-assembling complex nanoscale structures which can be tailored to optimize photovoltaic performance. The role of computer simulations, in correlating these intricate structures with their performance, can not only reveal interesting new insights into current devices, but also elucidate potentially new systems with more optimized nanostructures.

Nanoparticle Scattering, Absorption, and Interface Effects for Surface Plasmon Enhanced Thin Silicon Solar Cells

Recently, surface plasmons have been employed in a variety of methods to increase the efficiency of solar cells. Surface plasmons are oscillations of electrons that arise from surface effects of light interaction with materials that have appreciable free carrier densities; their resonance is confined to a region that depends on the dielectric response of the medium. It has been observed that noble metals exhibit this resonance within visible- near IR range, making them an attractive candidate for silicon solar cells whose primary absorption bands are in this region. Research in silicon-based plasmonic solar cells has utilized the high scattering cross section and favorable angular distributions of noble metal nanoparticle-scattered radiation to increase absorption of thin silicon devices, which are normally weakly absorbing for photons of energy below 2 eV. The interaction is subject to interface effects, interferences of scattered and incident radiation, and the dielectric nature of the embedding medium or surface. In addition, perturbations caused by the longitudinal field of the metal nanoparticle may theoretically enhance the direct interband transitions of free carriers near the particle surface, further enhancing the photocurrent. This latter possibility has yet to be fully explored experimentally in crystalline silicon photovoltaics.

Nanotechnology for Photovoltaic Energy

Solar radiation is plentiful and a clean source of power. However, despite the first practical use of silicon based solar cell more than 50 years ago, it has not been exploited to its full potential due to the high cost of electrical conversion on a per Watt basis. Many new kinds of photovoltaic cells such as multi-junction solar cells dye –sensitized solar cells and organic solar cell incorporating element of nanotechnology have been proposed to increase the efficiency and reduce the cost. Nanotechnology, in the form of quantum dots, nanorods, nanotubes, and grapheme, has been shown to enhance absorption of sunlight, makes low cost flexible solar panels and increases the efficiency of photovoltaic cells. The chapter reviews the state of current photovoltaic cells and challenges it presents. It also discusses the use of nanotechnology in the application of photovoltaic cells and future research directions to improve the efficiency of solar cells and reduce the cost.

Power Electronics and Controls in Solar Photovoltaic Systems

The use of renewable energy sources is increasingly being pursued as a supplemental and an alternative to traditional energy generation. Several distributed energy systems are expected to a have a significant impact on the energy industry in the near future. As such, the renewable energy systems are presently undergoing a rapid change in technology and use. Such a feature is enabled clearly by power electronics. Both the solar-thermal and photovoltaic (PV) technologies have an almost exponential growth in installed capacity and applications. Both of them contribute to the overall grid control and power electronics research and advancement. Among the renewable energy systems, photovoltaic (PV) systems are the ones that make use of an extended scale of the advanced power electronics technologies. The specification of a power electronics interface is subject to the requirements related not only to the renewable energy source itself but also to its effects on the operations of the systems on which it is connected, especially the ones where these intermittent energy sources constitute a significant part of the total system capacity. Power electronics can also play a significant role in enhancing the performance and efficiency of PV systems. Furthermore, the use of appropriate power electronics enables solar generated electricity to be integrated into power grid. Aside from improving the quality of solar panels themselves, power electronics can provide another means of improving energy efficiency in PV and solar-thermal energy systems.

Solar Energy Storage

With the urgent need to harvest and store solar energy, especially with the dramatic unexpected changes in oil prices, the design of new generation of solar energy storage systems has grown in importance. Besides diminishing the role of the oil, these systems provide green energy which would help reducing air pollution. Solar energy would be stored in different forms of energy; thermal, electric, hybrid thermal/electric, thermochemical, photochemical, and photocapacitors. The nature of solar energy, radiant thermal energy, magnifies the role and usage of thermal energy storage (TES) techniques. In this chapter, different techniques/technologies for solar thermal energy storage are introduced for both terrestrial and space applications. Enhancing the performance of these techniques using nanotechnology is introduced as well as using of advanced materials and structures. The chapter also introduces the main features of the other techniques for solar energy storage along with recent conducted research work. Economic and environment feasibility studies are also introduced.

Solar Energy Education and Training Programs in the USA

In the past, solar energy education was limited to scientists and engineers who could develop new technologies and conduct research. Later on, a need was recognized to educate those who design and construct buildings, because solar energy applications were well developed for such applications. At present, numerous solar energy applications have been developed. Solar energy is currently used for heating and cooling of buildings, production of electricity for stationary and mobile applications, solar lighting systems, crop drying, water treatment, and environmental cleanup. Given the expanding use of solar energy, there is a need to educate society about solar energy. Thus, solar energy education and training programs should be developed at different educational levels to fulfill this need. Such programs need to recognize the environmental value of solar energy and the life cycle advantages of solar energy systems. This manuscript provides an overview of the status of solar energy education and training in the United States. Though the focus of this chapter is on the solar energy education and training programs provided by the academic institutions in the USA, a short description of non-academic programs is also provided.