Solar power has received great interest recently as a renewable energy solution capable of providing energy independence and environmental stability while beginning to deliver power at a competitive price. Because of high costs relative to other energy generation technologies, solar power currently satisfies only a small fraction of the world’s energy need. Government support and private investments have led to a boom of technical advances over the past years that have continued to drive solar power toward eventually being a mainstream source of power.
Solar technologies fall primarily into two broad categories: photovoltaics (PV), which convert solar radiation directly into electricity, and concentrating solar power (CSP). CSP uses optical elements to focus the Sun’s energy, heating a liquid as part of a heat engine, to generate electricity. Once the Sun’s light is focused, it can heat an intermediate material, which can be used to drive a turbine to generate electricity. Concentrated photovoltaics also concentrate the Sun’s radiation, but not to the same extent that CSP does. With CPV, the light is concentrated so that high-efficiency solar cells can be used without there being too much concern about cell cost. The cost of the concentrating optics must of course be considered.
With current solar cells, the temperature of the cells must be kept near room temperature in order to maintain high efficiency, and so an efficient heat removal process must be used. CPV solar cells have been measured at 1,000 Suns concentration and 43 percent efficiency, and it is anticipated that at least 2,000 Suns concentration can be used, although it may cost some conversion efficiency.
Despite the rapid growth in installed capacity, photovoltaics are still expected to provide for only a small part of the world’s energy demand. As a point of comparison, the total electricity generated in the United States over the last few years has ranged from about 300-400 gigawatts while the total worldwide photovoltaic capacity in 2016 was only 303 gigawatts. (A gigawatt is equivalent to 1,000,000 kilowatts.) This represents 1.8% of electricity demand on the planet.
Photo Courtesy U.S. Air Force
Related Courses found in the B.S. in Photonic Science and Engineering Program at UCF:
This course describes the physical principles that determine how rays behave at various interfaces. These principles are then used to model simple optical systems with varying degrees of fidelity. Natural optical phenomena (rainbows, mirages, total-internal reflection) and classic optical systems (prisms, telescopes, cameras) are analyzed. Linear systems are introduced to analyze more complex optical systems. This course provides the fundamentals needed for optical engineering and optical system design.
This course introduces students to solid-state electronic devices. Students will learn about energy band diagrams, device physics and models of PN junctions, bipolar transistors, MOS structures, MOS field effect transistors, and other devices.
The course includes a description of the interaction of light with semiconductor materials in a p-n junction configuration, the phenomena of absorption, electroluminescence, and stimulated emission. The distinction between direct and indirect compound semiconductors materials is noted. Includes photodiodes, light emitting diodes (LEDs), semiconductor optical amplifiers, and laser diodes. Array detectors, including complementary metal-oxide-semiconductor (CMOS) and charge-coupled devices (CCD) arrays, and array LEDs are included. Basic specifications and applications of each of these devices are described, including solar cells, imaging with array detectors, and LED displays.
This class consists of analysis of optical systems consisting of lenses, mirrors, and apertures. Image plane, principal planes, and entrance and exit pupils. Magnification, field of view, F-number, image-plane irradiance. Assessment of image quality resulting from diffraction and geometrical and chromatic aberrations, using optical design software. Analysis and design of photonic systems including systems consisting of waveguides and integrated-optic components. Fidelity and noise in optical systems. Numerical simulation using photonic design software.