waves, and light which is produced by photons. Solar energy is the main source of most of the other forms of energy available on the Earth. The solar energy is directly or indirectly converted into other forms of energy, e.g. electrical energy produced through photovoltaic (PV) technologies.
The most important feature of solar energy is that it is clean and does not harm the environment. In the long run, PV power plants will make a significant contribution to the supply of primary energy in all sectors including domestic, commercial, industrial, and transportation consumers. Moreover, factors such as government support, price of fossil fuels, cost of gas emissions CO2, and costs of PV plant equipment affect the growth of PV plant installation capacity [1].
Figure 1.1 shows the energy conversion cycle. It shows that fossil fuels and the renewable energy sources such as biomass, wind and solar energy originate from the sun. The solar energy is stored in chemical bonds through photosynthesis of plants and produces fossil fuels millions of years later.
This book provides an overview of all aspects of designing a large‐scale PV power plant (LS‐PVPP) for the solar energy professionals and the university researchers. The book particularly focuses on the design of all equipment of a large‐scale PV plant from the basic to advanced parts.
1.2 Diverse Solar Energy Applications
Solar energy is used for two groups of applications: non‐power plant and power plant. Figure 1.2 shows various applications of solar energy [2]. Based on Figure 1.2, solar power plants are divided into three categories: solar thermal; PV thermal hybrid; and PV.
Figure 1.1 Energy conversion cycle.
Source: Modified from Twidell and Weir [1].
1.2.1 Solar Thermal Power Plant
In a solar thermal power plant, the solar energy is converted into thermal energy which is then converted into electrical energy. Figure 1.3 shows various types of solar thermal power plants as explained below [3].
1 Parabolic PlantThe parabolic plant has a linear parabolic collector consisting of few rows of parabolic reflectors. The reflectors absorb the reflected rays of solar radiation and warm up the heat transfer fluid.
2 Central Receiver PlantThe central receiver plant consists of a set of mirrors, where each separately concentrates solar energy and transmits it to a central receiver tower.
3 Parabolic Dish PlantIn a parabolic dish plant, the sun's rays reflected on a parabolic surface are concentrated at a focal point. The thermal energy is converted into mechanical energy by a Stirling engine. An electric generator converts the mechanical energy into the electrical energy.
4 Solar Chimney PlantIn a solar chimney plant, a combination of solar air collectors and air conduction towers are used to produce induced air currents. The currents provide mechanical forces in order to rotate a pressure step turbine coupled to a generator to produce electricity.Figure 1.2 Various solar power plant categories.Source: Dincer and Abu‐Rayash [2].Figure 1.3 Various applications of solar thermal energy: (a) Parabolic plant, (b) Central receiver plant, (c) Parabolic dish plant, (d) Solar chimney plant, and (e) Fresnel collector plant.Source: Modified from González‐Roubaud et al. [3].
5 Fresnel Collector PlantThe Fresnel collector plant includes flat mirror collectors with low width and long length that collect the incoming sunlight on the concentrator and send it to a receiver tube. The receiver tube heats up the fluid inside the tube.
1.2.2 PV Thermal Hybrid Power Plant
The PV thermal hybrid power plant consists of a combination of PV panels and a solar thermal collector. The PV panels convert the solar radiation into electrical energy. The solar thermal collector absorbs remaining energy of the solar rays and also removes wasted heat from the panels.
1.2.3 PV Power Plant
In a PV power plant, the sun's radiant energy is directly converted into electrical energy. There are two categories of PV power plants: conventional and concentrated. Unlike the conventional plants, the concentrated PV plants employ curved lenses or mirrors to focus sunlight on high‐efficiency PV cells. A concentrated plant has a solar tracker and a cooling system, in some cases, to further increase the plant efficiency.
Depending on the application, PV power plants are divided into five categories as briefly explained below.
1 Grid‐connected PV Power PlantPV power plants are usually connected to the local power network. The schematic diagram of a grid‐connected PV plant is shown in Figure 1.4. For the grid‐connected PV plant, the generated electricity is either consumed immediately by local loads or is sold to electricity supply companies. The local loads may include commercial and/or industrial consumers.For the grid‐connected PV plant, the grid acts as an energy storage system and, therefore, there is no need to have battery storage. In the evenings, when the PV plant is unable to produce power, the required electricity can be purchased back from the power network [4].
2 Stand‐alone PV Power PlantThe stand‐alone PV plants are used in the remote areas that have no access to the power grid. A stand‐alone PV plant operates independent of the grid, with part of the produced energy stored in energy storage systems such as batteries. A schematic diagram of a stand‐alone PV plant is shown in Figure 1.5. A stand‐alone PV plant includes PV modules, an inverter, batteries, and a charge controller. The inverter converts the direct current generated by the PV modules to the alternating current for AC applications. The PV plant can supply both the DC and AC loads [4].
3 Direct‐coupled PV Power PlantIn a direct‐coupled PV plant, the PV array is connected directly to the load. The schematic diagram of a direct‐coupled PV plant is shown in Figure 1.6. The load can operate only when there is solar radiation and, therefore, the plant has limited applications. An application of this type of plant is water pumping, where the load operates as long as sunshine is available, and instead of storing the electrical energy, water is usually stored [5].Figure 1.4 Schematic diagram of a grid‐connected PV plant.Source: Modified from Vázquez and Vázquez [4].Figure 1.5 Schematic diagram of a stand‐alone PV plant.Source: Modified from Vázquez and Vázquez [4].Figure 1.6 Schematic diagram of a direct‐coupled PV plant.Source: Modified from Kalogirou [5].
4 Hybrid‐connected PV Power PlantIn the hybrid‐connected PV plant, more than one type of generator is employed. In this type of power plant, one of the generators is a PV plant. The
