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On-grid solar energy in Asia
Published in Subhes C. Bhattacharyya, Routledge Handbook of Energy in Asia, 2018
The flat plate collector is the most common solar thermal technology, but it is only suitable for applications requiring temperatures of the order of up to about 80–85°C. When higher delivery temperatures are required (e.g. typically for electricity generation or for industrial process heat), as the input radiation cannot be increased, the reduction of heat losses could be possible by reducing the surface area of the absorber. In order to do that, an optical device is placed between the radiant source and the absorbing surface. Solar concentrators can be classified into three types: (1) planar and non-concentrating type; (2) line-focusing type that produces a high density of radiation on a line at the focus; (3) and point-focusing type that produces higher density of radiation in the vicinity of a point. Concentrating collectors need to follow the path of the sun during the day and according to the seasons continuously to focus the solar radiation on to the absorber. Likewise, trackers are used to follow the path of the sun in order to maximise the solar radiation incident on the photovoltaic surface. In the one-axis tracking, the array tracks the sun east to west, and so is used mostly with PV systems and with concentrator systems. On the other hand, in the two-axis tracking system, the panel or the concentrator points at the sun at all times.
Photovoltaic technology
Published in Susan Neill, Geoff Stapleton, Christopher Martell, Solar Farms, 2017
Susan Neill, Geoff Stapleton, Christopher Martell
Once the position of the sun is known, the optimal tilt angle and orientation for a PV module can be calculated to maximise the amount of irradiation received. The maximum amount of radiation received at any given time occurs when the sun's rays are perpendicular to the PV modules. While a solar tracker will give the maximum output by ensuring that the modules move with the sun, given the high capital cost and maintenance requirements of tracking technology, it is often not cost-effective. If the modules are to be mounted in a fixed, stationary position then the modules should be tilted at an angle to maximise the average annual output. To achieve this, the modules should be tilted to face the equator during solar noon on the equinoxes. Further details on selecting the optimal tilt angle, and exceptions to this general rule, are given in Chapter 4.
New PV Markets Sustaining Mass Production
Published in Peter F. Varadi, Wolfgang Palz, Michael Eckhart, Allan R. Hoffman, Paula Mints, Bill Rever, John Wohlgemuth, Frank P.H. Wouters, Sun Towards High Noon, 2017
As noted in the introduction, (CPV) uses mirrors and/or lenses to focus sunlight onto solar cells. Because the light is highly concentrated (most systems operate at hundreds of times the level of normal sunlight) specially designed PV cells are used to optimize performance under those conditions. In a concentrated solar cell system the solar cells always have to be at the focal point of the mirror or lens and therefore the system has to continuously track the sun so the sun’s rays are kept perpendicular to the mirror or the lens, which requires a tracking mechanism. The tracker is an electromechanical device, which is programmed to follow the sun keeping the sun’s rays perpendicular to the system.
Natural cooling of two axis tracking photovoltaic module
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Sun tracking is known to increase the power output for PV solar power systems depending on the geographic location. Typically, a single axis tracker would increase power output by 26%, while a dual axis tracker increases power by 32%. Single axis trackers follow the sun from east to west, while the two axes trackers track the sun altitude (up/down) as well. For a fixed solar PV panel, there is significant power lost during the day because the PV panel is not kept perpendicular to the sun’s rays. A tracking system persists to keep the angle of incidence within a certain margin and would be able to maximize the power generated. A stationary or fixed PV panel will observe a modest efficiency under operating conditions, while solar tracking has been known to greatly increase the efficiency under the same operating conditions (Abdolzadeh and Mehrabian, 2012; Solar Facts and Advice 2012; Khatib et al. 2015).
Techno-economic analysis of solar tracker-based hybrid energy systems in a rural residential building: A case study in South Africa
Published in International Journal of Green Energy, 2023
Xiaojing Liu, Qinyi Tan, Yitong Niu, Reza Babaei
In this regard, PV tracker techniques are utilized to harvest solar energy properly. It keeps the optimum position of the PV collector during daylight hours for gaining higher energy (Sidek et al. 2017). The tracking motion can be around one axis (single-axis tracker) or two axes (dual-axis tracker). Dual-axis tracking technologies are more efficient than single-axis tracking systems. Although, this benefit results in increased investment and complication (Sumathi et al. 2017), (Akbar, ISiddiq, and Aziz 2017). The prior studies have investigated the technical, financial, and environmental features of various tracking options in hybrid power systems in multiple areas. Table 1 represents studies on optimal sizing and feasibility analysis of PV tracking technologies worldwide.
Design of FOPID Controller Using BBBC via ZN Tuning Approach: Simulation and Experimental Validation
Published in IETE Journal of Research, 2022
A solar tracker is used to track the position of the sun across the sky to compensate the error between the sun position and the payload, thereby maximising solar energy output. Solar trackers can be categorised into single-axis and dual-axis solar tracker. In a single-axis tracking system, the tilt angle is fixed and azimuth angle is varied throughout the day, whereas in a dual-axis tracking system both the tilt angle and the azimuth angle are varied. In this work, optimal FOPID is designed for the position control of a dual axis solar tracker by using the proposed approach. Both the tilt angle and azimuth angle are controlled by DC motors and the control of the motors is implemented by FOPID controller which is tuned using BBBC algorithm. We also assume similar type of DC motors for both the axes of a solar tracker.