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Copyright of Piezoelectrics & Acoustooptics is the property of Piezoelectric & Acoustooptic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • Optimal PV system row spacing presented considering land-use and latitudes 15–75°N. • Latitude-based formulae given for optimum tracked, fixed-tilt, and vertical spacing. • Optimum tilt of fixed-tilt arrays can vary from 7° above to 60° below latitude-tilt. • Similar row spacing should be used for tracked and fixed-tilt PV arrays >55°N. • Bifacial arrays need up to 0.03 lower GCR than monofacial, depending on bifaciality. General guidelines for determining the layout of photovoltaic (PV) arrays were historically developed for monofacial fixed-tilt systems at low-to-moderate latitudes. As the PV market progresses toward bifacial technologies, tracked systems, higher latitudes, and land-constrained areas, updated flexible and representational guidelines are required. Using our 3D view-factor PV system model, DUET, we provide formulae for ground coverage ratios (GCRs –i.e., the ratio between PV collector length and row pitch) providing 5%, 10%, and 15% shading loss as a function of mounting type and module type (bifacial vs monofacial) between 17-75°N. Fixed-tilt arrays span a wide range of GCR (0.15–0.68, 5% loss) compared to single-axis tracked arrays (0.17–0.32) and vertical east–west arrays (0.11–0.16). We additionally optimize fixed-tilt module tilt, finding that the optimum tilt can vary from 7° above latitude-tilt to 60° below latitude-tilt in certain cases. We demonstrate that tracked and fixed-tilt PV arrays should have similar GCRs >55°N, but tracked systems are more sensitive to row-to-row shading losses <55°N. The GCR of fixed-tilt arrays at lower latitudes can reach 0.55 without introducing >2.5% shading loss, whereas tracked and vertical arrays reach 2.5% shading loss by GCRs <0.22 and <0.10, respectively. We additionally find that bifacial PV arrays require GCRs up to 0.03 lower than monofacial GCRs. These results can inform future deployment designs for latitudes >15°N. [ABSTRACT FROM AUTHOR]

Energi listrik merupakan komoditas utama yang digunakan oleh hampir seluruh sektor perekonomian. Oleh karena itu, kebutuhan masyarakat Indonesia akan energi listrik saat ini makin tinggi. Kebutuhan energi listrik yang makin meningkat berbanding terbalik dengan ketersediaan energi fosil dunia yang makin berkurang. Sumber energi dari matahari dapat dimanfaatkan sebagai energi alternatif, baik radiasi maupun termalnya, untuk memenuhi kebutuhan energi listrik sehari-hari. Tujuan penelitian ini adalah untuk mengoptimalkan produksi energi listrik dari panel surya berkapasitas 200 WP dengan merancang dan mengimplementasikan solar tracker system dual axis pada panel surya (photovoltaic). Penelitian ini menggunakan pendekatan campuran (mixed methods), yaitu merancang solar tracker system secara eksperimental dengan mengukur nilai tegangan dan arus pada panel surya, kemudian menghitung daya listrik yang dihasilkan oleh panel surya yang menggunakan kendali solar tracker system. Setelah itu, dilakukan perhitungan daya listrik yang dihasilkan oleh panel surya dan daya listrik yang digunakan (load) solar tracker system untuk mengendalikan pergerakan panel surya mengikuti pancaran sinar matahari. Solar tracker yang dikendalikan dengan single axis menghasilkan rata-rata tegangan 19,72 V, arus 1,34 A, dan daya listrik 26,82 W, sedangkan solar tracker yang dikendalikan dengan dual axis menghasilkan rata-rata tegangan 18,93 V, arus 1,9 A, dan daya listrik 35,76 W. Hasil pengujian menunjukkan bahwa total daya listrik yang dihasilkan panel surya dengan sistem kendali solar tracker system single axis adalah 455,93 W dan solar tracker system dual axis adalah 607,94 W. Data hasil pengujian menunjukkan bahwa solar tracker system dual axis mampu mengoptimalkan produksi energi listrik yang dihasilkan oleh panel surya kapasitas 200 WP.

Copyright of Piezoelectrics & Acoustooptics is the property of Piezoelectric & Acoustooptic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Piezoelectrics & Acoustooptics is the property of Piezoelectric & Acoustooptic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRAK Efisiensi yang rendah pada solar cell dipengaruhi oleh beberapa factor yaitu tingkat radiasi, suhu, dan sudut instalasi. Penelitian ini membahas upaya meningkatkan performa solar panel yaitu dengan menggunakan sistem pelacak surya sumbu tunggal. Dalam penelitian sistem pelacak surya sumbu tunggal ini dimodelkan dengan menggunakan PID controller pada software Matlab Simulink. Dalam metode tracking system, solar cell disimulasikan pada sumbu tunggal yang berorientasi pada sudut elevasi, sebagai masukan dan pengoptimasian kontrol posisi yang tepat terhadap arah pergerakan matahari pada pukul 07.00 – 17.00 wib. Hasil simulasi didapatkan penggunan kontrol PID pada perancangan single axis solar tracking system menunjukkan hasil yang baik, dimana kontroler yang dirancang dapat mendeteksi arah pergerakan matahari dengan cukup akurat. Sudut elevasi terendah yaitu 1,7 derajat dan tertinggi 68,21 derajat. Solar tracking system memiliki potensi menyerap lebih banyak radiasi matahari untuk mendapatkan output lebih baik yang dihasilkan dari solar cell. Kata kunci: solar cell, sumbu tunggal, tracking system, PID controller, Simulink Matlab ABSTRACT The low efficiency of the solar cell is influenced by several aspect, namely radiation levels, temperature, and tilt angle. This research discusses improving solar panels' performance using a single-axis tracking system. This research modelled a singleaxis of solar cell tracking system using a PID controller in Matlab Simulink software. In the tracking system method, the solar cell is simulated on a single axis oriented to elevation angle as input and optimization of precise position control to direct the sun's movement at 07.00 – 17.00 WIB. The simulation results shown that using a PID control in designing a single-axis of solar cell tracking system shows significant results, where the controller design can accurately detect the direction of the sun's movement. Furthermore, the lowest elevation angle is 1.7 degrees, and the highest is 68.21 degrees. Furthermore, solar tracking systems have the potential to absorb more radiation for a greater output of solar cells. Keywords: solar cells, single axis, tracking system, PID controller, Simulink Matlab

This work presents a study in the theoretical and experimental performance of PV cells and tracking surfaces using the isotropic and anisotropic (HDKR) models' simulations for single and dual axis systems. The solar spatial and temporal coordinates are obtained for the experiment site during Julian days throughout the year. From there, further simulations are performed using Typical Meteorological Year (TMY) data to evaluate various incident irradiance parameters on tracking surfaces. Experiments with different systems including fixed, single-axis, and dual-axis systems are conducted and compared with simulation results. The simulation outcomes show a gain in PV power generation of around 6% in the anisotropic system compared to the isotropic model prototype. However, experiments show no difference between both models in dual-axis trackers. By using TMY data for optimization of tracking angles, the dual-axis trackers performance gain is 8.5% in PV power generation compared to single-axis system, and a 37% gain is observed compared to fixed-tilted PV cell. Finally, the tracking systems' optimized angles are not a function of the model used (isotropic/anisotropic) during summer months. [ABSTRACT FROM AUTHOR]

Solar energy is the most feasible source of renewable energy especially in sun rich regions like Africa. In particular, electrically epileptic country like Nigeria with current power output of only about 3.5GW of energy has a relatively long sunny period for about 90% of the year, making Nigeria very rich in solar power. Maximally harnessing solar energy into usable electricity however, is still a fundamental problem as the existing models can harness only about 70% of the available energy. To maximally harness solar energy, a solar panel must be perpendicular to the energy source for all 12hours of sunlight availability, and must be able to follow the sun's movement all day long. Accordingly, this work considers the analysis, construction, and implementation of a single axis solar tracking dynamic system. Experimental result show that the proposed system outperforms the conventional static solar tracking system. [ABSTRACT FROM AUTHOR]

Abstract This paper proposes a discrete single-axis solar tracking system that only actuates three times a day in the azimuthal plane to follow the sun. The preset tracking angles for the system are based on simulation runs for the site with incorporation of weather data to find optimum angles of discrete tracking. Simulation results indicate that there are no significant differences in total solar energy generation when using tracking angles based on either the isotropic or anisotropic models. Moreover, experimental results in the summer season showed that tracking the sun in only three optimized angle movements yielded around 91–94% of solar energy collection as a continuous single-axis solar tracker that moves three times an hour based on solar calculations. Experimental results agree within 11–17% with simulation data. Highlights • The effect of a PV discrete solar tracking technique on system performance and total energy gain compared to an identical single-axis tracking approach. • Discrete and continuous systems tracking angles are obtained from simulations based on typical solar conditions. • Theoretical and experimental results show no significant impact of using either Isotropic or Anisotropic models on the total energy collection of the tracking system. • Experiment results show that implementing a three step per day discrete tracking technique achieves around 91-94% of solar energy collection. • Potential of discrete solar trackers is clearly demonstrated as the number of tracker actuations is reduced dramatically relative to a continuous tracker. [ABSTRACT FROM AUTHOR]

Advanced applications of a tilt sensor, such as in disaster management, requires a system to test the performance of a tilt sensor before being applied in the field. Commercially, Ideal Aerosmith developed various models of two- and three-axis positioning and rate table system with high resolution and accuracy. However, the utilization of the system is more suitable for military and aerospace technologies that require very high resolution and accuracy. The system is therefore expensive and not portable. This paper reports the development of simple single-axis motion table system to provide precise position and motion rate for testing a tilt sensor. The system was developed by using a stepper motor in which the direction of the movement can be set by adjusting the encountered electrical current in the motor. The resolution of stepper motor used in the developed system was 0.9 o /step, whereas various types of tilt sensors and their applications require a tester system with higher resolution. A gears system was employed to improve the stepper motor resolution used in the developed motion table system. Under a certain design of the gears system, the developed motion table system could achieve a higher resolution of 0.018 o /step. It has been found that the relationship between the number of steps of the stepper motor and the rotation angle of the developed motion table system was linear and same for forward and backward steps. Moreover, the developed single-axis motion table system moved consistently for either forward (up) or backward (down) rotations in the range of 0 to 180 o as assessed by the accelerometer-based tilt sensor. The developed single-axis motion table system can therefore be used for testing tilt sensor. [ABSTRACT FROM AUTHOR]

Finding energy sources to satisfy the world's growing demand is one of society's foremost challenges. The paper presents the design, construction and testing of a microcontroller-based, single axis solar panel tracking system, using locally available materials. The tracking system consists of two light sensors and an automated microcontroller to drive the motor and three batteries. Three parameters were considered: solar intensity, voltage and time of alignment/exposure of solar panel to solar radiation. Current and power were obtained and compared with those of a fixed axis solar panel of same specifications. The results indicated an energy surplus of about 30% from the designed tracker. The solar tracker provided a constant alignment, better orientation of the solar panel relative to the sun; and ensured production of more energy by capturing the maximum of sun rays hitting the surface of the panel from sunrise to sunset. It can be concluded that the designed solar tracking system is a sustainable energy solution, at low cost and minimum maintenance requirements. [ABSTRACT FROM AUTHOR]

The aim of this research is to reveal the real energy production over all Prefectures of Greece, produced by a typical medium scale photovoltaic (PV) power plant installed on one-axis and two-axis mounting systems. Previous investigations proved a remarkable difference between real and predicted energy production regarding fixed mounted PV systems. The main scope of this investigation is to further compare the efficiency and the energy produced by one and two axis tracking systems. Real measurements have been collected from more than 40 single and more than 80 dual axis PV plants all over Greece, while these measurements are compared to the simulation results for each corresponding site. It is shown that there is still a significant divergence between real measurements and simulations by known software packages. The produced photovoltaic energy yield maps concerning single and dual axis PV systems can be a powerful tool for potential investors, banks and installers for more accurate predictions of the expected annual energy yield of such PV installations. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 30-year-old male veteran with a traumatic hip disarticulation amputation. He was accordingly asked to perform a timed up and go and 2-minute walk tests upon the delivery of his permanent Helix three-dimensional (3D) hip joint prosthesis. Fifteen weeks after, the same test were consequently done employing an Otto Bock 7E7 single-axis hip joint prosthesis. The subject, however, is noted to have shown improvement with the timed up and go using the Helix 3D.

Abstract: In order to build a first model in single particle electron microscopy the relative angular orientation of each image of a protein complex must be determined. These orientations can be described by three Eulerian angles. Images of complexes that present the same view can be aligned in two-dimensions and averaged in order to increase their signal-to-noise ratio. Based on these averaged images, several standard approaches exist for determining Euler angles for randomly oriented projection images. The common lines and angular reconstitution methods work well for particles with symmetry while the random conical tilting and related orthogonal tilt reconstruction methods work in most cases but require the acquisition of tilt pairs of images. For the situation where views of particles can be identified that are rotations about a single axis parallel to the grid, an alternative algorithm to determine the orientations of class averages without the need to acquire tilt pairs can be applied. This type of view of a complex is usually called a side view. This paper describes the detailed workings and characterization of an algorithm, named rotational analysis, which uses real-space fiducial markers derived from the averages themselves to determine the Euler angles for side views. We demonstrate how this algorithm works in practice by applying it to a data set of images of affinity-purified bovine mitochondrial ATP synthase. [Copyright &y& Elsevier]