Fixed-tilt System Research Articles

Validation of Vertical Bifacial Agrivoltaic and Other Systems Modelling

In agrivoltaic systems combining solar photovoltaic and agricultural activities, ground albedo is mainly characterized by the crop and its seasonal variations. This study examines the effects of using fixed, satellite-derived, and hourly measured albedo on the performance of a vertical bifacial system and a 1-axis tracking system using a bifacial photovoltaic model (AgriOptiCE). The model is developed with Matlab® and partially based on the open-source package pvlib. AgriOptiCE is firstly validated by comparing estimated front and rear irradiances with on-site measurements for specific periods from a 1-axis tracker site in Golden, USA and a vertical agrivoltaic system in Västerås, Sweden. Furthermore, photovoltaic system power output estimations using AgriOptiCE are also validated for the vertical agrivoltaic system and the conventional ground-mounted fixed-tilt system at the same location. The validations demonstrate the high accuracy of the proposed model in estimating front and rear irradiances and power output, obtaining R2 > 0.85 for all the studied cases. The study results indicate that measured albedo provides the highest accuracy, while satellite-derived albedo has poorer results due to the broader spatial, temporal, and spectral resolution. Fixed albedo is not recommended for yearly assessment of bifacial PV systems because it cannot account for snow events and daily variations, resulting in lower overall accuracy.

Technical-economic evaluation of various photovoltaic tracking systems considering carbon emission trading

Renewable energy generation plays a crucial role in mitigating global climate change and achieving carbon peak and carbon neutrality targets. Photovoltaic (PV) power is an important component of renewable energy generation. With China's commitment to meet its dual carbon targets on time, the application of PV tracking systems, which significantly increase the amount of PV power generated, has become a trend for the future. However, the suitability of PV tracking systems varies significantly between regions. This paper aims to assess and compare the technical and economic performance of PV systems using different PV tracking systems in six different latitude regions in China under the consideration of carbon trading. By utilizing the PVsyst software, the monthly/yearly unit electricity generation of different tracking systems in each region is calculated. Furthermore, the technical and economic performance of these systems is assessed by computing the levelized cost of electricity (LCOE), net present value (NPV), and discounted payback period (DPP) with and without carbon benefits, taking into account sensitivity analyses. The results indicate that the dual-axis tracking (DAT) system achieves the highest electricity generation, providing a gain of 17.94 %–31.52 % compared to the fixed-tilt (FT) system. The horizontal axis tracking North-South (HATNS) system and the tilted-axis tracking (TAT) system are probably the most economically viable systems in areas with high radiation levels, with NPV values 2.02 %–25.55 % and 6.44 %–19.45 % higher, respectively, compared to the FT system. The introduction of carbon benefits significantly increases the economic viability of all tracking systems.

Clear-sky detection for PV degradation analysis using multiple regression

A method is presented to detect clear-sky periods for plane-of-array irradiance time-averaged data that is based on the algorithm originally described by Reno and Hansen. We show this new method improves the state-of-the-art by providing accurate detection at longer data averaging intervals. Moreover, our new method detects clear periods in plane-of-array data, which is novel. The new method is developed by applying a Design of Experiment approach to optimize the parameters used in the Reno method, and Monte Carlo simulations are used to understand the robustness of the found parameters. Clear-sky detection accuracy is compared among four methods: the Reno method, the default clear-sky filter in RdTools, the Ellis method, and the method outlined in this work, using a hand-labeled two-year data set of 1-min plane-of-array irradiance for a fixed tilt system. The RdTools clear-sky filter is marred by excessive false positives. The other methods all perform well at 1-min data intervals; the method developed here provides more accurate detection at longer data averaging intervals. We show that the parameters are directly linked to the data frequency in the hope that these input variables may not have to be optimized for every data frequency and location. However, only a single fixed system in one location was carefully examined. Finally, we illustrate how accurate determination of clear-sky conditions helps to eliminate data noise and bias in the assessment of long-term performance of PV plants.

Techno-economic comparative study of grid-connected PV/reformer/FC hybrid systems with distinct solar tracking systems

The purpose of this study is to analyze and compare the techno-economic performance of grid-connected Hybrid Energy Systems (HES) consisting of Photovoltaic (PV) and Reformer Fuel-Cell (RF-FC) using different types of solar PV tracking techniques to supply electricity to a small location in the City of Chlef, Algeria. The PV tracking systems considered in this study include fixed facing south at four different angles (32°, 34°, 36°, 38°), horizontal-axis with continuous adjustment, vertical-axis with continuous adjustment and a two-axis tracking system. The software tool HOMER Pro (Hybrid Optimization of Multiple Energy Resources) is used to simulate and analyze the technical feasibility and life-cycle cost of these different configurations. The meteorological data, consisting of global solar radiation and air temperature, used in this study was collected from the geographical area of the City of Chlef during the year 2020. This study has shown that the optimal design of a grid-connected hybrid PV/RF-FC energy system with Vertical Single Axis Tracker (VSAT) leads to the best economic performance with low values of Net Present Cost (NPC), Cost of Energy (COE) with a Positive Return on Investment (ROI) and the shortest Simple Payback (SP) period. In addition, from the simulation results obtained, it can be concluded that the Horizontal and Vertical Single-Axis Trackers (HSAT and VSAT) as well as the Dual-Axis Tracker (DAT) are not always cost effective compared to the Fixed Tilt System (FTS). Therefore, it is necessary to carefully analyze the use of each tracker to assess whether the energy gain achieved outweighs the overall shortcomings of the tracker.

Simple thermal-electrical model of photovoltaic panels with cooler-integrated sun tracker

This paper presents a simple thermal-electrical model of a photovoltaic panel with a cooler-integrated sun tracker. Based on the model and obtained weather data, we analyzed the improved overall efficiency in a year as well as the performance in each typical weather case for photovoltaic panels with fixed-tilt systems with a tilt angle equal to latitude, fixed-tilt systems with cooler, a single-axis sun tracker, and a cooler-integrated single-axis sun tracker. The results show that on a sunny summer day with few clouds, the performance of the photovoltaic panels with the proposed system improved and reached 32.76% compared with the fixed-tilt systems. On a sunny day with clouds in the wet, rainy season, because of the low air temperature and the high wind speed, the photovoltaic panel temperature was lower than the cooler’s initial set temperature; the performance of the photovoltaic panel with the proposed system improved by 12.55% compared with the fixed-tilt system. Simulation results show that, over one year, the overall efficiency of the proposed system markedly improved by 16.35, 13.03, and 3.68% compared with the photovoltaic panel with the fixed-tilt system, the cooler, and the single-axis sun tracker, respectively. The simulation results can serve as a premise for future experimental models.

Comparison, evaluation and prioritization of solar photovoltaic tracking systems using multi criteria decision making methods

The purpose of the present study is to evaluate and compare solar tracking systems connected to the grid. The solar systems considered were Fixed Tilt (FT), Vertical Continuous Adjustment (VCA), Horizontal adjustment (Monthly Adjustment (HMA), Continuous Adjustment (HCA)) and Two-Axis (TA) tracking system. Technical, economic and environmental assessment for an industrial consumer in southern Iran was performed by HOMER software. Unlike previous studies, multi-criteria approaches have been used to evaluate solar tracking systems. Due to the economic or technical superiority of each tracking system, solar tracking systems were prioritized using multi-criteria decision-making approaches. SWARA was used to weight criteria and WASPAS, EDAS and ARAS methods were used for prioritization of solar tracking systems. Technical evaluation showed that most of the electricity was generated by the TA and it was 31.8 % more than the FT system. Economic evaluation showed that the minimum LCOE was related to FT and the maximum LCOE was related to horizontal tracking systems (8.8 % more than FT system). Environmental assessment also showed that the reduction of CO2 emissions in the TA system is more than the FT system. This evaluation, taking into account all technical, economic and environmental aspects, showed that the priority of systems in the case study was HMA < HCA < FT < VCA < TA.

Open-Source Design and Economics of Manual Variable-Tilt Angle DIY Wood-Based Solar Photovoltaic Racking System

Fixed-tilt mechanical racking, consisting of proprietary aluminum extrusions, can dominate the capital costs of small-scale solar photovoltaic (PV) systems. Recent design research has shown that wood-racking can decrease the capital costs of small systems by more than 75% in North America. To determine if wood racking provides enough savings to enable labor to be exchanged profitably for higher solar electric output, this article develops a novel variable tilt angle open-source wood-based do-it-yourself (DIY) PV rack that can be built and adjusted at exceptionally low costs. A detailed levelized cost of electricity (LCOE) production analysis is performed after the optimal monthly tilt angles are determined for a range of latitudes. The results show the racking systems with an optimal variable seasonal tilt angle have the best lifetime energy production, with 5.2% more energy generated compared to the fixed-tilt system (or 4.8% more energy, if limited to a maximum tilt angle of 60°). Both fixed and variable wooden racking systems show similar LCOE, which is only 29% of the LCOE of commercial metal racking. The results of this study indicate that the novel variable tilt rack, whether used as a small-scale DIY project or scaled up to fulfill larger energy demands, provides both the lowest cost option even when modest labor costs are included and also may provide specific advantages for applications such as agrivoltaics.

Effect of PV material, texturing, orientation and tracking on glare impact: A simulation study from an Indian airport

There is a growing interest in airport-based solar PV systems. At the same time, there is the possibility of glare from the solar PV array, which is a potential aviation safety issue. This paper's main objective is to estimate the technical solar power potential of an airport and assess glare impact for six different scenarios of PV array. These configurations are smooth glass, smooth glass with Anti-Reflective Coating (ARC), light-textured glass with ARC, a variation of tilt & orientation angle, single-axis tracking, and dual-axis tracking. The potential for a land-based solar PV system is assessed based on vacant area and glare impact. The details of the airport site, solar PV array, and the position of observers are provided for software simulation. The occurrence and duration of glare for each scenario are simulated using ForgeSolar software. The impact of glare is assessed based on a standard set by the Federal Aviation Administration (FAA). The technical potential of solar PV in the selected airport is estimated at 9.8 MW. Among the studied scenarios, the safe value of glare is obtained in Scenario 4 (variation of tilt & orientation angle) and Scenario 5 (single-axis tracking). In Scenario 4120 configurations of tilt and orientation angle adhered to FAA's solar glare policy. It is observed that the variation of tilt and orientation angle resulted in zero minutes of glare in several configurations. However, the energy output of the solar PV array was affected. The single-axis tracking solar PV system is expected to generate 35% higher electricity than the fixed-tilt system. Hence, it is concluded that Scenario 5 is the desired arrangement in terms of glare mitigation and energy output. This work will benefit aviation stakeholders for assessing the solar power potential and deciding suitable glare mitigation measures.

Techno-economic potential assessment of mega scale grid-connected PV power plant in five climate zones of Pakistan

The industrial sector is of great importance for the economic development of any country. The current energy crisis in Pakistan is the major obstacle to its economic growth. Diesel generator is used as reliable backup power source in many industrial and commercial applications during load shedding hours, which increases the cost of energy per kWh and environmental emissions. The grid-connected PV plants increase the share of solar energy in the power grid toreduceenvironmental emissions. The purpose of this study is to analyze and compare the techno-economic assessment of mega-scale grid-connected PV plants for the industrial sector in Pakistan's five climate zones. Based on energy injected into the gird, payback period and GHG emission reduction, a detailed technical, economic, and environmental analysis is conducted by using the PVsyst software. This study concludes that PV plants for all five climatic zones are technically, economically, and environmentally feasible but Quetta (Zone-C) is the most feasible location with the highest annual generation 4441 MWh, highest capacity utilization factor 20.3%, lowest cost of energy 0.026 USD/kWh and lowest payback period 3.2 years for fixed tilt orientation. The designed system has the potential to reduce 39442.5 tCO2 emissions over its lifetime, resulting in a green environment. When compared to a fixed tilt system, the energy produced yearly by a single axis tracking system is 5.7% higher, while the energy produced yearly by a dual axis tracking system is 34.3% higher. Moreover, the validation of simulation results with actual results collected from an installed 2.5 MW solar plant at a cement factory in Fateh Jang (Zone-B), shows that actual plant performance is closely matched with simulation results. This study provides guidelines for researchers and policymakers to identify acceptable location-based PV technologies for the industrial sector.

Optimization of Photovoltaic Array Orientation and Performance Evaluation of Solar Tracking Systems

In recent years, solar energy has received tremendous attention in accordance with the global efforts in moving towards clean energy generation. A solar tracking system shifts the position of solar panel following the Sun's movement, allowing more energy to be harvested. This paper aims to evaluate the performance of solar tracking system in Malaysia, including the east-west single-axis tracking system, north-south single-axis tracking system, vertical axis tracking system, and dual-axis tracking system. The periodical tilt angle adjustment of fixed-tilt photovoltaic system is also investigated to optimize its performance. A mathematical model is formulated to compute the amount of solar radiation collected in a photovoltaic system and the optimization model is solved using genetic algorithm to determine the optimal tilt and azimuth angles for maximum solar radiation yield. Based on the results, PV system with dual-axis solar tracker has 22.14 % more solar radiation collected compared to the fixed-tilt system, while monthly tilt angle adjustment improves the yield by 2.15 %.

Economic Assessment of Photovoltaic-Based Microgrid Incorporated with Solar Tracking System

Solar energy is a major renewable energy source as it is clean and abundant. The solar radiation yield of a PV system can be enhanced by fixing the solar panel at optimal orientation or coupling with a solar tracking system. This study aims to evaluate the cost-effectiveness of incorporating solar trackers into microgrid to improve the energy gain. A mathematical model is formulated for the optimal sizing of microgrid and the model is implemented on a case study with 500 households. The study outcome suggests the feasibility of solar tracking system is greatly dependent on its cost. When the cost of solar tracker is low, east-west single-axis tracking system is the most feasible option, but the fixed-tilt system becomes more feasible when the cost of solar tracker is high. The threshold for east-west single-axis tracking system investment is found to be

The effect of wind direction on the performance of solar PV plants

The impact of wind direction on the overall performance of a utility-scale PV plant was studied by analyzing field data from Hadley solar farm in the UK. The solar PV plant utilizes a fixed-tilt system with the PV panels facing south at a 20 degree angle. The hypothesis is that when wind blows from the south the total power production of the solar PV plant increases in comparison with non-southerly wind events, provided that all other determining factors, such as solar irradiance, ambient temperature, and wind speed are the same. During the case study of January 1 to July 1, 2017, 42 pairs were identified, each of which includes two cases with equal solar irradiance, equal ambient temperature, and equal wind speeds but different wind directions; in one case wind is from the north and in the other one wind blows from the south. The hypothesis was found to be true across all 42 pairs, i.e., the power production of the solar PV plant was always greater in the event of southerly winds. One takeaway from this finding is that wind direction and wind speed frequencies need to be taken into account along with other climatic factors to have an optimal site selection for establishing a solar PV plant. The more frequent the southerly wind occurs, the more power can be extracted from the PV panels. The other practical conclusion of this study is that it is more efficient to build fixed-tilt solar PV plants on areas oriented along the west-east direction.

Relative performance of tracking versus fixed tilt photovoltaic systems in the USA

ABSTRACTTracking systems can increase the amount of electricity generated by photovoltaic (PV) modules, by actively orienting each module to intercept more solar energy. We find that horizontal one‐axis tracking systems can increase PV generation by 12–25% relative to south‐facing fixed mount PV systems with 25° tilts in the contiguous USA, and two‐axis tracking systems can increase PV generation by 30–45% relative to fixed mount systems. Tracking systems increase PV generation more significantly in arid regions such as the southwest USA than in humid regions with persistent cloud cover such as the Pacific Northwest and coastal Atlantic states. We find that fixed and tracking PV systems have similar interannual variability in their generation profiles, and this variability is primarily driven by project location. Tracking PV projects cost more than fixed tilt systems, per unit capacity, and we explore how much more tracking projects could cost while generating similar levelized costs of energy as fixed tilt systems. We define this as the breakeven additional cost of tracking and find that it is primarily driven by three factors: (i) regional tracking performance, (ii) fixed tilt system costs that tracking projects compete against, and (iii) additional tracking operation and maintenance costs. Using this framework, we explore the relative competitiveness of tracking systems for a range of fixed and tracking PV prices and evaluate how tracking competitiveness varies by region. Copyright © 2013 John Wiley &amp; Sons, Ltd.

Energy Yield of Tracking PV Systems in Jordan

This paper analyzes the energy yield of photovoltaic (PV) modules mounted on fixed tilt, one-axis, and two-axis tracking system towards maximizing the annual energy production. The performance evaluation of the proposed design of the tracking systems is carried via simulating the global radiation averages using METEONORM software and depicting the simulation results in figures using MATLAB software. The one-axis system is simulated by either fixing the azimuth angle while optimizing the inclination angles or fixing the inclination angle while optimizing the azimuth angles; simulation results show an increase in energy yield of 5.87% and 20.12% compared to that of fixed tilt system, respectively. In the two-axis system, optimization of both azimuth and inclination angles is carried out simultaneously which resulted in 30.82% improvement in energy yield. Therefore, 30% improvement in energy yield is directly reflected as saving in PV system cost due to reduction of the PV modules surface area.