Large Installations Research Articles

The long‐term influence of wind and temperature on performance and degradation within an utility‐scale photovoltaic plant

AbstractAn inverter‐level analysis of a large photovoltaic (PV) plant is evaluated over four years to investigate the long‐term performance and degradation caused by wind and temperature effects. The multi‐megawatt utility‐scale PV plant is located in a semi‐arid region in South Africa. The degradation rate is determined using the performance ratio as a comparison metric between the different inverters. The degradation from the first year of operation up to the fourth year shows that different areas of the PV plant have varying degradation rates. The spatial degradation analysis indicates that inverter blocks operating at higher ambient temperatures and lower wind frequency measurements show higher rates of degradation compared to inverter groups operating at lower temperatures and higher wind frequency. Notably, the lowest degradation rates correlate positively with wind direction and frequency from the North and North‐East, indicative of a cooling influence on the PV modules. The weather‐corrected performance analysis indicates that the most prominent wind direction (North) has the highest mean performance ratio, further supporting the claims that the cooling effect of wind improves performance and efficiency. The widening gap between the best‐ and worst‐performing inverters annually underscores the premise that specific inverters' PV modules degrade at disparate rates within the PV plant. The results of this work present future designs of PV plants that could potentially be optimised to take advantage of wind as a cooling tool, which may further enhance the longevity and sustainability of large PV installations.

Designing a Multivariate Belt Conveyor Idler Stall Detection and Identification System with Scalability Analysis.

Belt conveyor idlers are freely rotating idlers supporting the belt of a conveyor, and can induce severe frictional damage to the belt as they fail. Therefore, fast and accurate detection of idler faults is crucial for the effective maintenance of belt conveyor systems. In this article, we implement and evaluate the performance of an idler stall detection system based on a multivariate deep learning model using accelerometers and microphone sensor data. Emphasis is place on the scalability of the system, as large belt conveyor installations can span multiple kilometers, potentially requiring hundreds or even thousands of sensor units to monitor. The accuracy of the proposed system are analyzed and reported, along with its network bandwidth and energy requirements. The results suggest that while implementing accurate large-scale idler stall detection is feasible, careful consideration must be paid to observing the available network bandwidth and energy budget in order to avoid prolonged downtimes.

Numerical investigation of a PCM system for thermal management of large scale battery installation in remote area power systems

Numerical investigation of a PCM system for thermal management of large scale battery installation in remote area power systems

Large scale utility solar installation in the USA: Environmental impact and job creation

Large-scale utility solar installations in the United States have gained momentum as a key component of the nation's renewable energy transition. This review examines the environmental impact and job creation associated with these projects, focusing on their contribution to decarbonizing the energy sector and stimulating economic growth. Utility-scale solar installations offer significant environmental benefits, particularly in reducing greenhouse gas emissions and displacing fossil fuel-based energy sources. They also contribute to improving air quality and mitigating climate change. However, challenges such as land use, habitat disruption, and water usage in arid regions present potential environmental concerns. To address these, mitigation strategies such as dual-use projects and siting solar farms on degraded lands are becoming more common. In addition to environmental advantages, utility-scale solar installations play a pivotal role in job creation and economic development. These projects generate a wide range of employment opportunities, particularly in construction, operations, and maintenance. The solar energy sector has grown rapidly, creating tens of thousands of jobs across various regions, including economically disadvantaged and rural areas. The economic ripple effect of solar job creation extends to local communities and related industries, further boosting economic activity. Workforce training and development initiatives are crucial for preparing workers to meet the demands of this growing sector, ensuring that job creation benefits are widespread and inclusive. Despite the positive impacts, challenges related to regulatory barriers, grid integration, and financing remain. This review underscores the importance of supportive policy frameworks and continued innovation to overcome these obstacles and maximize the potential of large-scale solar installations. Looking ahead, advancements in technology, energy storage, and grid infrastructure will be essential for sustaining the environmental and economic gains from utility-scale solar energy in the U.S.

Design and implementation of a waterless solar panel cleaning system

Manual cleaning of large solar installations is often labor-intensive and time-consuming, primarily due to the accumulation of dust on solar panels, which significantly impairs their efficiency. The study introduces a novel, waterless, cost-effective automatic cleaning system for small solar panels. The rationale behind this innovation stems from the necessity to mitigate efficiency losses caused by dirt and contaminants on solar surfaces. The automated system employs an Arduino microcontroller enhanced with a real-time clock to optimize cleaning schedules based on environmental conditions. The system consists of a two-stage mechanism which includes an ejector blower that produces a strong air jet, complemented by a flexible brush that effectively removes dust as well as sticky dirt. Cleaning intervals are strategically determined to ensure consistent maintenance without manual intervention, thus maximizing energy output. Tests on a 60 W solar panel revealed an impressive average power output increase of 26.23 % following cleaning. This prototype demonstrates the efficacy of the cleaning approach and underscores its potential to alleviate efficiency losses attributed to dust accumulation. Particularly advantageous in arid regions where water conservation is paramount, this automated system enhances energy production and operational efficiency for solar plant operators, promoting sustainable energy practices.

The macro view of solar policy: The case for supporting utility-scale power

New solar energy generation is drastically needed as a source of clean electricity as the U.S. and the globe make the transition away from fossil fuels. Yet, even as solar costs have dramatically declined, solar sources still provide less than 5% of global electricity. We examine issues in solar policy leading to this low adoption rate. Examining the variables of cost, baseload power and intermittency, and land use, we evaluate the tradeoffs among policy support for utility-scale, commercial and residential solar systems. We argue that utility-scale solar power makes far more sense if there is adequate grid integration, so that such installations can be placed in locations that minimize land use tradeoffs. By focusing policy support on a few large solar installations, governments can vastly increase the solar contribution to electricity generation.

PV Silicon Recovery for Lithium Ion Battery Anodes

As solar photovoltaic (PV) devices across the globe reach the end of their approximately 30-year lifetimes, an emerging challenge is how to handle the waste from large volumes of end-of-life (EOL) PV modules. It is projected that the cumulative mass of EOL PV modules could be up to 8 million tonnes (Mt) by 2030 so recovery of high value materials from these EOL modules through a cost efficient recycling process would minimize environmental impacts compared to disposing them in landfills[1]. A typical recycling process for EOL PV modules involves mechanical disassembly, separation of the tempered cover glass and silicon wafer followed by purification and recovery of other constituents such as Pb or Ag with the goal of reinstating the recovered materials as a PV module. However, since new module prices continue to decline and the recovered PV modules typically have a shorter lifetime and lower efficiency, the economic value of using the recovered PV materials to manufacture a new PV module is uncertain[2]. Since silicon, particularly boron-doped, is a promising candidate for next-generation anodes for lithium-ion batteries (LIB), recovering the silicon from PV modules for use in LIB anodes could be an attractive alternative. A ball milling process was developed at Oak Ridge National Laboratory to prepare ball milled silicon from washed silicon boules as well as EOL PV modules sourced from a commercial PV module recycler. In this talk we will be discussing the purification process, contaminant removal requirements and key anode performance metrics of recycled PV silicon materials. Organic acid washing with and without microwave-treatment as the heat source was conducted on ball milled boron-doped silicon and reference undoped silicon. The organic acid washing was conducted several times and followed by centrifugation and drying to attempt to remove unwanted contaminant species and compared to a single step microwave-assisted process. The initial carbon species present after ball milling the silicon remained on the ball milled silicon based on FTIR data and the structure of the ball milled silicon was unchanged based on XRD analysis. Elemental analysis and half cells tests were conducted to observe the effect of boron-doping and contaminants inherent to the EoL PV Si material with pristine boron-doped silicon showing noticeably better performance than non-doped ball milled silicon or contaminated silicon PV silicon. Determining the maximum amount of each potential contaminant from PV panels will help facilitate these materials being introduced into local supply chains as a silicon precursor material for more highly engineered silicon anode materials. IRENA, I.-P., End-of-Life Management: Solar Photovoltaic Panels 2016: International Renewable Energy Agency and International Energy Agency Photovoltaic Power Systems.A. Wade, P.S., K. Drozdiak, E. Brutsch. Beyond Waste – The Fate of End-of-Life Photovoltaic Panels from Large Scale PV Installations in the EU. The Socio-Economic Benefits of High Value Recycling Compared to Re-Use. in 33rd European Photovoltaic Solar Energy Conference and Exhibition. 2017.

Evaluating the levelized costs and life cycle greenhouse gas emissions of electricity generation from rooftop solar photovoltaics: a Swiss case study

Abstract The transition to renewable energy sources is pivotal in addressing global climate change challenges, with rooftop solar photovoltaic (PV) systems playing a crucial role. For informed decision-making in energy policy, it is important to have a comprehensive understanding of both the economic and environmental performance of rooftop solar PV. This study provides a high-resolution analysis of existing rooftop solar PV systems in Switzerland by assessing the robustness of the potential estimation to properly derive the amount of electricity generated by individual systems, and subsequently quantify the levelized cost of electricity and life cycle greenhouse gas (GHG) emissions of electricity generation from PV and compare them with those of grid electricity supplies. Our results indicate substantial geographical variations between potential estimations and real-world installations, with notable underestimations of approximately 1.3 Gigawatt-peak, primarily for systems around 10 kWp in size, mainly due to the quality of input data and conservative estimation. The study finds that in many regions and for most of the installed capacity, electricity generated from rooftop PV systems is more economical than the grid electricity supply, mainly driven by factors including high electricity prices, larger installations and abundant solar irradiance. The GHG emissions assessment further emphasizes the importance of methodological choice, with stark contrasts between electricity certificate-based approaches and others that are based on the consumption mix. This study suggests the need for more accurate geographical potential estimations, enhanced support for small-scale rooftop PV systems, and more incentives to maximize the potential of their roof area for PV deployment. As Switzerland progresses towards its renewable energy goals, our research underscores the importance of informed policymaking based on a retrospective analysis of existing installations, essential for maximizing the potential and benefits of rooftop solar PV systems.

A Simple Procedure to Obtain the Grounding Resistance Measurement of Very Large and Urban Electrodes by a Modified Fall-of-Potential Method

The measurement of the grounding resistance of grounding grids in large installations as well as grounding electrodes in urban areas is addressed in this article. The resistance value is obtained using a three-pin array by measuring the fall-of-potential on the ground surface. The resistance measured by this method is adjusted to its true value using a correction factor that aligns the measured resistance with the actual value. The proposed measurement method obtains correct values of the grounding resistance even when the auxiliary and potential electrodes of the tree-pin array are close to the electrode to be measured. Thus, it can be applied to large electrodes as well as electrodes in urban areas. Several simulated examples are used to illustrate the method, and some real cases with field measurements are presented for a final validation of the method.

NUOVA OFFICINA ASSERGI: a novel infrastructure for the production of cryogenic and radiopure Si-based photodetectors

The NUOVA OFFICINA ASSERGI (NOA) is a new facility for the production and integration of large-area silicon photodetectors operating at cryogenic temperatures. Silicon photomultipliers are proving to be a promising technology for next-generation experiments searching for rare events in underground laboratories. New photosensor technology with high performance at cryogenic temperature has been developed by Fondazione Bruno Kessler (FBK) and integrated at Laboratori Nazionali del Gran Sasso (LNGS) into large-area optical units, thus opening the frontiers toward the realization of scalable liquid argon experiments probing dark matter. The massive production of such detectors is now feasible in NOA, a clean room of 421 m2 designed to operate in a radon-free mode. NOA, commissioned and operational at LNGS, hosts the most advanced packaging machines and electronic test facilities for the integration of silicon devices in a dust-controlled environment. The infrastructure layout is split into two experimental areas: one for the production of electronic devices and cryogenic temperature tests and the other for operating with large detector installations. The NOA facility can be operated with a radon abatement system, making it a unique facility for packaging and testing SiPM-based photosensors and for assembling detector components in a radon-free environment. Therefore, NOA supports the deployment of underground experiments at LNGS and the development of new technologies for the search of rare events, such as dark matter and neutrinoless double-beta decay.

Thermodynamic and economic analyses of the retrofit of existing electric power plants with fusion reactors

Electricity generation will need to reach net zero emissions globally in 2050. This will require an increase in share of renewable energy and the implementation of a controllable carbon-free base-load source. Nuclear fusion is a promising option to decarbonize base-load electricity production but its capital cost still doubles the one of technologically more mature alternatives such as large photovoltaic fields or off-shore wind installations. Within this framework, the retrofit of a dismissed power-plant could allow significant cost savings, thus facilitating the realization of a fusion electricity demonstrator. Among fusion reactors, stellarators are a valid alternative to tokamaks thanks to the higher blanket temperature and inherent continuous operation. In this scenario, we posit the challenge to use a nuclear fusion stellarator-based reactor to retrofit conventional power plants (PPs). Specifically, we select a nuclear fission plant in France and a supercritical coal fired site in Italy, by constructing 4 different retrofit scenarios as a function of the re-used components. We compare each option with a greenfield and optimized plant with the same reactor thermal power. through a thermodynamic, economic, and investment analysis.The results proves significant savings by retrofitting an existing plant, with a CapEx reduction up to 50% compared to the greenfield plants. Specifically, the most convenient retrofit strategy is to select a site that already implements cutting edge thermodynamic parameters while reusing the most existing systems (i.e. buildings, steam cycle, electricity generation, and heat rejection). This is the case of the 2 x 660 MWe supercritical coal-fired plant in Italy. Therein, the LCOEs are 39 $/MWh and 51 $/MWh, calculated with an interest rate of 2.7% and 6%, respectively, and compare with the conventional energy technologies. Moreover, such costs are competitive in the current European energy markets and yield significant net present values at the plant end of life.

Comparison of soil eDNA to camera traps for assessing mammal and bird community composition and site use.

Species detections often vary depending on the survey methods employed. Some species may go undetected when using only one approach in community-level inventory and monitoring programs, which has management and conservation implications. We conducted a comparative study of terrestrial mammal and bird detections in the spring and summer of 2021 by placing camera traps at 30 locations across a large military installation in northern Michigan, USA and testing replicate soil samples from these sites for environmental DNA (eDNA) using an established vertebrate metabarcoding assay. We detected a total of 48 taxa from both survey methods: 26 mammalian taxa (excluding humans, 24 to species and two to genus) and 22 avian taxa (21 to species and one to genus). We detected a relatively even distribution of mammalian taxa on cameras (17) and via eDNA analysis (15), with seven taxa detected from both methods. Most medium-to-large carnivores were detected only on cameras, whereas semi-fossorial small mammals were detected only via eDNA analysis. We detected higher bird diversity with camera traps (18 taxa) compared to eDNA analysis (eight taxa; four taxa were detected with both methods), but cameras alone were most effective at detecting smaller birds that frequently occupy arboreal environments. We also used Bayesian spatial occupancy models for two widely distributed game species (white-tailed deer, Odocoileus virginianus, and ruffed grouse, Bonasa umbellus) that were moderately detected with both survey methods and found species-specific site use (occupancy) estimates were similar between cameras and eDNA analysis. Concordant with similar studies, our findings suggest that a combination of camera trap and eDNA surveys could be most useful for assessing the composition of terrestrial mammal communities. Camera traps may be most efficient for assessing bird diversity but can be complemented with eDNA analysis, particularly for species that spend considerable time on the ground.

Integration of Wind Power for Sustainable Energy at Lagos State University of Science and Technology: A Feasibility Study

This study investigates the feasibility of integrating wind power generation at Lagos State University of Science and Technology, specifically within the Mechanical Engineering Department, to address persistent electricity supply challenges in Nigeria. The research focuses on the application of a five-bladed horizontal axis wind turbine (HAWT) and emphasizes the urgent need for sustainable energy solutions due to the depletion of conventional sources and the environmental impact of fossil-fuel-powered generators. The methodology involves mathematical modelling to analyze wind shear exponent, Weibull distribution, maximum power available, and capacity factor. Utilizing the FZ-3000 five-bladed HAWT, data is collected using a wireless wind anemometer. The results reveal a calculated wind shear exponent aligned with terrain characteristics, emphasizing the impact of obstructions on wind speed. Analysis of average wind speed throughout the day demonstrates the potential for continuous power generation at the Mechanical Engineering Department of the Lagos State University of Science and Technology. Examination of wind speed at different heights underscores the significance of elevated turbine towers for capturing higher wind speeds and optimizing power output in the specific context of Lagos State University of Science and Technology. The calculated capacity factor of 44.17% suggests the viability of large wind turbine installations within the Mechanical Engineering Department, with room for improvement through routine maintenance. This research contributes valuable insights into harnessing wind power at Lagos State University of Science and Technology, particularly within the Mechanical Engineering Department, addressing technical and environmental challenges for sustainable energy development.

Quantifying the Distribution of Evapotranspiration at PV and APV Sites Using Soil Moisture

Solar panels affect the distribution of water and energy reaching the ground causing changes in soil moisture, evapotranspiration and percolation. In the context of Agri-Photovoltaics those changes influence plant growth and yield as well as irrigation demands while large Photovoltaic installations could potentially lead to changes in the water balance of the catchment. In either case, evapotranspiration plays an important role as the installation of panels of any design leads to shading thereby reducing the water loss to the soil through evapotranspiration. As it is difficult to measure evapotranspiration, the authors proceeded using soil moisture observations to quantify evapotranspiration pattern in dry periods. They found on average a 44 % higher evapotranspiration rate over 12 dry periods of varying conditions under the panels compared to a reference area at the research site Pillnitz. However, similar observations at the second site, Weesow show also a reversed behaviour due to reduced soil water availability as a result of the higher evapotranspiration at the reference area.

Analysis and Experimental Study on Vibration Isolation Performance of Full-scale Turbofan Engine Mounting

At present, most of the turbofan engine use the articulated link mount to connect the engine to the wing, and the analysis and experimental research of articulated link mount are important means in the development of engine mount. In this paper, the vibration isolation performance analysis of a certain turbofan engine mounting was carried out, and a full-scale turbofan engine mounting vibration isolation test platform was established based on the four-terminal parameter method, and the engine simulation device - eccentric rotation excitation tester was developed, which simulates the real engine vibration through rotor imbalance, and the vibration isolation efficiency of a certain type of engine mount at the high and low pressure rotor frequency was obtained. The results show that the simulation and test results are very close, the error is within 15% at the low-frequency, and the error is within 5% at the high-frequency. The research of this paper can provide test evaluation means for my country to independently carry out the design and improvement for large passenger aircraft engine installation devices, and provide test basis for its design and finalization.

Physically based heat exchanger sizing method for the thermal management system of all-electric regional aircraft

Fully electric propulsion systems integrating hydrogen-powered fuel cells and batteries are promising options to reduce the overall climate impact of regional aircraft. However, the increase in low-temperature heat sources aboard the aircraft calls for advanced thermal management system solutions. To address this challenge, this study presents a sizing methodology for ram air heat exchangers in the nacelle-integrated cooling loop of an all-electric regional aircraft based on the ATR-72 platform. Different discretization schemes are compared to identify an optimal sizing method. The results highlight the simplicity and efficiency of the 0D ε-NTU model. Geometric design variables are optimized with respect to drag and mass during a hot-day take-off. The resulting Pareto front reveals a tendency for low airflow outlet temperatures and large diffuser area ratios to result in lightweight designs but in turn, induce high drag and require a large installation space. Comparative analyses of specific optimal ram air duct designs and equivalent skin heat exchangers demonstrate the potential of a second heat sink over a flight mission. The limited heat transfer area of the skin heat exchanger proves insufficient for hot-day take-off and climb but offers advantages during cruise and descent thanks to the reduced drag.

Analysis and verification of vibration isolation performance of engine mount based on low-frequency approximation method

At present, most of the turbofan engine use the articulated link mount to connect the engine to the wing. The mechanical modeling, analysis and experimental research of articulated link mount are important means in the development of engine mount. In this paper, multibody dynamics method is used to establish the dynamic theory equation for a certain type of turbofan engine mount, and the low-frequency approximation method of the MNF file is proposed, which greatly improves the calculation speed on the basis of ensuring the calculation accuracy. In addition, a full-scale engine mounting system vibration isolation performance test platform was developed, and the vibration isolation efficiency of a certain type of engine mount at the high and low pressure rotor frequency was obtained. The results show that the simulation and test results agree well, the error is within 15% at the low-frequency, and 5% at the high-frequency. This work provides theoretical method and test evaluation means for the design and improvement of large passenger aircraft engine installation devices.

Research on Non-Invasive Voltage Measurement Method Based on Impedance Adaptation

Transformer-based contact voltage measurement requires electrically charged installation during use. Moreover, there are problems with large sizes and restricted installation locations. The current non-contact voltage measurement technology is based on the principle of capacitive coupling in measurement. The capacitance between the probe and the wire is affected by the diameter of the wire and the insulation material. This results in an unstable sensor gain relationship, which leads to low measurement accuracy. This paper proposes a non-contact multi-wire adaptive voltage measurement method, and self-calibration of the sensor gain is achieved through practical measurements. First, the basic principle of capacitively coupled voltage measurement is introduced, from which the existing problems are condensed. An impedance-based adaptive method is proposed, based on which a new sensor probe is developed. The accuracy test reveals that the maximum relative error of voltage amplitude is 0.89 percent, the relative error of phase is 0.38%, and the relative phase error is within 1 degree for a specified voltage range (100 V-300V). The scenario adaptability test shows that the maximum relative error is 1.7% when performing tests on different types of lines. This sensor has the advantages of compactness, convenience, low cost, and high practicality.

The Interaction between Short- and Long-Term Energy Storage in an nZEB Office Building

The establishment of near-autonomous micro-grids in commercial or public building complexes is gaining increasing popularity. Short-term storage capacity is provided by means of large battery installations, or, more often, by the employees’ increasing use of electric vehicle batteries, which are allowed to operate in bi-directional charging mode. In addition to the above short-term storage means, a long-term storage medium is considered essential to the optimal operation of the building’s micro-grid. The most promising long-term energy storage carrier is hydrogen, which is produced by standard electrolyzer units by exploiting the surplus electricity produced by photovoltaic installation, due to the seasonal or weekly variation in a building’s electricity consumption. To this end, a novel concept is studied in this paper. The details of the proposed concept are described in the context of a nearly Zero Energy Building (nZEB) and the associated micro-grid. The hydrogen produced is stored in a high-pressure tank to be used occasionally as fuel in an advanced technology hydrogen spark ignition engine, which moves a synchronous generator. A size optimization study is carried out to determine the genset’s rating, the electrolyzer units’ capacity and the tilt angle of the rooftop’s photovoltaic panels, which minimize the building’s interaction with the external grid. The hydrogen-fueled genset engine is optimally sized to 40 kW (0.18 kW/kWp PV). The optimal tilt angle of the rooftop PV panels is 39°. The maximum capacity of the electrolyzer units is optimized to 72 kW (0.33 kWmax/kWp PV). The resulting system is tacitly assumed to integrate to an external hydrogen network to make up for the expected mismatches between hydrogen production and consumption. The significance of technology in addressing the current challenges in the field of energy storage and micro-grid optimization is discussed, with an emphasis on its potential benefits. Moreover, areas for further research are highlighted, aiming to further advance sustainable energy solutions.

Energy-Aware Multicriteria Control Performance Assessment

Generally, control system design and the associated assessment of control system quality focuses on cutting-edge performance. Most of the approaches and applied indicators aim for this goal. However, the current times increasingly indicate the need to consider, at least on an equal level, the issue of the resistance of the control system and the energy that it consumes. Indicators for the assessment of the quality of control system operation should take these aspects into account. This study focuses on energy issues. It should be noted that, very often, an actuator device, such as a pump, motor, or actuator, consumes energy. In small single-loop systems, the share of this energy is usually negligible, but in large installations, it begins to reach significant values. This work proposes a multi-criteria assessment of the operation of control systems using information about the control signal. The energy factor can be considered in the form of a quadratic relationship or using the valve travel and valve stroke indicators known in other contexts. The index ratio diagram (IRD) approach is utilized as an energy assessment tool. At the same time, an analysis is carried out showing the impact of energy on other known indicators based on the control error. Finally, a methodology incorporating energy consumed by the control system is proposed.