Large Plants Research Articles

European Green Deal + Poland + hydroelectric plants = Future?

This study considers the current state of hydropower in Poland and the legal and environmental conditions for its development. The research objective was to provide insights into the future of hydropower in Poland. An attempt was made to determine the direction of hydropower development in Poland by 2050, taking into account the requirements of the European Green Deal. The basic method used is logical argumentation, which is in turn based on a critical analysis of planning documents and scientific papers. Statistical data on the production and consumption of hydropower were also analysed. Currently, Poland’s potential for hydropower production is not being fully exploited. The main reasons for this are a lack of political support and socio-ecological issues associated with the need to take over inhabited areas or areas of high natural value. The analysis of the state of hydropower in Poland indicates that urgent intervention is required in many areas. This applies, especially, to issues of the control, modernisation and technical condition of hydropower plants and damming facilities. The potential for the development of hydropower in Poland is assessed to be very small. Environmental, socio-economic and legal conditions are unfavourable to the construction of new, large hydropower plants. The exception is pumped-storage power plants, which, acting as energy storage facilities, should in the future constitute an important element of the Polish energy system. The possibility of using defunct lignite mining pits for this purpose is indicated. It is shown that some of Poland’s former lignite mines are also conveniently located. The possible beneficial impact of building pumped-storage power plants into the water ecosystem of central Poland is emphasised.

Power reserve control for utility-scale PV power plants under cloud conditions

The photovoltaic generation growth has posed challenges for the control and operation of contemporary power systems, degrading the system frequency response and stability margins. The decrease of the system equivalent inertia and the performance deterioration of the primary frequency control are the main causes of these problems. Such challenges can be overcome by the provision of ancillary services from photovoltaic power plants. However, the provision of ancillary services based on active power, such as inertial response, frequency regulation, and curtailment, requires the de-loaded operation of the photovoltaic power plants. In such context, this work proposes a de-loaded control approach (or, equivalently, power reserve control) for large photovoltaic power plants under shading conditions caused by cloud movements. This kind of shading condition poses a significant challenge for the de-loaded control, as it causes large and fast variations in the maximum power point of the multiple photovoltaic generation units that compose the photovoltaic power plant. A test system corresponding to a 100 MWac photovoltaic power plant with 25 photovoltaic generation units of 4 MWac is employed to evaluate and validate the proposed control approach. The stochastic distribution and movement of clouds, as well as the solar irradiance over the photovoltaic power plant are generated by an approach based on the fractal geometry. The proposed control was effective and presented a good performance under different cloud coverage levels.

Identifying Onion Fields at Risk of Iris Yellow Spot Virus in New York.

Iris yellow spot virus (IYSV) poses a significant threat to dry bulb onion, Allium cepa L., production and can lead to substantial yield reductions. IYSV is transmitted by onion thrips, Thrips tabaci (Lindeman), but not via seed. Transplanted onion fields have been major early season sources of IYSV epidemics. As onion thrips tend to disperse short distances, seeded onion fields bordering transplanted onion fields may be at greater risk of IYSV infection than seeded fields isolated from transplanted ones. Additionally, seeded onion fields planted early may be at greater risk of IYSV infection than those seeded later. In a 2-year study in New York, we compared IYSV incidence and onion thrips populations in seeded onion fields relative to their proximity to transplanted onion fields. In a second study, we compared IYSV incidence in onion fields with either small or large plants during midseason. Results showed similar IYSV incidence and onion thrips populations in seeded onion fields regardless of their proximity to transplanted onion fields, while IYSV incidence was over four times greater in large onion plants than in small ones during midseason. These findings suggest a greater risk of onion thrips-mediated IYSV infection in onion fields with large plants compared with small ones during midseason and that proximity of seeded fields to transplanted ones is a poor indicator of IYSV risk. Our findings on IYSV spread dynamics provided valuable insights for developing integrated pest and disease management strategies for New York onion growers.

Effects of tree species mixing and soil depth on the soil bacterial and fungal communities in Chinese fir (Cunninghamia lanceolata) plantations

Chinese fir [Cunninghamia lanceolata (Lamb.) Hook.] is a critical timber tree species for its fast growth and high yield in southern China and is widely planted in subtropical regions of the country. However, the management of Chinese fir in the form of a monoculture plantation is not conducive to the maintenance of soil fertility and improvements in forest productivity. The establishment of mixed conifer–broad–leaved forests through near-natural transformation is developing into a promising method of forest cultivation for replacing large pure coniferous plantations. Bacteria and fungi are an important part of the soil microbiota and are involved in the soil nutrient cycle. Therefore, this study investigated the response of soil bacterial and fungal communities to the introduction of broad–leaved trees in three types of Chinese fir plantations [Cunninghamia lanceolata monoculture plantation (CMP), C. lanceolata–Castanopsis hystrix Hook. f. & Thomson ex A. DC.–Michelia hedyosperma Law. mixed plantation (CCM), and C. lanceolata–Castanopsis fissa (Champ. ex Benth.) Rehder & E.H.Wilson–Erythrophleum fordii Oliv. mixed plantation (CCE)] located in Guangxi Province, China. And the effect of soil layers (0–20, 20–40, and 40–60 cm soil depths) on the soil microbial communities was further analyzed. The results suggested that tree species mixing significantly affected bacterial and fungal communities, but soil depth only significantly affected bacterial communities (P < 0.01). The relative abundance of Basidiomycetes in CCE (53.91–78.76 %) was significantly higher than that in pure forest (P < 0.05). Bacteria exhibited more complex and multilinked networks in the mixed stands, particularly for the CCE plantation. Mixed planting patterns significantly enhanced bacterial nitrogen fixation and the presence of symbiotic fungi. Redundancy analysis (RDA) and correlation analyses indicated that the microbial community structure was strongly affected by soil environmental factors, with bacteria affected mainly by available phosphorous (AP) and fungi affected mainly by soil enzyme activity and total potassium (TK). In summary, the introduction of broad–leaved species (especially C. fissa and E. fordii) had a significant impact on the soil microbial community, increasing the relative abundance of bacterial nitrogen fixation and symbiotic fungi and generating a complex microbial network. We suggest that changes in AP, TK, and fungal communities should be considered in the near-natural transformation of Chinese fir or soil fertility maintenance and sustainable management to maintain soil fertility.

An improved technique for the estimation of local frequency, fundamental component phasor and instantaneous symmetrical components.

Generation of electrical energy in large conventional power plants (thermal, hydro and nuclear) in last ten years worldwide is being supplemented by small generation utilities that are fuelled by renewable sources, waste etc. In Republic of Croatia few years ago first small power plants projects were started. One such project was constructing small thermal power plant as a part of sanitary landfill treatment process in Zagreb, capital of Republic of Croatia. It is first power plant in Republic of Croatia of that kind which is fuelled by landfill gas that is result of decomposition process. After the commissioning of small thermal power plant (STPP) Jakusevec a detailed analysis of voltages and currents at the point of connection to the local distribution network was conducted. Results of that analysis are given in this paper.

Optimal control for quadrotors during inspection of power utility assets

Renewable energy and power utilities inspection by autonomous aircraft enables rapid and effective risk-free assessment of the state of systems, and provides a qualitative and accurate assessment of defects and damages. To realize maximum operational benefits of aerial inspections, effective controls for autonomous aircraft must be ensured and the system should be operated in an optimal policy. Hence, the objective of this paper is to consider optimal control strategies for a quadrotor helicopter type UAV. Based on some structural properties of the considered system, in particular the flatness property, we suggest a control strategy that ensures tracking a time parameterized path that connects two given points in the state space while minimizing the energy consumption. The proposed controller enables longer-endurance missions for the quadrotor and effective supervision and inspection of large energy systems and power plants. In this paper the analysis of the control law takes into consideration the highly nonlinear dynamic model of the quadrotor and the electrical actuator model. The current approach in solving the optimal control problem under consideration allows one to eliminate the differential equation and to reformulate the optimal control problem to a nonlinear dynamic programming problem. The approach can make monitoring operations of renewable energy plants by aerial vehicles, more efficient.

Identification of surface defects on solar PV panels and wind turbine blades using attention based deep learning model

The global generation of renewable energy has rapidly increased, primarily due to the installation of large-scale renewable energy power plants. However, monitoring renewable energy assets in these large plants remains challenging due to environmental factors that could result in reduced power generation, malfunctioning, and degradation of asset life. Therefore, the detection of surface defects on renewable energy assets is crucial for maintaining the performance and efficiency of these plants. This paper proposes an innovative detection framework to achieve an economical surface monitoring system for renewable energy assets. High-resolution images of the assets are captured regularly and inspected to identify surface or structural damages on solar panels and wind turbine blades. Vision transformer (ViT), one of the latest attention-based deep learning (DL) models in computer vision, is proposed in this work to classify surface defects. The ViT model outperforms other DL models, including MobileNet, VGG16, Xception, EfficientNetB7, and ResNet50, achieving high accuracy scores above 97% for both wind and solar plant assets. From the results, our proposed model demonstrates its potential for monitoring and detecting damages in renewable energy assets for efficient and reliable operation of renewable power plants.

A thorough analysis of the occurrence, removal and environmental risks of organic micropollutants in a full-scale hybrid membrane bioreactor fed by hospital wastewater

The Urban Wastewater Treatment Directive recent draft issued last October 2022 pays attention to contaminants of emerging concern including organic micropollutants (OMPs) and requires the removal of some of them at large urban wastewater treatment plants (WWTPs) calling for their upgrading. Many investigations to date have reported the occurrence of a vast group of OMPs in the influent and many technologies have been tested for their removal at a lab- or pilot-scale. Moreover, it is well-known that hospital wastewater (HWW) contains specific OMPs at high concentration and therefore its management and treatment deserves attention. In this study, a 1-year investigation was carried out at a full-scale membrane bioreactor (MBR) treating mainly HWW. To promote the removal of OMPs, powdered activated carbon (PAC) was added to the bioreactor at 0.1 g/L and 0.2 g/L which resulted in the MBR operating as a hybrid MBR. Its performance was tested for 232 target and 90 non-target OMPs, analyzed by UHPLC-QTOF-MS using a direct injection method. A new methodology was defined to select the key compounds in order to evaluate the performance of the treatments. It was based on their frequency, occurrence, persistence to removal, bioaccumulation and toxicity. Finally, an environmental risk assessment of the OMP residues was conducted by means of the risk quotient approach. The results indicate that PAC addition increased the removal of most of the key OMPs (e.g., sulfamethoxazole, diclofenac, lidocaine) and OMP classes (e.g., antibiotics, psychiatric drugs and stimulants) with the highest loads in the WWTP influent. The hybrid MBR also reduced the risk in the receiving water as the PAC dosage increased mainly for spiramycin, lorazepam, oleandomycin. Finally, uncertainties and issues related to the investigation being carried out at full-scale under real conditions are discussed.

Effective protection scheme for transmission lines connected to large scale photovoltaic power plants

The performance of a distance relay can be significantly affected by various uncontrolled factors such as fault resistance, fault type, fault location and noise. Moreover, when photovoltaic power plants are integrated into electrical grids, they exhibit distinct fault current characteristics compared to conventional power systems with synchronous generators. These factors introduce variations in the recorded apparent impedance, deviating from the predefined settings of the distance relay. This paper presents an effective scheme for fault detection using ITD methodology. The ITD method decomposes the target signal into proper rotation and monotonic signals, which are then used to calculate the Energy Index. The performance of this scheme has been extensively investigated under various scenarios, including fault resistance, fault location, fault type, CT saturation, GC compliance, noise, and sampling frequency. To validate the effectiveness of the proposed scheme, simulations are conducted using both the PSCAD/EMTDC and MATLAB software. The proposed scheme is assessed using both the 2-bus and IEEE 39-bus test systems. The results show the merit and effectiveness of the proposed scheme in the accurate diagnosis of fault detection with 400 Ω fault resistance, in the presence of 20 dB noise, with variable sampling frequency (0.5-16 kHz) and variable irradiance values (600-1000(W/m2)) in power systems.

Fast Partial Shading Detection on PV Modules for Precise Power Loss Ratio Estimation Using Digital Image Processing

Maintaining the maximum performance of solar panels poses the foremost challenge for solar photovoltaic power plants in this era. One of the common PV faults which decreases PV power output is a hot spot which is caused by a prolonged local partial shading from objects, such as dust piles or animal waste. To prevent it, an enormous effort for PV inspection is needed especially for large solar power plants. Hence, automatic partial shading detection is critical in preventing PV hot spots to assist maintenance activities which are associated with a drop in energy output. This research developed fast partial shading detection application on PV modules using digital image processing to detect the hot spot and PV modules areas and afterwards calculate the PV systems power loss ratio. The proposed method demonstrated a hot spot detection rate of 94.74% and a module detection rate of 100%. The power loss ratio calculation is compared and validated using IV curve measurement and has 91.26% similarity value which is a feasible application for the real-world system.

Unmanned Aerial Vehicle for Infrared Inspection of Photovoltaic Modules

Supervision and monitoring are mandatory for large PhotoVoltaic(PV)plants, because failures can cause high power loss, due to the large number of PVmodules. InfraRed(IR)analysis is effective and reliable to detect anomalies or failures in PVmodules, but it is time consuming and then expensive, when the infrared inspection of large PV plants is manual. The diffusion of Unmanned Aerial Vehicle(UAV)equipped by infrared camera can support the fast supervision of PVplants, but the use of UAVsis regulated by international and national rulesand its utilization is limited, based on geographic areas and/or authorizations. This article discusses these critical issues, directs the reader to official, national, geographic maps for the drones, and suggests technical solutions for some specific issues not considered in the technical specification for outdoor infrared thermography of PVmodules.

Potential of Radioactive Isotopes Production in DEMO for Commercial Use

There is widespread use of nuclear radiation for medical imagery and treatments. Worldwide, almost 40 million treatments are performed per year. There are also applications of radiation sources in other commercial fields, e.g., for weld inspection or steelmaking processes, in consumer products, in the food industry, and in agriculture. The large number of neutrons generated in a fusion reactor such as DEMO could potentially contribute to the production of the required radioactive isotopes. The associated commercial value of these isotopes could mitigate the capital investments and operating costs of a large fusion plant. The potential of producing various radioactive isotopes was studied from material pieces arranged inside a DEMO equatorial port plug. In this location, they are exposed to an intensive neutron spectrum suitable for a high isotope production rate. For this purpose, the full 3D geometry of one DEMO toroidal sector with an irradiation chamber in the equatorial port plug was modeled with an MCNP code to perform neutron transport simulations. Subsequent activation calculations provide detailed information on the quality and composition of the produced radioactive isotopes. The technical feasibility and the commercial potential of the production of various isotopes in the DEMO port are reported.

A green electrical matrix-based model for the energy transition: Maine, USA case example

Nowadays, climate change is a major global societal challenge that significantly increases environmental stress. Most international organizations and policies have promoted initiatives to minimize emissions, reduce fossil fuel dependence and increase renewable energy resource integration into different sectors. An energy transformation towards more renewable systems is thus a priority. Under this scenario, the present paper describes and evaluates an alternative energy conversion matrix-based model to combine sector electrification, power generation units from renewables, and new clean technologies. The proposed green matrix-based model allows analyzing future scenarios, including electricity participation in end-use consumption and electric power generated by renewables – potentially integrated into different sectors –. The proposed model is evaluated in the state of Maine (United States). This case study is focused on decarbonizing both residential heating and transport sector through the integration of large offshore wind power plant. Results and discussion is also included in the paper, providing expected energy demand reductions and decreasing emissions through the integration of renewables. This energy transition integration case study is proposed in three road-maps with different penetration rates and time scales. The proposed green matrix-based model can be also applied to other areas and energy resources, as an alternative way to analyze and estimate renewable integration into different sectors.

Atomic blackmail – Russia-Ukraine war and Ramberg’s theory of vulnerability

ABSTRACT The Russia-Ukraine War is being fought between states committed to nuclear power. This paper references Ramberg’s nuclear powerplant (NPP) vulnerability treatise, the IAEA’s Seven Pillars of Safety metric and Pidgeon and O’Leary’s safety imagination approach to assess the safety of Ukrainian and Russian NPPs. It suggests governments should reflect on events in Ukraine, and, with reference to the above-mentioned approaches, decide whether the upside of nuclear power – the largely carbon-neutral production of electricity – outweighs the downside – giving a blackmail opportunity to hostile states. Although a cost-benefit analysis to inform decision-making is effortful, the paper suggests that failure to consider every advantage and disadvantage of nuclear power could prove costly in human and environmental terms. Drawing on Ukraine’s experience, the paper suggests the national interest is best served in time of war by generating electricity in multiple small plants rather than a few large plants.

Growth and fecundity of Palmer amaranth escaping glufosinate in cotton with and without grass competition

Abstract Field experiments were conducted at Clayton and Rocky Mount, NC, during summer 2020 to determine the growth and fecundity of Palmer amaranth plants that survived glufosinate with and without grass competition in cotton. Glufosinate (590 g ai ha−1) was applied to Palmer amaranth early postemergence (5 cm tall), mid-postemergence (7 to 10 cm tall), and late postemergence (&gt;10 cm tall) and at orthogonal combinations of those timings. Nontreated Palmer amaranth was grown in weedy, weed-free in-crop (WFIC) and weed-free fallow (WFNC) conditions for comparisons. Palmer amaranth control decreased as larger plants were treated; no plants survived the sequential glufosinate applications in both experiments. The apical and circumferential growth of Palmer amaranth surviving glufosinate treatments was reduced by more than 44% compared to the WFIC and WFNC Palmer amaranth in both experiments. The biomass of Palmer amaranth plants surviving glufosinate was reduced by more than 62% when compared with the WFIC and WFNC in all experiments. The fecundity of Palmer amaranth surviving glufosinate treatments was reduced by more than 73% compared to WFNC Palmer amaranth in all experiments. Remarkably, the plants that survived glufosinate were fecund as WFIC plants only in the Grass Competition experiment. The results prove that despite decreased vegetative growth of Palmer amaranth surviving glufosinate treatment, plants remain fecund and can be fecund as nontreated plants in cotton. These results suggest that a glufosinate-treated grass weed may not have a significant interspecific competition effect on Palmer amaranth that survives glufosinate. Glufosinate should be applied to 5 to 7 cm Palmer amaranth to cease vegetative and reproductive capacities.

Genotoxic and Mutagenic Assessment Induced by Vinasse, Before and After Being Subjected to Bio-oxidation and Fenton Processes

Background: Colombia is joining global initiatives to mitigate climate change through bioethanol production, as it has large sugar cane plantations and sugar mills, particularly in the Valle del Cauca region. One of the main by-products of the bioethanol industry is vinasse, which consists mainly of water, organic solids and heavy metals. Some of the compounds present in vinasses, such as melanoidins and phthalates, show genotoxic, mutagenic and carcinogenic activity in onion cells, tilapia and aquatic organisms. Various methods, such as bio-oxidation and Fenton reaction, have been used to reduce the organic load of vinasses. Among the most commonly used assays to study genotoxicity and mutagenicity are single cell gel electrophoresis (comet assay) and the Ames test. Objective: In this study, the genotoxicity in human lymphocytes and the mutagenicity in Salmonella typhimurium induced by different dilutions of vinasse produced at the bioethanol production plant in Frontino, Antioquia, before and after being subjected to biooxidation and Fenton processes, were evaluated. Methods: Genotoxicity was evaluated by the comet assay in human lymphocytes, and mutagenic activity was evaluated by the Ames test using Salmonella typhimurium strains TA98 and TA100, with and without the addition of microsomal enzymes (S9). Both tests were applied to each type of vinasse considered in this study, including raw vinasse (RV), bio-oxidised vinasse (BV) and Fenton oxidised vinasse (FV). Results: The results showed that at RV doses above 3%, viability decreased to values between 70% and 88%, whereas for BV and FV, viability remained above 93% and 94%, respectively. Vinasse was also found to have a dose-dependent effect on genotoxicity. However, no mutagenic activity was observed in any of the Salmonella strains evaluated, indicating that vinasse does not induce mutations. Conclusion: The importance of addressing vinasse pollution and treatment methods to reduce its toxicity is emphasised. However, further research is needed to fully understand the risks associated with vinasse exposure and to develop effective mitigation strategies.

Nitrous Oxide Generation, Influencing Factors and Emission Reduction in Anaerobic-Anoxic-Oxic Process Wastewater Treatment Plant

To achieve the reduction of emissions and control of non-CO2 greenhouse gases in municipal wastewater treatment plants, this study conducted a one-year monitoring of N2O in the A2O process of a large municipal wastewater treatment plant in Beijing. N2O released from the water surface of the A2O process was collected by using a gas flux chamber, and the key influencing factors affecting N2O were analysed using statistics. The results showed that N2O was not easy to be released under non-aerated conditions, and the aerobic zone was its main emission area. Temperature leads to high N2O emissions in winter and low in summer. Correlation analyses showed that NO2-N is one of the most critical factors affecting N2O production, and its accumulation level directly affects the amount of N2O produced in the system. DO also has a great influence on the production of N2O, and the amount of N2O produced decreases with the increase of the DO concentration, and the effect on the enzyme activity also makes the pH have a significant effect on the production of N2O.

Method of determining volume yield of biogas during experimental research in biogas technologies

The article deals with the issue of determining the volume of biogas produced during experimental studies during the entire cycle of anaerobic fermentation of organic matter in biogas reactors. The design of the device for determining the volume of biogas produced during the period of the complete cycle of anaerobic fermentation of organic matter in biogas reactors is proposed and given. The use of the proposed device is aimed at both small and large biogas plants, in laboratory conditions and at production facilities. Mathematical dependences are presented, which allow to calculate the volume of biogas determined by the device given in the work. The results of the study of the device using 3D modeling in the Solidworks application program in the Flow Simulation package are presented. The result of the 3D modeling is the graphical dependence of the pressure distribution in the tubes of the measuring device, namely the gas pipeline and the Pitot tube, with the subsequent establishment of the amount of biogas passed through the measuring device in a certain time interval. The work noted a high convergence of the comparative analysis of the data obtained during 3D modeling and calculated analytically. Considered in the article, the main issues of the proposed method of determining the produced volume of biogas during experimental research will allow to increase the accuracy of the research work of scientists, organizations and enterprises in the field of biogas technologies and registration of the produced volume of biogas.

Planiranje i rad elektroenergetskog sistema u uslovima velike proizvodnje električne energije iz solarnih elektrana

Drop of solar panels prices at the world marked has caused construction of large number of solar power plants in relatively short time period. That is the reason why this type of renewable electricity sources is constructed far intensively than the other types of power plants. Capacities of solar power plants vary from those of several kW that are connected to distribution low voltage grid, to large ones, the capacities of which are order of magnitude of hundreds of MW, connected to transmission system. Expansion of solar power plants construction in Europe and world changes current electricity production profile opening questions of balancing of such production, its evacuation and future price. Future market price of electricity produced in solar power plants is the issue the investors are the most interested in and which is the most difficult to answer. On the other side, issue is raised about power system operation in conditions of large and variable solar power plants production. The paper considers and summarizes a number of issues related to power system operation in Southeast Europe in case of large electricity production in solar power plants.

Development of a Distributed Adaptive Dual MPC Scheme with Application to Control of an Octuple Tank System

The distributed model predictive control (dMPC) provides a computationally efficient framework for designing controllers for a large dimensional plant. The performance of such dMPC scheme critically depends upon the quality of the control relevant models used for predictions. In continuously operated processes, model plant mismatch (MPM) arises due to the time-varying nature of process parameters and shift in the operating conditions due to economic considerations and this results in performance degradation. Recently an adaptive version of dMPC (dAMPC) has been developed that achieves better control performance using online model parameter update. A conventional adaptive MPC scheme, however, requires external dither signal to be injected to generate sufficient excitation needed for parameter estimation. In this work, dAMPC is cast in the dual control framework (dADMPC) which ensured sufficient input excitation as and when needed for better online parameter estimation. The proposed controller is based on black-box models parameterized using generalized orthogonal basis filters (GOBF). The Fourier coefficients of the GOBF models are dynamically updated online using recursive parameter estimators to account for MPM. The efficacy of the proposed scheme is demonstrated by simulating servo and regulatory problems associated with the benchmark octuple tank process. The simulation study reveals that performance of the proposed dADMPC scheme is comparable to a centralized ADMPC while achieving a considerable reduction in the online computation time.