Large Electricity Generation Research Articles

Cantera-Based Python Computer Program for Solving Steam Power Cycles with Superheating

One of the main sources of electricity generation is power plants that use water (steam) to rotate turbines, which drive large electric generators. The steam can be generated from renewable or non-renewable energy sources, such as geothermal energy and nuclear fuels. Having an analysis tool for modeling the performance of such steam power plants can greatly help in reaching optimum designs, leading to less fuel consumption, reduced pollution, and cheaper electricity. It is further advantageous if such modeling tool is free to access, does not require many inputs from the user, and gives results in a very short time. These remarks establish a motivation for the current study. This article documents a computer code written in the Python programming language for numerically analysing the main processes in a steam power cycle with superheating. The code utilizes built-in thermodynamic properties for water in the open-source software package “Cantera”. A validation case with a benchmarking example in the literature using an independent source of water properties suggests that the developed code is correct. The code can be viewed as an extension to the Python examples for thermodynamic and power generation applications. Cantera can handle both subcritical and supercritical types of superheating. In the subcritical superheating, the steam absolute pressure does not exceed 220.9 bar. In the supercritical superheating, water becomes in a special condition called supercritical fluid, with absolute pressures above 220.9 bar. Keywords—Cantera, Python, Code, Program, Superheating

Inter- and intra-annual variability of wave energy in Northern mainland Portugal: Application to the HiWave-5 project

Ocean wave energy capacity has been pointed out as one of the unexplored renewable energy sources to help reach net zero carbon emissions by 2050, contributing to meeting the European Green Deal targets. However, despite the broad range of wave energy converter technologies already developed in a sustainable and economic model, there is still a lack of structured projects with high performance beyond the prototype stage. This paper investigates the potential for large-scale electricity production by the innovative HiWave-5 project in Aguçadoura (on the Northern coast of mainland Portugal). Wind–wave data (1950–2020) from the ERA5 reanalysis model are used to estimate inter- and intra-annual wave energy variability in Aguçadoura. ERA5 data is compared with field wind–wave data recorded between 2012–2019 near the study area. A mean wave power resource of 25.84 kW/m is obtained, for a possible device capture equal to 119.45 kW, despite a considerable intra-annual variability (ranging between 8.03 and 47.57 kW/m) and inter-annual variability (between 18.29 and 35.47 kW/m). Results show that local wave conditions do not substantially compromise the absolute performance of the device, given its survival limitations to adverse conditions. Considering a Levelized Cost of Energy of around €60/MWh, an annual investment of €62 885 is estimated, tending to meet targets for large sustainable electricity generation with the exponential growth expected until 2030, aided by the increase of devices in an energy farm concept. Wave power resources estimated using ERA5 data can underestimate about 7.20% values obtained with the wave buoy data.

Examination of excess electricity generation patterns in South Korea under the renewable initiative for 2030

According to the Renewable Energy 3020 Implementation Plan announced in 2017 by the South Korean government, the electricity share of renewable energy will be expanded to 20% of the total electricity generation by 2030. Given the intermittency of electricity generation from renewable energy, realization of such a plan presents challenges to managing South Korea's isolated national electric grid and implies potentially large excess electricity generation in certain situations. The purpose of this study is: 1) to develop a model to accurately simulate the effects of excess electricity generation from renewables which would arise during the transition, and 2) to propose strategies to manage excess electricity generation through effective utilization of domestic electricity generating capabilities. Our results show that in periods of greater PV and wind power, namely the spring and fall seasons, the frequency of excess electricity generation increases, while electricity demand decreases. This being the case, flexible operation of coal and nuclear power plants along with LNG and pumped-storage hydroelectricity can be used to counterbalance the excess electricity generation from renewables. In addition, nuclear energy plays an important role in reducing CO2 emissions and electricity costs unlike the fossil fuel-based generation sources outlined in the 8th Basic Plan.

Gas metal arc welding of metal-polymer-metal sheets

Metal-polymer-metal (MPM) sheets are sandwich panels used for housings of large industrial electric motors and generators, vehicle body panels, flooring, various bulkheads, wheel arching, engine and gearbox shielding, etc. Their main advantage over classic steel panels in form of plates is their acoustic dampening properties. Joining of such plating is challenging because the polymer interlayer evaporates and the resulting fumes may cause the plates to deform. In this paper, GMAW welding was used to join metal-polymer-metal sheets, with a square butt joint, single V butt joint combined in one sheet, as well as welding in one pass per side and in multiple bead segments. C1 (CO2) and M21 (Ar + 18 % CO2) shielding gases were used. Tensile, bending and hardness tests were performed, macro and microstructures were tested and the evaporation, melting and cross-linking distances were recorded. It was shown that contrary to the recent tendency of using M21 shielding gas for GMAW welding, C1 proved to offer superior tensile and bending properties of the joint. From the point of view of simplicity and productivity, a square butt joint proved to be optimal.

Solar Field Optimization and its Impact on Overall Design and Performance of Solar Tower Thermal Power Plant in Bangladesh

Electricity generation using solar thermal power systems can be made more efficient and both technically and economically feasible in countries receiving moderate solar radiation like Bangladesh through thorough optimization of different parts of the power plant. In this paper a theoretical and mathematical framework for optimization of a 150 MW solar tower thermal power plant in Bangladesh which uses molten salt as HTF has been developed by applying different methods of selecting crucial design aspects, such as design point DNI, solar multiple, design point temperature etc. after selecting the most appropriate location based on GHI and DNI data. The effect of these design aspects on the overall design of the power plant including the number of heliostats, solar field land area, tower height, receiver dimensions etc. have also been studied and finally the performance analysis of the power plant has been conducted. Analysis of performance reveals that the optimized power plant would be able to deliver 528.66 GW-h electricity annually to the national grid while operating at a capacity factor of 40.2% and gross-net conversion efficiency of 88.635%. The promising performance of the power plant would encourage further research and innovation regarding large scale electricity generation from solar energy in Bangladesh.

Device Performance of Emerging Photovoltaic Materials (Version 1)

AbstractEmerging photovoltaics (PVs) focus on a variety of applications complementing large scale electricity generation. Organic, dye‐sensitized, and some perovskite solar cells are considered in building integration, greenhouses, wearable, and indoor applications, thereby motivating research on flexible, transparent, semitransparent, and multi‐junction PVs. Nevertheless, it can be very time consuming to find or develop an up‐to‐date overview of the state‐of‐the‐art performance for these systems and applications. Two important resources for recording research cells efficiencies are the National Renewable Energy Laboratory chart and the efficiency tables compiled biannually by Martin Green and colleagues. Both publications provide an effective coverage over the established technologies, bridging research and industry. An alternative approach is proposed here summarizing the best reports in the diverse research subjects for emerging PVs. Best performance parameters are provided as a function of the photovoltaic bandgap energy for each technology and application, and are put into perspective using, e.g., the Shockley–Queisser limit. In all cases, the reported data correspond to published and/or properly described certified results, with enough details provided for prospective data reproduction. Additionally, the stability test energy yield is included as an analysis parameter among state‐of‐the‐art emerging PVs.

ENVIRONMENTAL IMPACT OF USING GENERATORS IN THE UNIVERSITY OF TECHNOLOGY IN BAGHDAD, IRAQ

The environmental impact of using large electrical generators in the University of Technology in Iraq is studied. These generators are utilised due to the lack of electricity from the national grid. The emissions are very high and exceed the acceptable limits set by the United States Environmental Protection Agency, the World Health Organization and Iraqi Standard No. 4950. The impact of switching to the use of photovoltaic cell systems, as what is done in the Energy and Renewable Energies Technology Center (ERETC), and the environmental impact of this transformation are also studied. Results show that when the generators are used, high concentrations of PM1, PM2.5 and PM10 are released, exposing students and staff to health hazards. The amounts of pollutants from SO2, H2S, NOx and volatile organic compounds are high due to the high sulphur content in Iraqi diesel fuel. Generator noise is extremely high that it could pose serious health risks to university staff and students. Furthermore, using the photovoltaic system considerably reduces PM1.0 and PM2.5 concentrations by 85.6% and 52.4%, respectively. The levels of CO2, CO, H2S and SO2 decrease by 60.5%, 49.6%, 91.7% and 95.3%, respectively. The noise inside ERETC is reduced by 29% compared with that in the external environment. Shifting towards the generation of photovoltaic electricity instead of using fossil fuel generators provides an immediate and appropriate treatment of Iraqi atmospheric pollution.

Incumbent lobbying as a barrier to forward-looking regulation: The case of demand-side response in the GB capacity market for electricity

The current transformation of energy systems around the world is fundamentally a policy-driven process, unlike previous socio-technical transitions. This article focuses on the challenges of constructing forward-looking policies for sustainable energy transitions in the presence of powerful incumbent interests, through an in-depth study of how the emerging option of demand-side response (DSR) was incorporated into the Capacity Market (CM) for electricity in Great Britain over the period 2010 to 2014. Drawing on extensive documentation related to the development of the CM rules and interviews with participants and close observers of the process, the paper provides an unusually detailed assessment of the influence of companies with large electricity generation assets. The evidence presented supports the hypotheses that these companies had influence through deploying public facing strategies, that they had been able to draw on close networks of contacts and networks with senior policy makers, and that the latter had internalised the ideas and interests of the former. Despite counter-lobbying by DSR firms and non-governmental organisations, institutional arrangements gave major generators an advantage in terms of access. The paper concludes by recommending the establishment of independent bodies to propose policies and monitor the process of their development during energy system transformations.

Avalanche charge generation in anhydrous glucosides excited by an external electric field

Glycolipids are components of cellular membranes comprising a hydrophobic lipid tail and one or more hydrophilic sugar heads, and are widely associated with the fields of life science and biochemistry. Due to the hygroscopic nature of sugar, the dry thermotropic phases of glycolipids have fewer studies. We report on the electric charge generation in anhydrous glucosides excited by the external high electric field (∼2 MV/m). This causes a large current in the smectic A phase, but not in the isotropic phase. Its intensity is about 100 times larger than the steady state current. The generation of the current was found to be irreversible by the repetition of the field application. The large electric carrier generation is originated in the smectic A phase, possibly due to an electron avalanche breakdown mechanism caused by the collisions of electrons through the impact ionization.

Unpacking ‘regime resistance’ in low-carbon transitions: The case of the British Capacity Market

The ability of powerful incumbent actors to resist technological or institutional changes that threaten their vested interests is a core part of the literature on sustainable energy transitions, but more often asserted in general than tested in specific cases. This article presents analysis of a detailed study of the introduction of a Capacity Market (CM) for electricity in Great Britain in the period 2010–2011, using a process tracing approach. The study finds evidence to support the view that large electricity generators have a significant degree of structural power in relation to decision makers, that such companies did lobby the government through the CM policy process, and that the ideas deployed had an effect on the shape of the CM. However, there were also divisions amongst the large generating companies on whether they wanted a CM or not, and what its design should be. We also show that the institutional circumstances of the CM policy process were quite specific, giving opportunities for lobbying that may not be present in other cases. We conclude it is essential to have an analysis of incumbent power that is contingent on institutional context, the specific nature of interests and the deployment of ideas. To counter incumbent power and structural dependency during sustainable energy transformation, an independent but legitimate body is needed to the direction of policy.

Using Pyrotechnic Current-Limiting Devices: A Case Study of What Went Right

The trend toward electrical rather than mechanical drivers for offshore installation has led to the implementation of large electrical systems and power generation. Due to the offshore environment constraints, such as weight and footprint limitations, most of the installation remains operated at voltages of 13.8 kV and lower, which leads to specific constraints on the electrical network design. This article provides an overview of the implementation of pyrotechnic current-limiting devices from the design stage through precommissioning, commissioning, and operation.

(Invited) Piezoelectric and Triboelectric Properties in 2D Materials for Energy Harvesting and Sensor Applications

As the first issue, transition-metal dichalcogenides (TMDs) have reported on the piezoresponse of the materials as an external force is applied due to their broken inversion symmetry. TMD materials exhibit a strong piezoelectricity in their monolayer configuration, but the piezoelectric effect disappears or is significantly reduced when more than two layers are present. Piezoelectric devices employing monolayer TMD materials are not practically feasible because they lack the mechanical durability that is needed, and such mechanical robustness is crucial to develop useful piezoelectric devices that can be engineered using a multilayered structure. However, multilayered TMDs have a greatly reduced or absent piezoelectricity since the continuous growth of multilayered TMD leads to a stable stacking structure with alternating polarization directions in neighboring layers. We report on a simulation and experimental observation of piezoelectricity in mono/bilayer WSe2 synthesized via CVD and turbostratic stacking. The piezoelectricity and mechanical durability of the mono/bilayer WSe2 were assessed by conducting PFM measurements, a DFT simulation, and fabricating and characterizing the piezoelectric energy harvesters. As the second issue, I will present about the demonstration of large electric power generation from a single moving water droplet on a monolayer graphene, producing an output power of about 1.9 μW, which is about 100 times larger than the power output achieved in previous reports. This result is explained to be a result of the change in triboelectrification-induced pseudocapacitance between a water droplet and the monolayer graphene on polytetrafluoroethylene (PTFE). Positive and negative charges were found to respectively accumulate at the bottom and top surfaces of graphene on PTFE by the triboelectric potential generated during the graphene transfer process. The negative charges accumulate onto the top surface of the graphene and are driven forward by the moving droplet, charging and discharging at the front and rear of the droplet. As the third topic, I am going to introduce a graphene tribotronic touch sensor which is based on coplanar coupling of a single electrode mode triboelectric nanogenerator (S-TENG) and a graphene FET. When any object (e.g. human finger) comes into contact with friction layer of the S-TENG, the charges are produced due to well-known triboelectric effect. The triboelectric charges act as a gate bias to the graphene FET and modulate its current transport. The tribotronic transistor therefore does not require any external gate voltage as in traditional metal oxide field effect transistors. The tribotronic sensors have displayed a sensitivity of ~2% kPa-1, a limit of detection <1 kPa, and a response time of ~30 ms.

Sustainability efficiency of Chinese cities involving coal-fired power plants with data envelopment analysis

ABSTRACTCoal currently accounts for nearly 70% of the energy consumption in China, and is expected to remain a vital energy source in the near future. Planning and construction of national large-scale coal-fired power plants (CFPPs) is an important aspect of China’s 12th coal industry five-year plan and the development strategy for future energy. CFPPs have large electricity generation potential and are important for maintaining energy security and structure. However, the construction and development of CFPPs leads to local ecological and environmental problems. The sustainable development of CFPPs is becoming increasingly important. The assessment of CFPP sustainable development would highlight the main problems in CFPP planning, construction, operation, and management, avoiding the adverse effects on local society, economy, ecosystems, and environment. This study demonstrated a sustainable development assessment framework for CFPPs and their regions, which concerned natural resources and environmental pollutants as the inputs and human well-being as the socio-economic output. Sustainable development would mandate lower inputs and higher well-being outputs. Using data envelopment analysis, the sustainable development efficiency of cities in CFPP regions was assessed. The results showed increases in urban sustainability efficiency for cities involving CFPPs from 1990 to 2010. Heavy water pollution and excess energy consumption were the main problems identified for urban and CFPP sustainable development. The findings of this study can be used as a reference for urban and CFPP sustainable development and provide guidance for future CFPP construction and development.

DYNAMIC SIMULATION MODEL OF ELECTRICITY ENERGY DEMAND AND POWER PLANT CAPACITY PLANNING IN MADURA

As a country that has many islands, Indonesia faces a challenge of inequality electrification ratio. The big islands with dense population such as Java and Sumatra could build large electricity generation plants and distribute electricity with economies scale. On the other hand, it is not economical to build large power plants on small and isolated islands; because of the investment cost per number of population is still very high. Therefore, a strategy to build an independent power plant in small island such as Madura is still a challenge for the government. In addition, to build a power plant in Madura, requires a comprehensive analysis of electricity energy needs in the future and capacity planning to fulfill the demand. Madura has the potential to develop its own power plant. However, Madura still relies on supplies from the island of Java. Therefore, in this research, we use system dynamics as a framework to develop a simulation model to project the future demand and power plant capacity planning based on consideration that system dynamics can conduct the demand projection and capacity planning as well as developing scenarios to fulfill demand in 25 years.

GMAW Welding of MPM Sheets in Active Gas

MPM sheets represent the sanwich panels consisted of two low carbon steel sheets 3 mm thick separated by a visco-elastic inner layer. It is used for dampening the structure borne sound and it replaces the structural sheet metal without taking up a considerable amount of space. The inner layer, however, makes the welding more difficult, since it burns when exposed to relatively high welding temperatures. This may cause distorsion and separation of sheet metal, as well as the loss in sound dampening properties. Therefore, it is of utmost importance that the visco-elastic inner layer remains intact as much as possible, while still maintaining a low cost and a high productivity during welding of MPM sheet housing of large industrial electric motors and generators. In this paper, gas metal arc welding (GMAW) with CO2 active gas was used in an attempt to produce suitable butt welds, welded from both sides. To prevent distorsion and burning of inner layer different butt welds were tested. Different combinations of the following welds were tested: open square weld, combined open square weld on one sheet and single V on the other side, welding in one pass on each side and welding in multiple bead segments on each side. It was found that in all cases, a full penetration was achieved. Furthermore, inner layer thickness near the weld and potential distorsion strongly depend on the welding methodology used.

Triboelectrification-Induced Large Electric Power Generation from a Single Moving Droplet on Graphene/Polytetrafluoroethylene

Recently, several reports have demonstrated that a moving droplet of seawater or ionic solution over monolayer graphene produces an electric power of about 19 nW, and this has been suggested to be a result of the pseudocapacitive effect between graphene and the liquid droplet. Here, we show that the change in the triboelectrification-induced pseudocapacitance between the water droplet and monolayer graphene on polytetrafluoroethylene (PTFE) results in a large power output of about 1.9 μW, which is about 100 times larger than that presented in previous research. During the graphene transfer process, a very strong negative triboelectric potential is generated on the surface of the PTFE. Positive and negative charge accumulation, respectively, occurs on the bottom and the top surfaces of graphene due to the triboelectric potential, and the negative charges that accumulate on the top surface of graphene are driven forward by the moving droplet, charging and discharging at the front and rear of the droplet.

Paths of technological capability building in complex capital goods: The case of hydro electricity generation systems in Iran

This paper investigates the accumulation of technological capability in latecomer suppliers of complex capital goods by exploring the issue in an Iranian supplier of large hydro electricity generation systems. The findings suggest that, contrary to the conventional paths of catch-up in Asian and Latin American mass-producing electronics firms, and instead of starting from early stages of product lifecycle, the technological capabilities in this case were acquired through a non-linear movement within the stages of designing and installing complex capital goods in projects: starting from the middle stage (engineering and realisation of complex goods in projects), moving to the last stage (operation and troubleshooting of complex goods), and eventually coming back to the first stage (conception and design of complex goods). A detailed analysis of learning mechanisms reveals that this path emerged largely due to the nature of “learning by projects” in this industry, engineering intensity of the tasks, and insufficiency of conventional knowledge transfer methods for building design capabilities in complex systems. The paper starts by developing an initial framework of technological capabilities that is then refined through this study and the resulting framework is presented as one of the contributions. Based on the findings, a set of new empirical categories of technological capabilities in complex capital goods is suggested to help future research in this area. Implications of this research are also discussed for global value chains literature. The conclusion touches upon the implications of the study for business strategy and policy.

Benchmarking supercritical carbon dioxide cycles against steam Rankine cycles for Concentrated Solar Power

Research into concentrated solar power (CSP) technologies has increased significantly due to environmental and energy security concerns. In particular, central receiver CSP technology is considered to be a viable option for large scale electricity generation. However, electricity cost associated with current commercial central receiver CSP technology is not yet competitive with conventional fossil-fuel based electricity generation technologies. In order to reach cost parity with conventional technologies, it is necessary to reduce capital requirements and increase efficiency. In order to meet these requirements, alternative power cycles to the current commercial steam Rankine cycle need to be considered.Supercritical carbon dioxide (S-CO2) has been considered as an alternative working fluid for power cycles in operation within a central receiver CSP plant. In this study, three different S-CO2 power cycle layouts are compared against a steam Rankine cycle at both superheated and supercritical conditions. The power cycle concepts are compared on a consistent basis in terms of both cost and thermal efficiency. Results show that S-CO2 power cycles are not competitive against the current steam Rankine technology. Therefore, based on the results of this study, research into power cycles for CSP application should target the steam Rankine cycle over S-CO2 power cycles.

The effect of increased levels of lead in serum on several antioxidants parameters assed among workers from a large private electrical generator company

Lead poisoning occurs when lead builds up in the body, regularly over a period of months or years. Insignificant amounts of lead can cause serious health complications. The main objective of this study is to determine the effect of gases rising from electric generators and the lead-induced oxidative stress and adversarial health properties by biochemical markers in Iraqi workers employed on the operation of diesel generators mainly increased lead poisoning symptoms. Serum lead, advanced oxidation protein products (AOPP), total antioxidant activity (TAA), malondialdehyde (MDA), and other biochemical parameters were analysed in fifty workers in a large private electrical generator. The results of the study showed a significant elevation in lead, AOPP and MDA activities in Iraqi workers employed on the operation of diesel generators in association to healthy control samples. The results showed that elevated serum lead has a significant correlation with oxidative stress, and biochemical markers that may be help to detect impairment in the body function in lead exposed workers.

차량 현가장치 선형 발전기 구조 검토 및 발전량 향상을 위한 다자유도 선형 발전기

현가장치에 적용 가능한 공진형 선형 발전시스템은 차량이 노면을 주행 시 발생되는 진동에너지를 수집하여 자가 발전기능을 수행하는 시스템으로써, 작은 노면 진동을 증폭하여 큰 발전량을 유도하기 위해 공진 현상을 적용하였다. 시스템 의 진동변위 해석을 통해 세 가지의 각기 다른 발전기 아마튜어의 동적 거동을 시뮬레이션하였고, 이를 전자기 유한요소해석 을 통해 실제 발전량을 계산 및 비교분석 하였다. 또한, 차량 노면주행 시, 다양한 가진 주파수에 공진현상을 적용하기 위해 발전기 아마튜어의 수를 증가시키는 다자유도 발전기로의 설계 개선을 수행하여 공진 점의 변화를 확인하고 이에 따른 발전 량의 변화를 확인하였다. 최종적으로 동일한 제한조건(설치공간)하에서 약 35% 축소된 아마튜어를 설계하여 이전 대비, 1Hz 및 4Hz 가진환경에서 8.5 %, 13.8 % 감소하였고, 15 Hz의 가진 환경에서는 14.7 % 의 증가 현상을 확인하였다.