Energy Power Plants Research Articles

Renewable Energy in Portugal - Legislation, Incentives and Suggestions.

This paper presents the evolution of renewable energy generation in Portugal in the last decade, and explains the legislation and incentives in existence. The paper also presents suggestions that could incentive small and medium consumers to install renewable energy power plants (namely of wind power and photovoltaic types) in their facilities. These power plants would have to accomplish present legislation regarding “reactive energy” production during peak power consumption period, and besides, would have to assure power quality levels. On the other hand, reversible energy meters should be used, so that it would be registered the consumption of energy from the energy company, or the delivery of energy to the energy company. The equipments which could implement these characteristics are briefly described.

Tungsten oxide nanostructures for all-vanadium redox flow battery: Enhancing the V(II)/(VIII) reaction and inhibiting H2 evolution

Vanadium redox flow batteries (VRFBs) offer remarkable performance capabilities for renewable energy power plants. However, the kinetics of the VRFBs' redox reactions are slow and the efficiency is low due to parasitic reactions such as the hydrogen evolution reaction (HER). In this work, to overcome these limitations, the effect of modifying the carbon cloth electrode with tungsten oxide nanowires, nanoflakes, and nanospheres prepared was elucidated for the negative half-cell reaction V(II)/V(III). The physical and chemical properties of those nanostructures were characterized using FESEM, XPS, XRD, FTIR, and contact angle measurements. The effect of the catalyst loading and structure, pH and composition of the synthesis solution, and the presence of binder on catalytic activity was evaluated using CV and EIS. The results showed that the effective loading of all three structures is ~2 mg/cm2, with all of the structures showing a significant enhancement of the V(II)/(VIII) reaction kinetics in comparison to the untreated carbon cloth and greater stability than the thermally treated carbon cloth. The tungsten oxide nanostructures prepared at pH 2 showed the best catalytic activity, with the suppression of hydrogen evolution reaction (HER) being inversely proportional to the number of defects. Tungsten oxide nanoflakes prepared at pH 2 using water as a solvent exhibited the optimum balance between promoting the V(II)/(VIII) reaction kinetics and suppressing the HER. The performance evaluation in a two-electrodes setup of all‑vanadium RFB revealed that the WNFs structure have the highest charge/discharge capacity and energy efficiency at a relatively high current density of 60 mA/cm2 due to its improved kinetics.

Modelling the operation modes of local MicroGrid networks with mobile wind and solar power plants

The basis for the development of the global energy sector is the introduction of alternative energy and, accordingly, a complete change in approaches to the structural reorganisation of energy systems. An analysis of the state of electric power networks in Ukraine shows their almost complete depreciation, low reliability and structural obsolescence, which makes further development and expansion difficult to ensure the rapid growth of electricity consumption. Therefore, a trendy solution to the problem of modernising electric power networks while increasing their capacity and reliability is the use of MicroGrid systems, which are structural elements of the Smart Grid concept based on the intellectualisation of the management of the full cycle of electricity generation, use and storage. The miniaturisation and localisation of smart electric networks makes it possible to minimise power losses and ensure full control over their operating modes. A MicroGrid provides management of distributed energy resources and is essentially a hybrid, as it includes renewable energy sources alongside traditional ones. Regulation of MicroGrid operation modes and power flows in it is the key to increasing the sustainability of the operation processes. The article proposes the use of mobile wind-solar power plants as sources of distributed generation in the MicroGrid system, which is a new technical solution for improving the structural scheme of its implementation and optimising the management of operating modes. The structure of MicroGrid is substantiated and developed, and mathematical modelling of autonomous and hybrid modes of operation of the system with mobile renewable energy power plants is performed. The obtained results show the feasibility and energy efficiency of the developed MicroGrid system. Conclusions are drawn regarding the prospects for further development of MicroGrid with mobile power plants.

Organisation of the Structure and Functioning of Self-Sufficient Distributed Power Generation

During the operation of solar and wind power plants, it is necessary to solve issues related to the guaranteed capacity of these plants, as well as the frequency stabilisation in the power system where they operate, and maintain an operating mode of self-sufficiency conditions. One of the solutions to these problems is the use of energy storage systems. This article proposes a mathematical model for the study of frequency and power regulation processes in power systems with distributed generation, which includes renewable energy resources and energy storage systems. The novelty of the model lies in the possibility of determining energy cost indicators based on instantaneous energy power data. The model allows us to estimate the conditions under which distributed generation becomes self-sufficient. The results of the model calculations of two variants of power system operation, which includes wind generators with a capacity of 1500 MW, demonstrate the ability of the proposed model to accurately reproduce the dynamics of the frequency stabilisation process. The calculation results of the energy-economic indicators of a real power system combined with a powerful subsystem of wind generation and a battery-type energy storage system prove the competitiveness of self-sufficient renewable energy power plants.

INTEGRATION OF HEATING SYSTEM OPERATION

Ukraine has a huge asset in the form of existing district heating (DH) networks and demand for related services. DH is transforming the European energy sector, attracting efficient, local and renewable energy resources where this was not possible. However, due to the old material base of spare parts, insufficient level of investment and low level of management, Ukrainian DH systems are ineffective and do not meet the needs of consumers. The experience of European Union member states in central Europe shows that deep and sustained reforms can address the current challenges of the heating sector, including improving energy efficiency and economic competitiveness, strengthening environmental sustainability and enhancing energy security. The DH sector in Ukraine has not yet undergone the structural reform that other sectors of the economy have already gone through: over the past 30 years, the quality of services has decreased; subsidies have increased; the old material base is falling apart; The question arises whether it is worth continuing to support DH. As a result, Ukraine's DH sector is in dire straits, with financial, operational and technical problems compounding each other. Comprehensive and well-planned efforts must be made to create the conditions for exiting this state. Such structural reforms are essential to attracting the investment needed to improve the quality, efficiency and long-term potential of the district heating sector.
 The article examines the possibility of using modern technological solutions to modernize heat supply systems in order to improve their efficiency, which can lead to improved district heating services, transparency and financial stability.
 Keywords: energy resources, renewable energy sources, fossil fuels, automated heat and power plant, electricity, hot water, hot air, heating, private households, electric water heater, geothermal heat pump, wind power generator, low-power boiler house.

The Effect of Laying Nozzle Distance Position on Operational Results Renewable Power Plant Pico-Hydro

New and renewable energy sources today and in the future are human needs that need to be sought and explored from all existing nature, especially in countries with many sources of application, such as Indonesia. Indonesia is an archipelagocountry that has a vast nature with abundant alternative energy sources such as river flow, irrigation which can be usedas a source of energy for pico-hydro power plant. The purpose of this study was to determine theperformance of pico-hydro with a test model for the position ofnozzle position mounted on the pico-hydro usingscrew Archimedes turbine. The research method is carried out by direct experimentation from a tool that has been made using water fluid that iscirculated continuously as if in actual operating conditions. The results of this research show that the positioning of the nozzle distance as the water output to drive the turbine blades affectoperational results obtained. The farther distance fromnozzle position tothread, the power and rotation also decrease, on the other hand, ifnozzle is tooclose, the water sprayed bynozzle causes a back force of water so that the results are not optimal. In this research, the greatest power is generated at a nozzle distance of 4 cm, which is 230 Wattat a flow rate of 24 m3/h, and the lowest power is obtained at 44 Wattat flow rate of 2 m3/h where this position is ideal for pico-hydro installation.The best turbine shaft rotation in this study was produced at a nozzle distance of 4 cm which is 195 rpm, in this condition the spray of water flowing out of the tip of the nozzle towards the screw blade of the first part of the turbine which hits the sidelines of the screw occurs without resistance.

Scenario mitigation of threats and disruptions to development plan of Nuclear Power Plan (NPP) in Indonesia

Plans for the development of nuclear power plants in Indonesia have existed since the Soekarno regime in 1945, but have never reached the policy implementation stage until the current presidency of Joko Widodo. This is related to obstacles that can be in the form of Threats, Disruptions, Obstacles and Challenges (AGHT), so that it always fails in the implementation process, both on a global, national and regional scale due to issues in the social, political, technological, and other realms. The purpose of this study is to analyze the scenario of Threats and Disruptions mitigation scenarios for the development of nuclear power plants in Indonesia. The results of the study indicate that the mitigation of the threat of nuclear power plant development plans in Indonesia is through First Track Diplomacy and Second Track Diplomacy, guided by Law No. 10 of 1997 in decision making, and integrated community involvement in supporting government programs. Mitigation of disruptions to the nuclear power plant development plan in Indonesia through a policy of targeting the energy mix by optimizing the use of NRE other than nuclear, while developing a nuclear power plant development plan, implementing a Carbon Tax, socialization through K/L cooperation regarding the use of nuclear energy for nuclear power plants, various fields and second track diplomacy.

Discussion on the development of nuclear energy and nuclear power plants

Nuclear energy is an extremely important source of energy. Nuclear energy always is considered a kind of clean energy, which has given it a lot of chances to develop. Nevertheless, the potential hazards associated with nuclear energy as well as concerns regarding resource depletion and environmental impact often result in strong opposition. Therefore, the future direction of nuclear power plants is particularly important. This paper aims to discuss the current state and prospects of nuclear energy development. While nuclear energy is experiencing rapid growth, it also faces various challenges simultaneously. These previous advancements serve as crucial foundations for future progress in nuclear energy. Therefore, this passage highlights the pivotal developments in the history of nuclear power plants, encompassing both fission and fusion reactions at their physical core. Additionally, it addresses the issues currently encountered by nuclear plants and proposes potential solutions to these concerns. Furthermore, it acknowledges that public perception plays a significant role in shaping the trajectory of nuclear energy development. Lastly, it introduces novel technologies and strategies that have the potential to enhance the future of nuclear energy. By analyzing emerging fusion-based nuclear energy approaches, we can discern valuable insights into the future direction of our existing nuclear technology landscape. Consequently, comprehending contemporary developments and challenges within the realm of nuclear energy enables us to better evaluate its role and impact within our future energy framework.

A GIS-based FAHP and FEDAS analysis framework for suitable site selection of a hybrid offshore wind and solar power plant

This study presents a Geographic Information System (GIS) based suitable site selection methodology for a hybrid system that includes offshore wind and solar PV. The methodology utilizes open source databases about decision criteria and applies this data using GIS to determine suitable sites for offshore wind and solar PV systems. For the assessment of multi-criteria which affect the potential hybrid energy power plants and the determination of the best suitable areas, Fuzzy Analytical Hierarchy Process (FAHP) and Fuzzy Evaluation based on Distance Average Solution (FEDAS) are used in the study. Results show that technical criteria has the priority weight of 0.60 while the weight of social criteria is about 0.07. Among sub-criteria, the wind speed has the highest priority weight while distance to port and visibility are the highest criteria of priority weight under economic and social main criteria, respectively. Among the alternatives, Area 2 (A-2) is determined as the best alternative for hybrid offshore power plants in the study area. This proposed methodology can be utilized by decision-makers to determine the best suitable locations for hybrid offshore wind and solar PV systems at any location. This paper suggests a new approach integrating GIS, fuzzy setbased AHP and EDAS as a novelty.

Analysis of the dynamic evolution process of the digital transformation of renewable energy enterprises based on the cooperative and evolutionary game model

Based on the cooperative-evolutionary game model, this paper studies the dynamic evolution process of the digital transformation strategy selection of renewable energy power plants and renewable energy selling enterprises under government supervision. Renewable energy power plants, renewable energy selling enterprises, and the government are taken as the game players. The Shapley value based on the cooperation game distributes the cooperation benefits brought about by the digital transformation of enterprises and analyses the dynamic evolution process of the strategy of the three-party game players based on evolutionary game theory. Then, based on the system dynamics model, Anylogic and Vensim software are used to simulate the cooperative evolutionary game model, and a sensitivity analysis of the key factors affecting the system stability is carried out. The results show that the "digital transformation" of renewable-energy power plants and renewable-energy selling enterprises will bring about cooperation benefits and promote their joint promotion of digital transformation. Government incentives can accelerate the digital transformation of renewable energy companies. The increase in economic, environmental, and social benefits brought about by the digital transformation of renewable energy enterprises promotes the speed of the digital transformation of renewable energy power plants and renewable energy selling enterprises.

Solving the Green Economic Load Dispatch by Applying the Novel Meta-heuristic Algorithm

This study focuses on solving the green economic load dispatch problem by considering the presence of green energy sources, including wind energy and solar power plants. The main objective function of the whole study is to minimize the total fuel cost (TFC) of all the thermal generating sources (TGSs) in the system. Moreover, the multiple selection of all TGSs is also evaluated. Fire hawk optimization (FHO) and the Zebra optimization algorithm (ZOA) are applied to solve the problem of achieving the best TFC value and satisfying all the constraints involved. The results indicated that ZOA can achieve a better optimal solution compared to FHO. Particularly, the results obtained by ZOA are completely superior to FHO in all comparison criteria at two load demand levels, such as Best TFC value (Best.Cost), Average TFC value (Aver.Cost), and Maximum TFC value (Max.Cost). On top of that, ZOA is the only algorithm of two applied ones providing the fast convergence capability to the optimal value of the main objective functions in two cases of load demand levels. Therefore, ZOA is an efficient search method to deal with such GELD problems.

Analysis of the joint trading of local green power certificates, carbon emissions rights, and electricity considering demand flexibility

Establishing synergy among distinct yet associated markets through market orientation is crucial because it can facilitate a clean and low-carbon energy transition. However, researchers have not yet developed a quantitative analytical dynamic model for studying market participants in the context of the joint electricity-carbon-green power certificates market. Moreover, the solution algorithm merits further exploration. This article proposes an analytical method for evaluating the joint trading of local green power certificates, carbon emission rights, and electricity, while taking into account the demand flexibility. First, a framework for the joint trading of local green power certificates, carbon emission rights, and electricity is designed. Second, market participants, such as traditional thermal power plants, renewable energy power plants, and load aggregators, are modelled via system dynamics theory. On this basis, a deep distributed reinforcement learning algorithm is applied to solve the problem. Finally, the effectiveness of the proposed theoretical approach is verified through real-life simulations, and the sensitivity of the key factors influencing joint trading is also analysed.

Does the change in incentive policies promote renewable energy power generation in China?

ABSTRACT To reduce the financial burden brought by the feed-in tariff (FIT) policy, China is shifting its renewable energy support policy to the renewable portfolio standard with tradable green certificates (RPS/TGC). Moreover, the two policies are being implemented in parallel in the transitional period. In this context, this study investigates the game between renewable energy power plants (REPPs) regarding electricity outputs and tradable green certificate (TGC) prices under different renewable energy support policies practiced in China. We focus on analyzing the impact of policy changes on the competing REPPs’ decisions and the renewable electricity market with TGCs. The results show that implementing the RPS/TGC policy inhibits the development of renewable electricity unless the subscription of TGCs is promoted. Government subsidy arrears significantly affect electricity outputs and TGC subscriptions. The low subscription rate of TGCs is caused not by the subsidy-based TGC pricing mechanism but by government subsidies. This suggests that the government should implement the RPS/TGC policy, and demand-side power consumption responsibility weights should also be strengthened to promote TGC subscriptions.

Optimal design of standalone hybrid solar-wind energy systems for hydrogen-refueling station Case study

The optimization of renewable energy power plants (REPPs) to provide electricity and hydrogen for charging Electric Vehicles (EVs) and Fuel Cells Vehicles (FCVs) permits to achieve the sustainability goals in the near future. Indeed, REEPs, EVs, and FCVs have zero greenhouses gas emission. The optimization of the REPPs according to renewable energy sources potential and load requirements, results in costs minimization and increase in the REPPs efficiency. In this context, this paper presents the optimization and the analysis of four standalone REPPs providing electricity required for charging EVS and producing green hydrogen for charging FCVs. The analyzed REPPs consist of wind turbines, photovoltaic panels, power converters, fuel cell, electrolyzers, and hydrogen tanks. The obtained results of each technical solution are analyzed apart and compared with other results to identify the system having the lowest Net Present Cost (NPC), and the lowest levelized electricity and hydrogen costs. The renewable energy potential shows a wind average speed, and average solar radiation of 5 m/s and 6 kWh/m2/day, respectively. The optimization results show that the PV-battery system has a lowest NPC of 11 M€. The PV-wind fuel cell system has the highest NPC due to the high price of wind turbines and fuel cells. The minimum and maximum levelized cost of hydrogen are 4.78 €/kg and 5.55 €/kg, respectively. The optimized configuration produces around 11,756,589 kWh/year of electricity and 177,607 kg of green hydrogen. The total required capacity is 6 MWp PV system with 1800 kWh of battery for the storage of electricity.

Non-State Actor's Strategy in Advocating the Movement to Reject Development Policy

Geothermal is one of the potential renewable energy sources in Indonesia. This great potential makes the government try to develop geothermal energy development, one of which is in Mount Talang. However, the development received a rejection from the community, including non-state actors. This study looks at the strategy of the YLBHI Padang Legal Aid Institute in advocating the movement against the construction of geothermal energy-powered power plants. The studying conducted for 6 (six) months. This research design uses qualitative methods. The data sources we collect are interview data, observation results, official texts or policies, journal articles, websites on the internet, newspapers, social media, and youtube. The advocacy strategies carried out by LBH YLBHI Padang are; understanding strategic issues, building opinions and facts to the public, building coalition networks with civil society such as local communities, NGOs, students, national networks, and academics, designing goals and strategies as well as monitor and assess movements. The result of the advocacy carried out by LBH YLBHI Padang was the "temporary" suspension of constructing a geothermal energy power plant in Mount Talang. This research ends with research recommendations such as the need for inclusive stakeholder involvement in the formulation of development policies and 2) the need to grow civil society in the regions to become non-structural control for the government.

Automating Quality Control of Irradiance Data with a Comprehensive Analysis for Southern Africa

A review of quality control for large irradiance datasets is applied as a case study for the Southern African Universities Radiometric Network (SAURAN) database. The quality control procedure is automated and applied to 24 stations from the database with a total of 848,189 hourly datapoints. From this, the individual station’s data quality is also analysed. The assessment validates the automated methodology without the need for a user-based review of the data. The SAURAN database can play a significant role in advancing solar and wind energy; however, the number of offline stations hinders this process. Data scarcity remains an obstacle to these goals, and therefore, recommendations are provided to address this. Recommendations regarding each site’s usability in time-series and discrete applications are made, which provides an overall indication of the SAURAN database’s irradiance measurement quality. Of the 24 measuring stations assessed, eight are recommended, 11 are recommended with cautious use, and five are recommended with extremely cautious use. These recommendations are based on multiple factors, such as whether a dataset has more than one full year of data or is missing minimal datapoints. Further, a study of the irradiance correlation between the stations was conducted. The results indicated groupings of different stations that showed highly correlated irradiance measurements and similar weather patterns. This is useful if a proposed renewable energy power plant, such as PV, falls within a cluster where the data from the SAURAN database can be used as a substitute if no data is available. SAURAN presents an opportunity for Southern Africa to increase its research outputs in solar and wind energy and lessen its dependency on fossil fuel-based energy production.

In-situ thermophysical measurement of flowing molten chloride salt using modulated photothermal radiometry

Molten salts are leading candidates for high-temperature heat transfer fluids (HTFs) for thermal energy storage and conversion systems in concentrated solar power (CSP) and nuclear energy power plants. The ability to probe molten salt thermal transport properties in both stationary and flowing status is important for the evaluation of their heat transfer performance under realistic operational conditions, including the temperature range and potential degradation due to corrosion and contamination. However, accurate thermal transport properties are usually challenging to obtain even for stagnant molten salts due to different sources of errors from convection, radiation, and corrosion, let alone at flowing status. To the best of authors’ knowledge, there is no available in-situ technique for measuring flowing molten salt thermal conductivity. Here, we report the first in-situ flowing molten salt thermal conductivity measurement using modulated photothermal radiometry (MPR). We could successfully perform the first in-situ thermal conductivity measurement of flowing molten NaCl-KCl-MgCl2 in the typical operating temperature (520 and 580 °C) with flow velocities ranging from around 0.3 to 1.0 m s−1. The relative change of the molten salt thermal conductivity was measured. Gnielinski’s correlation was also used to estimate the heat transfer coefficient h of the flowing NaCl-KCl-MgCl2 in the given experimental condition. The work showed the potential of the MPR technique serving as an in-situ diagnostics tool to evaluate the heat transfer performance of flowing molten salts and other high-temperature HTFs.

Integration of Renewable Energy Power Plants on a Large Scale and Flexible Demand in Bangladesh's Electric Grid-A Case Study

The fundamental objective of this article is to put in renewable energy sources strategically within the context of Bangladesh's electric infrastructure. Solar and wind energy are inherently intermittent and variable, depending on weather conditions. Because of this unpredictability, power generation can fluctuate, making it difficult to maintain a consistent and reliable energy supply. The case study focuses on the problems and opportunities given by large-scale renewable energy power plant integration and the construction of a flexible demand system. The study digs into the technical, economic, and environmental elements of this integration, taking into account factors like as grid stability, fluctuation in energy supply, and the possibility for lowering greenhouse gas emissions. The abstract shows the potential benefits of such integration for Bangladesh's energy landscape and provides useful insights into the broader subject of renewable energy integration in poor countries through a thorough examination. This study can help future recommendations by policy-makers, producers, entrepreneurs, and utilities grow to enable for large-scale renewable energy penetration into the primary utility grid of a community by providing an outline of the energy supply difficulties in Bangladesh considering techno-economic advantages.

A comparison of power plant energy flow prediction using real data applied to linear programming and if-else algorithms

In this paper, the energy flow prediction of a grid-connected Hybrid Microgrid (HMG) is studied. The studied system consists of a 19 kW photovoltaic (PV) array, a 6.5 kW wind turbine (WT), and a 59.32 kWh battery Energy Storage System (ESS). Two energy prediction and optimization algorithms, Linear Programming and If-Else (LP-If-Else), are applied to analyze the site's energy flow behavior and accurately predict it one day in advance. Meteorological data collected at the site and real load profiles are used in this study. To highlight the effectiveness of the offline prediction approach, three extreme cases are applied to three energy management strategies and compared. The results of the prediction performed by the two algorithms showed that a single prediction algorithm (LP) is not sufficient to accurately predict the energy flow for the next day.

Comprehensive technical study of a novel polygeneration arrangement using natural gas power plant and geothermal energy for producing electricity, heat, fresh water, and methanol

Structural modifications play a crucial role in enhancing the sustainability of natural gas power plants owing to their significant contribution to greenhouse gas emissions and irreversibility factors. One primary solution is using waste heat recovery systems integrated with these power plants, producing different products. Furthermore, integrating renewable energy resources into the entire system within a co-feed framework may be a viable method for further enhancements. The current study focuses on a novel heat integration process combined with a natural gas power plant, which uses geothermal energy as an auxiliary energy source. The newly designed system encompasses a gas turbine cycle, two modified geothermal power plants, a water electrolyzer unit, and a methanol synthesis unit. The process is simulated utilizing the Aspen HYSYS software, and to evaluate its viability, analyses are performed pertaining to energy, exergy, environment, and economics. Furthermore, a comprehensive parametric analysis is conducted on the primary performance indicators. The simulation results show that the process’s energy, exergy, and electrical efficiencies equal 53.85%, 47.30%, and 40.26%, respectively. The environmental evaluation demonstrates that the specific carbon dioxide emissions associated with the total energy produced and the sum of power and heating are 0.27 kg/kWh and 0.294 kg/kWh, respectively. From the economic aspect, the total unit cost of the products and the cost of energy of the system are 20.69 $/GJ and 0.086 $/kWh, respectively. Also, total annual cost, investment cost, and net present value of 222.81 M$, 1010.64 M$, and 1220.57 M$, respectively.