Combination Of Renewable Energy Sources Research Articles

Clean energy technologies and energy systems for industry and power generation: Current state, recent progress and way forward

This vision article accompanies a Special Issue of Applied Thermal Engineering dedicated to the Sustainable Development of Energy, Water and Environment Systems (SDEWES) conference series held during 2022, including the 5th SEE SDEWES Conference Vlore, 3rd LA SDEWES Conference Sao Paulo, and 17th SDEWES Conference Paphos. The article discusses a selection of papers presented at these conferences and selected for publication in Applied Thermal Engineering, all connected by a focus on clean energy technologies and systems for the advancement of sustainable thermal energy systems. This research area covers a wide range of technologies but is primarily focused on the power generation sector, energy storage and utilization, efficiency improvements, sustainable technical solutions, and the facilitation of the robust integration of renewable energy resources into wider energy systems. Additional work on previously established research topics is also present, but new directions have crystallized, especially research into thermal management for power devices and microelectronics. Based on the recent contributions to the research field presented in the included papers, this vision article discusses the development and application of cutting-edge technological solutions and identifies the challenges that require focused attention. Current shortcomings of developing and established technologies will be developed by the underlying fundamental research, reduction of prohibitively high costs, expansion of operating conditions, and the inclusion of advanced control approaches, sophisticated combinations of renewable energy sources, and modeling tools for system investigations. Scientists, researchers, and engineers can benefit from the summary of the topics at the forefront of the research field and find guidelines and ways forward for future research activities.

Clean energy technologies and energy systems for industry and power generation: Current state, recent progress and way forward

This vision article accompanies a Special Issue of Applied Thermal Engineering dedicated to the Sustainable Development of Energy, Water and Environment Systems (SDEWES) conference series held during 2022, including the 5th SEE SDEWES Conference Vlore, 3rd LA SDEWES Conference Sao Paulo, and 17th SDEWES Conference Paphos. The article discusses a selection of papers presented at these conferences and selected for publication in Applied Thermal Engineering, all connected by a focus on clean energy technologies and systems for the advancement of sustainable thermal energy systems. This research area covers a wide range of technologies but is primarily focused on the power generation sector, energy storage and utilization, efficiency improvements, sustainable technical solutions, and the facilitation of the robust integration of renewable energy resources into wider energy systems. Additional work on previously established research topics is also present, but new directions have crystallized, especially research into thermal management for power devices and microelectronics. Based on the recent contributions to the research field presented in the included papers, this vision article discusses the development and application of cutting-edge technological solutions and identifies the challenges that require focused attention. Current shortcomings of developing and established technologies will be developed by the underlying fundamental research, reduction of prohibitively high costs, expansion of operating conditions, and the inclusion of advanced control approaches, sophisticated combinations of renewable energy sources, and modeling tools for system investigations. Scientists, researchers, and engineers can benefit from the summary of the topics at the forefront of the research field and find guidelines and ways forward for future research activities.

OPTIMAL SCHEDULING OF RENEWABLE ENERGY RESOURCES IN ENERGY MANAGEMENT SYSTEMS USING HYBRID GENETIC ALGORITHM AND PARTICLE SWARM OPTIMIZATION

Emphasizing the importance of Energy Management (EM) systems, the rise in Distributed Generation (DG) and the introduction of multicarrier energy networks have become key factors. An EM is a novel concept introduced in multicarrier energy networks. It enables the transmission, reception, and storage of various types of energy. Thus, this paper presents an enhanced energy hub incorporating various renewable energy-based DG units and heating and power storage systems. It focuses on modeling the operational and organizing elements of the system. In addition, the modeling of optimal planning and scheduling for a multicarrier EM system considers the unpredictable nature of wind and Photovoltaic (PV) units. An effective solution to the EM problem, cost reduction, peak-to-average ratio (PAR), and carbon emission can be achieved through a seamless combination of Renewable Energy Sources (RES) and Power Storage Systems (PSS). This work presents an Optimal Scheduling and Energy Management System utilizing Hybrid Genetic Algorithm and Particle Swarm Optimization (OSEMS-HGA-PSO). This approach combines the strengths of both GA and PSO, resulting in better convergence and superior solutions for optimal scheduling of RES in EM systems. The numerical evaluation assesses the effectiveness of the heuristic algorithms and the proposed system. The results show that the HGA-PSO EM system significantly decreases the cost, PAR, and carbon emission by 58.74%, 57.19%, and 90%, respectively.

OPTIMAL SCHEDULING OF RENEWABLE ENERGY RESOURCES IN ENERGY MANAGEMENT SYSTEMS USING HYBRID GENETIC ALGORITHM AND PARTICLE SWARM OPTIMIZATION

Emphasizing the importance of Energy Management (EM) systems, the rise in Distributed Generation (DG) and the introduction of multicarrier energy networks have become key factors. An EM is a novel concept introduced in multicarrier energy networks. It enables the transmission, reception, and storage of various types of energy. Thus, this paper presents an enhanced energy hub incorporating various renewable energy-based DG units and heating and power storage systems. It focuses on modeling the operational and organizing elements of the system. In addition, the modeling of optimal planning and scheduling for a multicarrier EM system considers the unpredictable nature of wind and Photovoltaic (PV) units. An effective solution to the EM problem, cost reduction, peak-to-average ratio (PAR), and carbon emission can be achieved through a seamless combination of Renewable Energy Sources (RES) and Power Storage Systems (PSS). This work presents an Optimal Scheduling and Energy Management System utilizing Hybrid Genetic Algorithm and Particle Swarm Optimization (OSEMS-HGA-PSO). This approach combines the strengths of both GA and PSO, resulting in better convergence and superior solutions for optimal scheduling of RES in EM systems. The numerical evaluation assesses the effectiveness of the heuristic algorithms and the proposed system. The results show that the HGA-PSO EM system significantly decreases the cost, PAR, and carbon emission by 58.74%, 57.19%, and 90%, respectively.

ОБОСНОВАНИЕ ПРИМЕНЕНИЯ ДИФФЕРЕНЦИРОВАННОГО СОЦИАЛЬНОГО ТАРИФА НА ЭЛЕКТРИЧЕСКУЮ ЭНЕРГИЮ ПРИ РЕАЛИЗАЦИИ ПРОЕКТА ЭЛЕКТРОСНАБЖЕНИЯ ОТ АВТОНОМНОЙ ГИБРИДНОЙ ЭНЕРГЕТИЧЕСКОЙ УСТАНОВКИ

The issue of uninterrupted power supply to remote settlements is relevant in many countries of the world, but especially in Russia. Modern autonomous hybrid power plants (AHPP), namely solar power plants (SPP), wind power plants (WPP) and other power plants using renewable energy sources (RES), combined with diesel electric power plants (DES), provide not only an increase in the amount of electricity generated, but, most importantly, they ensure uninterrupted power supply to consumers through a combination of renewable energy sources and covering the missing energy from diesel power plants. In the conditions of the northern areas of the Krasnoyarsk Region, this is especially important. ASPPs make it possible to reduce the cost of electrical energy by saving fuel consumption and budgetary subsidies for its supply to remote areas of the region. The purpose of the study was to substantiate the areas of application of autonomous hybrid power plants for the regions of the Far North with the possibility of establishing a differentiated social tariff for household consumers. To achieve the goal, load coverage graphs were constructed for Vanavara settlement; the parameters of the ASPP were studied for the conditions of Vanavara settlement; simulation of the operating modes of the ASPP was carried out; calculation of the main technical and economic indicators of the use of ASPP for power supply to Vanavara settlement was carried out; recommendations were given on rational areas of application of ASPPs with the possibility of applying special tariffs for the electricity they produce. The authors of the paper carried out a technical and economic assessment of ASUE in the Vanavara settlement with a capacity of 10 MW, including a solar power plant with a capacity of 2,5 MW. It was established that the cost of electrical energy in the first option when powered by diesel power plants is 36,75 rubles/kW.h. In the second option, the cost depends on the time of year and is 32,7 rubles/kW.h in winter, 11.6 in spring, 6.05 in summer, and 12,2 rubles/kW.h in autumn, which makes it possible to establish a differential social tariff for household consumers based on a lower cost in the summer in the amount of 7–9 rubles/kW.h.

Investigation of a community-based clean energy system holistically with renewable and hydrogen energy options for better sustainable development

This study develops a novel community-based integrated energy system where hydrogen and a combination of renewable energy sources are considered uniquely for implementation. In this regard, three different communities situated in Kenya, the United States and Australia are studied to cover their needs potentially by producing hydrogen, biogas, power, residential space and industrial heating, hot water and fresh water. where a multigenerational geothermal plant integrated with a solar power plant (using both concentrated solar power (CSP) and photovoltaic (PV) panels) is considered to provide the energy inputs. Innovations in hydrogen production and renewable energy are essential for reducing carbon emissions. By combining the production of hydrogen with renewable energy sources, this system seeks to move away from the reliance on fossil fuels and toward sustainability. The study investigates various research subjects using a variety of methods. The performance of the geothermal source is considered through energetic and exergetic thermodynamic analysis. The software System Advisor Model (SAM) and RETscreen software packages are used to analyze the other sub-systems, including CSP and PV units and a combined heat and power plant. The Australian, American, and Kenyan communities considered for this study are found to have promising potential for producing hydrogen and electricity from renewable sources. The geothermal output is expected to be 35.83 MW for electrical power, 122.8 MW for space heating, 151.9 MW for industrial heating, and 64.25 MW for hot water. The overall multigenerational geothermal energy and exergy efficiencies are reported as 65.15% and 63.54% respectively. These selected communities are expected to have annual solar power generation and hydrogen production capacities of 158 MW, 237 MW, 186 MW, 235 tons, 216 tons, and 313 tons respectively.

Hybrid Wind-Solar System with UPQC

The hybrid wind-solar system is a combination of renewable energy sources, specifically wind and solar, that is utilized for power generation. While wind power has historically been used for various purposes such as sails, windmills, and wind pumps, it is now predominantly used for electricity generation. This system incorporates solar panels and small wind turbine generators to produce electricity. The advantage of hybrid systems is that they can generate electricity as needed, taking into account the varying peak working hours of solar and wind systems throughout the year. To ensure a stable power system, UPQC (Unified Power Quality Conditioner) is employed. This multipurpose power conditioner serves multiple functions, including preventing harmonic load current from entering the power system, rectifying voltage fluctuations, and compensating for voltage disturbances from different power sources. It is specifically designed to minimize interference with sensitive or critical loads. With its series and shunt compensation capabilities, UPQC effectively manages power flow, reactive power, harmonics, and voltage disturbances. In this paper, the work addresses the issue of electricity quality that arises from the installation of wind turbines in the grid. To get over this issue, the suggested course of action demonstrates how to install a BESS and a unified power quality conditioner (UPQC) at the connection point. Even though wind power fluctuates, the use of battery energy storage technology helps to provide a constant power supply. With the power system block established in MATLAB/SIMULINK, one can simulate the UPQC control method of a grid-connected wind energy generating plant. As a result, the power's quality will increase. When the recommended approach lowers the load's and the induction generator's reactive power requirements, it is successful. Furthermore, the plan for raising the grid's power quality criteria and developing the grid coordination rule are also provided.

Energy efficiency in healthcare institutions

AbstractThe Environmental Protection Agency classifies healthcare as one of the leading energy-consuming industries. Extensive energy is needed around the clock in healthcare institutions for lighting, ventilation, and operating medical equipment. However, there is a growing concern over the sustainability of energy utilization by healthcare institutions worldwide. This narrative review thus seeks to examine energy efficiency and utilization in healthcare institutions and energy management and conservation techniques and make recommendations for future optimal usage. The paper notes that healthcare institutions use different quantities of energy from diverse sources, including hydropower, biomass, solar energy, and wind power. However, energy consumption varies from one institution to another, with the number of beds and intensity of healthcare operations, with an average of 0.27 MWh m−2. Moreover, this review also identified various techniques and measures to enhance energy efficiency, such as the variant refrigerant flow technology and the combination of renewable energy sources with diesel generators to reduce the cost of electricity. Overall, healthcare institutions need energy management systems such as automated energy monitoring technologies, to check the systems' efficiency. The same techniques can also help Middle Eastern healthcare institutions with efficient energy utilization. Ultimately, the literature review aims to introduce an approach that focuses on reducing site-level consumption of energy while increasing the quality of the energy used and hence, helping reduce energy costs while conserving the environment.

The role of LCA in the renovation’s early decision-making for the design of a multifunctional, modular building envelope system

The renovation of buildings has a high capacity to influence the environmental impacts and global objectives of climate change mitigation. In the context of designing low-energy buildings with minimized environmental impacts, the life cycle assessment (LCA) has been proven a straightforward method, to evaluate the direct and indirect environmental impacts of a building concept. Even though it is the most energy-intensive element, the use phase is not only a source of environmental concern but also the whole life cycle of the building and its components. However, energy-efficient renovation decisions tend to be financially motivated events, subject to exogenous constraints or barriers, that do not integrate whole life cycle thinking. This study aims to identify how the LCA information can be considered in comparing renovation options. compare renovation options, taking into account the modular envelope system developed as part of the European research project ENSNARE (ENvelope meSh aNd digitAl framework for building Renovation) case study. The study analysed different renovation scenarios, generated according to combinations of renewable energy sources and compare them to the base case and typical renovation scenario. Such information can support the design team in making decisions that consider the whole building and its components’ life cycles.

Optimal management of an energy-water-carbon nexus employing carbon capturing and storing technology via downside risk constraint approach

The development of infrastructures in a sustainable manner ensures the preservation of human life. It means that societies should have constant access to clean energy and water resources. The focus on nexus planning and operation including renewable energy sources has covered the requirements for the development of sustainable integrated systems to provide secure energy and water while minimizing carbon footprint. However, the uncertainty of renewable energy resources challenges the operation of such integrated nexuses. In this regard, this paper proposes a risk-constrained operation of a sustainable energy-water nexus with the aim to reduce operational costs as well as carbon dioxide (CO2) emissions amount (t CO2). To supply the energy and water demands, a combination of renewable energy sources and desalination systems are considered. The downside risk constraint is proposed to investigate the impacts of risks of uncertainties associated with renewable energy production and electricity consumption as well as water demands. Electrical and water storage infrastructures are involved to increase the flexibility of scheduling and ensure affordability and sustainability. The problem is modeled as a mixed-integer programming problem resulting in optimal decision-making to manage the energy/water resources and storage systems to provide clean and safe energy and water with the minimum CO2 emission. For the emission sector, the carbon capturing and storing (CCS) technology is proposed to capture the CO2 defusing by the energy sector and resolve the carbon-related issues. To restrict carbon production, both CO2 taxes and cap policies are examined and the results showed that the latter has a considerable effect to incentivize the decision-maker to use CCS technology.

Development and assessment of integrated hydrogen and renewable energy systems for a sustainable city

Advances in renewable energies, hydrogen, electrification, and improvements in efficiency are projected to be the main avenues for carbon emission reductions. Therefore, a combination of renewable energy sources integrated with hydrogen production is needed to meet the climate targets. The novel system combinations studied in this paper promote renewable energies, hydrogen production, and electrification to reduce and/or eliminate the dependency on fossil fuels for sustainability. The communities chosen for this study were in Canada [A], South Africa [B], the Netherlands [C] and Denmark [D]. The proposed systems consisted of wind plants (including offshore), solar photovoltaics, and biomass-based integrated systems for power generation, heat recovery, fresh water, bioethanol and hydrogen production. The hydrogen production is considered using a proton exchange membrane (PEM) electrolyzer and excess electricity generated from renewables. Sustainable fuel sources for transportation proposed in this system are hydrogen, electrical charging stations and bioethanol. All locations had good potential for renewable power generation and hydrogen production. The maximum capacities for the wind and solar farms in the selected locations are identified as 187.5 MW and 32.7 MW respectively. The actual power generated from the plants varies based on the climate conditions of different locations. At the maximum wind and solar power generated (without accounting for community electrical demand), the maximum annual potential capacities obtained for hydrogen generation are 307 tons for location [A], 232 tons for location [B], 399 tons for location [C] and 487 tons for location [D].

Design of type-2 fuzzy logic controller in a smart home energy management system with a combination of renewable energy and an electric vehicle

Home energy management is one of the most important parts of a smart home that manages the efficient use of energy in the smart home. This paper aims to design two type-2 fuzzy logic controllers in the demand-side energy management system. For this purpose, a combination of renewable energy sources, such as fuel cells, photovoltaic solar panels, vertical axis wind turbines with a helical savonius rotor, and an electric vehicle and energy storage system along with an external grid are utilized to supply the electricity usage of home appliances in a smart home. By using the proposed method, higher quality, more economical, and environmentally friendly energy can be accomplished. To this end, the outputs of the proposed controllers are defined to make appropriate decisions about the generated energy, how to supply energy for own consumption, and controllable loads. The number and distribution of membership functions of type-2 fuzzy logic controllers are selected according to the measured real input data over a year in Tehran, Iran. To demonstrate the effectiveness of the proposed method it is simulated by MATLAB/Simulink software, which indicates that the proposed system causes the smart home to receive 49.186 kWh less electricity energy from the grid to supply daily power for home appliances and therefore can weekly consume approximately 343.95 kWh less electricity energy from the grid. it is shown that after applying the proposed strategy, electricity costs were reduced by 71.5%, and the peak-to-average ratio was reduced by 64.6%.

An Improvement of Power Control Method in Microgrid Based PV-Wind Integration of Renewable Energy Sources

Microgrids are quickly becoming a great success for the future of electricity. The notion of the microgrid combines several microsources without interfering with the functioning of the larger utility grid. The DC and AC networks of this hybrid Microgrid are powered by photovoltaic and wind generators. Both AC and DC Microgrids may couple with energy storage devices. A microgrid powered by a combination of renewable energy sources, such as wind and solar, is shown and controlled in this project. The wind energy conversion machine is a doubly fed induction generator (DFIG), and it is coupled to a battery bank through a DC bus. Solar power is efficiently converted utilising a DC-DC boost converter from a solar photovoltaic (PV) array and then evacuated at the common DC bus of DFIG. With the line side converter's droop characteristics implemented, voltage and frequency may be regulated using an indirect vector control. A battery's energy level is monitored, and the frequency set point is adjusted accordingly to prevent excessive charging or discharging. When wind power is not available, the system can still function. Maximum power point tracking (MPPT) is a feature of the control algorithm used by both wind and solar energy blocks. All conceivable operational scenarios have been accounted for in the system's design, making it fully autonomous. An external power supply is included into the system and may be used to charge the batteries whenever needed. The feasibility of wind and solar energy, imbalanced and nonlinear loads, and a depleted battery are only some of the scenarios simulated in this paper, along with the corresponding simulation findings.

Optimal Planning of Hybrid DER Penetration in Distribution Network under Actual Geographical Condition: A Case Study

Integration of distributed energy resources into optimum location and a suitable size is still one of the major issues faced by electric utilities. In this article, a model is proposed that highlights the key issues of hybrid penetration and integrates renewable resources. In this context, optimization has been done that suggests the optimal combination of renewable energy sources based on cost and carbon emissions for the implementation of an integrated assessment of available energy resources. The proposed model is compared with grid-connected and various hybrid energy models. In addition to renewable penetration, the study also focused on significant reductions in greenhouse gas emissions. For analysis of the proposed approach, a study has been carried out on a selected test feeder named Ramchandrapura feeder of Kota, Rajasthan, India. The results obtained from the simulations include the optimal combination of cost-effective distributed energy resources considering actual weather conditions such as solar radiation, temperature, and wind speed. The overall optimization is done with the help of Homer-Pro software. The major contribution of the article is the economic study of test feeders with real geographic data which also considers the environmental impact of DER integration.

Economic Enhancement of Wind–Thermal–Hydro System Considering Imbalance Cost in Deregulated Power Market

Studying the property of the combination of renewable energy sources in the existing power systems is of great importance, and especially in the case of deregulated systems. The uncertainty of renewable sources is the largest barrier to integrating renewable-energy-producing units into the existing electrical infrastructure. Due to its uncertainty, integrating wind power into an existing power system requires extra consideration. In this work, the impacts of wind farm (WF) integration and a pumped hydroelectric storage system (PHES) on the electric losses, voltage profiles, generation costs, and system economy in a deregulated power market were studied. A comparative study was performed to determine the impact of wind farm integration on regulated and deregulated environments. Four locations in India were chosen at random for this work, and we used the real-time statistics for the actual wind speeds (AWSs) and forecasted wind speeds (FWSs) for each chosen location. To determine the system economy, surplus charge rates and deficit charge rates were developed to evaluate the imbalance cost resulting from the mismatch between the predicted and actual wind speeds. Considering the effect of the imbalance cost, the system profit/day varies by an average of 1.6% for the locations studied. Because of the reorganization of the power system, consumers constantly look for reliable and affordable power that is also efficient. As a result, the system security limit may be breached, or the system may run in a dangerous state. Lastly, in this paper, an economic risk analysis is presented with the help of heuristic algorithms (i.e., artificial bee colony algorithm (ABC) and moth–flame optimization algorithm (MFO)), along with sequential quadratic programming (SQP), and the way in which the PHES is used to compensate for the deviation in the WF integration in the real-time electricity market is also presented. The value at risk (VaR) and conditional value at risk (CVaR) were used as the economic risk analysis tools. According to the work, with the increase in the wind generation, the system risk improves. The results show that, as the wind generation increases by three times, there is an improvement in the risk coefficient values by 1%. A modified IEEE 14-bus test system was used for the validation of the entire work.

Prospects of Cross Border Energy Trade in South Asia

The majority of South Asian nations use a combination of renewable energy sources like hydro, solar, and wind power together with nonrenewable energy sources like nuclear, coal, and natural gas to generate their electricity. Both of these sources are indigenous to some degree. Every nation in the area benefits from one type of resource or another. In India, coal is available. Natural gas is also abundant in Bangladesh, Pakistan, Nepal, and Bhutan, as well as hydropower. Using panel data from 2001 to 2015, this study examines the relationship between electricity consumption and changes in income, population, and foreign direct investment in Pakistan, India, Bangladesh, Sri Lanka, and Nepal, five South Asian nations. Additionally, the demand for electricity can be satisfied by imports or electrical production. The OLS results confirm that there is significant relationship between electricity consumption and GDP in South Asia. The OLS result further suggests that there is significant positive relation between GDP and electricity imports for India and Pakistan where as Nepal and Bangladesh have significant positive relation between GDP and electricity production. It is therefore concluded that there is a huge potential of cross border energy trade in South Asia and enhance economic growth in the region.

A Chaotic Krill Herd Optimizer for Efficient Combination of Renewable Energy Sources in Isolated Microgrid Mode

Microgrids consist of small energy resources such as the solar power, wind power, and many distributed generation units. This article focuses on the application of a chaotic krill herd (CKH) algorithm for solving economic dispatch (ED) and combined economic emission dispatch (CEED) problems in a microgrid. The ED problem finds the power scheduling of renewable energy resources (RESs) units to minimize the entire production costs of generation while all system constraints are preserved into their acceptable limitations. Meanwhile, achieving this value from the fuel cost and fossil fuel fired power plant emission should be as little as possible. The proposed CKH is a bio-inspired optimization algorithm that is built in the Lagrangian and evolutionary behavior of krill people in nature. The Chaotic guide is a variation in qualities combined with KH. A singer map is integrated with the KH algorithm and tested on different scenarios for improving its global research and enhancing its performance. The elitism scheme is also served to save the best krill during amid the procedure when updating the krill. The results clearly show the superiority of the CKH algorithm to search for the best function values when compared with the standard KH and other well-known meta-heuristic search algorithms.

Transient Stability Analysis of a Multi-Machine Power System Integrated with Renewables

The impact on the stability of power systems is rising as the penetration level of renewable energy with sporadic natures rises rapidly on the grid. However, the impact of different types of renewable energy sources (wind, solar) and their combination on system stability varies even with the same penetration level. This paper concentrates mainly on the stability analysis of multi-machine systems connected to various types of renewable energy sources. The study presents a simple and novel control technique named automatic reactive power support (ARS) for both single and combinations of renewable sources by injecting the available reactive power into the system during fault through converters to enhance system stability. The permanent magnet synchronous generator (PMSG) and doubly fed induction generator (DFIG) are both considered as wind generators in this paper for comparison. In addition, transient stability enhancement is carried out by improving critical clearing time of a three-phase fault in the power system. With the creation of a 3-phase fault at various buses, stability analysis is carried out on the 9-bus WSCC test bus system and also on the 68-bus IEEE test system. Comparative analysis of six test case conditions is provided and the considered cases are without renewable source, with DFIG as a wind generator, PMSG as a wind generator, solar PV farm, wind farm with DFIG and solar PV in combination and the combination of wind farm with PMSG and solar PV. Moreover, the improvement in critical clearing time of the system is compared using conventional and proposed controls with all the aforementioned renewable sources. Comparative results show that the proposed control technique improves system stability and also that the combination of renewable energy sources ought to enhance the critical clearing time of system.

China's Electric Power Industry: State and Development Prospects in the Context of Carbon Neutral Industry

China has set a goal of achieving peak carbon emissions by 2030 and carbon neutrality by 2060. Increasing the electricity utilization factor is the key to achieving this goal. The article considers the development of China's electric power industry in recent years and compares the installed electrical capacity, electricity production and consumption, investments in the electric power industry, and analyzes the characteristics and potential of China's renewable energy sources, including hydraulic, wind and solar energy. Increasing the electricity production from renewable energy sources, promoting the substitution of conventional fossil energy sources such as oil with electricity, increasing the share of electricity in the total energy consumption, and strengthening international cooperation in the field of electricity generation from renewable energy sources are important measures to reduce carbon dioxide emissions and solve the climate change problem. The promotion of environmentally clean transport facilities such as electric vehicles and electric bicycles, combination of renewable energy sources with energy storages, and prioritizing the construction of demonstration projects in remote industrial and rural areas are measures that will help to gradually increase the utilization factor of renewable energy sources in China.

Smart control of interconnected district heating networks on the example of “100% Renewable District Heating Leibnitz”

District heating (DH) networks have the potential for intelligent integration and combination of renewable energy sources, waste heat, thermal energy storage, heat consumers, and coupling with other sectors. As cities and municipalities grow, so do the corresponding networks. This growth of district heating networks introduces the possibility of interconnecting them with neighbouring networks. Interconnecting formerly separated DH networks can result in many advantages concerning flexibility, overall efficiency, the share of renewable sources, and security of supply. Apart from the problem of hydraulically connecting the networks, the main challenge of interconnected DH systems is the coordination of multiple feed-in points. It can be faced with control concepts for the overall DH system which define optimal operation strategies. This paper presents two control approaches for interconnected DH networks that optimize the supply as well as the demand side to reduce CO2 emissions. On the supply side, an optimization-based energy management system defines operation strategies based on demand forecasts. On the demand side, the operation of consumer substations is influenced in favour of the supply using demand side management. The proposed approaches were tested both in simulation and in a real implementation on the DH network of Leibnitz, Austria. First results show a promising reduction of CO2 emissions by 35% and a fuel cost reduction of 7% due to better utilization of the production capacities of the overall DH system.