Search Results (26)

In line with the goals of “peak carbon emissions and carbon neutrality”, this study aims to develop a market-coordinated operation mechanism to promote renewable energy adoption and consumption, addressing the challenges of integrating medium- and long-term trading with spot markets in power systems with high renewable energy penetration. A three-stage joint operation framework is proposed. First, a medium- and long-term trading game model is established, considering multiple energy types to optimize the benefits of market participants. Second, machine learning algorithms are employed to predict renewable energy output, and a contract decomposition mechanism is developed to ensure a smooth transition from medium- and long-term contracts to real-time market operations. Finally, a day-ahead market-clearing strategy and an incentive-compatible settlement mechanism, incorporating the constraints from contract decomposition, are proposed to link the two markets effectively. Simulation results demonstrate that the proposed mechanism effectively enhances resource allocation and stabilizes market operations, leading to significant revenue improvements across various generation units and increased renewable energy utilization. Specifically, thermal power units achieve a 19.12% increase in revenue, while wind and photovoltaic units show more substantial gains of 38.76% and 47.52%, respectively. Concurrently, the mechanism drives a 10.61% increase in renewable energy absorption capacity and yields a 13.47% improvement in Tradable Green Certificate (TGC) utilization efficiency, confirming its overall effectiveness. This research shows that coordinated optimization between medium- and long-term/spot markets, combined with a well-designed settlement mechanism, significantly strengthens the market competitiveness of renewable energy, providing theoretical support for the market-based operation of the new power system. Full article

To address the limited flexibility of pumped storage power stations (PSPSs) under hierarchical clearing of energy and ancillary service markets, this study proposes a joint clearing mechanism for multi-level electricity markets. A bi-level optimization model based on the Stackelberg game is developed to characterize the strategic interaction between PSPSs and the market operator. Simulation results on the IEEE 30-bus system demonstrate that the proposed mechanism captures the dynamics of nodal supply and demand, as well as time-varying network congestion. It guides PSPSs to operate more flexibly and economically. Additionally, the mechanism increases PSPS profitability, reduces system costs, and improves frequency regulation performance. This game-theoretic framework offers quantitative decision support for PSPS participation in multi-level spot markets and provides insights for optimal storage deployment and market mechanism improvement. Full article

To facilitate the adoption of a food safety standard by producers, it is essential to understand their perception of it. However, few empirical studies have examined how livestock farmers perceive food safety standards in Vietnam. This research examines sheep farmers’ attitudes towards Vietnamese Good Agricultural Practices (VietGAP), a type of a food safety standard in Vietnam. A sample size of 109 farmers was selected for interviews and a structured questionnaire was generated to collect data. Descriptive and bivariate analyses were employed. The study results show that sheep farmers were well aware of most VietGAP requirements. They perceived that adopting VietGAP requires practical changes in sheep farming systems, including: selecting breeding stock from clear sources to ensure sheep product traceability, collecting and treating wastes daily to protect the environment, and frequent sterilization of sheep cages. The farmers were changing several practices to comply with VietGAP. Key changed practices identified included: bought breeding stock from clear and reliable sources, frequent collecting and treating of sheep wastes, and used veterinary medicine according to instructions of veterinary medicine producers. Statistically significant relationships existing between the sheep farmers’ perceptions and their education level (Pearson = 0.229, p = 0.017), farm size (Pearson = −0.193; p = 0.049), gender (Eta = 0.173, p = 0.060), practice of using labours (Eta = 0.202, p = 0.028), training participation (Eta = 0.211, p = 0.022), credit participation (Eta = 0.177, p = 0.050), community-based organisations (Eta = 0.153, p = 0.087), and veterinary/extension contacts (Eta = 0.217, p = 0.019) were found. This means that a male sheep farmer who had a higher education level, possessed a smaller farm, practiced hired labours, participated in training/credit programs, was a member of community-based organisation, and had contacts with veterinary/extension workers likely perceived VietGAP better than their counterparts. Based on the findings of this study, it is recommended that the promotion of VietGAP for livestock farmers should be developed and carried out as joint attempts along the value chain actors. New food marketing practices and legal framework and policy for using safe food certifications are required to address to promote farmers’ adoption of VietGAP and facilitate transition towards a sustainable agri-food system in Vietnam. This study provides significant insights into safety food standard adoption by livestock farmers and highlights aspects that require to be considered when developing policies to improve the adoption of safety food standards in developing countries. Full article

Aggregating and scheduling flexible resources through virtual power plants (VPPs) is a key measure used to improve the flexibility of new power systems. To maximize the regulation potential of flexible resources and achieve the efficient, unified scheduling of flexible resource clusters by VPPs, this study proposed a flexible resource aggregation method for VPPs and a bidding strategy for participation in the electricity and frequency regulation markets. First, considering the differences in the grid frequency regulation demand across periods, an improved zonotope approximation method was adopted to internally approximate the feasible region of flexible resources, thereby achieving the efficient aggregation of feasible regions. On this basis, the aggregation model was applied to the optimization model for VPPs, and a day-ahead double-layer bidding model of VPPs participating in the electricity and frequency regulation markets was proposed. The upper layer optimizes the bidding strategies to maximize the VPP revenue, while the lower layer achieves joint market clearing with the goal of maximizing social welfare. Finally, case studies were undertaken to validate the effectiveness of the proposed method. Full article

As the second largest power source in the world, hydropower plays a crucial role in the operation of power systems. This paper focuses on the key issues of regulating hydropower stations participating in the spot market. It aims at the core challenges, such as the conflict of cascade hydro plants’ joint clearing, the lack of adaptability for different types of power supply bidding on the same platform, and the contradiction between long-term operation and the spot market. Through the construction of a water spillage management strategy and settlement compensation mechanism, the competitive abandoned water problem caused by mismatched quotations of cascade hydro plants can be solved. In order to achieve reasonable recovery of the power cost, a separate bidding mechanism and capacity cost recovery model are designed. Subsequently, the sufficient electricity supply constraint of the remaining period is integrated into the spot-clearing model, which can coordinate short-term hydropower dispatch with long-term energy storage demand. The operation of the Yunnan electricity spot market is being simulated to verify the effectiveness of the proposed method. Full article

With the transformation of the energy structure, the integration of numerous small-scale, widely distributed renewable energy sources into the power grid has introduced operational safety challenges. To enhance the operational competitiveness, the virtual power plant (VPP) has emerged to aggregate and manage these distributed energy resources (DERs). However, current research on the VPP’s frequency modulation performance and bidding strategy remains insufficient in the joint market of electrical energy and frequency modulation (FM) ancillary services, with inadequate coordination of internally distributed resources. To fully leverage the flexibility of VPPs and incentivize their participation in electricity market operations, this paper investigates game-based bidding strategies and internal distributed resources allocation methods for VPPs in the joint market for electrical energy and frequency ancillary services. Firstly, the regulatory performance indicators of VPPs participating in the joint market and develops the corresponding market-clearing model. Secondly, to address the competition among distributed resources within VPPs, a master-slave game approach is innovatively employed to optimize the VPP’s trading strategies. This method ensures the rational allocation of electricity consumption among distributed energy resources within the VPP and derives the optimized bidding prices and quantities for both the VPP and its internal members. Finally, the case study shows that the proposed trading strategy provides effective bidding strategies for distributed energy resources participating in the joint market for energy and frequency regulation ancillary services. It enhances the regulatory performance of VPPs in the energy-frequency regulation market, ensures the profitability of distributed energy resources, and contributes to the economically stable operation of the market. Full article

A new type of power system with a high proportion of renewable energy sources (RES) penetration has become a global development trend. Meanwhile, the marketization reforms of the electricity market pose challenges to traditional energy. A multi-energy model including a wind turbine (WT), photovoltaic (PV) energy, energy storage (ES), and a thermal power system is proposed in this paper, participating in a joint market mechanism for energy and frequency regulation ancillary services. Unlike existing joint markets, this paper considers the market coupling clearing of various energy sources and the uncertainty of RES generation. Specially, a mechanism for the participation of storage and thermal power units in the frequency regulation ancillary service market is designed. Finally, a practical 118-node case study is provided to validate the impact of renewable generation uncertainty on the participation of multi-energy coupled systems in joint and single energy markets. Compared to the single electricity energy market, the simulation results show that the model can reduce the impact of RES uncertainty on ES generation and increase the cleared electricity quantity of thermal power units by 16%. Moreover, the model also increases the market revenue of thermal power units and storage by 30% and 44%, respectively. Full article

With the development of the economy and society, the importance of a secure and stable electricity supply continues to increase. However, the power grid is facing the test of excess installed capacity, the waste of renewable energy, and a low comprehensive utilization rate. This problem stems from the inconsistent peak–valley differences between power production and consumption, and the lack of clear electricity price signals, which disrupts the safe and stable operation of the power market. This paper combines the interactive transactions among clean energy power generation companies, users, and energy storage, explores how the system optimization model can be reflected in the power market through regulatory measures, and formulates the optimal output scheme of the system under the constraints of clean energy power generation forecast data, user base load forecast data, demand-side resource regulation ability, and energy storage system regulation ability to achieve the goals of comprehensive clean energy power consumption and minimum cost for users. A comprehensive analysis of the proposed model was conducted using actual data from a certain province in China, the results show that the consumption of clean energy will increase by 3% to full consumption and the total cost of users will be 32% lower than that of time-of-use (TOU) power prices, which proves the potential of the proposed joint optimization model in absorbing clean energy and the effectiveness of the market mechanism. Full article

National pricing and reimbursement agencies face growing challenges with complex health technologies, prompting European policy advancements. Beneluxa is a cross-country collaboration involving Belgium, the Netherlands, Luxemburg, Austria, and Ireland that aims to address sustainable access to medicines. In view of the soon-to-be-implemented EU HTA Regulation, insights and experiences from stakeholders with Beneluxa cross-country collaboration could provide possible transferable learnings. Therefore, this research aims to (i) identify the opportunities and challenges faced by Beneluxa, (ii) gather insights from stakeholders, namely (possible) applicants and policymakers, within and beyond Beneluxa on the initiative and broader cross-country collaboration principles, and (iii) transfer these insights into learnings and recommendations in anticipation of the full implementation of the new HTA Regulation. Fifteen semi-structured interviews were conducted with industry and European HTA/policy stakeholders. The principal challenges discussed by stakeholders encompass hesitancy from the industry toward Beneluxa assessments, which were attributed to procedural and timeline uncertainties, legislative framework ambiguity, and challenges in terms of industry’s internal organization. Another challenge highlighted is the resource-intensive nature of the procedure due to diverse approaches among member states. In addition, industry stakeholders mentioned limited communication and procedural complexity. Despite challenges, both stakeholder groups recognized important opportunities for cross-country collaboration. Transferable insights for future cross-country collaboration include transparent communication, clear legislative embedding, internal industry restructuring to facilitate joint HTAs, and member state support for conducting collaborative assessments. The study underscores diverging views among stakeholders on cross-country collaboration’s potential to support HTA and the market access of complex health technologies. While acknowledging benefits, there still are challenges, including industry hesitancy, emphasizing the need for transparent communication and clear guidance in the evolving EU HTA landscape. Full article

As the proportion of new energy sources, such as wind power, in the electricity system rapidly increases, their participation in spot market competition has become an inevitable trend. However, the uncertainty of clearing price and wind power output will lead to bidding deviation and bring revenue risks. In response to this, a bidding strategy is proposed for wind farms to participate in the spot market jointly with carbon capture power plants (CCPP) that have flexible regulation capabilities. First, a two-stage decision model is constructed in the day-ahead market and real-time balancing market. Under the joint bidding mode, CCPP can help alleviate wind power output deviations, thereby reducing real-time imbalanced power settlement. On this basis, a tiered carbon trading mechanism is introduced to optimize day-ahead bidding, aiming at maximizing revenue in both the electricity spot market and carbon trading market. Secondly, conditional value at risk (CVaR) is introduced to quantitatively assess the risks posed by uncertainties in the two-stage decision model, and the risk aversion coefficient is used to represent the decision-maker’s risk preference, providing corresponding strategies. The model is transformed into a mixed-integer linear programming model using piecewise linearization and McCormick enveloping. Finally, the effectiveness of the proposed model and methods is verified through numerical examples. Full article

A high proportion of renewable energy access makes the net load of the power system volatile and uncertain, increasing the demand for the ramping capacity of the power system. Traditional electricity spot markets compensate for the power imbalances caused by an insufficient ramping capacity through traditional flexibility services such as ancillary services and interconnection power. However, conventional flexibility services may lead to frequency deviations in the power system, increased response costs, spikes in electricity prices, and dramatic price volatility in the traditional spot market. To solve the above problems, this paper proposes an FRP and convex electricity spot market joint clearing (FCESMJC) market mechanism. The FCESMJC model can more accurately represent the relationship between electrical power output and the price of electricity and reduces the number of spikes in electricity prices. In addition, a novel FRP pricing method is proposed to compensate FRP market participants for their FRP costs more reasonably. Additionally, the difference in system performance is provided by comparing the energy prices, pricing method, clearing prices, and system costs in the FCESMJC method and the traditional electricity spot market. The FCESMJC system reduces the total system cost by 18.6% compared with the electricity spot market. Numerical experiments are simulated on the IEEE 14-bus test system to validate the superiority of the proposed model. Full article

The development of modern technologies has made it much easier to regain the ability to walk after losing a lower limb. The variety of prosthetic feet available on the market allows for optimal choice and appropriate adjustment of the foot prosthesis to the trans-tibial amputee patient’s needs. Unfortunately, the best solutions are often not available to everyone due to their high prices. This study compares the gait patterns of patients using the new concept of an affordable dynamic foot with those of other commonly available but much more expensive foot prostheses. The kinematic and spatio-temporal parameters of gait obtained using the motion capture system were analyzed. For a clear picture of changes in bilateral deficits during gait for the pelvis, hip, knee, and ankle joints, the symmetry function was used. The results indicate that the new and cheaper concept of foot prostheses offers a very similar level of gait quality to that provided by more expensive and popular solutions. The authors suggest that the use of symmetry function thresholds of 10% does not work for amputees. Full article

The large-scale integration of renewable energy into the grid has led to a gradual diversification of power generation trading units on the power-side, with varying operational characteristics, costs, and trading needs among diverse power generation trading units. Traditional power system clearing models face challenges. Block order is a bidding type that allows for multiple volume–price combinations. At the same time, the randomness and volatility of renewable energy poses challenges to the safe and stable operation of the system. Building a power system clearing model that meets the diverse and flexible needs of the power system has become an important consideration. Therefore, this paper considers the design of three flexible energy blocks: a sustaining block, flux block, and adjustment block to meet the differential needs of diverse trading units and establishes a flexible block order clearing model. Secondly, it establishes a joint clearing model of electrical energy and frequency modulation (FM) to ensure the stable and reliable operation of the system, and solves the model based on relevant constraints to determine the winning electrical energy price and FM price. The CPLEX and Yalmip algorithms are used to solve the model. Finally, a case study was conducted based on an improved IEEE 14-bus system. The results showed that the model proposed in this paper can satisfy the differential needs of diverse trading units, effectively improve the renewable energy consumption capacity, and reduce the prices of the energy market and frequency modulation market. Also, the standard deviation of the net load of the system is relatively low, which improves the reliability of the power system’s operation. Full article

The aim of this article is to identify the benefits perceived by individual recipients that are achieved by consumer energy suppliers on the market, through multilateral trade cooperation, and to define the structure of these benefits according to the declared readiness of recipients to cooperate with the suppliers. The results of the analysis of the available literature on the subject indicate that there is a cognitive and research gap in relation to the perceived benefits achieved by the suppliers through joint marketing activities. The benefits are not being analyzed; especially from the perspective of individual recipients’ readiness for this cooperation. This gap is noticeable not only in relation to the energy market, but also in other areas of the consumer market. In an effort to reduce the identified gap, an online survey was conducted among 1196 adult individual energy recipients in Poland. The primary data collected was subjected to quantitative analysis using the following research methods: average grade analysis, comparative analysis, and exploratory factor analysis. The Kruskal–Wallis test was also conducted. The results of the quantitative analysis indicate, inter alia, that the majority of the respondents declared their readiness to cooperate with energy suppliers on the preparation of marketing offers. This variable statistically significantly differentiated nine out of twelve analyzed benefits that, according to the respondents, suppliers obtain as a result of cooperation. This differentiation was not found only in the case of three benefits related to the cost-free acquisition of recipient potential. For all respondents, as well as for the respondents willing to cooperate with suppliers and for those who did not express such willingness, three sections were identified, including the respondents who saw the same benefits achieved by suppliers. The conclusions drawn on the basis of the analysis results constitute a significant contribution to the theory of marketing and the theory of market behavior of individual recipients in the energy market. They also bear clear application advantages, making it easier for energy suppliers to effectively initiate cooperation with individual recipients and/or strengthen this cooperation. Full article

With the restructuring of the power system, household-level end users are becoming more prominent participants by integrating renewable energy sources and smart devices and becoming flexible prosumers. The use of microgrids is a way of aggregating local end users into a single entity and catering for the consumption needs of shareholders. Various microgrid architectures are the result of the local energy community following different decarbonisation strategies and are frequently not optimised in terms of size, technology or other influential factors for energy systems. This paper discusses the operational and planning aspects of three different microgrid setups, looking at them as individual market participants within a local electricity market. This kind of implementation enables mutual trade between microgrids without additional charges, where they can provide flexibility and balance for one another. The developed models take into account multiple uncertainties arising from photovoltaic production, day-ahead electricity prices and electricity load. A total number of nine case studies and sensitivity analyses are presented, from daily operation to the annual planning perspective. The systematic study of different microgrid setups, operational principles/goals and cooperation mechanisms provides a clear understanding of operational and planning benefits: the electrification strategy of decarbonising microgrids outperforms gas and hydrogen technologies by a significant margin. The value of coupling different types of multi-energy microgrids, with the goal of joint market participation, was not proven to be better on a yearly level compared to the operation of same technology-type microgrids. Additional analyses focus on introducing distribution and transmission fees to an MG cooperation model and allow us to come to the conclusion of there being a minor impact on the overall operation. Full article