Direct Power Purchase Research Articles

Blockchain and Green Certificates Based Market Structure and Transaction Mechanism of Direct Power-Purchase for Industrial Users

Blockchain and Green Certificates Based Market Structure and Transaction Mechanism of Direct Power-Purchase for Industrial Users

A demand side controller of electrolytic aluminum industrial microgrids considering wind power fluctuations

Direct wind power purchase for large industrial users is a meaningful way to improve wind power consumption and decrease industrial production costs. Short-term wind power fluctuations may lead to large-scale wind power curtailment problems. To promote use of wind energy, a demand side control method is proposed based on output regulator theory for a grid-connected industrial microgrid with electrolytic aluminum loads to continuously track and respond to wind power fluctuations. The control model of the EALs and the dominant frequencies of the wind power fluctuation signals are analyzed and incorporated into the demand side control plant. The feedback control signals with active power deviations on the tie-line are used to design the demand side controller. Simulations are conducted for an actual industrial microgrid to validate the feasibility and effectiveness of the proposed method. The results demonstrate that the proposed controller based on output regulator theory is able to effectively track wind power fluctuations.

A study on financial mechanisms to develop the power system in Vietnam

Vietnam’s commercial electricity demand grew by 9.6% per year during 2011 - 2020. The Ministry of Industry and Trade (MOIT) forecasts that the average annual investment cost for the power system over 2021 - 2030 will be around USD 9.0 billion to USD 12.6 billion per year for generation sources and USD 1.5 billion to USD 1.6 billion for the grid. This article discusses the financial options to mobilise this capital. The private sector interest in financing new thermal power projects is low for coal and uncertain for gas; the current energy price crisis suggests deferring any new LNG power plant openings until after 2026. There, the state-owned sector takes the lead. For renewable energy, private investors have shown eagerness to finance new solar and onshore/nearshore wind projects under the feed-in-tariff regime. The subsequent mechanisms will be market-based: auctions and direct power purchase agreements. Offshore wind projects allow the state-owned oil and gas industry to invest jointly with international private developers and reorient its strategy in response to the energy transition. Developing the green bond market is an opportunity for Vietnamese banks. State-owned enterprises can use them to raise money through non-sovereign debt. Finally, a gradual increase in electricity prices will improve the sector’s ability to finance the necessary power system expansion.

Study on the strategy of improving the life cycle economic sustainability of wind power heating projects in northern China.

The profitability of electric heating projects in Northern China is poor. A kind of combined market-oriented trading strategy to improve the economy of electric heating projects is put forward. The price game model for direct power purchase, compensation model for carbon emission reduction benefits and load aggregation revenue model are constructed, and the optimal proportion of clean energy and conventional energy consumed under the condition of ensuring heating reliability is analyzed. An electric heating project was analyzed as an example, the results showed that in the direct power purchase transaction, the power price is 0.2125 RMB/kWh, which is 0.0591 RMB/kWh lower than the catalogue tariff. Revenue from carbon trading and auxiliary service transaction is 469,913.87 RMB and 289,218.09 RMB, respectively, which is equivalent to reducing electricity cost of 0.0253 RMB/kWh and 0.0156 RMB/kWh, respectively. The ultimate power cost is 0.1716RMB/kWh, which is 0.1 RMB/kWh lower than the current catalogue tariff. Besides, the more clean energy an electric heating project consumes, the better its economy will be, and in this example, the best proportion of clean energy and conventional energy is 80% and 20%. The research results could help to promote the sustainable development of clean heating in northern China.

Exploring the strategy of direct power purchase transac- tions in the power market based on game theory

In the mode of direct power purchase transactions for large customers, improv- ing the efficiency of transactions is a prominent issue. The transaction volume and unit price in the electricity market belong to public information, which is the basis for negotiating the price between large users and power generators, and the final transaction price is lower than the market transaction price, which becomes the motivation for large users to choose to con- tinue the transaction. In the game on the transaction volume and transaction price, the expec- tations of both parties on the transaction price and the type of both parties belong to private information. In this paper, based on the knowledge of the static game with incomplete infor- mation, the conditions for transaction realization are constrained, the payment matrix is ex- pressed based on the consideration factors, the Bayesian Nash equilibrium model is established to design the offer strategy, and the expression of the optimal response strategy is finally given.

Strategy decision game approach of the combination generation system of wind and thermal power participating in the direct power purchase transaction of large consumer

The participation of thermal power in the direct power purchase transaction (DPPT) of large consumer (LC) reduces the ability of transmission to consume wind power. This article proposes a novel strategy decision game approach framework of the wind-thermal combined generation (W&T-CoGen) participating in the DPPT of LC, to promote the consumption of wind power under the background of Renewables Portfolio Standards (RPS). The game model, with the goal of maximizing the profit of W&T-CoGen and LC, is established based on dynamic non-cooperative game theory. A novel profit distribution method, considering the power generation cost, risk cost and the satisfaction of wind and thermal power generation, is specially designed based on Nash negotiation method. The reverse induction method is adopted to solve the Nash equilibrium of the proposed full-information dynamic game model. The feasibility and effectiveness of this framework is verified by specific example, which shows that the participation of W&T-CoGen in the DPPT of LC can increase profits of all participants, promote the consumption of wind power and improve the energy system flexibility. This novel framework provides a novel way to construct power market optimal model in the power system containing large scale wind power.

An Analysis From the Perspective of Direct Power-Purchase for Industrial Users: Should the Power Grid Company Implement Incentive-Based Demand Response Management?

As a means for the power grid company to guide industrial users to reduce power consumption through economic compensation, incentive-based demand response management (IBDRM) plays an important role in the process that industrial users purchase power directly from power plants (direct power-purchase for short). Therefore, this paper studies the impacts of IBDRM on the power grid company, power plants, and industrial users from the perspective of industrial users’ direct power-purchase, so as to analyze whether the power grid company should implement IBDRM in direct power-purchase. First, we model the interactions of the power grid company, the power plant, and the industrial user under different scenarios, including Case N (the power grid company does not implement IBDRM) and Case R (the power grid company implements IBDRM) by using Stackelberg game. Then, we solve the models to get equilibrium results. The primary contributions of this article include following parts: 1) Compared with Case N, the power plant’s power selling price and the industrial user’s power-purchase quantity are higher under Case R, and both are negatively correlated with the compensation for the power plant. 2) The power grid company should implement IBDRM in direct power-purchase. Because under Case R, the industrial user reduces the power consumption, the profits of the power grid company and the power plant are higher, and the social welfare is also greater. 3) Under Case R, we also find that the social welfare is positively correlated with the compensation for the industrial user.

Decisions in Power Supply Chain with Emission Reduction Effort of Coal-Fired Power Plant under the Power Market Reform

Sustainability in power supply chain has been supported by emission reduction of coal-fired power generation and increasing renewable energy power generation. Under the power market reform of direct power purchase transactions, this paper focuses on the channel selection and emission reduction decisions of power supply chain. From the theoretical perspective, this paper develops the decision-making models of centralized and decentralized power supply chain, which consist of one renewable energy power generation enterprise, one coal-fired power plant and one power grid enterprise. The optimal strategies of power quantities and profits for power supply chain members and their corresponding numerical experiments are analyzed in different cases. The results show that there are qA1Nc*<qA1Lc* for renewable energy power generation enterprise A, qB1Nc*>qB1Lc* and eBNc*>eBLc* for coal-fired power plant B, which indicate that the direct power purchase channel in the centralized scenario is conducive to promoting the transaction quantity of renewable energy power generation, as well as the on-grid power quantity and emission reduction efforts of coal-fired power plant B. Furthermore, the profit of whole power supply chain could be enhanced by the increasing on-grid power preference coefficient of coal-fired power generation, subsidy for renewable energy power generation and preference coefficient for clean production, and by the decreasing emission reduction cost coefficient of coal-fired power plant. Additionally, the emission reduction effort of coal-fired power plant is positively relevant with preference coefficient for clean production, whereas it is negatively relevant with power grid wheeling charge, emission reduction cost coefficient and subsidy for renewable energy power generation. Our findings can provide useful managerial insights for policymakers and enterprises in the sustainability of power supply chain.

Determination of Transfer Capacity Region of Tie Lines in Electricity Markets: Theory and Analysis

In power industries, it is a common practice to use an equivalent model of the external power network in an optimization model of the internal power network in order to protect data privacy. However, existing equivalent models cannot accurately consider the operational constraints of an external power network. In this paper, a unified equivalent model is proposed to precisely capture the transfer capacity region of tie lines. The operational constraints of the external power network are preserved via multi-parametric programming. The operational costs of the external power network are formulated as an explicit function of power transmission on tie lines. This unified equivalent model can consider both AC and DC tie lines. The intuitive difference between the transfer capacity of AC and DC tie lines is revealed from a new perspective. On this basis, a market model for the internal power network with the equivalence of the operational constraints for the external power network is presented. Two typical trading modes are considered: the bulk sale mode and the direct power purchase mode. The exact convex relaxation formulation of the market model is derived under the direct power purchase mode.

Economic dispatch of power system containing UHVDC with direct power purchase by large consumers

Economic dispatch of power system containing UHVDC with direct power purchase by large consumers

Risk assessment of contract execution in large consumer direct power purchase

Nowadays, China is steadily advancing the reform of the electricity market. The direct power purchase by large consumers, as an important form of which has the characteristics of large participation of renewable energy and huge trading power, has a very important impact on the stability of the power system. Therefore, it is necessary to carry out an effective risk assessment method on the bilateral user transactions of supply and demand side, and to reasonably control the risk factors that have greater risk. Direct power purchase by large consumers involve both sides of supply and demand and many possible risk factors. We construct the risk assessment index system from five aspects and the corresponding 17 second-level evaluation indexes are established as AHP method to evaluate the risk. In addition, after rating the risk factors, the weights are determined and the consistency is verified. The results show that AHP can balance the subjective and objective factors and determine the relative weight of each evaluation index. It can also calculate the subordination degree of risk index to each level of risk level and achieve the combination of qualitative and quantitative analysis so that the result of risk assessment is more scientific and accurate.

Comprehensive benefit evaluation of direct power-purchase for large consumers

Based on "several opinions of the CPC Central Committee and the State Council on further deepening the reform of electric power system" in 2015, this paper analyses the influence of direct power-purchase for large consumers on operation benefit of power grid. In three aspects, such as economic benefit, cleaning benefit and social benefit, the index system is proposed. In which, the profit of saving coal energy consumption, reducing carbon emissions and reducing pollutant emissions is quantitative calculated. Then the subjective and objective weights and index scores are figured out through the analytic hierarchy process, entropy weight method and interval number method. Finally, the comprehensive benefit is evaluated combined with the actual study, and some suggestions are made.

Research on trading patterns of large users' direct power purchase considering consumption of clean energy

In order to reduce the stochastic volatility of supply and demand, and maintain the electric power system's stability after large scale stochastic renewable energy sources connected to grid, the development and consumption should be promoted by marketing means. Bilateral contract transaction model of large users' direct power purchase conforms to the actual situation of our country. Trading pattern of large users' direct power purchase is analyzed in this paper, characteristics of each power generation are summed up, and centralized matching mode is mainly introduced. Through the establishment of power generation enterprises' priority evaluation index system and the analysis of power generation enterprises' priority based on fuzzy clustering, the sorting method of power generation enterprises' priority in trading patterns of large users' direct power purchase is put forward. Suggestions for trading mechanism of large users' direct power purchase are offered by this method, which is good for expand the promotion of large users' direct power purchase further.

考虑大用户直购电交易约束的中长期调度计划优化研究与应用

宁夏电网考虑大用户直购电约束的中长期调度计划优化研究与应用在优化模式上兼顾了节能发电调度、经济调度、兼顾节能的经济调度等模式，在时间维度上跨越了年度、季度、月度、周、日前等多个时间维度，立足于电力系统基础理论和数学优化理论，充分考虑实际调度经验和实际运行中的实际需求，以及大用户直购电交易约束，采用先进的设计思想，并对应研究开发相应的关键性技术和模型，全面实现年度电量分解、机组组合制定、年度电量分解与机组组合相协调的中长期调度计划一体优化决策，从调度计划的制定精度、制定效率、计划结果合理性等多个方面全面提升调度计划的质量。 This paper takes account of the mode of energy generation dispatch, economic dispatch and energy conservation dispatch which has been across multiple time dimensions including year, quarter, month, week and day. This paper is based on power system basic theory and mathematical opti-mization theory. It utilizes advanced design ideas to develop key technologies and models which take adequate account of actual scheduling experiences, actual needs in operation and trading constraints of direct power purchase of large consumers and also implement long-term scheduling optimization decisions on annual electricity decomposition, unit combination formulation and the coordination of them. The research improves the quality of scheduling in many methods like the precision and efficiency of scheduling, and the rationality of scheduling results.

Coordination between clean energy generation and thermal power generation under the policy of “direct power-purchase for large users” in China

The inefficient utilization of clean energy and distorted pricing mechanism are the most critical problems that have hampered the reform of China's electric power industry for many years. A large number of clean energy generators have recently been constructed, but water spillage at hydroelectric facilities and wind curtailment persist due to integration challenges. The adjustment of electricity price has relied on executive orders of the Chinese government and the National Development and Reform Commission (NDRC). Distorted prices that are not derived from a market economy have seriously hampered the development of China's electricity market. Therefore, in recent years, the Chinese government has issued a number of reform measures concerning “direct power-purchase for large users”. The main idea of this pricing mechanism is to form direct negotiations between large users and generators to determine the electricity price. To a certain extent, this pricing mechanism is conducive to the electricity market reform in China. However, the coordination between clean energy generation and thermal power generation under the policy of “direct power-purchase for large users” has become the key issue in China's electric power industry. This paper summarizes the policies of “direct power-purchase for large users” in different provinces in China. The electricity market in Yunnan, for which the contradiction between thermal power generation and hydropower generation is increasingly severe, is the focus of the research. At last, a feasible electricity market scheme has been derived to coordinate thermal power generation and hydropower generation. This scheme has considerable theoretical and practical significance to the future of China's electricity market reform.

The Mechanism Design to Direct Power-Purchase Transaction Considering Market Supply and Demand

At present, direct power-purchase for large consumers is difficult to carry out effectively when demand exceeds supply. Interest demand of direct power-purchase for large consumers under different conditions of supply and demand is analyzed in this paper. Therefore, design principle of transaction mechanism for direct transaction adapting to different supply and demand situation is also applied. The purpose is striving to carry out the direct transaction effectively when market demand exceeds supply situation, adjusting the supply and demand and solving the "soft lack of electricity" phenomenon due to fluctuation of coal price. In the end, some suggestions are put forward to the current transaction rules.

Economic Analysis about Big Consumers Purchasing Electricity Directly

If the big users electricity consumption kept the same, while comparing through grid direct-purchasing power with building the power plant and purchasing the power by grid, and then establish the profit and loss model and point to point mode. Finally, we need to demonstrate the economy of direct power purchase through the example and value.