In order to solve the problem of building microgrid consuming renewable energy where distributed generation and flexible load resources are integrated, this paper takes electric vehicles as flexible resources, and constructs a scheduling optimization model for building microgrids considering demand response and charging/discharging uncertainty. Firstly, the price-based demand-response model and incentive-based demand-response model of flexible load resources are constructed. Secondly, the electric vehicle is regarded as an integrator of production and consumption, and Markov chain and information gap decision theory (IGDT) are used to deal with the uncertainties of charging and discharging, respectively. Finally, the deterministic scheduling optimization model is constructed by maximizing the net revenue of the system, photovoltaic accommodation, users’ satisfaction, and minimizing carbon dioxide emissions. The effectiveness of the constructed optimization model is verified by example analysis. The model not only enhances the clean energy accommodation rate of the system and reduces carbon dioxide emissions, but also can bring certain benefits to users, tap the potential of flexible load resources to participate in microgrid scheduling, and realize finally the win-win benefits of both supply and demand sides.

In the context of the global low-carbon transition, low-carbon and zero-carbon technologies such as hydrogen and ammonia are gradually gaining popularity, and are considered to be one of long-term technological choices for tackling climate change. Focusing on the strategic requirements of realizing the carbon neutrality target, this paper sorted out the characteristics of ammonia fuel, discussedits advantages, opportunities and challenges as a zero-carbon fuel, and analyzed the experience and enlightenment of developing ammonia industry in other countries. The research believes that ammonia fuel is one of the important zero-carbon energy sources under the background of carbon neutrality, and it has wide application prospects in fields of industry, electric power, and transportation. It is suggested that China should consider the development pace of global “ammonia economy”, deploy the “green ammonia” industry timely, and promote the pilot demonstration and application of ammonia fuel.

Co-firing “zero-carbon, hydrogen rich, high nitrogen” ammonia (NH₃) fuel in coal-fired power plant is an important technical route to mitigate CO₂ emission. To explore the impacts of co-firing ammonia fuel on coal combustion and pollutant formation behaviour, the coal-ammonia co-firing experiments were carried out on a McKenna type flat-flame burner system. Combined with visible-light camera, flue gas analyser and thermophoresis probe sampling system, the influence of co-firing ammonia on the flame properties, gaseous pollutant and particulate matter formation was explored. The results show that the ammonia fuel ignites ahead of coal, and the additional heat released from ammonia combustion promotes the pyrolysis of coal and the release of volatile. Thereafter, it promotes the ignition and combustion of volatile, resulting in the increase of flame height and temperature. The added NH₃ is partially converted into NO in the volatile flame, resulting in a notable increase in NO concentration. Adding NH₃ improves the equivalent ratio of gaseous fuel, which promotes the conversion of volatile to soot, and finally increases the yield of soot particles.

With the development of demand response technology, demand-side resources with flexible regulation characteristics such as temperature-controlled loads and electric vehicles can be used as generalized energy storage to participate in the control of power fluctuations in island distribution networks. This paper is oriented to two types of generalized energy storage, air conditioners and electric vehicles, and proposes a collaborative control strategy for distribution network that considers the participation of generalized energy storage clusters. Firstly, the load aggregator is used as the control center to build a multi-dimensional generalized energy storage cluster control architecture. Secondly, the generalized energy storage control model for the air-conditioning cluster and the electric vehicle cluster is established separately, and the number of controlled times of each air-conditioning is considered in the air-conditioning group. In the electric vehicle group, a power distribution strategy based on the state of charge is proposed. Then, according to the power response characteristics of the air-conditioning cluster and the electric vehicle cluster, a low-pass filtering-based multiple generalized energy storage coordinated control strategy is given. Finally, the simulation results based on Matlab/Simulink verify the effectiveness of this control strategy.

With the proposal of a "carbon reduction" global goal, hydrogen is considered the ideal clean energy, but problems such as high production cost, storage, and transportation difficulties limit the large-scale energy application of hydrogen. Used as the carrier of hydrogen. green ammonia, with the meaning of zero carbon footprint, has attracted more and more attention. This study provides an overview of the potential energy applications for green ammonia, the development of green ammonia, and the application progress of ammonia fuel. Furthermore, this study introduces the source of green ammonia. The prospect and challenges of large-scale application of green ammonia are analyzed according to the production cost, technology maturity, and policy factors of green ammonia. Presently, ship transportation and power generation are essential target application fields of ammonia fuel. However, there are still some problems, including the safety of ammonia, mixed combustion theory, and combustion system transformation, among others. An ammonia fuel cell is an essential technology for the energy conversion of ammonia. The research progress of ammonia fuel cell is introduced in detail, including oxygen ion-conducting electrolyte ammonia solid oxide fuel cell, proton-conducting electrolyte ammonia solid oxide fuel cell, proton membrane-ammonia fuel cell and alkaline ammonia fuel cell. The comprehensive analysis shows that the global carbon reduction policy is essential for developing green ammonia at this stage. In the short term, proton membrane-ammonia fuel cell and alkaline ammonia fuel cell would not be able to handle the large-scale application of ammonia fuel. Solid oxide fuel cell with high fuel flexibility is the most promising type of ammonia fuel cell.

Aiming at the distribution network with microgrid, a distribution network planning method considering the flexibility resource attribute of microgrids is proposed. The flexibility resource attribute of microgrids is considered from substation planning and grid planning. Firstly, the mathematical models of flexible resources in microgrids are established and then the external equivalent model of microgrids is formed. Then, the flexibility resources are considered by updating the constant volume formula and adding constraints in network planning. Finally, a distribution network programming model with minimum investment and operating cost as the objective function is established and it is solved by improved genetic algorithm. Case study is designed according to the area to be planned with three microgrids. The results show that the planning method proposed in the paper can improve the system transmission flexibility with a small increase in cost, so when the distributed power supply fluctuates or the load forecast is inaccurate during the operation of the distribution network in the future, the line will have enough flexibility for the main network or the microgrid to transmit power, which proves the rationality and effectiveness of the proposed model.

At present, the interaction among the indices is usually not considered in the multi-index evaluation of planning schemes for park-level integrated energy system (PIES), which results in the evaluation results are not general, and even have some problems. Therefore, an improved VIKOR method considering the interaction of indices is proposed for the planning schemes of the PIES. Firstly, the evaluation index models of PIES are established from the four aspects of economy, reliability, environmental protection and energy efficiency, and then the comprehensive evaluation system is constructed. Then, on the basis of the conception of the dual hesitant fuzzy set and fuzzy measure, the classical VIKOR method is improved, and each index is weighted by fuzzy measure, so that the interaction between each evaluation index is fully considered when evaluating the planning schemes. Finally, an example is given to verify the rationality and objectivity of the proposed method.