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Abstract In order to alleviate the risk of energy transactions in networked microgrids (MGs) under uncertainties, such as renewable energy and transaction prices, a risk-averse energy transaction approach is proposed based on robust optimization. A systematic combinatorial optimization is applied to model energy exchanges among MGs, and then a two-stage robust optimization model for energy transactions is formulated to optimize the joint operation of networked MGs. Furthermore, the proposed model can be effectively solved by column-and-constraint generation (C&CG) algorithm. Under different budgets of price uncertainty, the results show the proposed approach can not only achieve the optimal operational cost of networked MGs, but also ensure the robustness of energy transactions among MGs. [ABSTRACT FROM AUTHOR]

Abstract Stearic acid/amorphous TiO 2 composites were synthesized by a Sol-gel way with different pH values. The as-prepared PCMs were characterized by XRD, SEM, FTIR to determine the chemical compositions and structure to find out the influence of synthesis condition (pH valves). The thermal performance and thermal stability of the composite phase change material were determined by DSC and TGA. It was found that the composite PCMs prepared in the acidic condition exhibited better than that under alkaline condition. The addition of CNTs enhanced the thermal conductivity of the as-prepared PCMs. The purpose of our study is to provide a sample way to synthesis of composite PCM for thermal energy storage. [ABSTRACT FROM AUTHOR]

Abstract Air - conditioning systems are the main energy consumer and the main cause of the difference of on -peak load and off-peak load in community scale micro-grid. The switching sequence optimization method of heat pumps for micro-grid peak clipping being illustrated, which control principles considered the building's thermal inertia and acceptable indoor temperature fluctuation. The novel method considers of the building thermal inertia and acceptable room temperature fluctuation, which can reduce power load without affecting the normal use of buildings when micro-grid need peak clipping. A room energy equilibrium model is proposed to calculate the acceptable interrupting time and room temperature recovery time. Based on allowable interrupting time and room temperature recovery time, heat pumps switching sequence optimization model were introduced. Combined with a case study, the switching sequence optimization method of heat pumps and the clipping of electricity load being verified. The case study indicated that switching sequence optimization of heat pumps has the potential to reduce electricity peak load and available strategy for demand-side management. [ABSTRACT FROM AUTHOR]

Integrated Energy System (IES) is built by the optimal combination of multiple energy conversion technologies. Multi-energy resource input and multi-energy production output can be deemed as one of the notable characteristics of IES. The price fluctuation of any kinds of energy (such as electricity, gas, hot or chilled water, vapour) has an essential effect on IES’s operation. To distinguish the relationship between system operation mode and energy price has greatly contributed to operators. In this discussion, we propose a parametric equation to determine IES’s generating schedule based on the typical energy flow of IES. The direct analytical method for IES’s cost-benefit analysis is illustrated combined with a case study. Compared with system optimization model method, this multi-parameter analysis method is more concise and convenient. [ABSTRACT FROM AUTHOR]