Environmental issues in energy policy, especially global warming, have received more attention lately than ever before. Excessive dependence on fossil fuels, deforestation, and land degradation are the three main factors that lead to increased carbon dioxide (CO2) emissions. Consequently, the global average temperature has doubled compared to anticipation. Various international protocols and agendas have been established, pledged to restore the global average temperature to the 1990 level. As a result, energy policies worldwide have also undergone various transformations to align with these protocols since then. As a developing nation, Malaysian’s electricity demand has continuously grown in the past two decades. To date, the electricity sector is still dominated by fossil fuels. Government incentives have been the most influential factor in the nation’s energy mix trend. Several energy policies implemented throughout the past 22 years have seen the shift from natural gas to coal power in power plants, and in more recent years, renewable energy resources. Numerous studies in the past have independently outlined the status of various energy source in Malaysia. However, they all fell short in providing the greenhouse gas (GHG) emissions in the Malaysian energy sector. Notably, the question that remains to be answered is how GHG emissions have changed in response to the amendment in the energy mix; hence, the effectiveness of policy change in this aspect remains unknown. This paper analysed the past and present trend of Malaysia electricity generation mix and the resultant GHG emissions. In particular, this paper focused on investigating the variation of combined specific GHG emissions in the Malaysian electricity sector, in response to the policy change within the past 22 years. This provides the insight for Malaysian policymakers to evaluate the effectiveness of past policies in GHG emissions and the measures to be taken in future. The finding of this paper shows the attention on the nation’s GHG emissions has evolved over the years, following the diversification in energy mix driven by the policy change. It was also found that, on average, it took a decade for a significant reduction in specific GHG emission to be visible since the government’s energy policy implementation.

综合能源系统是实现“双碳”目标的有效途径,为进一步挖掘其需求侧可调节潜力对碳减排的作用,提出了一种碳交易机制下考虑需求响应的综合能源系统优化运行模型。首先,根据负荷响应特性将需求响应分为价格型和替代型2类,分别建立了基于价格弹性矩阵的价格型需求响应模型,及考虑用能侧电能和热能相互转换的替代型需求响应模型;其次,采用基准线法为系统无偿分配碳排放配额,并考虑燃气轮机和燃气锅炉的实际碳排放量,构建一种面向综合能源系统的碳交易机制;最后,以购能成本、碳交易成本及运维成本之和最小为目标函数,建立综合能源系统低碳优化运行模型,并通过4类典型场景对所提模型的有效性进行了验证。通过对需求响应灵敏度、燃气轮机热分配比例和不同碳交易价格下系统的运行状态分析发现,合理分配价格型和替代型需求响应及燃气轮机产热比例有利于提高系统运行经济性,制定合理的碳交易价格可以实现系统经济性和低碳性协同。

The integrated energy system (IES) is an effective way to achieve the“carbon neutrality and emission peak”goal. In order to further explore the role of the adjustable potential of demand side on carbon emission reduction, an optimized operation model of IES considering the demand response under the carbon trading mechanism is proposed. Firstly, according to the characteristics of load response, the demand response is divided into two types: price-type and substitution-type. The price-type demand response model is established on the basis of price elasticity matrix, and the substitution-type demand response model is constructed by considering the conversion of electricity and heat. Secondly, base-line method is used to allocate free carbon emission quota for the system, and considering the actual carbon emissions of gas turbine and gas boiler, a carbon trading mechanism for the IES is constructed. Finally, a low-carbon optimal operation model of IES is established, whose objective is to minimize the sum cost of energy purchase, cost of carbon transaction and cost of IES operation and maintenance. The effectiveness of the proposed model is verified through four typical scenarios. By analyzing the sensitivity of demand response, heat distribution ratio of gas turbine and the operating state of the system under different carbon trading prices, it is found that reasonable allocation of price-type and substitution-type demand response and heat production ratio of gas turbine is beneficial to improve the operating economy of the system. Making reasonable carbon trading price can realize the coordination of system economy and low carbon.

Considering the characteristics of the power system, where “the source moves with the load”, the load side is primarily responsible for the carbon emissions of the regional power grid. Consequently, users’ electricity consumption behavior has a significant impact on system carbon emissions. Therefore, this paper proposes a multi-objective bi-level optimization strategy for source-load coordination, considering dual demand responses for both electricity and carbon. The upper layer establishes a multi-objective low-carbon economic dispatch model for power grid operators, aiming to minimize the system’s total operating cost, the total direct carbon emissions of the power grid, and the disparity in regional carbon emissions. In the lower layer, a low-carbon economic dispatch model for load aggregators is established to minimize the total cost for load aggregators. To obtain the dynamic carbon emission factor signal, a complex power flow tracking method that considers the power supply path is proposed, and a carbon flow tracking model is established. NSGA-II is used to obtain the Pareto optimal frontier set for the upper model, and the ‘optimal’ scheme is determined based on the fuzzy satisfaction decision. The example analysis demonstrates that the interactive carbon reduction effect under the guidance of dual signals is the most effective. This approach fully exploits the carbon reduction potential of the flexible load, enhancing both the economic efficiency and low-carbon operation of the system.

针对目前低碳调度中负荷侧低碳手段单一且源荷两侧减碳方法相对独立缺乏联动的问题，在利用碳排放流引导多类型负荷需求响应模型的基础上，提出考虑利用碳势耦合源荷多降碳手段的电力系统双层低碳经济调度模型。上层模型基于阶梯碳交易市场，计算源侧的碳市场交易成本，并按照负荷分类进行针对性区域碳排约束，建立考虑源-荷碳势约束的电力系统低碳经济调度模型，求解机组初始调度方案；下层模型利用碳排放流理论，基于上层模型的调度方案计算负荷侧各节点碳势指标和碳排责任分摊量，建立负荷侧多类型需求响应模型，利用用户侧调节能力优化负荷分布进一步实现系统低碳效益。最后在考虑风电不确定性建模的前提下，基于改进的IEEE 30节点系统进行算例分析，结果表明所提调度方法能够有效促进风电消纳，降低碳排放量。

Aiming at the current low-carbon scheduling on the load side of a single low-carbon means, and the source and load sides of the carbon reduction method being relatively independent of the lack of linkage, this study establishes a two-layer low-carbon optimization scheduling model of a power system considering the source-load carbon potential coupling in the market a few days ago. The upper model is based on the ladder carbon trading market, calculates the carbon market transaction cost of the source side, and establishes a low-carbon economic dispatch model of the power system considering the source-load carbon potential constraints in accordance with the load classification, and solves the initial scheduling scheme of the units; the lower model adopts the theory of carbon emission flow, and calculates the carbon potential indexes of each node of the load side and the carbon emission responsibility sharing amount, and establishes a two-layer low-carbon optimization dispatch model of the power system considering the source-load carbon potential constraints. The lower model employs the carbon emission flow theory to calculate the carbon potential index of each node on the load side and the carbon emission responsibility sharing amount based on the scheduling scheme of the upper model, establishes a multi-type demand response model on the load side, and utilizes the user-side regulation ability to optimize the load distribution to further realize low-carbon system benefits. Finally, under the premise of wind power uncertainty modeling, an example analysis is conducted based on the improved IEEE 30-node system, and the results indicate that the scheduling method can effectively promote wind power consumption and reduce carbon emissions.