This contribution presents an hourly-based optimization of a biogas supply network to generate electricity, heat and organic fertilizer while considering multiple objectives and auction trading prices of electricity. The optimization model is formulated as a mixed-integer linear programming (MILP) utilizing a four-layer biogas supply chain. The model accounts for biogas plants based on two capacity levels of methane to produce on average 1 ± 0.1 MW and 5 ± 0.2 MW electricity. Three objectives are put forward: i) maximization of economic profit, ii) maximization of economic profit while considering cost/benefits from greenhouse gas (GHG) emissions (economic+GHG profit) and iii) maximization of sustainability profit. The results show that the economic profit accrued on hourly-based auction trading prices is negative (loss), hence, four additional scenarios are put forward: i) a scenario whereby carbon prices are steadily increased to the prevalent eco-costs/eco-benefits of global warming; ii) a scenario whereby all the electricity auction trading prices are multiplied by certain factors to find the profitability breakeven factor, iii) a scenario whereby shorter time periods are applied, and investment cost of biogas storage is reduced showing a relationship between cost, volume of biogas stored and the variations in electricity production and (iv) a scenario whereby the capacity of the biogas plant is varied from 1 MW and 5 MW as it affects economics of the process. The models are applied to an illustrative case study of agricultural biogas plants in Slovenia where a maximum of three biogas plants could be selected. The results hence present the effects of the simultaneous relationship of economic profit, economic+GHG profit and sustainability profit on the supply and its benefit to decision-making.

中文翻译：

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考虑多个目标和电力拍卖交易价格的沼气供应网络优化

该贡献提出了基于小时的沼气供应网络优化，以产生电力，热量和有机肥料，同时考虑了多个目标和电力拍卖价格。优化模型被公式化为利用四层沼气供应链的混合整数线性规划（MILP）。该模型考虑了沼气厂，该沼气厂基于产生平均1±0.1 MW和5±0.2 MW电力的两种甲烷产能水平。提出了三个目标：i）经济利益的最大化，ii）经济利益的最大化，同时考虑温室气体（GHG）排放的成本/收益（经济+ GHG利润），iii）可持续性利益的最大化。结果表明，按小时拍卖交易价格产生的经济利润为负（亏损），因此，提出了另外四个情景：i）碳价格稳步上升至全球变暖普遍的生态成本/生态效益的情景；ii）将所有电力拍卖交易价格乘以某些因素以找到获利能力盈亏平衡因素的方案，iii）应用较短时间段并减少沼气存储投资成本的方案，表明成本，产量的关系储存的沼气以及发电量的变化；（iv）沼气厂的产能从1兆瓦到5兆瓦不等的情景，因为这会影响流程的经济性。该模型被用于斯洛文尼亚农业沼气厂的示例性案例研究，其中最多可以选择三个沼气厂。