Economic and Global Warming Potential Assessment of Flexible Power Generation with Biogas Plants

Evaluating the sustainability of demand oriented biogas supply programs under different flexible hierarchies: A suggested approach based on the triple bottom line principle

In this paper, a decision-making approach based on the triple bottom line concept is presented for evaluating the sustainability of demand-oriented biogas supply (DOBS) programs with regard to their environmental, economic, and social impacts. For the assessment, an indicator system was developed, whose main parameters were quantified by integrating emergy analysis, economic benefit assessment, and a proposed social risk accounting method. The Charnes-Cooper-Wei-Huang (CCWH) model with constrained cone was adopted to calculate the comprehensive sustainability via the synthesis of the economic, environmental, and social indicators, in which eight scenarios were set according to the flexibility hierarchy of biogas supplied for load demand, biogas production mode, and feeding substrates. The evaluation results show that the DOBS scenario of supplying for real-time varying power demand by using straw and livestock manure has the highest sustainability score in our case study. Based on the results, corresponding managerial implications are proposed.

An analytical hierarchy process based decision support system for the selection of biogas up-gradation technologies

Recent developments in biogas upgradation have opened new horizons for its utilisation because upgradation technologies are fully developed and commercially available. However, the implementation of biogas upgrading technologies is not at the scale required to harness the full potential of biogas. Therefore, it is requisite to adopt a multicriteria decision-making methodology (MCDM) to select the most appropriate biogas up-gradation technology as each technology has its own set of benefits and downside. In this multifaceted scenario, the analytical hierarchy Process (AHP), one of the most preferred MCDM methods in rational decision-making, is applied in this study to select the most appropriate biogas upgrading technology. The broader recognition of AHP is its provision for converting multifaceted problems into a simple hierarchy. The research results reveal that biogas up-gradation technologies based on water scrubbing and membrane separation rank first and second among the alternatives. This research will show a direction to researchers and the MCDM community involved in biogas upgradation technologies on a broader scale.

Research on the Optimal Operation of a Novel Renewable Multi-Energy Complementary System in Rural Areas

Sustainable development is an inevitable choice for the development of human society, and energy is closely related to sustainable development. Improving energy structure, increasing energy efficiency, and vigorously developing renewable energy are of great significance to the sustainable development of rural areas. Moreover, the establishment of a distributed multi-energy complementary system (MECS) using abundant renewable energy such as wind, solar, and biomass energy is an effective way to solve the rapid growth of rural power demand, weak rural power grids, and rural environmental pollution. This paper proposes a new type of Wind–Solar–Biomass–Storage MECS composed of wind power generation (WPG), photovoltaic power generation (PVG), biogas power generation (BPG) and energy storage system (ESS) and establishes a MECS optimization operation model with the goal of maximizing daily operating economic benefits, considering the characteristics of each power generation system and power demand characteristics. By using the multi-population genetic algorithm (MPGA), the simulation experiments of the MECS operation under four typical weather scenarios are carried out. The results show that the MECS can operate stably in different scenarios and achieve the goal of maximizing economic benefits, which verifies the feasibility of the MECS model. In addition, the simulation results are compared with the standard genetic algorithm (SGA), which shows the effectiveness of the optimization method. This paper takes Chinese rural areas as an example for research. The proposed MECS and optimal operation model are also applicable to developing countries with a high proportion of the rural population.

Optimization Model for Biogas Power Plant Feedstock Mixture Considering Feedstock and Transportation Costs Using a Differential Evolution Algorithm

In this paper, an optimization model for biogas power plant feedstock mixture with respect to feedstock and transportation costs using a differential evolution algorithm (DEA) is presented. A mathematical model and an optimization problem are presented. The proposed model introduces an optimal mixture of different feedstock combinations in a biogas power plant and informs about the maximal transportation distance for each feedstock before being unprofitable. In the case study, the proposed model is applied to five most commonly used feedstock in biogas power plants in Croatia and Hungary. The research is performed for a situation when the biogas power plant is not owned by the farm owner but by a third party. An optimization procedure is performed for each scenario with a cost of methane production that does not exceed 0.75 EUR/m3 in 1 MWe biogas power plant. The results show the needed yearly amounts and the maximum transportation distance of each feedstock.

The Analysis of the Economic Effects on the Greening and Recovery of the Sludge Waste Resulting from the Biogas Production Activity

Starting from identifying an upward trend in waste disposal costs at the municipal landfill, the research aims to analyze the viability of investment to integrate a compost platform, which transforms the sludge resulting from the biogas production process into a soil improver for agricultural land. The economic entity analyzed activates agri-food and uses a biogas plant as a management tool for the waste from slaughtering chickens, to obtain biogas, heat, and electricity. The study is carried out through the multi-criteria analysis based on the following variants: The operation of the biogas plant with sludge disposal as waste (V1), the operation with recovery of waste as soil improver (V2), the closure of the biogas plant (V3). The economic effects regarding the greening and capitalization of the sludge waste are quantified from a monetary point of view and based on the analysis the optimal variant, V2, is established. It has been proven that the investment generates: Positive results increased by 70.52%, a positive and upward opportunity cost by 37.96%, and marginal profit growth of 53.17%. The study emphasizes that efficient waste management turns an environmental problem and cost into an economic and ecological advantage for the economic entities.