Abstract written for an poster presentation at the EBA conference in Alkmaar. The flexibility of biogas makes it a very capable load balancer within decentralized smart energy systems. However, within this context the sustainability of biogas production is not fully understood. What is needed is a tool for analyzing the ustainability of biogas production pathways. The main goal, of this research is to design a transparent flexible planning tool capable determining the sustainability of decentralized biogas production chains. This insight will help in designing a tailor-made biogas production chain for a specific geographic location, increasing the effectiveness and sustainability of biogas as a renewable resource.
The need to reduce carbon emissions calls for more use of renewable generation, particularly distributed resources. The intermittency of renewable generation, and concerns about energy security, require us to become more independent of central grid operation by use of local or regional (micro-grid) electricity systems. Distributed generation, allied to the commercial availability of battery storage products, permits this–the pathway to energy autonomy. This paper reviews the contribution of different renewable energy sources (RES), trends in energy storage technologies to enable energy autonomy, and the centralised and decentralised techniques that coordinate the associated energy management. The paper covers energy autonomy at different scales, ranging from household levels to district levels. The improvements in grid independency are measured accordingly. There is discussion of this measurement and of the economic and ecological benefits from energy autonomy in the context of policy frameworks.
Biogas produced through Anaerobic Digestion can be seen as a flexible and storable energy carrier. However, the environmental sustainability and efficiency of biogas production is not fully understood. Within this article the use, operation, structure, validation, and results of a model for the environmental assessment of anaerobic biogas production pathways is discussed. The (Excel) BioGas Simulator or EBS model is capable of calculating the economic cost, efficiency, carbon footprint, and sustainability of small scale anaerobic digestion biogas production pathways (from 2000 up to 50000 ton/a biomass input). The results from the model are expressed in four main indicators: the economic cost in Net Present Value (NPV), the efficiency in Process Energy Returned On Invested or (P)EROI, the carbon footprint in Global Warming potential 100 year scale (GWP100), and the environmental impact in EcoPoints. The economic indicator is given in Euros in Net Present Value over a period of 25 years, the other indicators are given per Giga Joule of energy produced (e.g. kgCO2eq/GJ). The EBS model is based on a clear methodology, structured around the modular approach, energy and material flow analysis, and life cycle analysis. The modular approach separates the biogas production pathway into individual physical processes, which makes the model more transparent, flexible in use, and programmable with different settings. The aforementioned allows the research of several aspects of the biogas production pathway. Furthermore, the indication of sustainability in four clear indicators gives an understandable reference for comparison with other scenarios. Overall, the EBS model can help give insight on the sustainability of specific biogas production pathways and help indicate options for improvement. Results from the model indicate that from an energy efficiency and sustainability point of view, the anaerobic digestion process should be utilized for treating locally available waste feedstocks with the added advantage of producing energy, which should preferentially be used internally for powering the waste treatment process.
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