In Europe, green hydrogen and biogas/green gas are considered important renewable energy carriers, besides renewable electricity and heat. Still, incentives proceed slowly, and the feasibility of local green gas is questioned. A supply chain of decentralised green hydrogen production from locally generated electricity (PV or wind) and decentralised green gas production from locally collected biomass and biological power-to-methane technology was analysed and compared to a green hydrogen scenario. We developed a novel method for assessing local options. Meeting the heating demand of households was constrained by the current EU law (RED II) to reduce greenhouse gas (GHG) emissions by 80% relative to fossil (natural) gas. Levelised cost of energy (LCOE) analyses at 80% GHG emission savings indicate that locally produced green gas (LCOE = 24.0 €ct kWh−1) is more attractive for individual citizens than locally produced green hydrogen (LCOE = 43.5 €ct kWh−1). In case higher GHG emission savings are desired, both LCOEs go up. Data indicate an apparent mismatch between heat demand in winter and PV electricity generation in summer. Besides, at the current state of technology, local onshore wind turbines have less GHG emissions than PV panels. Wind turbines may therefore have advantages over PV fields despite the various concerns in society. Our study confirms that biomass availability in a dedicated region is a challenge.
The growing appetite of cities is one of the greatest future challenges. There is no set menu for meeting this appetite, but a trend is observed in which city authorities focus on region-based food provision. Regionalism is motivated by the importance of increased self-reliance. Besides, regional food systems, are associated with more sustainable production and reduced carbon footprints, the reconnection of consumers with production, and the increased uptake of whole foods in urban diets. However, the question remains to what extend region based food systems may become self-reliant? How may they contribute to improved sustainability and healthy lifestyles? With the Dutch city of Almere as a case in point this paper provides a food flow data-based analysis of the opportunities and limitations of regional based food system approaches. The paper sets off with defining the concepts of sustainable self-reliance and regionalism. Next, it describes the methodology of measuring and mapping the actual food flows. We combined secondary, publicly available, with primary quantitative and qualitative datasets, involving regional businesses, urban policymakers, and residents. Our study uncovers the coinciding disconnect and interconnectedness of local, regional and global food systems. The regional scale offers opportunities for tackling many food related challenges, however, sustainable urban food security demands connections beyond the regional sphere and beyond the food domain. To assess the effects of the policy options available at the local and regional level, a solid evidence base is essential. This paper advances the development of evidence-based methodologies to monitor and inform food system policies.
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This paper descibes a study that shows that glycogen-lowering exercise, performed the evening before an exercise bout in combination with glycogen restriction leads to a reduction of the oxidation rate of ingested glucose during moderate-intensity exercise
