• Energy Research
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Abstract Alternative fuel vehicles (AFV) may help to reduce global CO2 emissions from the transport sector. One obstacle for AFV market diffusion is the lack of refueling infrastructure which prevents potential users from buying AFVs. Meanwhile infrastructure suppliers await market developments before investing in an extensive infrastructure roll-out. This mutual interaction has been a field of research for several years and a variety of modeling approaches have been applied. This paper aims at reviewing models of combined AFV and refueling infrastructure market diffusion and pointing out research gaps. We retrieve stylized facts which models should account for from empirical studies on natural gas vehicles, user acceptance analyses on AFVs and technical restraints of plug-in electric vehicles (PEVs) and fuel cell electric vehicles (FCEVs). Ten interaction models are evaluated with respect to the identified aspects. We find that simulation is the most common approach for an interaction model. Besides, the majority of the examined stylized facts is covered by the models. However, models for FCEVs could be improved by reflecting the transport of fuel to refueling infrastructure while new models on PEVs should include charging duration, frequency and charging station ownership.

SummaryThe German government has adopted a law that requires sewage plants to go beyond the recovery of phosphorus from wastewater and to promote recycling. We argue that there is no physical global short‐ or mid‐term phosphorus scarcity. However, we also argue that there are legitimate reasons for policies such as those of Germany, including: precaution as a way to ensure future generations’ long‐term supply security, promotion of technologies for closed‐loop economics in a promising stage of technology development, and decrease in the current supply risk with a new resource pool.

Six corrosion protection systems for offshore wind power constructions have been subjected to offshore conditions on a test site in the North Sea in three different exposure zones, namely splash zone, intermediate zone, and underwater zone. The systems included single- and multiple-layered organic coatings, metal-spray coatings, and duplex coatings. Special testing specimens were designed and manufactured and exposed to an offshore environment for three years in order to characterize particular constructive details for different corrosivity zones. The following target parameters were investigated: intensity of fouling, anti-corrosive effect, coating adhesion, coating integrity, flange corrosion, coating performance over welds, and condition of screw connections. Fouling was an issue in the underwater zone and in the intermediate zone, but it did not affect the coating corrosion protection capacity. It was found that duplex systems, consisting of Zn/Al spray metallization, intermediate particle-reinforced epoxy coating, and polyurethane top layer, provided the highest anti-corrosive effect. Mechanical damage to the coatings initiated coating delamination and substrate corrosion. Effective coating systems should be either very resistant to impact or able to compensate for corrosion of the steel. Flange connections were found to be critical structural parts in the splash zone in terms of corrosion. Notable crevice corrosion was observed at places. Except for one coating system, welds have been protected well. Welds, however, affected the corrosion of the steel inside the uncoated internal sections in the underwater samples. Coating integrity on difficult-to-coat structural parts was satisfactory for all systems.

Abstract Waste disposal is a core issue worldwide. Different researches are being carried out in order to handle waste materials, generated in industrial production and application processes, e.g. paint residue from metal coating in the automobile industry. Often waste is disposed in landfills at substantial economic and environmental cost. Combustion is another way to get rid of possibly hazardous waste. Pulverized fuel combustion is one of the latest combustion technologies. However, pulverized fuel combustion faces severe problems if the waste (fuel) contains components with low melting point. Having a low melting point, it gets difficult to manage and convey the pulverized material to the hot combustion chamber. The melting of fuel causes clogging in the fuel transport nozzle used to convey the material into the combustion chamber. In this work, a new technology for combustion of materials with low melting points is proposed, focusing on apparatus and nozzle design to prevent clogging. For this purpose, different nozzle designs were evaluated by multi-phase CFD simulations. Two sets of nozzle air flow rates were used in four nozzles. Effect of different flow rates and fuel particle size on combustion temperatures are also discussed. It was noted that nozzle air flow rate has a strong influence on the temperature distributions. Small fuel particle sizes result in wider combustion zones while larger particles give longer combustion zones. The results come up with optimized nozzle design and nozzle air flow for transportation of pulverized material with low melting point.

The investigation of degradation of seven distinct sets (with a number of individual cells of n $ 12) of state of the art organic photovoltaic devices prepared by leading research laboratories with a combination of imaging methods is reported. All devices have been shipped to and degraded at Risø DTU up to 1830 hours in accordance with established ISOS-3 protocols under defined illumination conditions. Imaging of device function at different stages of degradation was performed by laser-beam induced current (LBIC) scanning; luminescence imaging, specifically photoluminescence (PLI) and electroluminescence (ELI); as well as by lock-in thermography (LIT). Each of the imaging techniques exhibits its specific advantages with respect to sensing certain degradation features, which will be compared and discussed here in detail. As a consequence, a combination of several imaging techniques yields very conclusive information about the degradation processes controlling device function. The large variety of device architectures in turn enables valuable progress in the proper interpretation of imaging results—hence revealing the benefits of this large scale cooperation in making a step forward in the understanding of organic solar cell aging and its interpretation by state-of-the-art imaging methods.

Abstract The increasing global energy demand, the foreseen reduction of available fossil fuels and the increasing evidence off global warming during the last decades have generated a high interest in renewable energy sources. However, renewable energy sources, such as wind and solar power, have an intrinsic variability that can seriously affect the stability of the energy system if they account for a high percentage of the total generation. The Energy Flexibility of buildings is commonly suggested as part of the solution to alleviate some of the upcoming challenges in the future demand-respond energy systems (electrical, district heating and gas grids). Buildings can supply flexibility services in different ways, e.g. utilization of thermal mass, adjustability of HVAC system use (e.g. heating/cooling/ventilation), charging of electric vehicles, and shifting of plug-loads. However, there is currently no overview or insight into how much Energy Flexibility different building may be able to offer to the future energy systems in the sense of avoiding excess energy production, increase the stability of the energy networks, minimize congestion problems, enhance the efficiency and cost effectiveness of the future energy networks. Therefore, there is a need for increasing knowledge on and demonstration of the Energy Flexibility buildings can provide to energy networks. At the same time, there is a need for identifying critical aspects and possible solutions to manage this Energy Flexibility, while maintaining the comfort of the occupants and minimizing the use of non-renewable energy. In this context, the IEA (International Energy Agency) EBC (Energy in Buildings and Communities program) Annex 67: “Energy Flexible Buildings” was started in 2015. The article presents the background and the work plan of IEA EBC Annex 67 as well as already obtained results. Annex 67 is a corporation between participants from 16 countries: Austria, Belgium, Canada, China, Denmark, Finland, France, Germany, Ireland, Italy, The Netherlands, Norway, Portugal, Spain, Switzerland and UK.

Abstract Despite the comparatively limited stock of vehicles, heavy-duty road transport is responsible for a major share of CO2 emissions from the European transport sector. Electric trucks powered by overhead lines, so-called trolley trucks or catenary hybrid trucks, have been proposed as a potential GHG mitigation option. However, from the perspective of the energy system, trolley trucks constitute an additional and inflexible electricity demand. Here, we analyse scenarios with an ambitious European market diffusion of trolley trucks and their impact on the electricity system and CO2 emissions. Our results show that trolley trucks can noteworthily reduce the CO2 emissions from heavy road transport even when the additional CO2 emissions from electricity generation are taken into account. Furthermore, the actual impact of the additional load from trolley trucks on the total energy system is limited. Compared to the anticipated electricity demand from passenger cars in 2030, trolley trucks require less energy and the load is more equally distributed over daytime. Our findings thus show that electric trucks are an interesting option for CO2 mitigation in heavy road transport.

With the Paris target of limiting global warming to well below 2 °C until 2100, at best even 1.5 °C, the question arises what this implies for the EU’s mitigation targets and strategies. In this article, the reduction of carbon intensities and energy uses in the most ambitious mitigation scenarios for the EU, France, Germany, Italy, and the UK are compared to those of the EU in global 1.5 and 2 °C scenarios. An index decomposition analysis is applied to energy supply and each end-use sector (industry, buildings, and transport) to identify the main differences. From this, we derive conclusions concerning policies and indicators for an EU mitigation strategy compatible with limiting global warming to 1.5 °C. The index decomposition shows that reducing energy use is a stronger lever in the evaluated national scenarios than in the international scenarios for all end-use sectors. The reasons for that are the lower utilization of CCS, the inclusion of additional technology options, and a detailed consideration of sufficiency in the national scenarios. The results suggest that including more ambitious demand-side mitigation options (sufficiency, energy efficiency, electrification, and fuel switching) can significantly reduce the need for negative emissions that are required in all the existing 1.5 °C-compatible global scenarios. Driving these options requires substantial enhancement of current policies for all end-use sectors. In addition, certain index decomposition approaches are shown to underrate the long-term contributions of demand-side mitigation. Accordingly, demand-side mitigation tends to be under-represented in progress indicators for the Paris Agreement, which calls for improvements.