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[en] Highlights: • HOMER optimisation analysis to plan smart Island energy systems. • Comparison between different storage solutions and power-to transport strategies. • Hydrogen potential use in insular public transport sector. • Comparison between fuel cell electric buses and enriched natural gas fuelled buses. - Abstract: Energy costs, carbon dioxide emissions, security of supply and system stability are common challenges in small islands. Many European islands have become pilot sites of energy innovation, but this green transition goes slowly in other ones usually not connected to the national grid. This study investigates the economic and environmental sustainability related to the integration of hydrogen and batteries storage in small islands, considering at the same time the use of the stored hydrogen for fuelling Fuel Cell Electric Vehicles and Hydrogen Compressed Natural Gas vehicles to meet electricity and public transportation demand of islands, so as to increase the Renewable Energy Sources penetration level. Selecting the island of Favignana (Italy) as case study, HOMER software has been used to carry out the energy analysis of different scenarios, in order to identify the most effective energy solution from both technological and economical point of views. Using economic and environmental indicators, the outcomes show that the implementation of a hybrid storage system with batteries and electrolyser can be an adequate and reliable option for increasing energy independency of small island and decarbonizing transport sector optimizing economic and environmental sustainability.
[en] Phase change material (PCM) can store large amount of thermal energy at phase change temperature. Determination of thermophysical properties of PCM plays an important role in estimation of energy stored or released in storage device. Properties of PCM are key factors for designing a latent heat thermal energy storage system. This paper deals with the study of effect of heating/cooling rate on thermophysical properties, especially on melting temperature and latent heat of fusion /solidification. Results indicate that latent heat of fusion has more dependence on heating/cooling rate than onset, peak and end temperature. (author)
[en] Safety is the important aspect for Li-ion cells/ batteries. Even a single battery fire could turn the public opinion against Li-ion cells and the damage will be more in case of space systems. Proper care should be taken in thermal management of the cell to avoid Thermal Runaway (TR). Also the design of battery system should be in such that Thermal Runaway event is completely contained within the battery and to have no impact to other spacecraft/ Launch Vehicle systems
[en] Highlights: • The ReSOC EES system can achieve LCOS • Balance-of-plant hardware can be compatible between operating modes. • Storage tank dynamics have minimal impact on system performance. • The ReSOC system can operate down to 15% of rated capacity and with RTE of 54%. • The ReSOC system investigated is economically competitive with other technologies. - Abstract: Reversible solid oxide cells may be a cost competitive energy storage technology at the distributed scale. Leveraging C–O–H chemistry and operating near 600 °C allows the cells to be exothermic in both modes, improving efficiency and operability. This study characterizes ReSOC balance-of-plant hardware off-design performance to investigate component mode compatibility, the effect of tank dynamics, and part-load performance for a 100 kW/800 kWh plant. We also introduce a variable volume floating piston tank concept to improve energy storage density and evaluate operability advantages. Results show that with proper system design, balance-of-plant components are compatible, and tank dynamics have minimal impact when tanks are uninsulated and designed for storage near ambient temperature. System AC roundtrip efficiency is between 53% and 54%, depending on the tank technology selected and the compressor operating approach. Energy density is 84.4 kWh/m3 for rigid tanks, and 146.1 kWh/m3 for the variable volume tank concept at 100 bar storage pressure. This study also shows that ReSOC systems can maintain high efficiency at part-loads as low as 15% of rated capacity. Economic analysis of the system estimates an installed capital cost of $422–452/kWh, and a levelized cost of storage of 18.8–19.6 ¢/kWh, values competitive with state-of-the-art battery technology.
[en] The aim of our research is to prepare high sulfur composite materials with the highest capacity, efficiency and cyclability. Subsequently, the best materials are also tested in real small prototypes of Li-S batteries. In particular, these cells should be much safer, more stable and cheaper than today's batteries. (authors)
[en] As a major global electricity operator, EDF manages a significant number of industrial assets to meet the needs of more than 37 million customers. Ensuring a supply-demand balance around the clock requires significant flexibility in the resources. With major advances in storage technologies and cost reductions, primarily for batteries, EDF is pro-actively investigating and testing services and value streams that distributed storage can provide to various locations, such as behind the meter, distribution, and transmission level interconnections. This brochure presents EDF Renewables' expertise and technical skills in: batteries and other storage technologies as a cost-effective addition to intermittent energy generation projects; distributed storage projects, R and D activities in: new battery technologies at lower costs and/or improved capabilities, stationary storage technologies for commercial electric vehicle, smart-grids, simulation tools, battery storage scheduling and real-time control systems, advanced forecasting tools, smart control systems and energy management algorithms. The company's global renewable energy presence in the Americas, Europe, Africa, India and Asia are summarized at the end of the document with the respective installed capacities
[en] Here, the development of next-generation lithium-based rechargeable batteries with high energy density, low cost, and improved safety is a great challenge with profound technological significance for portable electronics, electric vehicles, and grid-scale energy storage. Specifically, advanced lithium battery chemistries call for a paradigm shift to electrodes with high Li to host ratio based on a conversion or alloying mechanism, where the increased capacity is often accompanied by drastic volumetric changes, significant bond breaking, limited electronic/ionic conductivity, and unstable electrode/electrolyte interphase.
[en] Highlights: • An efficient modeling method for PCM solidification with fins was developed. • A finned heat pipe structure was optimized with negligible computational cost. • Suggestions to economically weld fins on a heat pipe are given. - Abstract: Phase Change Materials (PCMs) are gaining importance in energy storage applications. However, many PCMs are poor thermal conductors and thus can benefit from the optimal use of appropriate fins. This work introduces a PCM-fin structure optimization framework. Typically, the non-linear solidification process increases the complexity associated with solving the mathematical equations for the PCM-fin structure optimization problem, making it computationally expensive. In this paper a modeling approach called Layered Thermal Resistance (LTR) model is extended and developed in 2D cylindrical geometry in order to enable efficient PCM-fin structure optimization. The finned LTR model represents the nonlinear transient solidification process by analytic equations. This significantly reduces the computational cost associated with optimization. A finned heat pipe structure modeled by the finned LTR approach is optimized based on minimizing cost while meeting operational requirements. The optimal results imply that thinner fins result in lower system cost and that there is a thickness limit for the fins to be economically welded on a heat pipe. The finned LTR model also gives the optimal cost of material usage for a large scale latent thermal energy storage system in terms of dollars per kilowatt and it was found that the system cost is slightly lower by using carbon-steel as the construction material for the heat pipes and fins than by using Al 6061.