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Abstract Methane hydrates (MH) have been viewed as an important potential energy resource. Assessments about the MH formation and dissociation behavior in porous deposits which are consistent to in-situ reservoir conditions are essential for the safe and efficient production of natural gas hydrates in submarine sediments. In this study, the formation and decomposition behavior of MH in unconsolidated sands recovered from the South China Sea were investigated by the charge-coupled-device (CCD) camera visualization. Deformation of the sediment was observed during both MH formation and decomposition processes. The experimental results indicated that the interactions between MH and the host porous materials during the phase-transition processes could play an important role for the deformation of the sediment. Thus, further studies are needed.

AbstractWithin the Aktifas project, a road map is being developed for research and development of façade-integrated solar thermal systems. The road map is based on an analysis of the barriers for façade-integrated solar thermal systems as well as a market overview of existing components. This paper presents the methodology for creating the road map as well as first results. The final road map will be published on http://bit.ly/Z0hkso at the beginning of 2015.

AbstractIn 2008 the German Ministry of Economic Affairs and Energy launched an initiative for new or retrofitted energy-efficient school buildings as focus area within their research programme “EnOB” (Energy Optimised Buildings). The initiative (www.eneff-schule.de) comprises three different energy levels:•Best practice schools with energy-efficient renovations above the requirements in the energy-saving ordinance•Three-liter-house schools with energy needs for heating, hot water and auxiliary below 34 kWh/m2year•Plus energy schools that produce more energy than they use in the annual balanceCurrently three different plus energy school buildings have been planned, realized and monitored within the initiative, two of them being renovations (Stuttgart and Rostock), the last one being a new school building (Hohen Neuendorf). The three energy concepts include rather different technologies to generate heat and to reduce the energy consumption of ventilation and lighting systems. This is partly due to the research initiative approach of “EnEff:Schule” that asks for testing innovative technologies. There is however a general tendency to:•Low U-values of the building envelope with about 0.11–0.15W/m2K at the walls and roof, 0.10W/m2K for new base plates and 0.20–0.34W/m2K for renovated ground slabs and basement ceilings and 0.80W/m2K for windows•Large PV areas to compensate for the remaining energy use, sometimes in combination with other technologies or systems that generate electricity•Mechanical ventilation systems with high heat recovery rates but in combination with natural ventilation•User-dependent control strategies for ventilation and heating•Use of daylight at both the window/solar shading side and the electrical lighting controlThe paper compares the different technologies used at the building envelope, the heating, ventilation and lighting systems, the calculated and measured energy consumptions and the building costs.

Abstract Due to the ability to obtain energy from direct connection to the electricity grid, plug-in hybrid electric vehicles benefit both society and drivers environmentally and economically by reducing energy consumption and emissions. To extend the travel range, existing studies focus mostly on optimizing the power split of the internal combustion engine and battery without considering the impact of the transmission system. This paper deals with the optimization of a continuously variable transmission (CVT) operation for a parallel pre-transmission hybrid powertrain. The novelty of this paper is that the operation of both engine and CVT transmission are optimized together, resulting in a better fuel efficiency. Simulation work has been carried out to compare the performance of the optimized CVT transmission with a fixed transmission, showing that the fuel consumption is reduced and hence the range is increased for the optimized CVT, which makes the engine to operate in higher efficiency points. A key advantage of the formulation proposed is that the result of the optimization process may be expressed in terms of a 2D map that for any pair of vehicle speed and traction force gives the optimal value of the CVT transmission ratio. Such a map may be easily implemented in real vehicular applications.

Abstract With the reduction of Feed-in Tariff support in many countries, self-consumption of distributed energy resources (DERs) is encouraged and energy sharing between neighbouring prosumers is becoming more attractive than the conventional peer-to-grid (P2G) trading. This work investigated a peer-to-peer (P2P) energy sharing method, allowing the surplus DERs to be shared between prosumers in a neighbourhood. An aggregated control of many small-scale batteries was adopted considering the energy requirement of the entire community. This method significantly reduces the amount of electricity fed back into the grid, allowing individual prosumers to obtain economic benefits. Results showed that, with a moderate proportion (e.g. 40%) of customers having individual photovoltaic (PV) systems, P2P energy sharing is able to reduce the energy cost of the community by 30%, compared to P2G trading.

AbstractThis paper assesses how parameter uncertainties in the model for rise velocity of CO2 droplets in the ocean cause uncertainties in their rise and dissolution in marine waters. The parameter uncertainties in the rise velocity for both hydrate coated and hydrate free droplets are estimated from experiment data. Thereafter the rise velocity is coupled with a mass transfer model to simulate the fate of dissolution of a single droplet.The assessment shows that parameter uncertainties are highest for large droplets. However, it is also shown that in some circumstances varying the temperature gives significant change in rise distance of droplets.

The effort to reduce energy consumption and carbon emission is driving companies to integrate multiple energy technologies to achieve the goal of reducing overall energy consumption, enhancing efficiency and decreasing operational cost. This paper outlines an innovative approach for integrating energy from flooded coal mines via a Ground Source Heat Pump (GSHP) to provide heating to buildings and at the same time to pre-warm a gas engine in standby mode. Once operational, the gas engine will produce significant waste heat that will replace the GSHP in heating the buildings. The results show that this energy integration technology provides much improved overall Coefficient of Performance and reduce carbon emission.