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Abstract In this paper, a strategy is proposed in order to introduce in a realistic way wind generation into a transmission power system non sequential Monte Carlo adequacy study with economic dispatch. Thanks to the implemented solution, wind generation is consequently confronted to operational constraints related to high powered thermal units, nuclear parks or thermal machines with technical minimum value. Moreover, during each simulated system state, a DC load flow is also calculated in order to evaluate reinforcements optimizing the large scale integration of wind power production. The simulation tool modified during the present work is called Scanner© and is the property of Tractebel Engineering (Gaz de France – Suez) company. It has been here applied to an academic test system: the Roy Billinton Test System (RBTS).

Five different pre-treatments were investigated to enhance the solubilisation and anaerobic biodegradability of kitchen waste (KW) in thermophilic batch and continuous tests. In the batch solubilisation tests, the highest and the lowest solubilisation efficiency were achieved with the thermo-acid and the pressure-depressure pre-treatments, respectively. However, in the batch biodegradability tests, the highest cumulative biogas production was obtained with the pressure-depressure method. In the continuous tests, the best performance in terms of an acceptable biogas production efficiency of 60% and stable in-reactor CODs and VFA concentrations corresponded to the pressure-depressure reactor, followed by freeze-thaw, acid, thermo-acid, thermo and control. The maximum OLR (5 g COD L(-1) d(-1)) applied in the pressure-depressure and freeze-thaw reactors almost doubled the control reactor. From the overall analysis, the freeze-thaw pre-treatment was the most profitable process with a net potential profit of around 11.5 € ton(-1) KW.

Abstract In many visions and roadmaps, there is a broad agreement that fuel cells – both for stationary and mobile applications – are the key technology to allow the development of a hydrogen infrastructure. Furthermore, this development is generally thought to be based on a gradual, decentralised evolution. Nevertheless, in this paper it is argued that, taking into account the entire hydrogen chain (production, transport, storage, distribution and end-use), this decentralised fuel-cell based philosophy shows some serious flaws. Therefore, a new hydrogen-transition approach was pushed forward: mixing in of hydrogen into the natural-gas bulk. Using Flanders – the Northern part of Belgium – as a case study, the development of a transitory hydrogen infrastructure has been studied, taking into account the entire hydrogen chain and its dynamics, from production to end use. In a next step, this transition is being quantified. An optimisation model has been developed using Matlab and the commercial solvers GAMS and CPLEX. Following a mixed-integer linear-programming approach, this model is able to determine the economically optimal hydrogen-production mix and operational behaviour of each hydrogen-production plant separately. The model then allows gaining valuable insights in the importance of storage and the influence of fuel prices and carbon taxes with regard to the development of an early hydrogen economy.

Recently, studies have appeared pointing out that aerosols can dominate the total amine emission from amine based PCCC pilot plant scale installations. For the design of countermeasure types (upstream or downstream of the PCCC installation), it is crucial to have an idea of the aerosol size distribution and numbers entering or leaving the absorber. This study is the first to present this kind of data and should serve future installations when designing aerosol emission countermeasures. H2SO4 aerosols entering the absorber are observed to be extremely small (i.e. <0.2μm) with number concentrations exceeding 1E8cm-3. The aerosols grow in size as they travel through the absorber through the taking up of water and amine to sizes close to but staying below 1μm. However, despite the fact that most of the aerosols (expressed in number concentrations) are well below 1μm, most of the water (and thus amine) is found in the aerosol sizes between 0.5 and 2μm. Therefore, if one aims at designing efficient countermeasures, eliminating this size fraction is crucial. This amine emission stream is therefore very difficult to remove using water washes as aerosols are known to travel through water wash sections. Moreover, also classical demisters show very little efficiency for these small aerosol sizes and are therefore believed not to be suitable for the removal of aerosols. This information will therefore serve future installations when designing aerosol emission countermeasures. © 2014 Elsevier Ltd.

This paper presents an approach to model the transfer function of a four-conductor power-line cable for power-line communications. The model is derived from multiconductor transmission-line theory by taking into account all couplings between the conductors. The model allows one not only to determine the transfer function, but also the interference characteristics of that transmission medium. The transfer function for a straight line without branches is obtained first, and then crosstalk is derived. Finally, an N-branch network is simplified based on a generalization of the transmission matrix method. The transfer characteristics of the equivalent network are derived in a similar way as for a straight line.

Abstract The current evolutions in electricity market policies combined with the technical progress in wind farm control encourage Wind Power Producers (WPPs) to participate in the joint day-ahead energy and reserve market (JERM). In this paper, an advanced bidding strategy dedicated to optimal dispatch of the WPP in the JERM is proposed. The suggested strategy exploits a novel bi-objective two-stage chance-constrained stochastic model in which various revenue streams, stemming from both day-ahead and real-time stages, are fully accounted for. The first objective of the presented model is to allocate the optimal share of the power assigned to each market floor in the day-ahead stage so as to maximize the WPP’s profit. Then, the formulation considers the confidence level of delivering the contracted reserve power in real-time through an additional competing objective. Meanwhile, the presented method allows us to also illustrate the effect of reserve availability as a probabilistic measure on WPP’s profit. In this regard, the wind speed and system frequency uncertainties are introduced as stochastic inputs in the proposed framework. The obtained revenue streams regarding each market floor as well as the total revenue of the WPP are then evaluated in a Monte Carlo out-of-sample analysis. The ex-post samples contain system frequency data from the Belgian market along with wind speed data representing the wind turbulence intensity level. Outcomes reveal not only the effectiveness and flexibility of the proposed model for enhancing WPPs’ revenues, but also the importance of properly considering the uncertain real-time delivery of the contracted reserve power.

Abstract We propose a new concept suitable for performing static state estimation in large scale electric power systems. It consists in decomposing the over-all system into sub-systems and in carrying out a two-level calculation. In a lower hierarchical level, a standard state estimation is at first performed in parallel for all sub-systems and independently from each other. A coordination of these local estimations is then realized at the second (upper) hierarchical level which, by this means, receives and treats only a small number of variables. It may therefore obey various requirements, such as goegraphical, economical, etc. The advantages of this hierarchical procedure over the standard “integrated” one are drawn in the Conclusions.