Volume 2, Issue 2-3 -

In this review, we summarize our research on the characterization of FeCu/C catalyst and its effect in non-aqueous electrolyte Li/air cells. The catalyst is synthesized by impregnating metal phthalocyanine complex into a high surface area carbon, followed by pyrolyzing the complex-loaded carbon under argon atmosphere. High resolution X-ray photoelectron spectroscopy (HR-XPS) results indicate that the metals in the catalyst are present in the form of a mixture of metal-nitrogen complexes (MN) and metal oxides (MO). Using coin-type Li/air cells as the testing vehicle, the FeCu/C is determined to affect the Li/air cells in three manners: (1) It catalyzes two-electron oxygen reduction reaction (ORR) to form Li 2 O 2 , which reduces discharge polarization of the Li/air cells, (2) It promotes chemical disproportionation of Li 2 O 2 , which leads to an apparent four-electron ORR, and (3) It induces reduction of electrolyte solvents, which adds a second lower discharge voltage plateau at ∼1.7 V. In addition, the FeCu/C catalyst increases the open circle voltage (OCV) recovery rate of the Li/air cells as a result of the chemical disproportionation of Li 2 O 2 , which releases oxygen and the resulting oxygen participates in OCV recovery.

A gasification plant is integrated on the top of a solid oxide fuel cell (SOFC) cycle, while a steam turbine (ST) cycle is used as a bottoming cycle for the SOFC plant. The gasification plant was fueled by woodchips to produce biogas and the SOFC stacks were fired with biogas. The produced gas was rather clean for feeding to the SOFC stacks after a simple cleaning step. Because all the fuel cannot be burned in the SOFC stacks, a burner was used to combust the remaining fuel. The off-gases from the burner were then used to produce steam for the bottoming steam cycle in a heat recovery steam generator (HRSG). The steam cycle was modeled with a simple single pressure level. In addition, a hybrid recuperator was used to recover more energy from the HRSG and send it back to the SOFC cycle. Thus two different configurations were investigated to study the plants characteristic. Such system integration configurations are completely novel and have not been studied elsewhere. Plant efficiencies of 56% were achieved under normal operation which was considerably higher than the IGCC (Integrated Gasification Combined Cycle) in which a gasification plant is integrated with a gas turbine and a steam turbine. Furthermore, it is shown that under certain operating conditions, plant efficiency of about 62 is also possible to achieve.

This paper investigates a fully submerged, symmetric, three-dimensional wave energy device utilizing two phenomena: (i) under certain conditions, a submerged fixed circular disc has the effect of focusing the incident wave field so that considerable energy concentration can occur over a region behind the disc center; and (ii) the dynamic interaction of two stiffness-coupled bodies causes the oscillation amplitude of one of the bodies to be nearly zero in harmonic forcing at a certain frequency. The goal of the paper is to examine whether the combined effect of (i) and (ii) enables high efficiency energy conversion, in particular with the application of active control to extend the effect (ii) to a range of frequencies. The work reported here considers a three-body device where controlled dynamic interaction between two of the bodies holds one nearly fixed, so as (a) to enable the focusing effect in (i), and to provide a stationary reference for energy absorption via oscillations of the third body. The paper also discusses the control approach used, and evaluates performance results based on a simple analytical model. An appreciable enhancement of the `bandwidth' of efficient energy absorption is observed with control.

In Portugal, the increase in the production of electricity based on renewable energy sources has been achieved based mainly on hydro and wind resources. The sun has been underexploited so far. The Portuguese territory presents high levels of solar radiation, and thus it is urged to find solutions that take advantage of this widely recognized fact. In this context, it is important to come forward with concentrated solar power systems as an option. The most mature of these technologies is the parabolic trough. The purpose of this paper is to report the outcomes of a study concerning a parabolic trough power plant, with thermal storage. This paper aims to present a model of a parabolic trough power plant, including the associated thermal storage system, to validate it against results reported in the literature and to build up a simulator enabling the assessment of the performance of the plant for several locations in the Portuguese territory. Based on the obtained results, some conclusions regarding the behavior of the system are drawn.

The option of decarbonisation of the European power sector with the help of significant imports of renewable electricity from North Africa via a trans-continental electricity Supergrid is increasingly gaining attention. In this paper, we investigate the geopolitical risks to European energy security in such a future, and discuss cornerstones for possible policy strategies to reduce these risks. The strategies are rooted in the interdependence between exporter and importer. We come to the conclusion that fostering and deepening, as opposed to reducing, the dependence of both sides on each other may be a valuable and powerful way to reduce the geopolitical risks of renewable electricity trade between Europe and North Africa.

Now that the decision has been made to give up all production of electricity through nuclear reactors by 2022, Germany is in the position to develop all sorts of new energies. I would like to point out that Germany has a unique chance to develop large hot water reservoirs by using the pits left behind after brown coal production or cement production. They can be mainly used for keeping hot water produced year-round as waste heat of industry or especially hot water produced by hybrid solar panels. The water will be used mainly for heating central heated buildings in the winter. As the increase of the need of air conditioning in summer is expected, the same system could be used to cover the need of more electricity in summer. Possible designs of the large hot water reservoir, requirements for the site, and eventual extension to other countries are discussed.