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A new concept of a system for Combined Heat and Power generation is presented. The concept is based on hybrid use of two renewable energy sources, direct solar (thermodynamic solar) and biomass (indirect solar energy). Biomass combustion is conducted using a fluidized bed combustor. A second source of energy, given by the direct irradiation of the bed with a concentrated solar radiation, is integrated in the same system, using the fluidized bed as solar receiver. A Stirling engine converts heat into mechanical power. A Scheffler type mirror is adopted to allow irradiation of the system in a fixed focal point. Advantages of the proposed solution are illustrated and some preliminary results on the performance of the system, obtained with a simple model, are presented. The principal improvements with respect to existing systems of similar size and primary energy source are illustrated. The most important are the enhanced heat transfer processes that are realized with the help of the fluidized bed, and the possibility of continuous cogeneration during the day. Different working conditions are considered to estimate the contribution given by the burning of fuel, in presence as well as in absence of sun irradiation (as during the night). The distribution of energy shares among the different flux contributes is reported versus the amount of biomass burned per unit time. The results clearly demonstrate the advantage of coupling, in the same system, two sources for heat generation, thus maintaining the option of producing electricity without the supply of biomass fuel.

ON 16 NOVEMBER 2000, the final report of the World Commission on Dams (WCD) was launched in London, in the presence of South Africa’s former president Nelson Mandela. This represented a remarkable milestone in the history of dam policy and politics. During its two-year existence, WCD had conducted the most extensive review of research and evidence regarding the planning, impacts, and management of large dams. It had engaged with numerous stakeholders around the globe. It also made comprehensive recommendations about how to improve dam planning and management.

This contribution presents a user-friendly data reduction routine for Pitot probes based on widely available software with a fluid properties interface. The data reduction process rests on the general balance equations and the fluid database and calculation program REFPROP by NIST. In the corresponding calculation sheet, the user can easily select the fluid and manually or automatically insert the probe data and stagnation conditions of the measurement. A robust algorithm directly calculates the freestream Mach number and other flow and thermodynamic quantities. The new Pitot probe data reduction routine's accuracy is assessed through several test cases, including the subsonic and supersonic flow of dry air, Novec 649, and siloxane MM in the dilute and dense gas regime. For compressible non-ideal gas flows, it is found the classical Rayleigh-Pitot equation is systematically in error even in the dilute gas regime where relative deviations of more than 10 % were noticed. In the dense gas regime, the Rayleigh-Pitot equation fails dramatically in calculating the freestream Mach number, and errors larger than 60 % were observed.

The paper presents the Danish case of development of wave energy devices and outlines the established best practice. A brief overview of international standardization efforts is given and the Danish involvement in this described.The developed Danish best practice, which is being carried over to the work on the international standardization efforts, involves a development divided in four phases (up to demonstration level). The methodology followed in the individual phases (with focus on the first two) is described. The main idea is that each of the phases should provide valuable information for the developers and investors, before the project is taken to the next phase. The paper presents the Danish case of development of wave energy devices and outlines the established best practice. A brief overview of international standardization efforts is given and the Danish involvement in this described.The developed Danish best practice, which is being carried over to the work on the international standardization efforts, involves a development divided in four phases (up to demonstration level). The methodology followed in the individual phases (with focus on the first two) is described. The main idea is that each of the phases should provide valuable information for the developers and investors, before the project is taken to the next phase.

A promising way to store alternating electricity from renewable sources like wind and sun is to produce pure hydrogen via electrolysis and to use this hydrogen to synthesize liquid transportation fuels and chemicals. As presented in 2015, the Winddiesel project, carried out at Güssing, Austria, is a potential strategy to use surplus wind energy to produce hydrocarbon-based fuels, chemicals, and bio-waxes via water electrolysis and Fischer-Tropsch synthesis (FTS). By using Fischer-Tropsch (FT) diesel as a blending component with fossil diesel, a massive reduction of CO2 emissions within the transport sector can be achieved. The FT laboratory-scale plant at Güssing uses slurry reactor technology to produce hydrocarbons from biomass-derived syngas. A commercial biomass gasification plant using the dual fluidized bed technology produces the biomass-based syngas. To simulate the fluctuating hydrogen production from renewable energy sources, the load of the FT plant is varied from 70 to 150% of the standard base-load conditions. To gain comprehensive data concerning the plant performance under load-change conditions, experiments lasting 500 hours are performed with two different catalyst charges. First, a 500-hour experiment with base-load settings is carried out to obtain reference data. In the second experiment, load changes are performed using an equivalent catalyst charge. It was observed that, depending on the catalyst, almost equal results for product distribution and composition could be reached for base-load and load-change settings. Furthermore, catalytic attrition to fine particles (< 5 µm) was investigated. The amount of catalyst fines ranges from well below 20 up to 60 mg/kg of dry product wax. This means that 0.5 to 2wt.% of catalyst undergoes attrition to fines in one year. Proceedings of the 25th European Biomass Conference and Exhibition, 12-15 June 2017, Stockholm, Sweden, pp. 960-966