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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.

Many developing countries face a dilemma between meeting the intensive growth in electricity demand, broadening an electricity access, as well as tackling climate change. The use of renewable energy is considered as an option for meeting both electrification and climate change objectives. In this study, long-term forecasting of electricity supply for the Java-Bali power system – the main power system in Indonesia – is presented. The forecasts take into consideration the Indonesian government policy of increasing the share of new and renewable energy in the national energy mix up to 23% by 2025 and 30% by 2050. After a systematic review of energy system models, we perform the analysis of the Java-Bali power system expansion using the Long-range Energy Alternative Planning system (LEAP) model. Three scenarios are developed over the planning horizon (2016-2050) including the business as usual scenario (BAU), the renewable energy scenario (REN) and the optimization scenario (OPT). The results of the three scenarios are analyzed in terms of the changes in resource/technology deployment, CO2 emissions and total costs.

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.

The European Union defined itself as a global leader in the promotion and development of renewable energy sources. The European Union initiated crucial changes in renewable energy policies in its Member States. This paper presents the results of a comprehensive analysis of policy debate and policy outputs adopted by the European Union and by the Czech Republic over a fourteen-year period (2004–2018). We investigate how the Czech Republic’s domestic policy on renewable energy sources has reacted to EU-level policy norms, strategies and institutional developments. There are different theories used to explain differentiated processes of Europeanization of domestic structures. One of them, the institutionalist approach reveals how the European Union effect is filtered and mediated through pre-existing domestic institutions, rules, norms and political cultures. We demonstrate that Czech policy makers implemented crucial EU-level policy norms to the national legislative framework, but these norms have not been fully internalized by political actors and society. Thus, the promotion of renewable energy sources in the Czech Republic can be considered as a direct effect of policy development at the EU level, not as output of autonomous Czech policy debate. It poses certain risk for the future development of renewable energy sources policy support. ; Čánek ukazuje, že Česká republika implementovala klíčové veřejně-politické normy a principy v oblasti politiky obnovitelných zdrojů, nicméně tyto normy nebyly na národní úrovni internalizovány politickými aktéry a společností.

Distributed power generation and cogeneration of heat and power is an attractive way toward a more rational conversion of fossil and bio fuels. Solid oxide fuel cell (SOFC) – gas turbine (GT) hybrid systems are emerging as the most promising candidates enabling the achievement of a cleaner and more efficient conversion of a large variety of resources across a broad power range covering from small to medium scale applications. This thesis introduces an innovative concept of SOFC-GT hybrid system that allows reaching efficiencies higher than the state of the art while enabling the carbon dioxide separation and avoiding fuel cell pressurisation technical issues. Several hybrid system design alternatives based on this concept are analysed through a thermodynamic optimisation approach combining process modelling, advanced process integration techniques and multi-objective optimisation. A number of optimal hybrid system configurations are determined for different design targets. The results consistently demonstrate the higher energy conversion performance and flexibility enabled with respect to the state of the art. The innovative concept analysis is extended to two applications for which SOFC-GT hybrid cycles are expected to provide the most significant impact toward sustainability: the small scale distributed generation and the conversion of renewable resources. A simplified version of the new hybrid system layout is especially developed for small scale distributed generation, typical of residential building applications (5-10 kWel). Experimental data are used to prove the technical feasibility of the system and to assess the performance potentially achievable with currently feasible technologies. The results of the analysis underline that energy conversion efficiencies higher than traditional centralised power generation can be achieved even at such a small scale. A systematic process integration and optimisation approach is used to assess the energy conversion performance of the original SOFC-GT hybrid cycle fuelled with hydrothermally gasified wet waste biomass. The analysis highlights the considerable potential of the integrated system that allows for converting wet waste biomass into electricity with First Law efficiency higher than 60% while simultaneously enabling the separation of the biogenic carbon dioxide.

With an increasing share of regenerative wind and solar energy in electricity supply, the aspect of load flexibility will gain importance, i.e. there is an increasing need for buffer capacities and / or power plants must be able to react more flexibly to changes of the demand. As an alternative or in addition to the new construction of peak­load power plants (pump storage systems, gas power plants), load-flexible dust burner technologies can be used in existing incinerators to increase the load flexibility and the fuel flexibility when using especially local regenerative fuel sources. Flexibility of the burner concept means an increase in changing fuel composition and non-stationary operation, which may cause changes of the combustion behavior and, hence, of the emission behavior. Flexibility in fuel sources changes the combustion and emission behavior, too, especially with regard to low rank fuels with high ash contents containing chlorine and alkali species. To control these non-stationary processes in the burner and downstream boiler area for an efficient operation, contact-free optical measurement methods are applied in addition to the measurement systems existing in the furnace chamber and furthermore control methods based on computational intelligence. Proceedings of the 19th European Biomass Conference and Exhibition, 6-10 June 2011, Berlin, Germany, pp. 1334-1337