Keynotes cover the status, experiences, challenges, and opportunities of renewables in the German energy system, alongside the potential and policies for renewable energy in Greece. Energy policies supporting renewable development are discussed, highlighting selected issues in solar energy, including power production from solar thermal energy via ORC technology and sustainable applications in Mediterranean islands. The annotation also addresses advancements in laser processing of thin film photovoltaic modules and the spectral performance of various PV technologies. In bioenergy, topics include agro-energy chains and the energy potential of biomass from agricultural residues, emphasizing their promise for bioenergy production and assessing biomass potential for sustainable energy in European regions. The production of biokerosene and its evaluation are also explored. Integrated renewable energy systems are examined, focusing on hydrogen production from water electrolysis for energy storage and seawater desalination using renewable energy. The integration of solar thermal systems in buildings presents both perspectives and challenges. Wind energy discussions include further exploitation in island systems through pump storage units. The Young Scientist/Student Symposium highlights building insulation, energy management, and agricultural residues as energy sources, with case studies on banana residues and solar thermal systems
