1. What does it mean? Hybrid poly-generation systems (PGSs) 2. How to use renewable energy sources in poly-generation systems? 3. Energy storage type and size in PGSs 4. Exergy, energy, environmental and economic analysis of hybrid poly-generation systems: methods and approaches 5. Solar based hybrid energy systems 6. Technical and economic prospects of fuel cells combination with PGSs? 7. Biomass based hybrid energy systems 8. Chemical looping combustion in PGSs 9. A framework for sustainable hydrogen production by PGSs 10. Integration of oxy-fuel power plants in PGSs 11. Basic power and cooling production systems in combination with PGSs to tri-generation of cold, heat and power 12. Integration of carbon dioxide capturing processes in hybrid energy systems 13. Advanced economic, environmental and exergy analyses of PGSs