Development in Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems

The conference series International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems – abbreviated ECOS has been at the forefront of the scientific development in energy systems for over three decades. 2018 saw the 31st edition of ECOS held in Guimarães, Portugal. The venue received the contribution of over three hundred papers ranging over selected 19 topics, covering aspects related to thermodynamics, energy systems integration and optimization, planning, cogeneration of heat and power, environmental issues, amongst others. A number of the contributions were invited to the present special issue of the International Journal of Sustainable Energy Planning and Management, and eight of these were after the selection and reviewing process considered to bring the best contributions to the field. These articles address rural household appliance ownership, how much flexibility there is in the Bolivian electricity system to accommodate wind power and photo voltaics, national exergy analyses of Bolivia and thermal imagery of buildings to asses heat losses from these. Other work focus on polygeneration system combining renewable energy sources, cogeneration of heat, cooling and power to supply district heating and cooling in a case area in Italy. In the same area, a mobile thermal energy storage using phase change material is proposed as a way to connect heat sources and heat demands. For the future electrification of the transportation sector and for system design, reliable data on driving cycles are required thus methods for assessing these are presented, followed by analyses of high penetrations of electricity in the transportation system through various technological options.