Sustainable Development of Energy, Water and Environmental Systems and Smart Energy Systems

This 34th volume of the International Journal of Sustainable Energy Planning and Management includes papers from the 2021 conference on Sustainable Development of Energy, Water and Environmental Systems (SDEWES) held October 10-15, 2021, in Dubrovnik, Croatia as well as the 7th International Conference on Smart Energy Systems held September 21-22 in Copenhagen, Denmark and two normal papers. A focus area of this issue is district heating and district cooling systems, with articles addressing resources for district heating and cooling systems, impacts of having individual district heating metres for consumers and approaches to analysing district heating systems. Another focus area is stakeholder involvement where two groups of researchers focus on stakeholders from an energy island perspective as well as from a positive energy district perspective. Both groups note the importance of factoring in stakeholders when devising transition plans. Plans for increasing the penetration of renewable energy sources for the Estonian, Latvia and Lithuanian systems are analysed using the Backbone model, finding modest increases in system costs. Lastly, an article sets up an indicator system for assessing environmental performance of European Union member states ranking, e.g., Estonian, Latvia and Lithuanian as moderate (Estonia and Latvia) to weak (Lithuania) in terms of sustainable energy performance score, based on 2019 data.