• Energy Research

Today, coal is responsible for 40% of annual CO2 emissions. At the same time, global warming causes climate changes accompanied with catastrophic meteorological phenomena all over the world. After the 2015 Paris Agriment many countries set ambitious energy policy to reduce the annual greenhouse gas emission. The 2021 UN Climate Change Conference, COP26 - Glasgow, ended with the adoption of a less stringent resolution than some anticipated: countries only agreed to “phase down” rather than “phase out” coal. Is possible the realization of the Paris Agreement after COP-26? For achieving this ambitious targets in such conditions, the support of the multi-disciplinary scientific knowledge is needed. Since 2002 a series of SDEWES Conferences were founded. This paper presents an overview of published researches in special issues of leading journals dedicated to the series SDEWES Conferences, including also the papers in current special issue presented on Conferences held in 2020: 2nd LA SDEWES Conference - Buenos Aires, 1st AP SDEWES Conference - Gold Coast, 4th SEE SDEWES Conference - Sarajevo and 15th SDEWES Conference - Cologne. The focus is on five main fields: (1) energy system analysis ; (2) energy savings in the building sector ; (3) district heating ; (4) electrification of transport and (5) water-energy nexus. Undoubtedly, the researches presented in this special issue as well as in previous ones, will contribute to the achievement of the goals of the Paris Agreement in difficult conditions after COP26.

Today, coal is responsible for 40% of annual CO2 emissions. At the same time, global warming causes climate changes accompanied with catastrophic meteorological phenomena all over the world. After the 2015 Paris Agriment many countries set ambitious energy policy to reduce the annual greenhouse gas emission. The 2021 UN Climate Change Conference, COP26 - Glasgow, ended with the adoption of a less stringent resolution than some anticipated: countries only agreed to “phase down” rather than “phase out” coal. Is possible the realization of the Paris Agreement after COP-26? For achieving this ambitious targets in such conditions, the support of the multi-disciplinary scientific knowledge is needed. Since 2002 a series of SDEWES Conferences were founded. This paper presents an overview of published researches in special issues of leading journals dedicated to the series SDEWES Conferences, including also the papers in current special issue presented on Conferences held in 2020: 2nd LA SDEWES Conference - Buenos Aires, 1st AP SDEWES Conference - Gold Coast, 4th SEE SDEWES Conference - Sarajevo and 15th SDEWES Conference - Cologne. The focus is on five main fields: (1) energy system analysis ; (2) energy savings in the building sector ; (3) district heating ; (4) electrification of transport and (5) water-energy nexus. Undoubtedly, the researches presented in this special issue as well as in previous ones, will contribute to the achievement of the goals of the Paris Agreement in difficult conditions after COP26.

The environmental impact of the energy sector and the security and economics of energy supply and utilisation have been raising increasing concerns, stimulating the search for innovative solutions for a sustainable use of resources. This article provides an overview of published research in this area, with a focus on papers contributed in special issues of leading journals dedicated to the series of Conferences on Sustainable Development of Energy, Water and Environment Systems (SDEWES), including the articles in the current special issue. Based on this review, research trends are identified and achievements supporting the energy transition are highlighted. The studies that focused on regional or urban energy planning have aimed at (a) increasing penetration of renewable energy sources, (b) optimizing the mix of centralized and distributed technologies (c) introducing additional flexibility in the power sector and (d) identifying solutions for sustainable heating. Conversely, researches focused on single plants or users have targeted the development of technologies for efficient energy use in industry and buildings, with emphasis on multi-generation and waste heat utilisation. The review highlights that future scenarios based on sustainable energy systems are viable, although their implementation will require further efforts by researchers and investors and active involvement of consumers.

The environmental impact of the energy sector and the security and economics of energy supply and utilisation have been raising increasing concerns, stimulating the search for innovative solutions for a sustainable use of resources. This article provides an overview of published research in this area, with a focus on papers contributed in special issues of leading journals dedicated to the series of Conferences on Sustainable Development of Energy, Water and Environment Systems (SDEWES), including the articles in the current special issue. Based on this review, research trends are identified and achievements supporting the energy transition are highlighted. The studies that focused on regional or urban energy planning have aimed at (a) increasing penetration of renewable energy sources, (b) optimizing the mix of centralized and distributed technologies (c) introducing additional flexibility in the power sector and (d) identifying solutions for sustainable heating. Conversely, researches focused on single plants or users have targeted the development of technologies for efficient energy use in industry and buildings, with emphasis on multi-generation and waste heat utilisation. The review highlights that future scenarios based on sustainable energy systems are viable, although their implementation will require further efforts by researchers and investors and active involvement of consumers.

This paper defines the concept of 4th Generation District Heating (4GDH) including the relations to District Cooling and the concepts of smart energy and smart thermal grids. The motive is to identify the future challenges of reaching a future renewable non-fossil heat supply as part of the implementation of overall sustainable energy systems. The basic assumption is that district heating and cooling has an important role to play in future sustainable energy systems – including 100 percent renewable energy systems – but the present generation of district heating and cooling technologies will have to be developed further into a new generation in order to play such a role. Unlike the first three generations, the development of 4GDH involves meeting the challenge of more energy efficient buildings as well as being an integrated part of the operation of smart energy systems, i.e. integrated smart electricity, gas and thermal grids.

This paper defines the concept of 4th Generation District Heating (4GDH) including the relations to District Cooling and the concepts of smart energy and smart thermal grids. The motive is to identify the future challenges of reaching a future renewable non-fossil heat supply as part of the implementation of overall sustainable energy systems. The basic assumption is that district heating and cooling has an important role to play in future sustainable energy systems – including 100 percent renewable energy systems – but the present generation of district heating and cooling technologies will have to be developed further into a new generation in order to play such a role. Unlike the first three generations, the development of 4GDH involves meeting the challenge of more energy efficient buildings as well as being an integrated part of the operation of smart energy systems, i.e. integrated smart electricity, gas and thermal grids.