Green Energy and Sustainability ISSN 2771-1641

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Green Energy and Sustainability 2021;1(2):0005 | https://doi.org/10.47248/HKOD902101020005

Editorial Open Access

Renewable energy sources: prospects and technologies

Giorgos Panaras 1,† , Thomas Kotsopoulos 2,† , Georgios Martinopoulos 3,†

  • Department of Mechanical Engineering, University of Western Macedonia, Greece
  • Faculty of Agriculture, Aristotle University of Thessaloniki, Greece
  • School of Science and Technology, University Center of International Programmes of Studies, International Hellenic University, Greece
  • These authors contributed equally to this work.

Correspondence: Giorgos Panaras

Academic Editor(s): George Papadakis

Received: Dec 6, 2021 | Accepted: Dec 7, 2021 | Published: Dec 17, 2021

This article belongs to the Special Issue

© 2021 by the author(s). This is an Open Access article distributed under the terms of the Creative Commons License Attribution 4.0 International (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium or format, provided the original work is correctly credited.

Cite this article: Panaras G, Kotsopoulos T, Martinopoulos G. Renewable energy sources: prospects and technologies. Green Energy Sustain 2021; 1(2):0005. https://doi.org/10.47248/HKOD902101020005

The role of renewable energy in the present and future of mankind is highly significant. The inevitability of climate change makes this prospect necessary. More specifically, the Intergovernmental Panel on Climate Change indicates a 50% chance of exceeding a 1.5°C temperature threshold within the next few decades [1], while the United Nations Environment Programme (UNEP), suggests that reductions of 30% are needed to stay on the least-cost pathway for 2°C and 55% for 1.5°C [2], in order to be in line with the Paris Agreement [3] and the recent Glasgow Climate Pact [4]. To achieve and support these targets, the EU policy group has published the “Clean energy for all Europeans’ package” [5], consisting of specific legislative proposals. The promotion of renewable energy sources (RES) occupies a fundamental position in this institutional revision. More specifically, the recast of the Renewable Energy Directive 2018/2001/EU [6] established a new binding target for renewable energy in the EU of at least 32% by 2030. In terms of electricity, the current prospects are positive, while for heat and transportation, the path is not so easy [7]. In terms of heat demand level, there is concern over the possible further penetration of RES in buildings and in the industry [8].

Beyond an institutional level, the technological progress of RES has been significant, centering on high-efficiency systems that can be integrated towards multi-energy uses, supporting the concept of an energy hub [9]. The three D’s concept (namely decarbonization, digitalization, and decentralization) paves the way for low-carbon energy generation and decentralization of the energy supply, leading to self-contained small distribution networks, integrating smart technologies, especially on the control level [10]. Although, this concept has initially appeared on electricity generation, a similar trend for heating can be seen as well, highlighting the role of district heating networks and heat pumps [11]. The significant penetration of heat pumps onto the heat sector, together with the prospects of hydrogen, demonstrate a future potential unification of the main energy demands of electricity, heat and transportation, through a holistic energy system perspective. The terms of “sector coupling” or “integrated energy” are also referred to in the relevant literature [12]. For this goal, priorities should be set, with regard to the matching of the different energy sources to the respective energy demand. More specifically, while hydrogen can be the solution for high-temperature heat demand, for lower temperatures, such as on the building level, the discussion is still open [13,14]. Within this context, the EPBD recast [15], predicts the potential for buildings to act as chargers for electric vehicles, whereas the “prosumer” initiative lies within the concept of autonomy [15]. Given the complexity of the aforementioned integrated energy hubs, energy flexibility can be a challenging concept [16], enabling demand response control, while enhancing effective and efficient operation of the respective systems. Towards this direction, optimization processes should be implemented; the criteria should include energetic, economical and environmental elements, but LCA philosophy will also be important [17].

The 12th National Conference on Renewable Energy Sources had the ambitious goal of highlighting the current research and implementation aspects towards the broader dissemination of RES, including experimental and simulation analyses. The conference was organized by the Institute of Solar Technology (IST). IST is a scientific and educational organization, established in 1980 to encourage research, development and exploitation of renewable energy sources (RES), while establishing international collaborations, as well as proposing more efficient policies for the wider dissemination and implementation of RES.

The targeted special issue aims at highlighting some of the main concepts presented at the conference. The works include a variety of energy sources and applications, design and operation issues, within this dynamically evolving environment (soon to be carbon-free). Special thanks are extended to the Department of Mechanical Engineering and the Faculty of Engineering of the Aristotle University of Thessaloniki for their financial support, as well as the Research Committee of the Aristotle University of Thessaloniki for its intention to provide free conference venues in case the conference was held in person.

References

1. IPCC. Global Warming of 1.5°C. An IPCC special report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty. 2018. In press.
2. United Nations Environment Programme. Emissions Gap Report 2021: The Heat Is On – A World of Climate Promises Not Yet Delivered. Nairobi. 2021.
3. United Nations. Paris Agreement. 2015.
4. United Nations. Glasgow Climate Pact. 2021.
5. IEC. Clean energy for all Europeans. 2019.
6. EU. DIRECTIVE (EU) 2018/2001 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 11 December 2018 on the promotion of the use of energy from renewable sources. 2018.
7. Eurostat. Renewable energy statistics. 2019.
8. EC. Heating and cooling. 2015.
9. Mohammadi M, Noorollahi Y, Mohammadi-ivatloo B, Yousefi H. Energy hub: From a model to a concept – A review. Renew Sust Energ Rev 2017;80:1512-1527. [Google Scholar] [CrossRef]
10. Di Silvestre ML, Favuzza S, Sanseverino ER, Zizzo G. How Decarbonization, Digitalization and Decentralization are changing key power infrastructures. Renew Sust Energ Rev 2018;93:483-498. [Google Scholar] [CrossRef]
11. Mathiesen BV, Bertelsen N, Schneider NCA, García LS, Paardekooper S, Thellufsen JZ, Djørup SR. Towards a decarbonised heating and cooling sector in Europe: Unlocking the potential of energy efficiency and district energy. Denmark: Aalborg Universitet; 2019.
12. Wietschel M, Held A, Pfluger B, Ragwitz M. Energy integration across electricity, heating & cooling and the transport sector - Sector coupling. Working Paper Sustainability and Innovation, No. S08/2020. Karlsruhe, Germany: Fraunhofer-Institut für System und Innovationsforschung ISI; 2020. [Google Scholar]
13. Gerhardt N, Bard J, Schmitz R, Beil M, Pfennig M, Kneiske T. A study on the use of hydrogen in the energy system of the future, with a special focus on heat in buildings. HYDROGEN IN THE ENERGY SYSTEM OF THE FUTURE: FOCUS ON HEAT IN BUILDINGS. Kassel, Germany: Fraunhofer Institute for Energy Economics and Energy System Technology (IEE); 2020. [Google Scholar]
14. Clark S. Is hydrogen the solution to net-zero home heating?. Accessed 28 November 2021. Available from: www.theguardian.com/science/2020/mar/21/is-hydrogen-the-solution-to-net-zero-home-heating.
15. EU. Directive (EU) 2018/844 of the European Parliament and of the Council of 30 May 2018 amending Directive 2010/31/EU on the energy performance of buildings and Directive 2012/27/EU on energy efficiency. 2018.
16. Jensen SØ, Marszal-Pomianowska A, Lollini R, Pasut W, Knotzer A, Engelmann P, Stafford A, Reynders G. IEA EBC Annex 67 energy flexible buildings. Energy Build 2017;155:25-34. [Google Scholar] [CrossRef]
17. Hilal Bahlawan H, Morini M, Pinelli M, Spina PR, Venturini M. Simultaneous optimization of the design and operation of multi-generation energy systems based on life cycle energy and economic assessment. Energy Convers Manag 2021;249:114883. [Google Scholar] [CrossRef]
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