One of the most crucial factors for energy transition and the incorporation of renewable energy sources into the existing energy map is citizen engagement. Local energy communities (LECs), which are cooperative-based coalitions aimed at reducing the carbon footprint of the residential building sector, have received increasing attention in the past decade. This is because residential buildings account for almost half of the total energy consumed worldwide. A resounding 75% of it is used for thermal energy consumption, heating and cooling, cooking and bathing. However, the main focus of the literature worldwide is explicitly on electrical LECs, despite the fact that the significant increase in natural gas and oil prices, creates instability in the heating and cooling prices. The scope of this study is to provide an overview of the research field regarding Thermal LECs, using both a thorough literature review as well as bibliometric analysis (VOSviewer software), in order to validate the findings of the review. The results indicate a collective scarcity of literature in the field of thermal/cooling energy communities, despite their proven value to the energy transition. A significant lack of directives, research background and state initiatives in the context of LECs incorporating thermal/cooling energy production, storage and distribution systems, was also observed. Case studies and the applications of such systems are scarce in the available literature, while published studies need further feasibility assessments.

Democritus University of Thrace (DUTh) has formed, under the European Project Renaissance (Renewable Integration & Sustainability in Energy Communities, HORIZON 2020, GA 824342), a virtual Renewable Energy Community (REC) in Greece located nearby Kimmeria at the northeast of the city of Xanthi, at the North-eastern Greece. The REC formed is the first energy community designed in a public housing settlement in Greece and its members are: (a) the Democritus University of Thrace, (b) the Municipality of Xanthi and (c) a local industry. DUTh’s main objective is to explore, leverage and mobilize stakeholders to apply schemes for a social group of end users (i.e., students from low-income families) in order to participate in the operation and management of a local renewable energy community, gaining also non-financial benefits. This paper presents the business case scenario and the market players evolving at an Energy Community which includes a public establishment of student residences in Greece.

The present work is focused on the development of a simulation model for an existing co-generation power plant, which utilizes a solar thermal field with parabolic trough solar collectors coupled to an ORC engine. The power plant is modeled in TRNSYS v.17 software package and its performance has been validated with real operating conditions. The simulated system (CSP field and ORC engine) is part of a larger hybrid power plant located near “Ziloti” village of the Municipality of Xanthi, in northeastern Greece. The construction of the hybrid power plant was funded by the Strategic Co-Funded Project of the European Territorial Cooperation Program Greece-Bulgaria 2007-2013 with the acronym ENERGEIA. The power plant simulated in this paper includes a 234 kW_th solar parabolic trough collectors (PTC) field, a 5 m³ thermal energy storage tank and a 5 kW_e ORC engine, for production of thermal and electrical energy. The results of the simulations present small deviation in contrast to the real operating data of the CSP power plant coupled on the ORC engine, therefore simulation model is considered as reliable.

Three-dimensional (3D) printing is a leading manufacturing technique in the medical field. The constantly improving quality of 3D printers has revolutionized the approach to new challenges in medicine for a wide range of applications including otoplasty, medical devices, and tissue engineering. The aim of this study is to provide a comprehensive overview of an artificial ear splint model applied to the human auricle for the treatment of stick-out protruding ears. The deformity of stick-out protruding ears remains a significant challenge, where the complex and distinctive shape preservation are key factors. To address this challenge, we have developed a protocol that involves photogrammetry techniques, reverse engineering technologies, a smart prototype design, and 3D printing processes. Specifically, we fabricated a 3D printed ear splint model via fused deposition modelling (FDM) technology by testing two materials, a thermoplastic polyester elastomer material (Z-Flex) and polycaprolactone (PCL 100). Our strategy affords a custom-made and patient-specific artificial ear aligner with mechanical properties that ensures sufficient preservation of the auricular shape by applying a force on the helix and antihelix and enables the ears to pin back to the head.

Nowadays, the availability of wind turbines usually approaches the 98%. The objective is to increase the turbines availability, by improving the wind turbine reliability especially for offshore plants. The wind turbines reliability is a pivotal factor in the successfully function of a wind power plant. High reliability can be achieved by understanding and minimizing the failures of the system. Maintenance planning could make maintenance more efficient and could lead to a reduction of failure events. In order to decide the most effective maintenance strategy, it should be identified the most critical components of the wind turbines, which are prone to failures. The maintenance strategy should take into both the reliability improvement and the reduction of maintenance cost. Moreover, it is essential to determine and record the main cause that provokes the failure event. The data logging and statistical processing of failure information could improve the reliability of the system components. A wind turbine is a complex power generating system consisting of several structural, electrical and mechanical components. Its efficiency depends largely on its reliability level. In the present study, the factors that affect the reliability of a wind turbine are presented, as well as the analytical way of calculating its reliability. The reliability analysis of the wind turbine is based on the systemic approach of the wind turbine subsystems, as its total reliability depends directly on the reliability of the subsystems. Moreover, it is based on a technical analysis of the reliability of complex systems. The model used is the Fault Tree Analysis (FTA), which is an identification method for probable causes of system failure. The relation of reliability, maintainability and availability is also presented and explained by the example of a small wind farm.

The transition to a carbon-reduced future for one of the most energy-intensive actors, the building sector, requires the development of appropriate tools and methods. One such approach is local energy communities (LECs), especially thermal LECs (TLECs), which provide a promising vector towards that transition. LECs exploit energy users as key actors in the energy production process. However, their formation, creation, and continuation are still an ongoing endeavor. Many research efforts focus on creating and continuing LECs in an economic, legal, and incentivized manner, sparsely addressing the formation process. In this Part A, a collective tool for decision-making for potential TLECs is presented. The current study proposes a unified approach to classify the prosumers of energy (consumers who both produce and consume energy) using conventional methodologies (RenewIslands, Kaya Identity). A case study is presented in a fully operating LEC in Kimmeria, Greece, in which both the traditional methods of classifying users are applied as well as the proposed methodology, in comparison. The results indicate a significant improvement to the conventional solutions, which tend to overestimate the needed equipment, leading to extensive installation and operational costs.