Local Energy Exchange Market for Community Off-Grid Microgrids: Case Study Los Molinos del Rio Aguas

The energy transition to renewable energy in a democratic way is directly connected to the development of energy communities and community microgrids. Los Molinos del Rio Aguas (LMRA), an ecological community in the south of Spain, offers a promising case study for an off-grid community-owned microgrid. In this paper, the interconnection of autonomous solar home systems is proposed with the addition of community assets in order to create an off-grid community microgrid that is financially beneficial for the community. Based on this scenario, a Local Energy Market (LEM) based on Distributed Ledger (DL) technologies is implemented in order to foster the energy exchange and contribute to the social welfare of the community. The results provide a win-win scenario for the community and provides an example of an off-grid community microgrid in combination with a LEM that takes into consideration the social aspect of the community

Experimental verification of self-adapting data-driven controllers in active distribution grids

Lately, data-driven algorithms have been proposed to design local controls for Distributed Generators (DGs) that can emulate the optimal behaviour without any need for communication or centralised control. The design is based on historical data, advanced off-line optimization techniques and machine learning methods, and has shown great potential when the operating conditions are similar to the training data. However, safety issues arise when the real-time conditions start to drift away from the training set, leading to the need for online self-adapting algorithms and experimental verification of data-driven controllers. In this paper, we propose an online self-adapting algorithm that adjusts the DG controls to tackle local power quality issues. Furthermore, we provide experimental verification of the data-driven controllers through power Hardware-in-the-Loop experiments using an industrial inverter. The results presented for a low-voltage distribution network show that data-driven schemes can emulate the optimal behaviour and the online modification scheme can mitigate local power quality issues

PHIL and CHIL simulation for education, research and testing

PHIL and CHIL simulation is proving to be an efficient tool for education, research and testing. The development of hands-on laboratory exercises at NTUA using HIL simulation and experiential learning will be presented. The combination of CHIL and PHIL for testing smart grid control algorithms will be reported as well as the use of “testing chains” for system-level controllers. Most of the presented activities have been performed in the framework of the H2020 ERIGrid project

Are We on the Right Track? Collective Self-Consumption and Energy Communities in the European Union

To accelerate the energy transition, the EU “Clean Energy for all Europeans” package aims to strengthen the involvement of end consumers in the energy market. To this end, together with so-called “active consumers” and provisions for individual and collective renewable energy self-consumption, two types of energy communities were introduced. The EU framework, however, leaves many details of the transposition process to the national level. The corresponding directives were supposed to be transposed by the end of December 2020 (recast Electricity Market Directive, defining active consumers and citizen energy communities) and by the end of June 2021 (Renewable Energy Directive, defining renewables self-consumption and renewable energy communities). In this paper, we critically discuss major developments of the transposition, including questions of the general distinction of the different concepts, governance and ownership, physical expansion, administrative barriers and the overall integration of energy communities into the energy system. The analysis builds on country case studies as well as on previous work by the authors on the status of the transposition process throughout the EU. The paper shows that the national approaches differ greatly and are at very different stages. While basic provisions are in place in most Member States to meet the fundamental EU requirements, the overall integration into the energy system and market is only partly addressed. This concerns, for instance, the analysis of system impacts of energy communities and measures that would allow and support energy system-friendly behaviour. In addition, several practical hurdles need to be overcome. These often relate to administrative requirements such as complex registration and licensing procedures, the need for the involvement of several institutions, or difficult procedures for access to relevant data. The paper concludes that discussed barriers will need to be carefully addressed if the high expectations for the role of energy communities are to be met

Contribution to the molecular taxonomy of mastic tree morphotypes on Chios Island

Background: The mastic tree (formal name: Pistacia lentiscus var. Chia) is extensively cultivated on the southern part of the Greek island of Chios. Its extensive cultivation is due to the production of a special resin, known as mastic gum, or mastiha, which is widely used in several dietary, pharmaceutical and other products since ancient times. Mastic tree is an evergreen, dioecious (consisting of male and female individuals), woody plant. Furthermore, a number of morphological characteristics suggest the existence of several different plant groups, called here “morpho-varieties”, but it is probable that there exist an unknown number of different, deviating genotypes on the island. Nevertheless, five major morphologically determined morpho-varieties of mastic tree are mainly cultivated, namely “Votomos”, “Maroulitis”, “Mavroschinos”, “Stenophyllos” and “Fardyphyllos”. The morpho-varieties exhibit mostly, but not always, distinct morphology, on which their taxonomy was initially based. Since it is observed that different plant populations differ in the quantity and quality of the produced resin, it is important to explore whether these differences have a genetic basis, or are due to other factors, such as agricultural practices, or soil composition. To this end, the genetic diversity among these five morpho-varieties and within each one of them was investigated in the present study, using in a first approximation their Random Amplified Polymorphic DNA profiles and subsequently the sequence divergence of their Internal Transcribed Spacer regions 1 and 2.Results: The results confirm the existence of a considerable genotypic diversity among the five morpho-varieties studied and, furthermore, reveal the existence of genotypic diversity within each one of them, as well as the existence of a number of further deviating genotypes. The possibility, this diversity to be partly a result of reticulate evolution events is also discussed.Conclusions: This study provides evidence that the population of cultivated mastic trees on the island of Chios consists mainly of two species, i.e. Pistacia lentiscus and Pistacia x saportae, although it is clear that there also exist genetically deviating mastic trees, as well as individual plants, probably produced through hybridization between the two afore mentioned species

Propagation of <i>Pistacia lentiscus</i> var. Chia Genotypes and Determination of Their Ornamental Traits Combined with a Genetic Analysis Using ISSR Markers

Pistacia lentiscus L. is a dioecious shrub or small tree with high drought resistance, native in the entire Mediterranean basin. The variety ‘Chia’ (mastic tree) is cultivated for the production of mastic gum (a resin produced after wounding of the trunks and thick branches) in the Island of Chios (Greece), but it also has a significant ornamental value. In the present study, ten male and ten female genotypes of P. lentiscus var. Chia from the natural habitats of Chios were selected and examined with respect to the rooting efficiency of their shoot cuttings. The germination ability of the seeds was also tested. The 20 plants were morphologically described, mainly with respect to traits related to their ornamental value. Furthermore, leaves were collected from the 20 genotypes, from which genomic DNA (gDNA) was isolated, followed by amplification of gDNA fragments using the polymerase chain reaction (PCR) and inter simple sequence repeat (ISSR) primers. This was done aiming both at the determination of their genetic distance and the establishment of possible correlations between the amplified bands and certain morphological traits. The results of the study showed that there were differences among the genotypes for both methods of propagation. Regarding the rooting of the shoot cuttings, the best genotype was 8M (cv. ‘Psilophyllos’), achieving a rooting rate of 62.5% in winter with the application of indolebutyric acid (potassium salt of IBA), while regarding the seed germination capacity the genotype 2F exhibited the highest germination rate (57%). Genetic analysis using ISSRs separated the plants into four groups, one group consisting of male genotypes, one of the female genotypes, one consisting of members from both genders and a fourth containing a single male genotype. The genetic analysis of the male genotypes only produced a dendrogram showing the cultivars clustering in three different groups. Regardless of the genetic analysis, it seems that there were correlations between the ISSR markers and the leaf traits and also the gender and the asexual propagation. These correlations can assist future breeding programs of P. lentiscus var. Chia

Propagation of Pistacia lentiscus var. Chia Genotypes and Determination of Their Ornamental Traits Combined with a Genetic Analysis Using ISSR Markers

Pistacia lentiscus L. is a dioecious shrub or small tree with high drought resistance, native in the entire Mediterranean basin. The variety &lsquo;Chia&rsquo; (mastic tree) is cultivated for the production of mastic gum (a resin produced after wounding of the trunks and thick branches) in the Island of Chios (Greece), but it also has a significant ornamental value. In the present study, ten male and ten female genotypes of P. lentiscus var. Chia from the natural habitats of Chios were selected and examined with respect to the rooting efficiency of their shoot cuttings. The germination ability of the seeds was also tested. The 20 plants were morphologically described, mainly with respect to traits related to their ornamental value. Furthermore, leaves were collected from the 20 genotypes, from which genomic DNA (gDNA) was isolated, followed by amplification of gDNA fragments using the polymerase chain reaction (PCR) and inter simple sequence repeat (ISSR) primers. This was done aiming both at the determination of their genetic distance and the establishment of possible correlations between the amplified bands and certain morphological traits. The results of the study showed that there were differences among the genotypes for both methods of propagation. Regarding the rooting of the shoot cuttings, the best genotype was 8M (cv. &lsquo;Psilophyllos&rsquo;), achieving a rooting rate of 62.5% in winter with the application of indolebutyric acid (potassium salt of IBA), while regarding the seed germination capacity the genotype 2F exhibited the highest germination rate (57%). Genetic analysis using ISSRs separated the plants into four groups, one group consisting of male genotypes, one of the female genotypes, one consisting of members from both genders and a fourth containing a single male genotype. The genetic analysis of the male genotypes only produced a dendrogram showing the cultivars clustering in three different groups. Regardless of the genetic analysis, it seems that there were correlations between the ISSR markers and the leaf traits and also the gender and the asexual propagation. These correlations can assist future breeding programs of P. lentiscus var. Chia

Evaluating the implementation of an Olympic Education Program in Greece

The aim of this study was to develop an instrument for evaluating how an education program has been implemented. Such evaluation can provide insight into the effectiveness of a program. Examined here was the Olympic Education Program used in Greek schools since 2000. In it, students learn the history of the Olympic games and the importance of exercise for health along with the principles and values of sports and volunteerism. The evaluation instrument underlying this study addressed the following six factors: 'facilities', 'administration', 'educational material', 'student-teacher relationships', 'educational procedures', and 'training'. Results indicate that the instrument, while adequate for assessing effectiveness, should be combined with advanced statistical methods. © Springer 2005