Analyzing the social parameters and the advantages of local energy cooperatives regarding the energy transition and the expansion of renewable energy sources

The social acceptance of the renewable energy sources is an important factor for the success of the energy transition. The feedback of the citizens of the local communities needs to be taken into account in the decision making procedure. The energy cooperatives, especially at the local level, have a major role and can put the society in the center of the renewable strategies. For this reason, the presentation of specific scientific data, the life cycle sustainability assessment and the dissemination of good practices are critical for the expansion of the renewables in a positive and sustainable way, by taking into account the emergence of climate crisis

Sustainability Assessment: Offsetting Carbon Emissions from Energy Use at the Orthodox Academy of Crete (OAC)

Mitigation of climate change and development of ecological practices is an important goal in religious organizations. Current work aims in the investigation of the possibility of offsetting the net carbon emissions due to energy use in the Orthodox Academy of Crete (OAC), Greece. Energy generated by fossil fuels and renewable energy sources is currently used in the premises of the Academy. The total annual energy consumption and the energy sources currently used in the religious organization are initially estimated. Various future scenarios are investigated regarding energy consumption in the Academy, energy sources used and their carbon emissions, as well as the possibility of carbon emissions sequestration with various tree plantations. The annual energy consumption in the Academy has been estimated at 264,257 KWh while its energy consumption per covered area is 31.31 KWh/m2. Among various energy sources used, electricity has the highest share at 95.76%, while 32.47% of the overall energy consumption is currently generated by a solar-PV system installed on-site. It is indicated that the combined use of energy-saving techniques and technologies, the higher use of various renewable energy sources and the sequestration of any remaining carbon emissions with tree plantations could eliminate all carbon emissions due to energy use in the Academy.  The most appropriate sustainable energy technologies are solar-thermal, solar-PV and high efficiency heat pumps which are currently mature, reliable and cost-effective. Additionally olive tree orchards, carob tree orchards and Eucalyptus tree plantations could be created for carbon emissions sequestration. It has been concluded that with the reduction of the current energy consumption by 20%, the installation of a solar-PV system at 50 KWp, and the creation of an olive tree orchard at 14 ha, the net annual carbon emissions due to energy use in the Academy could be eliminated. The results indicate the way that the Orthodox Academy of Crete could zero its impacts on climate change due to energy use in its premises

Should photovoltaics stay at home? Comparative life cycle environmental assessment on roof-mounted and ground-mounted photovoltaics

Renewable energy technologies like photovoltaics may be considered an indispensable component of a low-carbon electricity mix, but social acceptance should not be taken for granted. For instance, in Greece there are still claims, especially in rural areas, regarding the land use and the competition against more traditional economic activities such as grazing. An argument in favor of confining to roof-mounted photovoltaic installations is the additional infrastructure requirements for ground-mounted larger-scale photovoltaics. These requirements reduce and could potentially negate their environmental benefits. The aim of this study is to investigate the life cycle environmental impacts of commercial ground-mounted photovoltaic farms and compare them against residential roof-mounted photovoltaic installations. Data were gathered for a 500 kW ground-mounted photovoltaic installation and for five roof-mounted installations of 10 kW capacity, each from the same area at the prefecture of Pella in Northern Greece. An LCA (Life Cycle Assessment) was performed and results show that panel production is the main contributor for both types and that ground-mounted photovoltaics—when no transmission/distribution infrastructure is considered—have lower impacts than the roof-mounted residential photovoltaic installations for all impact categories except terrestrial ecotoxicity. However, when located further than 10.22 km from grid connection, ground-mounted photovoltaics have higher impacts for almost all environmental impact categories

Water-sand-clay interactions as monitored by low field NMR

Bibliography: p. 111-12

Στατιστική ανάλυση λειτουργίας ομάδας φωτοβολταϊκών πάρκων στην Κρήτη

Περίληψη: Η συνεχής αύξηση των ενεργειακών απαιτήσεων, σε συνδυασμό με την επιβάρυνση του περιβάλλοντος και την σταδιακή εξάντληση των φυσικών πόρων, έχουν οδηγήσει στην χρήση των ανανεώσιμων πηγών ενέργειας. Στην παρούσα διπλωματική εργασία γίνεται στατιστική ανάλυση της λειτουργίας μιας ομάδας φωτοβολταϊκών πάρκων στην Κρήτη, με τη χρήση του προγράμματος Matlab. Αρχικά, συλλέγονται οι τιμές παραγωγής ημερήσιας ενέργειας από όλα τα εξεταζόμενα πάρκα, για το διάστημα από 1η Δεκεμβρίου του 2015 έως την 30η Νοεμβρίου του 2016. Στη συνέχεια, αποτυπώνονται γραφικά τα δεδομένα και δημιουργείται ένα μέσο πάρκο που η παραγωγή του είναι ο μέσος όρος της παραγωγής των πάρκων που μελετάμε. Ακολούθως, παρατίθενται ποιοτική σύγκριση των αποτελεσμάτων της ομάδας Φ/Β πάρκων με τα αντίστοιχα των μεμονωμένων. Τέλος, γίνεται αναφορά στην αποθήκευση ενέργειας προερχόμενη από Φ/Β πάρκα, σε μπαταρίες και την συμπεριφορά που θα έχουν τα πάρκα που μελετάμε, καθώς και το ενδεικτικό κόστος τους

Should photovoltaics stay at home? Comparative life cycle environmental assessment on roof-mounted and ground-mounted photovoltaics

Summarization: Renewable energy technologies like photovoltaics may be considered an indispensable component of a low-carbon electricity mix, but social acceptance should not be taken for granted. For instance, in Greece there are still claims, especially in rural areas, regarding the land use and the competition against more traditional economic activities such as grazing. An argument in favor of confining to roof-mounted photovoltaic installations is the additional infrastructure requirements for ground-mounted larger-scale photovoltaics. These requirements reduce and could potentially negate their environmental benefits. The aim of this study is to investigate the life cycle environmental impacts of commercial ground-mounted photovoltaic farms and compare them against residential roof-mounted photovoltaic installations. Data were gathered for a 500 kW ground-mounted photovoltaic installation and for five roof-mounted installations of 10 kW capacity, each from the same area at the prefecture of Pella in Northern Greece. An LCA (Life Cycle Assessment) was performed and results show that panel production is the main contributor for both types and that ground-mounted photovoltaics—when no transmission/distribution infrastructure is considered—have lower impacts than the roof-mounted residential photovoltaic installations for all impact categories except terrestrial ecotoxicity. However, when located further than 10.22 km from grid connection, ground-mounted photovoltaics have higher impacts for almost all environmental impact categories.Presented on: Sustainabilit

Μελέτη των δυνατοτήτων παραγωγής βιοντίζελ από ελληνικές πρώτες ύλες

Περίληψη: Τα αναμφισβήτητα περιβαλλοντικά πλεονεκτήματά των βιοκαυσίμων έναντι των συμβατικών καυσίμων καθιστούν την ανάπτυξη της παραγωγής τους πρόκληση για τη βελτίωση βασικών περιβαλλοντικών δεικτών στη χώρα μας. Η ανάπτυξη αυτή βέβαια απαιτεί έρευνα προσαρμοσμένη στις ελληνικές συνθήκες, βελτιστοποιώντας τα πλεονεκτήματα των βιοκαυσίμων για τις εγχώριες ανάγκες. Στα πλαίσια της εργασίας αυτής παρουσιάζονται τα εργαστηριακά αποτελέσματα από τη σύνθεση βιοντίζελ από πρώτες ύλες διαθέσιμες στην ελληνική αγορά (ηλιέλαιο, σογιέλαιο και αραβοσιτέλαιο) υπό διαφορετικές πειραματικές συνθήκες (θερμοκρασία και αναλογία ελαίου/διαλύτη). Η αξιολόγηση των παραχθέντων δειγμάτων βιοντίζελ με βάση διεθνή εγκεκριμένα εργαστηριακά πρότυπα έδειξε ότι με κατάλληλη επιλογή των συνθηκών παραγωγής είναι δυνατή η δημιουργία βιοντίζελ αποδεκτής εμπορικής ποιότητας από τις πρώτες ύλες που μελετήθηκαν.Παρουσιάστηκε στο: 2ο Πανελλήνιο Συνέδριο Εναλλακτικών Καυσίµων και Βιοκαυσίµω