2.3. El reconocimiento mutuo
2.3.2. Las dificultades de aplicación de principio de reconocimiento mutuo por las autoridades
Baseline model development
• The baseline model of the Athens external water supply network developed in UWOT showed an overall good performance in terms of simulating the water balance of the particularly complex urban water system of Athens. This fact indicates that the assumptions used were valid and model performance is not compromised.
• Similarly in terms of energy balance the model showed satisfactory behaviour in terms of simulating energy consumption, as well as energy production from the existing hydropower plants at the external water supply system. Energy production from the existing hydropower plants is the highest during the summer months when water demand is increased.
Identified energy related interventions
• The short term interventions included in Phases 1 and 2 are estimated to have a considerable impact on the net energy consumption and renewable energy fraction. Moreover, most of these interventions are quite straightforward since they already are in EYDAP’s strategic plans.
• The development however of the photovoltaic park in Acharnes included in Phase 2 seems at this point quite uncertain. It is currently considered by EYDAP a risky investment mainly due to the unstable economic environment and especially due to the fact that the renewable electricity tariffs in the Greek market are no longer guaranteed.
• The preliminary analysis indicated that the extension of Giona small hydropower plant is probably a quite attractive technical option. Even though it is not currently in EYDAP’s agenda, the implementation shouldn’t require too much time and resources since a lot of infrastructure is already in place. Furthermore, the exploited flows by the new hydropower plant are expected to increase in the future if the capacity of Mornos aqueduct is to be increased. In order to get more accurate estimations of the average annual energy production by the specific hydropower plant more detailed analysis is required based on daily flow data and model simulation with daily time step. However, the development of this hydropower project will probably require high-level negotiations and cooperation between the two companies, PPC and EYDAP.
• From all interventions examined the development of the hydropower plant at the outlet of Evinos – Mornos tunnel seems to have the biggest impact on net energy consumption and renewable energy fraction. The specific location has a significant energy production potential due to the substantial volume of water transported from Evinos to Mornos reservoir and the elevation difference between the two reservoirs. The results indicate that contrary to most of the other hydropower plants, the Evinos – Mornos HPP has the highest renewable energy production during the winter months when the abstractions from Evinos to Mornos are increased. However, it should be noted that the analysis was carried out using current operation rules and therefore higher energy production could probably be achieved by optimising the Evinos-Mornos discharge operation rules. A more detailed technical analysis, as well as a financial feasibility study is required for more accurate estimations.
• The most significant disadvantage in the development of the pump storage scheme between Evinos and Mornos reservoirs is the relatively big longitudinal distance between the reservoirs in combination with the relatively low elevation difference between them, which results in high friction losses and a relatively low hydropower production potential. The development of such a scheme with conventional fuels probably wouldn’t be a financially attractive option. The coupling with renewable energy sources such as wind power seems more promising but a detailed technical analysis with further refinement of the modelling approach, as well as a cost
benefit analysis are required to assess the technical and financial feasibility of such an investment.
9.6.2 Challenges & uncertainties
There are various potential challenges and uncertainties linked with the implementation of the identified energy related interventions and the proposed water energy Roadmap for the Athens urban water system; the most significant of which are:
• The complicated and time-consuming administrative, legislative and bureaucratic processes related to renewable energy sources development in Greece are very significant impediments for further exploitation and development by EYDAP. These processes are causing significant delays in the implementation of relevant projects. • EYDAP has serious issues related with the guarding of renewable energy sources
facilities and also difficulties are arising with the maintenance of such projects. • An important barrier for the implementation of renewable energy sources projects
and associated investments is the unstable economic environment and especially the fact that the renewable electricity tariffs are no longer guaranteed.
9.7 References
Brilakis, D. (2009). Small hydropower plants on EYDAP’s network: Experience – Future Prospects; Presented at the conference: Contribution of hydro power works to the country’s energy planning, organised by the Technical Chamber of Greece (TEE-TCG), 20-21 March 2009, Ioannina.
Efstratiadis, G. Karavokiros, G. and Mamassis, N. (2009) Master plan of the Athens water resource system - Year 2009, Maintenance, upgrading and extension of the Decision Support System for the management of the Athens water resource system, Report 1, Department of Water Resources and Environmental Engineering – National Technical University of Athens. EYDAP (2013), Athens Water Supply Company, information concering energy available onlile at http://www.eydap.gr/index.asp?a_id=730, accessed on 22/07/2013.
Katerinopoulou, A., Kagia, K., Karapiperi, M., Kassela, A., Paschalis, A., Tsarouchi, G.- M., Markonis, Y., Papalexiou, S.M., Koutsoyiannis, D., 2009. Reservoir yield reliability relationship and frequency of multi-year droughts for scaling and non-scaling reservoir inflows. In: European Geosciences Union General Assembly 2009. Geophysical Research Abstracts, vol. 11. European Geosciences Union, Vienna, p. 8063.
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Kozanis, S., Christofides, A., Efstratiadis, A., Koukouvinos, A., Karavokiros, G., Mamassis, N., Koutsoyiannis, D., Nikolopoulos, D., (2012). Using open source software for the supervision and management of the water resources system of Athens. In: European Geosciences Union General Assembly 2012. Geophysical Research Abstracts, vol. 14. European Geosciences Union, Vienna, p. 7158.
Makropoulos, C. K., Natsis, K., Liu, S., Mittas, K., and Butler, D. (2008). Decision Support for Sustainable Option Selection in Integrated Urban Water Management, Environmental Modelling and Software, 23(12), pp. 1448-1460.
Makropoulos, C., Efstratiadis, A. and Koukouvinos, A. (2010) Appraisal of financial cost and proposals for a rational management of the hydrosystem, Untreated water costing for the water supply of Athens, 73 pages, Department of Water Resources and Environmental Engineering – National Technical University of Athens.
Mamassis, N., Efstratiadis, A., Karavokiros, G., Kozanis, S. and Koukouvinos, A. (2011). Maintenance, upgrading and extension of the Decision Support System for the management of the Athens water resource system, Final report, Department of Water Resources and Environmental Engineering – National Technical University of Athens, 84 pp.
Nasikas, A. (2013). Reduction of the energy cost for EYDAP, presented during meeting with EYDAP, January 2013.
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Rozos, E., and Makropoulos, C., (2013) Source to tap urban water cycle modelling, Environmental Modelling and Software, 41, 139–150, doi:10.1016/j.envsoft.2012.11.015, Elsevier.
Rozos, E., Makropoulos, C., and Butler, D.(2010). Design robustness of local water-recycling schemes, Journal of Water Resources Planning and Management - ASCE, 136 (5), 531–538, doi:/10.1061/(ASCE)WR.19, 2010.
U.S. Bureau of Reclamation (1976). Selecting Hydraulic Reaction Turbines, A Water Resources Technical Publication, Engineering Monograph No.20, U.S. Department of the Interior, U.S. Government Printing Office, Washington.