D. P. Lalas

National Observatory of Athens, Athínai, Attica, Greece

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Publications (72)107.62 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this paper is twofold: first, to calculate the “green” energy investments, by industrial sector, that Greece would need in order to satisfy a number of energy and environmental targets adopted in the context of the European Commission’s energy and climate change package; and second, to calculate the macro-economic impacts of these “green” investments on production and employment in the Greek economy. To this end, the input–output analysis has been exploited for estimating the direct, indirect and induced macroeconomic effects associated with the implementation of selected energy conservation measures, the promotion of renewable energy technologies, etc. Our findings show that the required investments would reach the amount of €47.9 billion, over the period 2010–2020. These investments will result in an average annual increase of the national product by €9.4 billion, creating simultaneously 108,000 full-time equivalent jobs for the entire period under consideration. The employment generated per €1 million investment is relatively higher in energy saving projects in buildings and transport in comparison with the development of RES in power generation sector.
    Energy Policy 02/2013; Vol. 57:pp. 263–275. · 2.74 Impact Factor
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    ABSTRACT: To date, the majority of the research literature on the impacts of climate change has addressed the negative aspect, i.e. the risks associated with a future permanent modification of climate. Potential opportunities have received much less attention and are rarely transformed into monetary values. Furthermore, manufacturing is one of the economic sectors where the influ-ence of climate change remains practically unknown, although the economic performance of some industrial activities depends directly on climatic conditions – bottled water and non-alcoholic beverages (i.e. soft drinks and fruit juices) are among these. This paper aims to explore the link between weather and product sales in these sectors, and estimate in quantitative terms the potential impact of future climate change on their revenues. Historic data were explored through statistical analysis and appropriate regression models were developed. Models were applied for the historic (1961–90) and future climate (2021–50) and the difference in sales forms the expected quantified impact of climate change. The results indicate that significant opportunities may arise for some sectors from modifica-tions in climate, provided their production infrastructure can meet the expected demand and their management strategies can successfully adapt to altered climatic conditions.
    Business Strategy and the Environment 01/2013; · 2.88 Impact Factor
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    ABSTRACT: Semi-arid coastal zones often suffer water-stress, as water demand is high and markedly seasonal, due to agriculture and tourism. Driven by scarcity of surface water, the communities in semi-arid coastal regions turn to aquifers as prime water source; but intensive exploitation of coastal aquifers causes seawater intrusion, which degrades the quality of groundwater. The cost-efficient and sustainable development of coastal aquifers can be achieved through a holistic management scheme which combines two non-traditional water sources: (a) saltwater, to be treated to the desired quality, and (b) wastewater, to be re-claimed to augment aquifer recharge for control of seawater intrusion, and also to meet certain demands. This management scheme is based on the idea that it is cost-advantageous to: (i) desalt brackish groundwater, instead of seawater, as the former requires far less energy, and (ii) to re‐use wastewater at only the differential cost to any treatment already practiced. In this paper, we present the general framework of the proposed management scheme, and a decision aid tool (DAT) which has been developed to assist decision makers to explore the scheme's decision space. The DAT uses cost as optimization criterion to screen various management scenarios, via modelling of the dynamic natural-engineered system behaviour, and identifies those cost-efficient ones that meet the water demand and achieve aquifer protection.Citation Koussis, A. D., Georgopoulou, E., Kotronarou, A., Lalas, D. P., Restrepo, P., Destouni, G., Prieto, C., Rodriguez, J. J., Rodriguez-Mirasol, J., Cordero, T. & Gomez-Gotor, A. (2010) Cost-efficient management of coastal aquifers via recharge with treated wastewater and desalination of brackish groundwater: general framework. Hydrol. Sci. J.55(7),1217–1233.
    Hydrological Sciences Journal-journal Des Sciences Hydrologiques - HYDROLOG SCI J. 01/2010; 55(7):1217-1233.
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    ABSTRACT: Η εργασία αυτή αναφέρεται στην καταγραφή και ποιοτική αξιολόγηση του ελληνικού κτιριακού αποθέματος, καθώς επίσης και στην αξιολόγηση του δυναμικού εξοικονόμησης ενέργειας και μείωσης της εκπομπής αερίων ρύπων CO2 στον κτιριακό τομέα. Προσδιορίζονται τα Μέτρα Εξοικονόμησης Ενέργειας (ΜΕΕ) που μπορούν να βελτιώσουν την ενεργειακή απόδοση των κτιρίων, καθώς και οι προτεραιότητες που πρέπει να δοθούν για την εφαρμογή τους με κριτήρια την ενεργειακή απόδοσή τους, την οικονομική βιωσιμότητά τους και τις οικονομικές υποστηρικτικές πολιτικές (επιδοτήσεις) που απαιτούνται για την εφαρμογή τους. Τα πιο ενεργειακά αποδοτικά και οικονομικά ελκυστικά μέτρα είναι: θερμομόνωση εξωτερικών τοίχων στα ξενοδοχεία, νοσοκομεία και κατοικίες, εγκατάσταση BMS στα ξενοδοχεία, νοσοκομεία και γραφεία, χρήση λαμπτήρων υψηλής απόδοσης, χρήση φυσικού αερίου για θέρμανση και αντικατάσταση των παλιών κεντρικών θερμάνσεων.
    9ο Εθνικό Συνέδριο για τις Ανανεώσιμες Πηγές Ενέργειας, Πάφος, Κύπρος; 03/2009
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    ABSTRACT: The introduction of best available techniques (BAT) with the European Commission's directive 96/61, created a new framework for ‘cleaner’ production in the industrial sector. BATs practically constitute recommended techniques for each of the steps in the manufacturing process. Thus, the industries must decide on which BATs are most appropriate for their processes. In the current study, an integrated approach is applied in order to find the mixture of BATs for the entire industrial sector that satisfies as much as possible the economic and the environmental criteria. The former represent the industry owner's point of view expressed by the Net Present Value of the projects and the latter represent the society's point of view quantified by the emission reduction in some major pollutants. The developed multi-objective optimization model is addressed using two methods: (1) goal programming and (2) generation of the Pareto optimal solutions using an augmented version of the ε-constraint method followed by an interactive filtering process in order to select the most preferred Pareto optimal solution. The generation of the Pareto optimal solutions is performed using an improved version of the widely used ε-constraint method that overcomes some of its known drawbacks. The COMBAT tool (combinatorial optimization with multiple criteria for BAT selection) that is developed for implementing these methods is also described and the results from its application in the industrial sector of the greater Athens area are presented.Journal of the Operational Research Society (2009) 60, 906–920. doi:10.1057/palgrave.jors.2602618 Published online 4 June 2008
    Journal of the Operational Research Society 01/2009; 60:906-920. · 0.99 Impact Factor
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    ABSTRACT: Attributing costs to the environmental impacts associated with industrial activities can greatly assist in protecting human health and the natural environment as monetary values are capable of directly influencing technological and policy decisions without changing the rules of the market. This paper attempts to estimate the external cost attributable to the atmospheric pollution from ‘medium and high environmental burden’ industrial activities located in the greater Athens area and the benefits from Best Available Techniques (BAT) introduction. To this end a number of typical installations were defined to be used in conjunction with the Impact Pathway Approach developed in the context of the ExternE project to model all industrial sectors/sub-sectors located in the area of interest. Total environmental externalities due to air pollutants emitted by these industrial activities were found to reach 211 M€ per year, associated mainly with human mortality and morbidity due to PM10 emissions, as well as with climate change impacts due to CO2 emissions for which non-metallic minerals and oil processing industries are the main sources. The results obtained can be used as the basis for an integrated evaluation of potential BAT, taking into account not only private costs and benefits but also the environmental externalities, thus leading to policy decisions that maximize social welfare in each industrial sector/sub-sector.
    Environmental Impact Assessment Review 01/2008; · 2.60 Impact Factor
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    ABSTRACT: The implementation of Best Available Techniques (BATs) in industry can contribute significantly to the reduction of environmental burdens caused by industrial activities, yet it requires additional expenses, for investment, operation and maintenance, while providing environmental, and in many cases, even economic benefits. When examining BATs for potential application both economic and environmental costs and benefits affect the decision-making process. In view of the large number of BATs available for adoption and the difficulties in computing and comparing costs and benefits, especially environmental with economic ones, a decision-support tool for public and private administrators and managers has been developed, which offers rapid assessment of different BATs and their combinations both in terms of economic costs and environmental benefits that may result. This paper presents its methodological framework, main features and structure, together with some results of its application to the industrial sectors of the metropolitan area of Athens, Greece.
    Journal of Cleaner Production. 01/2008;
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    ABSTRACT: In the frame of this work, “current” climate (1961–1990) simulations using the regional climate change model PRECIS were performed 25 km grid spacing. The 30-year simulations are compared with the available surface station data, focusing on near-surface air temperature and precipitation. The analysis has shown that the model overestimates the diurnal temperature variation during the cold period of the year (DJF) in the majority of the stations. During the warm period (JJA) the simulated daily temperature range is shifted towards warmer values, while during the transient periods of the year (MAM and SON) it is shifted towards cooler values. Both usual goodness of fit indices and tests and some more advanced methods for comparing statistical distributions were used. The latter indicate that both a scale and location adjustment needs to be applied on the model results distribution in order to sufficiently describe the observed temperature distribution. Regarding rainfall, it was found that the model underestimates the seasonal rainfall during DJF and SON, mainly over the stations of the Mediterranean coast that receive most of the yearly rainfall during autumn and, mainly, winter. An interesting feature is that, during JJA, the model was able to reproduce quite efficiently the seasonal rainfall in the central Balkans that receive as much rain during summer as during winter.
    Global and Planetary Change 01/2008; · 3.71 Impact Factor
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    ABSTRACT: Best Available Techniques (BATs) contribute significantly to the reduction of industrial environmental burdens with respect to air pollution, wastewater, and solid wastes. In Europe, the application of BATs is prescribed by Directive 96/61/EC, which, however, leaves the selection of specific BATs to plant operators. In making their choices, installations have to consider not only the environmental benefits of BATs, but also all relevant cost components. In assessing the economic attractiveness of potential BATs and their combinations, as well as incentives and disincentives to be instituted, the cost of environmental externalities, usually not reflected in market prices, should be taken into account. In this paper, a decision-aid framework combining an assessment of environmental externalities and the utilization of multicriteria methods and, more specifically, Multiobjective Mathematical Programming, capable of addressing all these issues in a comprehensive and coherent manner, is presented. This is illustrated by its application for the region of Attica in Greece, where over 50% of the industrial basis and Athens, with its 4 million inhabitants, are located. The implementation of the framework and its associated tools to 800 installations led to the identification of the specific BATs, alone or in combination, that provide the most cost-effective reductions of four air pollutants (PM10, SO(2), NO(x), VOC) and CO(2). The results also clearly demonstrate the increased pollution reductions that would result from the adoption of BATs made economically attractive by the inclusion of externalities. Estimates of investments and net present values with and without incentives/disincentives are also provided.
    Environmental Management 10/2007; 40(3):413-29. · 1.65 Impact Factor
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    ABSTRACT: Comprehensive information and detailed data for the non-residential (NR) building stock is rather limited, although it is the fastest growing energy demand sector. This paper elaborates the approach used to determine the potential energy conservation in the Hellenic NR building stock. A major obstacle that had to be overcome was the need to make suitable assumptions for missing detailed primary data. A qualitative and quantitative assessment of scattered national data resulted in a realistic assessment of the existing NR building stock and energy consumption. Different energy conservation scenarios and their impact on the reduction of CO2 emissions were evaluated. Accordingly, the most effective energy conservation measures are: addition of thermal insulation of exposed external walls, primarily in hotels and hospitals; installation of energy efficient lamps; installation of solar collectors for sanitary hot water production, primarily in hotels and health care; installation of building management systems in office/commercial and hotel buildings; replacement of old inefficient boilers; and regular maintenance of central heating boilers.
    Energy Conversion and Management 04/2007; · 3.59 Impact Factor
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    ABSTRACT: The existing building stock in European countries accounts for over 40% of final energy consumption in the European Union (EU) member states, of which residential use represents 63% of total energy consumption in the buildings sector. Consequently, an increase of building energy performance can constitute an important instrument in the efforts to alleviate the EU energy import dependency (currently at about 48%) and comply with the Kyoto Protocol to reduce carbon dioxide emissions. This is also in accordance to the European Directive (EPBD 2002/91/EC) on the energy performance of buildings, which is currently under consideration in all EU member states. This paper presents an overview of the EU residential building stock and focuses on the Hellenic buildings. It elaborates the methodology used to determine the priorities for energy conservation measures (ECMs) in Hellenic residential buildings to reduce the environmental impact from CO2 emissions, through the implementation of a realistic and effective national action plan. A major obstacle that had to overcome was the need to make suitable assumptions for missing detailed primary data. Accordingly, a qualitative and quantitative assessment of scattered national data resulted to a realistic assessment of the existing residential building stock and energy consumption. This is the first time that this kind of aggregate data is presented on a national level. Different energy conservation scenarios and their impact on the reduction of CO2 emissions were evaluated. Accordingly, the most effective ECMs are the insulation of external walls (33–60% energy savings), weather proofing of openings (16–21%), the installation of double-glazed windows (14–20%), the regular maintenance of central heating boilers (10–12%), and the installation of solar collectors for sanitary hot water production (50–80%).
    Building and Environment. 01/2007;
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    ABSTRACT: Recognizing that the industrial sector is one of the major sources of environmental impacts, there is a strong effort towards “cleaner” production. In this context, the European Union strongly encourages the adaptation of Best Available Techniques (BATs) which practically constitute recommended techniques for each one of the steps in the manufacturing process (Directive 96/61 EC). In the current case study, we examine the industrial sector of the greater Athens area under the prism of BATs introduction. The aim of the analysis is to find the mixture of BATs for the entire industrial sector that satisfies as much as possible the economic criteria (expressed by the Net Present Value of the projects) and the environmental criteria (quantified by the emission reduction in major pollutants). The obtained multi-objective optimization problem is addressed using two methods: (1) goal programming and (2) generation of the Pareto optimal solutions using the ε-constraint method, followed by an interactive filtering procedure in order to select the most preferred Pareto optimal solution (BAT mixture). The computational tool for implementing these methods is also described and the results from the application in the industrial sector of the greater Athens area are presented.
    Energy Economics. 01/2007;
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    ABSTRACT: This paper focuses on the potential upcoming impacts of climate change in the 21st century on electricity demand at regional/national levels for regions where topography and location result in large differences in local climate. To address this issue, a regional climate model, PRECIS, has been used to predict future climatic conditions under different emissions scenarios (namely A2 and B2 of the IPCC special report on emissions scenarios (SRES)) as an input to a multiple regression model of the sensitivity of electricity demand in the Greek interconnected power system to climate and socio-economic factors. The economic development input to the multiple regression model follows the same storylines of the SRES scenarios upto 2100 and includes sub-scenarios to cover larger and smaller economic development rates. The results of the analysis indicate an increase of the annual electricity demand attributable solely to climate change of 3.6–5.5% under all scenarios examined, most of which results from increased annual variability with substantial increases during the summer period that outweighs moderate declines estimated for the winter period. This becomes more pronounced if inter-annual variability, especially of summer months, is taken into consideration. It was also found that in the long run, economic development will have a strong effect on future electricity demand, thus increasing substantially the total amount of energy consumed for cooling and heating purposes. This substantial increase in energy demand with strong annual variability will lead to the need for inordinate increases of installed capacity, a large percentage of which will be underutilized. Thus, appropriate adaptation strategies (e.g. new investments, interconnections with other power systems, energy saving programmes, etc.) need to be developed at the state level in order to ensure the security of energy supply.
    Energy Conversion and Management. 01/2007;
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    ABSTRACT: The aim of the present paper is to investigate the prospects for the exploitation of the Kyoto Protocol's Clean Development Mechanism (CDM) in Greece. The paper is addressing 3 questions: in which country, what kind of investment, with which economic and environmental return? The proposed approach is based on a multicriteria analysis for identifying priority countries and interesting investment opportunities in each priority country. These opportunities are then evaluated through a conventional financial analysis in order to assess their economic and environmental attractiveness. To this purpose, the IRR of a typical project in each investment category is calculated by taking into account country-specific parameters, such as baseline emission factors, load factors, costs, energy prices etc. The results reveal substantial differences in the economic and environmental return of different types of projects in different host-countries and show that for the full exploitation of the CDM a multifaceted approach to decision-making is necessary.
    Energy Policy. 01/2007;
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    E. Akylas, Y. Tsakos, M. Tombrou, D. P. Lalas
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    ABSTRACT: The concept of the minimum friction velocity is studied using three different methods of scalar averaging for the calculation of the stresses. Particular emphasis is given to the extraction of the influence of a non-zero ambient wind shear observed in field measurements. Data from three different experimental sites in Athens with high roughness values are analysed in order to provide information concerning the dependence of the dimensionless minimum friction velocity on the dimensionless roughness length. Data from the BOREX-95 experiment have also been re-analysed according to the methodologies presented in this study. The results are compared to the large-eddy simulations that are considered to be a reference study on shear-free convection. Copyright © 2003 Royal Meteorological Society
    Quarterly Journal of the Royal Meteorological Society 12/2006; 129(591):1929 - 1943. · 3.33 Impact Factor
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    ABSTRACT: In this study, theoretical models of Schumann, Sykes et al., Beljaars, and Zilitinkevich et al. are examined, compared with data, and evaluated with regard to the calculation of the minimum friction velocity and the heat transfer coefficient. All data employed in earlier papers, namely those from meteorological campaigns SCOPE, TOGA COARE and BOREX-95, and the Schmidt and Schumann and Sykes and Henn large-eddy simulations (LESs), are considered. To achieve objective comparison between different formulae, empirical coefficients are recalculated by fitting theoretical curves separately for field data and for data from LESs. Despite essential differences in the shapes of the vertical profiles and the surface-layer height formulations applied in different models, practically all of them perform rather similarly and in fairly good correspondence with the chosen data set. However, a remarkable systematic difference is observed between data from measurements, on the one hand, and LES data, on the other. It is argued that this difference results from a contribution from uncounted mean-wind shear to the friction velocity in the field experiments. By this expedient, applicability of LESs to the resistance and heat-mass transfer problem is confirmed, and empirical coefficients in the resistance and heat transfer formulations are refined.
    Quarterly Journal of the Royal Meteorological Society 12/2006; 127(574):1183 - 1197. · 3.33 Impact Factor
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    ABSTRACT: The Etesians (northern sector winds), which blow over the Aegean Sea during summer, affect human activities in the area. The numerous islands of the Aegean and especially Crete (a mountainous island in the southern Aegean oriented perpendicular to the surface flow) seem to play an important role in the modification of the wind field during the Etesians. The Crete mountain ranges, surrounded as they are by water, are an excellent example of a major isolated topographic feature which significantly modifies the regional airflow and pressure; however, this modification can hardly be defined due to the lack of observing stations over the sea. For this reason, the available land surface and ship synoptic observations are used, together with ERS scatterometer wind data in order to identify the regions over the Aegean where the wind reaches its maximum intensity, and to assess the influence of Crete on the wind field. Moreover, numerical modelling is used to provide some further insight on the orographically disturbed wind flow. Sensitivity tests performed with the hydrostatic model BOLAM show that the interaction of the Etesian wind flow with the mountains of Crete produces deceleration of the Etesians up to almost 120 km upstream, the leftward deflection of the air as it approaches the mountains, and the associated intensification of the flow east of the island.
    Quarterly Journal of the Royal Meteorological Society 12/2006; 127(576):1917 - 1937. · 3.33 Impact Factor
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    ABSTRACT: During the last decade the CO2 emissions from the residential and tertiary sectors have been rising continuously. This is cause for concern but also an area to be targeted for emission reduction measures in national action plans. This paper proposes a methodological framework, using the Greek building sector (characterized by an aging building stock constructed mostly in the period before 1980) as a case study for the examination of the economic attractiveness of possible measures, which incorporates crucial parameters such as local climate, use of buildings, age of building stock, etc. that affect the energy conservation potential and consequently the economic performance of available measures. Utilizing this framework, the approach is able to classify measures into three categories, namely ‘win–win’ cases (i.e. where the implementation of emission reduction measures presents a net economic benefit for end-users), measures that require the implementation of appropriate economic support policies in order to make them economically attractive for end-users, and measures that have excessive cost. The results indicate that the emissions reduction potential of ‘win–win’ cases is significant. They also demonstrate how individual measures can provide significant reductions if carefully targeted economic support policies are applied. Finally, sensitivity analyses performed with respect to the discount rate applied indicate that it has a substantial impact on the economic performance of some measures and consequently on the magnitude of the ‘win–win’ potential associated to emissions reduction.
    Energy Policy. 02/2006;
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    ABSTRACT: Electricity demand forecasting is becoming an essential tool for energy management, maintenance scheduling and investment decisions in the future liberalized energy markets and fluctuating fuel prices. To address these needs, appropriate forecasting tools for the electricity demand in Greece have been developed and tested. Electricity demand depends on economic variables and national circumstances as well as on climatic conditions. Following the analysis of the time series of electricity demand in the past decade, two statistical models have been developed, one providing daily and the other monthly demand predictions, to estimate medium term demand up to 12 months ahead, utilizing primitive (relative humidity) and derived (heating and cooling degree-days) meteorological parameters. Autoregressive structures were incorporated in both models, aiming at reducing serial correlation, which appears to bias the estimated effects of meteorological parameters on electricity demand. Both modeling approaches show a high predictive value with adjusted R2 above 96%. Their advantages and disadvantages are discussed in this paper. The effect of the climatic conditions on the electricity demand is then further investigated via predictions under four different scenarios for the weather conditions of the coming year, which include both normal and recently observed extreme behavior.
    Energy. 01/2006;
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    ABSTRACT: Close to the surface large coherent eddies consisting of plumes and downdraughts cause convergent winds blowing towards the plume axes, which in turn cause wind shears and generation of turbulence. This mechanism strongly enhances the convective heat/mass transfer at the surface and, in contrast to the classical formulation, implies an important role of the surface roughness. In this context we introduce the stability-dependence of the roughness length. The latter is important over very rough surfaces, when the height of the roughness elements becomes comparable with the large-eddy Monin–Obukhov length. A consistent theoretical model covering convective regimes over all types of natural surfaces, from the smooth still sea to the very rough city of Athens, is developed; it is also comprehensively validated against data from measurements at different sites and also through the convective boundary layer. Good correspondence between model results, field observations and large-eddy simulation is achieved over a wide range of surface roughness lengths and convective boundary-layer heights.
    Quarterly Journal of the Royal Meteorological Society 01/2006; 132:1423-1456. · 3.33 Impact Factor

Publication Stats

1k Citations
107.62 Total Impact Points

Institutions

  • 1984–2009
    • National Observatory of Athens
      • Institute of Environmental Research and Sustainable Development (IERSD)
      Athínai, Attica, Greece
  • 1994
    • Harokopion University of Athens
      Athínai, Attica, Greece
  • 1992
    • Centre for Renewable Energy Sources and Saving
      Káto Pikérmi, Attica, Greece
  • 1976–1991
    • Wayne State University
      • Department of Mechanical Engineering
      Detroit, Michigan, United States
  • 1978–1983
    • Athens State University
      Athens, Alabama, United States