A neural network controller for hydronic heating systems of solar buildings

An artificial neural network (ANN)-based controller for hydronic heating plants of buildings is presented. The controller has forecasting capabilities: it includes a meteorological module, forecasting the ambient temperature and solar irradiance, an indoor temperature predictor module, a supply temperature predictor module and an optimizing module for the water supply temperature. All ANN modules are based on the Feed Forward Back Propagation (FFBP) model. The operation of the controller has been tested experimentally, on a real-scale office building during real operating conditions. The operation results were compared to those of a conventional controller. The performance was also assessed via numerical simulation. The detailed thermal simulation tool for solar systems and buildings TRNSYS was used. Both experimental and numerical results showed that the expected percentage of energy savings with respect to a conventional controller is of about 15% under North European weather conditions

Weather maps classification over Greek domain based on isobaric line patterns: A pattern recognition approach

The paper presents a semi-supervised weather classification method based on 850-hPa isobaric level maps. A preprocessing step is employed, where isolines of geopotential height are extracted from weather map images via an image processing procedure. Α feature extraction stage follows where two techniques are applied. The first technique implements phase space reconstruction, and yields multidimensional delay distributions. The second technique is based on chain code representation of signals, from which histogram features are derived. Similarity measures are used to compare multidimensional data and the k-means algorithm is applied in the final stage. The method is applied over the area of Greece, and the resulting catalogues are compared to a subjective classification for this area. Numerical experiments with datasets derived from the European Meteorological Bulletin archives exhibit an up to 91 % accurate agreement with the subjective weather patterns. © 2013 Springer-Verlag Wien

Energy policy and an action plan for renewable energy sources (RES) for the Hellenic islands of the North Aegean region

The resource base for RES is vast, but only a small fraction is being exploited with available technology. The full potential of RES for the European Union (EU) is estimated at 408 Mtoe by 2020. Here we review data on energy supplies and demand with emphasis on RES and also assess the potential for energy conservation by using RES in remote regions. Our case study deals with the Hellenic islands of the North Aegean region. These islands have a high RES potential because of their dependence on external energy sources, absence of control over fossil-fuel costs and periodic power shortages, especiallly during summers when energy demands peak as a result of tourism. The resource base for RES is vast, but only a small fraction is being exploited with available technology. The full potential of RES for the European Union (EU) is estimated at 408 Mtoe by 2020. Here, we review data on energy supplies and demand with emphasis on RES and also assess the potential for energy conservation by using RES in remote regions. Our case study deals with the Hellenic islands of the North Aegean region. These islands have a high RES potential because of their dependence on external energy sources, absence of control over fossil-fuel costs and periodic power shortages, especially during summers when energy demands peak as a result of tourism

Energy policy and an action plan for renewable energy sources (RES) for the Hellenic islands of the North Aegean region

The resource base for RES is vast, but only a small fraction is being exploited with available technology. The full potential of RES for the European Union (EU) is estimated at 408 Mtoe by 2020. Here we review data on energy supplies and demand with emphasis on RES and also assess the potential for energy conservation by using RES in remote regions. Our case study deals with the Hellenic islands of the North Aegean region. These islands have a high RES potential because of their dependence on external energy sources, absence of control over fossil-fuel costs and periodic power shortages, especiallly during summers when energy demands peak as a result of tourism. The resource base for RES is vast, but only a small fraction is being exploited with available technology. The full potential of RES for the European Union (EU) is estimated at 408 Mtoe by 2020. Here, we review data on energy supplies and demand with emphasis on RES and also assess the potential for energy conservation by using RES in remote regions. Our case study deals with the Hellenic islands of the North Aegean region. These islands have a high RES potential because of their dependence on external energy sources, absence of control over fossil-fuel costs and periodic power shortages, especially during summers when energy demands peak as a result of tourism