Abstract: In this paper a study of forest vegetation in the territory of East Rhodope based on satellites, GPS and other terrestrial data is presented. The local areas of forest communities in classes and their distribution depending on the topography are defined. In this study we analyzed the Normalized Deferential Vegetation Index (NDVI) between forest classes. The study is the result of cooperation between specialists from SSTRI-BAS and Sofia University. This study is the initial stage of a comprehensive research on the dynamics and development of natural systems in Bulgaria.

Key words: ecological dynamics, forest community, satellites data, terrestrial data, East Rhodope Mountains

Abstract: This paper deals with the pumping storage system analysis. The water reservoir serves for daily and seasonal energy storage, thus basically solving the problem of energy storage, which is the biggest problem of wider use of renewable energy sources. The electrical energy produced in excess by the renewable energy system is converted in potential energy by pumping water to a higher elevation where it can be stored indefinitely and then released to pass through hydraulic turbines and generate electricity. The estimation of the stored energy, the nominal electrical power of the hydroelectric plant and the evaporation rate of the water reservoir is presented.

Keywords: solar energy; wind energy; hybrid systems; pumped storage.

Abstract. The use of biomass as energy source has high priority in order to comply with the Kyoto Protocol for global reduction of the greenhouse emission. As result of scientific contacts and studies of researchers from Bulgaria and India begin join work in the field of biomass energy utilization in particular with biomass gasification. The aim of the paper is to present the initial results from the studies and possibilities for biomass utilization and gasification in the both countries Bulgaria and India. The paper describes in brief some studies regarding biomass potential, the policy and legislation and some measures implemented in Bulgaria. On the other hand it presents the experience in India regarding biomass gasification and possibilities for utilisation of biomass at low investments and high efficiencies. The applied method of a very high temperature biomass gasification technology has technical advantages. In this connection are presented some results of experiments in pilot installations concerning gasification of solid agriculture waste. As results are presented temperature of the gas outlet, inlet air pressures measured in time of the experiments and some dependencies and conclusions.