ASSESSMENT OF GREEN HOUSE GAS EMISSIONS FROM STORAGE BASED HYDROPOWER SCHEMES

Abstract

There is a growing interest and concern regarding Green House Gas (GHG) emissions as these are the major contributors of global warming. Carbon dioxide (CO.)) and Methane (CH4) are two main GHGs which get emitted from both natural aquatic and terrestrial ecosystems as well as from anthropogenic activities. In natural aquatic system water storage is an important aspect for meeting the requirements of drinking water, food, and energy. However, development of such water bodies will impact the environment. Recent studies have shown that water bodies play a significant role as the sources of GHG emission, particularly in tropical climatic zones. One possible reason for this is the annual water temperature is much higher in tropical climates. This means that the rate of decomposition is faster leading to higher CO2 and CH4 flux in the water. Indian reservoirs indicate the complete spectrum of different types of reservoir found in the world. Their performance in terms of emission of GHGs is more difficult to trace out. In this study, pathways of GHG emission from a reservoir 4 have been discussed and a tool suggested by UNESCO/IHA has been used to assess the GHG emissions from eleven existing reservoirs in India. These reservoirs are of different age and are located in different parts and climatic zones of India. Predicted GHG emissions in terms of CO2eq have been estimated for the year 2013 as well as for over 100 years of their existence in terms of Tonnes CO2eq. Finally a result of 59 million tons of CO2eq has been obtained for all the hydropower schemes over a particular age and a whopping value of 518 million tons of CO2 over 100 years has been obtained for diffusive flux. While considering each pathway of the emissions from the SBI-IP (Storage Based Hydropower) scheme, emission through degassing should also be considered since it is one of the pathways that release a huge amount of CH4 into atmosphere. Finally, the predicted amount of eleven SBHP schemes including each pathway of emission comes about 59 million tons of CO2eq at particular age and mean emission over 100 years, about 5932469 tCO2eq/year.