Carbon Footprint Of Typical Hydro-projects In Jinsha River

Hydropower is a clean,renewable energy with mature technology.Hydropower has represented 6.8 per cent of global energy usage by 2015.For the pressure of the carbon emission reduction,many countries have to explore a sustainable energy transformation model to control carbon emissions.The best choice for China is the development of hydropower for China is rich in hydropower resources.However,carbon emissions may also occur in the development of hydropower.The research of carbon emissions of hydropower will provide scientific information for the operation decision making and management of hydropower.This study applied life cycle assessment method to estimate the greenhouse gas（GHGs）emission according to the standardized processes（ISO14067）for carbon footprint quantification and focused on the difference before and after the impoundment from four stages-pre-impoundment clearance,construction,operation and decommission stage.To improve the reliability of the assessment results,we constructed a new hybrid method integrating Bayesian Network,triangular distribution and the statistical method on the basis of the traditional LCA uncertainty analysis method.It took full consideration of both the calculation and assessment of the hydropower footprint assessment and made a balance between uncertainty of the data and parameters.The new hybrid method can reduce the subjectivity of uncertainty-analyses and take account of various factors,which strengthens the credibility of carbon footprint of hydropower.This paper selects cascade hydropower stations system in the upper Yangtze River as a case for carbon footprint quantization.Results showed that the carbon emission for 1kW·h in the confidence level of 95%was 5.00-13.28 g CO_2eq/kW·h（Wudongde station）,7.57-13.64 g CO_2eq/kW·h（Baihetan station）,3.49-6.53 gCO_2eq/kW·h（Xiluodu station）and 5.03-9.46 gCO_2eq/kW·h（Xiangjiaba station）.The carbon footprint of operation become the most important resource of GHGs and reached more than 50 per cent of total carbon footprint.Then the manufacturing of materials and equipment make up about 20%of total carbon footprint.The result that the variance contribute rate of GHGs of reservoir reached to 90%has shown the fact that reducing GHGs of reservoir will reduce the carbon footprint of hydropower.Compared with other kinds of power plants and hydropower stations,the carbon footprint of the reservoir is obviously lower,showing the high quality and cleanliness of hydropower resources in the southwest China.