| Abstract |
This study investigates the feasibility of renewable energy utilization in Tibet, China. Based on the available energy assessment and market analysis, a technical and economic feasibility study is carried out on geothermal development and utilization of Yangbajain field with the objective of solving both electricity shortage and lack of space heating in order to improve living conditions of the Tibetan people. The technical feasibility study contains thermodynamic models of proposed different power generation scenarios and long distance district heating system to analyze and optimize each scenario by using EES and Matlab programs. The four alternative scenarios optimized for new power plant design are double flash cycle (Scenario 1), hybrid single flash and ORC cycle with isopentane as the working fluid (Scenario 2), pure ORC cycle with isobutane as the working fluid (Scenario 3), and a hybrid single flash and Kalina cycle (Scenario 4). The conceptual design of district heating system with about 90km distance from Yangbajain to Lhasa is carried out as well. The results indicate that all power cycles are technically feasible at different efficiencies and that the district heating system can be implemented with appropriate design and construction considerations. A financial viability evaluation is performed for all scenarios using engineering economic Present Worth (PW) value analysis method with the objective to determine the Internal Rate of Return (IRR) of each system. The optimum power cycle scenario is Scenario 1 with IRR value of 31.84%, followed by Scenario 2 with IRR value of 22.15%. The district heating system has a low IRR value of 3.13% due to the high investment cost of a long distance transmission pipeline. However, as part of an entire system of CHP power plant, the optimum system can yield 8.92% IRR value at pure commercial investment level. Since it will be a subsidized program from the central government, it can reach 10.78% of IRR value without incurring loan interest payments. If the expected IRR of the investment company is 10.00%, it proves this project is economically feasible. |