THERMODYNAMIC AND ECONOMICAL ANALYSIS FOR GEOTHERMAL-FOSSIL HYBRID ELECTRICITY CONVERSION SYSTEM

• Main Author: Imbar Fitriadi, Mohamad
• Format: Theses
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/39470
• Institution: Institut Teknologi Bandung

A hybrid power plant is a power plant utilizing two energy sources. There are a lot of research has been carried out to develop a hybrid power plants system. However, there are no hybrid power plant has been built from the research. Therefore, it is necessary to do thermodynamic analysis and economical feasibility analysis of fossil geothermal hybrid power plants. This research used geothermal fluid with a temperature of 179.8oC which will be heated to a temperature of 479.8oC by hot gas from fossil fuels combustion, so that additional power generation can be obtained as the result of increasing enthalpy of geothermal fluid. There are two designs of the hybrid system. The design of the first system is direct heating using a hot gas generator, which produces power generation to 83,5 MWe. For the second hybrid power plant, the fossil fuel is used to generate gas turbines first, and the exhaust gas from the generation is later used to heat geothermal fluid in a superheater. The design of a hybrid plant with the addition of a gas turbine (the second design) can increase generating capacity up to 101,1 MWe uses LPG and 97,1 MWe uses LNG. Additional power from the plant is then became one of input data for economic model to obtain the required investment costs, construction prices per MW electricity, and the selling price of electricity per kWh. For the selling price of electricity, levelized electricity price method is used, to accommodate the escalation of fossil fuel price every year. The selling price of electricity for direct heating power plants using hot gas generators (first design) is at the range between US$ 12,26 – 21,74 sens/kWh,with the lowest price uses coal fuel and the highest price uses diesel oil fuel. The selling price of electricity from merger design of additional gas turbine (second design) was obtained at the range between US$ 12,14 – 15,38 sens/kWh,with the lowest price uses LPG fuel and the highest price uses LNG.