LCS-FY2014-PP-07
Geothermal Power (Vol. 1):
Design and Estimation to increase Generation Power
Summary
The power output of Japanese Geothermal power plants are almost 520MW and the untapped potential, more than 150℃, is estimated to be 14GW. In the first place, construction of new geothermal power plants should be promoted to increase power output. Further, improvement of generation efficiency by effective use of conventional technologies is also important.
The power output of single and double flash type geothermal power plants are calculated on the basis of open operating data of commercial geothermal power plants, for the comparison. Output power is increased by 10 to 20 %, generation efficiency is improved by 1 to 2 % and generation cost is decreased 0.7¥/kWh, when double flash type is applied to geothermal fluid in “low enthalpy” group. It is important to select a generation type according to the characteristics of geothermal fluid. The increase of output power 100MW can be expected by applying double flash type to geothermal power plants in totally 1000MW, which are under development based on “Geothermal Development Promotion Survey” by NEDO.
On the other hands, the scale is likely to occur in the re-injection well of double flash type power plants because of low temperature of the re-injection water. We will discuss this problem in near future.