Abstract
For many years the authors have been engaged in development of numerical models to contribute to the design of Hot Dry Rock geothermal power generation. In Japan, however, the research projects concerned in HDR were discontinued in 2004, leaving a part of the research works unfinished. This paper documents two of the fully 3D modeling systems originally developed in this research: one is a finite difference based model and the other is a boundary element based model. Our hope is that this paper will support future reopening of investigation into HDR geothermal energy development.