Binary-flashing geothermal power plants - the choice of the working fluid
Geothermal energy has proven to be a great renewable energy source that has not quite been completely utilized yet. Currently, the majority of geothermal power is generated by power systems that directly use the geofluid from a geothermal reservoir to produce electricity, such as dry steam and flashing power systems. These power plants typically need higher temperatures, temperatures that are typically greater than 160°C, to produce power. The problem with this is that there are not that many resources with the temperature ranges needed. There are, however, plenty of low temperature geothermal reservoirs, which either already exist, or can be created with Enhanced Geothermal Systems that can be utilized to create power.
Currently, there are different ways to exploit low temperature geothermal resources. This thesis takes a look at a binary-flashing system and compares it to a binary system using six different working fluids (Butane, Iso-Butane, Hexane, Pentane, R-114, and Ammonia).