Moderate Temperature
From Open Energy Information
Moderate Temperature:
No definition has been provided for this term. Sanyal Temp Classification
This temperature scheme was developed by Sanyal in 2005 at the request of DOE and GEA, as reported in Classification of Geothermal Systems: A Possible Scheme.
Reservoir fluid between 190°C and 230°C is considered by Sanyal to be "moderate temperature."
"The next higher resource temperature limit is chosen as 230°C, which is lower than the minimum initial resource temperature encountered in vapor-dominated reservoirs worldwide. Vapor-dominated reservoirs have such a unique set of characteristics that these have been grouped as a separate class as described below. Reservoirs above a temperature level of 230°C may have free steam saturation initially or develop steam saturation upon exploitation, but this would be unlikely for a reservoir below a 230°C temperature level. Thus, reservoirs in the 190° to 230°C range should have liquid water as the mobile fluid phase, and as such, this class is reasonably well constrained. The wells for this class would be too hot to pump and must be self-flowed. Therefore, the productivity of wells in this class would be more variable, typically in the range of 3 to 12 MWe" (reference: http://www.geothermal-energy.org/pdf/IGAstandard/SGW/2005/sanyal1.pdf).