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RE: Go somewhere else
By Fritzr on 7/20/2009 4:38:42 AM , Rating: 2
Here is the relevant part of the linked article. In an H2O steam turbine system, water is biphasic--liquid & vapor.

PNNL's conversion system will take advantage of the rapid expansion and contraction capabilities of a new liquid developed by PNNL researchers called biphasic fluid. When exposed to heat brought to the surface from water circulating in moderately hot, underground rock, the thermal-cycling of the biphasic fluid will power a turbine to generate electricity.


They say that they are using a "steam" cycle. The breakthrough was identifying a working fluid that offers almost as much efficiency as an H2O steam system. Then a turbine assembly needed to be designed to work with this new working fluid.

They are working on a demonstration unit now. Since the breakthrough is a method of using a relatively low temp heat source to drive a "steam" turbine this could be used to scavenge more power from the exhaust of conventional steam turbines as well as other "low" temp heat sources.

Just because they are focused on using it to expand the number of geothermal sites that can generate power will not prevent others from using this tech to extract power from other heat sources.

