Innovation Spotlight: Technology hot enough to fry an egg

Far below the Earth’s surface lie networks of fractured rock filled with reservoirs of hot water.

 

And we’re talking hot. Conventional hydrothermal reservoirs at intermediate depths can house hotter-than-boiling water, and at depths of 10km or below, enhanced geothermal systems (EGS) reservoirs can exceed 300^oC.  In order to develop EGS reservoirs into energy-producing systems, obtaining accurate real-time temperature and other data in extreme conditions is required.  While this has proven to be a challenge, it is a critical need in maintaining the stability and consistent energy output from EGS reservoirs.

 

So how does one create sensitive electronics that can survive such intense subterranean conditions?  This is where General Electric scientist Vinay Tilak and his team of researchers come in.  Through a $1.6 million grant from the Geothermal Technologies Program, Tilak and GE are developing a temperature sensor and electronics platform able to withstand such harsh conditions. 

 

Tilak’s challenge is to create an integrated circuit and circuit board, active and passive sensor components, and an encasing package that will survive laboratory tests at 300^oC for 1000 hours.  GE is utilizing innovative temperature-hardened materials for sensor components, such as silicon carbide to develop an integrated circuit; ceramic for the circuit board and packaging materials; and alumina, gold film and nickel-plated molybdenum for other parts.

 

To see a demonstration of this hotter-than-hot research, check out Tilak’s video .

 

The importance of this technology lies in its capability to support long-term maintenance of EGS reservoirs.  Accurate, predictive reservoir models are required for maintaining constant energy output throughout the lifetime of the EGS reservoir.  To validate these reservoir models, temperature-hardened real-time monitoring sensors and logging tools are essential to generate accurate field data that tracks the development of the reservoir as temperature and fluid conditions evolve. Ultimately, the platform in development will also be able to measure pressure, flow rate, and seismicity of geothermal reservoirs.

 

To date, incremental stress tests and high-temperature validation have been successful.  GE expects to have an accurately measuring and thermally durable temperature sensor and platform completed by late 2011.

 

For more information about this and other projects, please see the Geothermal Technologies Program’s project database .