|Abstract: ||A system and method for powering a borehole sensor with thermal energy is
disclosed. The system includes a tubular pipe inserted into a subsurface
borehole. A borehole casing is coaxially disposed with the tubular pipe.
An annular space between the casing and the tubular pipe has a power
source placed in the borehole to power a sensor in response to a
temperature gradient between a surface of the casing and a surface of the
tubular pipe. The method includes attaching thermopiles on the borehole
casing or tubing; placing the thermopile in the annulus between the
casing and the tubing; inducing a thermal gradient across the thermopile;
generating an electrical energy in response to the temperature gradient;
powering the sensor from the generated energy; and monitoring vertical
expansion of a CO.sub.2 plume.