In article .com,
says...
Utilities buy "screw-in" ground rods that are driven in with a
gas-powered tool and have a cast screw on the end that goes in the
ground. Some of these can be "extended" to your desired 17 feet. But
these rods are not cheap (hundreds of dollars) and the tools are
exquisitely specialized.

A threaded 3/4" grounding rod is around $25 for 10 feet, including
the pointed end. Couplings are around $8. Not as beefy as what the
utilities use, but how many amps do you plan to dump down a household
ground rod?

--
is Joshua Putnam
http://www.phred.org/~josh/
Braze your own bicycle frames. See
http://www.phred.org/~josh/build/build.html