I really found this site informative for DIY (do it yourself) well drilling for both irrigation AND geothermal.
If you have been considering switching to geothermal but found the cost of drilling made it impractical, you might want to have a look here.
If you can get about 10 GPM out of the ground water, this may be for you.
I have used a similar method for safely drilling fence post holes near buried utility cables using a sidewalk tunneling device sold at hardware stores for $5.
It uses a water pressure jet attached to a pipe and water hose to blast out a horizontal hole under a sidewalk.
I used it to blast out a 3 foot deep hole for a fence post.
This guy's method uses water pressure to drill a vertical well 25 to 30 feet deep without expensive equipment.
Another guy from Florida uses a modified arrangement quite successfully.
Another contributor uses a "mud pump" for an even larger, faster drill.
I have one piece of property very close to the Arkansas river.
It has very little top soil and I hit sand at just a few feet below.
It has me thinking...
PS: The guy says he think installing solar powered attic vents and a variable speed swimming pool pump offers more immediate savings than his DIY geothermal system.
Edited by Rogerdodger, 01 January 2012 - 01:44 PM.