Front Yard Geothermal: Drilling

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Flowers and Drilling RigToday the drilling went on in earnest.  Bruce and Herb finished the first hole, 180' deep, and inserted the first "loop" to the bottom of it.

The "loop" is a pair of black tubes, a bit bigger and stiffer than garden hose, joined at the end to make a "U".  This "U" joint goes at the bottom of the well hole, and the 2 ends stick out the top.  Next week they will be connected with the tubes from the other wells and fed into our basement.

Things did go a bit slower than expected.  Feeding the loop into the hole is done by hand.  If bits of stone from high up in the well fall down and get stuck, it prevents the loop from being fed down to the bottom of the well.  This happened several times today.  When it did, Bruce had to run the drill down 180' just to clear the obstruction.

Some people asked about the cost of this work.  At the risk of losing the interest of you, my dedicated reader, I'm just going to say it: $19,000 up front, 30% recovered in tax credits for a net of $13,300.  Does not include landscape recovery.  There are caveats if you want to apply this to your house, notably that our house is fairly small and well insulated, and we are using the existing natural gas furnace as the air blower and emergency backup.  Also this was the result of getting 5 bids and refining exactly what was being bid on to meet our needs (including keeping the price down).  So this is almost certainly on the very low end for a "vertical loop" system.

The other money question is, how much will it save?  I don't know yet, of course.  We don't have central air now, and we will when this is done.  So it won't save us anything there, although it probably would for someone who used a lot of A/C.  On heat, natural gas is really cheap now.  Based on the projections from Mark (our contractor, Professional Geothermal), I still expect it to save us $100 or $200 per season.  Or more to the point, 5,000 or 6,000 pound of CO2.

Now to the movies...

Here Herb clears some limestone as it comes out from the well...

Now Bruce is pulling the rods out in preparation for inserting the "loop" into the hole.  As it happened, this was the first of 3 attempts (because rock from higher up the hole fell down and prevented the "loop" from reaching the bottom).

Another good day!

Mike and Herb

[Click on links for part 1, anticipation, part 2, it begins, and part 4, digging]

Last Updated on Tuesday, 08 November 2011 07:44