We dug the trenches this week for the geothermal heating and cooling system.  The idea is that you bury hundreds of feet of pipe several feet underground, and pump water through it.  When it comes out the far end, it will be at the temperature of the ground, which around here is something like 55 degrees year ’round.  That water has a lot of heat in it.  Extract the heat from it, pump it back out, and the ground will heat it back up.  Rinse and repeat all winter long.  Basically, it’s a solar water heater – it just doesn’t rely on the sun that particular day, but the average sun all year long that warms up the earth.  Somewhere around 70% of our heat will come from the sun through this system.

A closed-loop geothermal system like this does require a good bit of land, though.  We had to dig 5 trenches 6 ft deep by about 150 ft long.

Geothermal Trenching

Wouldn’t you know we would have to put the trenches in this small field next to the house.  The Healing Harvest folks and myself spent hundreds of hours clearing this field, which wasn’t a field at all when we bought the farm, but a tangle of pines, roses, ailanthus, and dying locust.  We had BIG burn piles going pretty much all summer and fall here last year.  The topsoil is a good 12 inches deep, and we did everything we could to preserve it.  When we finished clearing it, I planted yellow blossom sweet clover on it and had a really nice stand going when it was decided to dig it all up.  So we decided to first scrape all the precious and beautiful topsoil away into a windrow first, and then dig the trenches.

Next week, we’ll lay the pipe into the bottom of the 6′ trenches, cover them with 2′ of subsoil, lay another run of pipe, and then fill in the ditches with the rest of the subsoil, compact it all down, then cover everything again with the topsoil.  I’ll then disc it and plant it again, this time probably with a mixture of annual rye, three types of clovers, and timothy, as this field is likely to become horse pasture.