We are building a 12,000 sq ft home and recently received quotes for 6 geothermal units and the bore holes @ 180,000!! wow!

I am wondering what other options there might be

In my case the next size up,3 ton, would have been $5000 more

Due to the installation cost of a Geo unit you don't want to size for 100% load. 80%-90% is a good target, the additional load can be covered with backup heat.

They said that's what their load calc gave them, maintaining 70F on the average of coldest days (10F).

around 50k for a 4 ton with a vertical loop.

Yeah that's weighing on my mind as well. The life issue isn't a big one for me as I hopefully have a good bit of years left.

But what is driving me towards this is that energy prices are pretty much guaranteed to go up. Relying on fossil fuels is a pretty bad idea.

I looked at geothermal and my HVAC company who installs these systems. We could not make it viable and the recommendation from them was a Trane 16 SEER air source.

The ROI with my energy usage would far exceed the life of the equipment and most probably my life.

That's actually not that bad, considering I'll be getting a 30% tax credit which brings my total cost down to about 35k. (yeah, I know, taxpayer money propping up green energy yada yada)

Got an estimate from a local geothermal contractor. It is coming in around 50k for a 4 ton with a vertical loop. The largest cost is well drilling (as expected).

That's actually not that bad, considering I'll be getting a 30% tax credit which brings my total cost down to about 35k. (yeah, I know, taxpayer money propping up green energy yada yada)

First off, I know that geothermal is better than an air source heat pump.

But my question is, how much?

The house is I would say not so well insulated. Built in 1998. We've added to the attic but little else. We are willing to work on that though.

Drilling costs? Yup, I would need a vertical loop. The horizontal area where I would put a loop has trees. I need separation from the well and septic as well. This is NJ so I'd imagine drilling costs are not as cheap as other places. The soil is not solid rock but moderately rocky.

This year, I installed a pellet stove insert in my fireplace. I am heating the house 100% with it. It runs off a thermostat, I just have to keep the hopper full and clean it once a week which takes about a half-hour to 45 minutes.

What if you only have about a foot of soil, and then limestone below that? Digging a hole in my yard isn't any fun, but does it bother the well drillers much? Being at $.14/kwh I'm considering geothermal when I replace my system in the future.

How cold does the lake water get in winter? Would that not negate some from the natural warmth of the well method? We looked at putting it in the water but we're on the coast and the marine life would coat it in about a year.

How cold does the lake water get in winter? Would that not negate some from the natural warmth of the well method? We looked at putting it in the water but we're on the coast and the marine life would coat it in about a year.

An open system utilizing my well and dumping the water was a better option but wasteful.

with a total cost of $15,000 with about $5,000 for the loop

Shallow-well uses drilled wells as opposed to simply placing coils horizontally in the ground. Shallow well requires less land than horizontal but still takes a lot of land depending on its application.

We are looking at either a horizontal loop or vertical loop. We have the land for both but the horizontal loop involves significant tree cutting.

Geothermal comes in basically three flavors: horizontal surface coils, shallow-well and deep-well. It sounds as if the OP is talking about surface geothermal. This requires a relatively large amount of land to bury the coils; horizontally buried at typically about ten feet deep. Shallow-well uses drilled wells as opposed to simply placing coils horizontally in the ground. Shallow well requires less land than horizontal but still takes a lot of land depending on its application. And its not as shallow as you think; the wells can be from 50' to hundreds of feet deep; most typically about 80' to 100' feet deep. Deep well is used where there is not enough land to have many, many wells.

The better term to use should be ground source heatpump, rather than geothermal. Geothermal would usually be like alkizmo was referring to about volcanic type heat .

Ground source heatpumps should even work up there in the GWN.