THE Geothermal Thread (merged)

[JPL]

New homes build should have geothermal heating and cooling systems put in instead of the standard AC and heaters. They are 20% to 40% more efficient and would be even more efficient if you use solar to power the unit.
IF your changing out you heating and cooling system I would change over to a geothermal unit.

I do wish people these days would seperate geothermal from heat pumps. The first one is an energy source, the second is an energy technology. There is a thumping difference between the two...
Grumble...

[Lore]

In my new "Fortress America", here in the the woods of western Michigan, I'm finishing off the new place. I've been in a bit of a whirl, trying to figure out the best heating system to put in the house The GeoThermal prices are coming in at around $30,000 for a closed loop system. I've considered this as an alternative to a high efficiency propane gas boiler system with an external wood fired boiler backup. It would be cheaper to go with "pump and dump" for GeoThermal, but the water here in MI is full of rust and calcium. My problem as well with GeoThermal is that I have radiant floor heating in both my lower level walk out and garage/workshop, which is already installed in concrete, with not enough of the PEX tubing for heating it with such a system. So the GeoThermal would not work as affectively as it should.

My heating guy suggested why not try a heat pump, an addition of only $1,500 more plus the boiler backup. They are putting in a few and consider the savings to be a 1/3 off the expences of the propane boiler alone for heating in a season. The Heat Pump would work well to about 20 degrees and then the boiler would take over. Plus, I would still qualify for a 40% reduction from the power company for putting in this type of system.

Does anyone have experience with Heat Pumps?

[Cashmere]

Heat pump works till 20?

That would be a newer feature.

Back when we were on HP in a small apartment, it worked until about 40 - below that it wouldn't warm the place past about 60.

Then the giant hair dryers would come on and you could hear the electric bill piling up.

I don't know how much of a DIY type of guy you are, but I've seen systems for 5 grand (no ductwork) that you install yourself.

You could rent a backhoe or find a friend with one, and lay the lines in in a day.

Maybe even a ditch witch would work, if it went deep enough.

The inside system looked simple.

30 grand? Man that seems steep.

Good luck.

[frankthetank]

My brother was telling me his friend that has a geothermal system (the one with the tubes in the front yard full of antifreeze stuff) is not saving him much. It was put in less then 2 years ago (brand new home). This is in southwest Wi, where temps last winter hit -20F+ and went below 0F many, many times.

Heres the kicker, his buddy said that he can turn the whole system off and just use gas. When he did that one month (because it was too cold????for the geothermal pump) he only spent $30 more on his heating bill...meaning he's saving VERY little on his investment...

I told him something has to be wrong...

The guy paid around $25K for the system.

[mos6507]

because it was too cold????for the geothermal pump

Sounds like someone scammed him.

[Starvid]

Are you talking about a groundcoupled heat pump, or one put in a lake, or one taking energy out of the air?

The latter is much cheaper but stops working when it gets too cold outside, while the two previous work even if temperatures fall to -20 C, but they require much more capital, mainly because of the cost of drilling the well.

Heat pumps of different kinds are used extensively in Sweden and would be considered a rather mature technology over here. Heat factors are usually about 5 (that is you get 5 kWh of heat for every kWh of electricity inserted into the pump) as long as the medium you take heat from is warm enough. Another good thing is that can run it backwards in summer so you don't need air conditioning, even if that shouldn't be needed in the first place in Michigan.

It's important to know how much heat you have in the ground/lake. If you overestimate it the well will produce too little heat and if you underestimate it you will make the well deeper and more expensive than needed.

An interesting way to change the capital cost requirement is to drill a more shallow well but adding a solar heating system. This means that solar collectors are installed on your roof and recharges the well with energy during summer which means there is more energy to take out of it in winter. The well becomes cheaper to drill but you get the added cost of installing the solar system. It's the one solar technology that can actually make economic sense.

If you get a heat pump (and I generally think they are a good idea), make sure you use a big well-known company and can get a refund/free repairs if the system breaks down within 5-10 years, especially if you don't take the cheaper aircoupled heat pump. These things have a tendency to break or not to deliver the expected capacity if they are done sloppily.

One of these quality companies is NIBE. They don't sell their products in the US, but they do sell them in the UK. I'm sure you can mail them and ask them what companies in the US make quality equipment. They should know.

http://www.nibe.co.uk/

[IslandCrow]

I went the ground heat exchange route rather than air heat exchange. The capital costs were much much higher, but it was more efficient (and as Starvid wrote works at colder temperatures).

Doing some spreadsheets on likely costs it was a toss up (depending on just how fast energy costs will rise), but at time stage I put it in, I had enough cash for ground system so I went for that. This was in part to reduce future costs as much as possible given uncertain economic conditions (and retirement coming up in the not to distant future).

The heat pump has worked well - we have a south facing outcrop of granite into which the well was drilled, so it stores plenty of heat in summer. Last winter the axillary heating coils only came on for a couple of hours all winter! On very cold days we plan to use the wood stove in the kitchen as extra heat.

[To make Starvid happy: the equipment came from Sweden ]

[skyemoor]

Tell us about your square footage (and if you will be heating the garage most of the time). What is your wall insulation (R-21? R-25? other?), ceiling insulation?

All things being equal, the geothermal heat pump will cost about 1/4 to 1/3 the electricity of an air source heat pump. Since you have a fossil fuel backup, it may be closer to 1/3 to 1/2, though then you have to add in fuel costs.

If you are in the woods, I'd say put in an efficient woodstove and use that primarily (or at least when the temps are below freezing). Then a $30k geothermal system wouldn't be necessary.

[Kingcoal]

A friend of mine has a "pump and dump" and is very happy with it. However, you have to keep after the heat exchanger, cleaning it regularly of mineral deposits. We also have hard water here.

They give you almost free air conditioning in the summer and work well in the winter even with sub zero temps because the well water stays at a constant 45 degrees year round. He's gone through some pretty cold winters and has never had the exchanger freeze up.

[purdum]

Lore - I'm also in Michigan, near Lansing. We installed a ground-loop geothermal system in 2005 and have been very happy with it, saving a lot of money each year compared to the oil furnace we had before. Our basic costs were $11K for the heat pump and $7K for excavating and installing the loops. The total cost was closer to $25K because we had to install a separate 70-amp electrical panel and ended up replacing just about all the ductwork in the basement. With heating oil likely to be around $4.75/gal, we will save nearly $3500 just this coming season. And it has been costing us about $125 for the entire summer for air conditioning. So yes, $25K is a lot of money up front but it will pay for itself by 2012. PM me if you want more details.

[Lore]

Tell us about your square footage (and if you will be heating the garage most of the time). What is your wall insulation (R-21? R-25? other?), ceiling insulation?

All things being equal, the geothermal heat pump will cost about 1/4 to 1/3 the electricity of an air source heat pump. Since you have a fossil fuel backup, it may be closer to 1/3 to 1/2, though then you have to add in fuel costs.

If you are in the woods, I'd say put in an efficient woodstove and use that primarily (or at least when the temps are below freezing). Then a $30k geothermal system wouldn't be necessary.

Thanks everyone for the feedback. I really wish I could go with the GeoThermal. Looks like I may have to do the heat pump/propane boiler combo though because of the construction and water quality.Pump and dump, as mentioned, requires a lot of maintenance with the water here.

I would have to do just about the same setup as purdum mentioned if I were to do it at all. I'm running AC so at worst I'm out the expence of the heat pump which adds about $2,000 with my boiler combo. You still need a source of backup with the electric company as I understand it to get the seperate meter and best rate with either GeoThermal or a heat pump.

The the house is 2,200 sq/ft log cabin exterior 2" pine, with 6" insulated sidewalls and 12" in the ceiling. Every crevice and crack is sealed with expanded foam. Half of the footage is lower level walkout.

[hydrocarbon]

Ive heard lots of good things about geothermal energy, supposedly energy almost anywhere if you drill far enough down "six to ten miles down in some areas". The set backs to this unlimited amount of energy source is drilling cost and lack of drilling technology. Right now companies and private citizens are investing heavily in drilling research, for example drilling not with a drill bit but with an extreme source of heat such as a modified gas torch to burn through the rocks or with an electric carbon arc. They also had another problem with thermal quakes but i read they are researching and may have a solution by creating a complex heat exchanger so water and steam wouldn't build up in rocks. I think if fusion doesn't pan out this is the next best thing because we all know about the other alternatives and they do not sound too promising.

[vaseline2008]

Seems like they are already "on it".

Geothermal Power

My only concern is what affects will it have on the Earth's core temperature. Will it ultimately cool down the core? What are the affects of a cooler core?

[MadScientist]

on a microscale (individual home) geothermal is awesome.

There are two main systems. One uses air. One uses water.

The basic idea is that you run coils through the ground around your home. These coils bring in air/water at ground temperature (40-55 degrees depending on your area.)

So you get nice AC for free in the summer.

In the winter you have air/water which only has to be heated up 20 degrees or so.

I am a residential contractor. IMO geothermal is an essential part of any energy conscious structure. Combine with an ultrainsulated shell and high efficiency (masonry) wood heater for ultimate results.

[lostinspace]

Oil wells are on the way out so what will be the next source of big energy-? Here is one concept. What do you think-?[img]http://www.imageurlhost.com/viewer.php?file=et0m7mbbsbwafkevmanc.jpg][img]http://www.imageurlhost.com/images/et0m7mbbsbwafkevmanc_thumb.jpg[/img][/URL[/img]

[Dawn]

I have been bouncing around a few ideas for heating our home. I would love to install a woodstove, but I don't see how I could possibly add one to this house... Unless, I add a stove to the outside of this home and attach it to the ductwork. I have seen that before, however, I think those were corn burners and not wood. I also do not have any mature trees in my yard and worry that many people soon may be relying on wood as a source of heating/cooking.

Anyway, I am seriously considering geothermal and one of my neighbors is an installer of geothermal for a company... He gave me an estimate about 10,000 - 14,000 less than the larger companies. Hum, around where I live the electric company charges about half the normal rate to operate these systems.

As a back-up I would also like to install a turbine to generate electricity. I'm just waiting for the township to pass the ordnance that would allow me to put a turbine in my yard.

What would you do? Any thoughts or ideas?

TIA

[purdum]

Just working some numbers through my head, I think you would need at least a 10-15kw wind turbine to meet peak winter heating demand. I am near Lansing and have a geothermal system installed. PM me and I can give you details.

[deMolay]

Geothermal is very expensive here in Alberta. Above 30,000 dollars. I think the piping and system would be worn out before you got payback. It is also realatively high tech and expensive to maintain.

[WisJim]

In addition to expense every "geothermal" heating system--I am assuming you are talking about ground source heat pumps--have had compressor and /or control problems, and there aren't a lot of people that know how to fix them. Insulation is cheaper.

[Ludi]

I agree, wisjim. I know I'm not really qualified to respond to this thread because I live in a warm climate, but, if I had that kind of money to put in a geothermal system, I would instead use it for insulation, quality windows, and a small efficient woodstove. Our house is horribly insulated with miserable windows, and we heat entirely with a small woodstove.