[Retsel]

Also, are you using long narrow trenches, shorter wider trenches with looped piping, or drilled holes?
My half acre lot is not large enough to do trenches. Instead, we had 4 holes drilled to 150 foot depth with 3/4 inch polyethylene piping loops inserted into each hole. All four loops are brought together into a single manifold where they are hooked up into parallel. Then a pair of 1 1/2 inch (I believe) pipes will run from the manifold to the heat pump unit in the house.
Trenching is a lot cheaper, although you end up damaging more of your yard.
Another option is to put a series of loops into a pond. We have a pond behind our house, but I don't own the land upon which the pond sits so it was not an option.

[snax]

$this->bbcode_second_pass_quote('Retsel', 'M')y half acre lot is not large enough to do trenches. . . .

[aahala]

For US taxpapers, for tax years 2006 and 2007(I think), there is a residential energy credit that may cover a portion of ground sourcing installation costs. The form number is 5695.

[gampy]

I don't know a whole lot about the geothermal angle, except what is descibed here as home heating, and cooling. Is it possible to "mine geothermal heat"? My thinking is to find a way to get to the heat far down and get it to the surface to create electricity. Any research done on this?
Drilling a hole deep enough, then allowing water or some other heat media, to get pumped back up to produce steam for turbines?

How far do you have to drill to get temp. hot enough to produce steam?
I imagine that the oil companies could develop a method, seeing as they are involved in deep drilling presently.
I imagine that geologic activity would be a problem, and numerous other problems come to mind, but it seems doable, it's just an engineering problem. Any thoughts on this?

[Graeme]

Here are some more general references on geothermal:
geothermal-biz

worldenergy

wikipedia

eere

GEO

renewableenergyaccess

ucsusa

hotrock

[gampy]

Thanks guys!

[Retsel]

To be clear, there are really two categories for deriving energy from the earth. One is called geothermal and it involves accessing heat which has penetrated a large part of the earth's core to be much more accessible from the earth's surface. Thus you pump a liquid such as water down into the earth where it is converted to steam and when the steam has made its way to the earth's surface you can use it to do work. Only certain areas of the world have relatively easy access to this form of energy.

The second category of geothermal energy is at a much more moderate temperature because it is the temperature of the ground several feet below the surface. This energy source can be tapped using a heat pump, thus it can provide both heating and cooling. This is more accurately called a ground-sourced heat pump. In this case, energy must still be provided, but the energy used results in several times more energy extracted for cooling or heating.

Retsel

[Graeme]

Silence on geothermal deafening
$this->bbcode_second_pass_quote('', 'T')hree months ago, the Toronto Star ran a lengthy story about an oil-industry consortium that is quietly exploring the use of geothermal heat as an alternative to using natural gas in the oil sands.
Today, natural gas is burned to produce the hot steam that's needed to extract bitumen from the tar sands. Alberta's world-famous sands are already the fastest-growing source of greenhouse gases in the country, and on the current growth path, emissions are expected to jump more than four-fold over the next 10 years.

Replacing much of this natural gas with clean, emission-free heat under the Earth's crust, a completely feasible option according to a recent research report out of the Massachusetts Institute of Technology, would go an enormous way toward achieving a halt, and eventually a decline, in Canada's carbon emissions.
The problem is, nobody is making noise about it. Not Ottawa. Not the provinces. Not even environmental groups.

In March, a natural resources parliamentary committee advised in a report that any decision to put a nuclear plant in the oil sands should be put on hold until the impact can be assessed and other options are studied.
Meanwhile, major players in the sands – Shell Canada, Suncor Energy and Nexen, to name a few – are doing just that. As members of the GeoPower In The Oil Sands consortium, they are doing their homework, consulting with geologists and engineers, analyzing the business case in a quiet effort to understand geothermal's potential.

In other words, like a nuclear plant, a geothermal setup would cost a lot upfront but would pay off over 20 or 30 years because of lower operating costs. The only difference is that geothermal doesn't require a fuel like uranium, which is skyrocketing in price.
Mory Ghomshei, a UBC professor leading the project, says another advantage of geothermal is that a number of smaller, medium-temperature plants can be scattered around the oil sands where low-quality heat is directly needed at well depths of just 3 kilometres. The heat from a big central nuclear plant, on the other hand, can only be transported 10 kilometres by pipeline before losing its energy.
"Geothermal can also be developed much faster than nuclear," says Ghomshei. "A comprehensive study, of course, is needed to evaluate and validate the application."

[Tanada]

Related question, not about heat but about water. Why can't you use deep saline aquifer water for tar sand processing instead of wasting valuable fresh water? As long as the saline water is impounded after use and reused as much as possible is there some technical reason why it is unworkable, or is it just easier to use of the good water so that is how they do it?

[Newsseeker]

The question is will they do it? Oil sands = massive pollution in my book. It will be interesting to see how this one goes....

[steam_cannon]

$this->bbcode_second_pass_quote('', '"')Geothermal can also be developed much faster than nuclear," says Ghomshei.

[Electric_Economy_2025]

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.

[JPL]

$this->bbcode_second_pass_quote('Electric_Economy_2025', 'N')ew 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.

[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]

$this->bbcode_second_pass_quote('frankthetank', '
')because it was too cold????for the geothermal pump

[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.