The problem with integrating a geothermal system into a lake is that it's not a viable heating option for the vast majority of us. Sadly, it becomes most appealing to those who own a summer cottage in addition to their city home. Hardly Treehugging at it's best. Even integration with groundwater systems is fraught with problems.

I wonder if in cities it could somehow be integrated with the water distribution system. Either on the input or output side.

Of course geothermal can be used by burying a closed-loop of pipes in the ground (horizontally or vertically), but I think that it would be even more efficient with a not-closed system.

It is still a closed loop system, right? Otherwise wouldn't you lose efficiency as muck and whatnot infiltrates the lines in the system?

The system in the picture seems to be closed, but I've read many times about open systems used in rivers and lakes.

Not sure how hard it is to keep the pipes clean, though. It might be a paint o keep changing filters.

Wouldn't it heat up the lake?
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The lakes are thermally stratified over several meters of depth and you are circulating a bit of warm back through a very long half inch tube -- the effect will be very gradual and localized. Not something to recommend for a huge building I suppose but for shoreline houses the result should be easy to quantify, should state authorities wish to model the impact.

Obviously it would have to be closed loop to avoid having to apply for a discharge permit from State and Federal authorities.

it seems obvious to me that geothermal is the wave of the future. we just need to figure out how to clean up the electrical generation.

im hoping to install a geothermal system to run the majority of my greenhouse heating needs in 2007.

i could also imagine that the future designs of cities could use alot more geothermal infrastructure. seems like an smart investment. imagine the roads, lakes and farmlands being also the aircon/heating drivers of our society. now that is an efficency!

DD is right, that type of heat pump directly affects the ecology of the body of water. Its not far off from sticking an exhaust pipe next to a penguin.
EWO

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Affects is the operant word.

Global warming increases heat content of land and surface water. Taking some of it out for home heating seems like exactly the right course of action. Not so to pump in during summer of course.

Regarding the concern about affecting the ecology of the pond -

retention ponds are, in my experience, usually human made features anyway, so any frogs, fish, water plants etc that live there are only there because people built the retention pond in the first place. So, while I can see that you're affecting the ecology, you've already affected it by flooding the field or whatever it was that was there to begin with. I don't have a problem with it.

On the other hand, if you're talking about really big lakes or boddies of water, I would think that if the pipes were spread far enough and the lake was bog enough, the effect would be marginal at best. And what effect do people have as a result of pollution, irrigation, extracting water for power stations and then dumping it back in again... etc.
Granted, there might be a tiny effect, and it needs to be weighed up, but in the scheme of things, if it reduces burning carbon fuels, I think you'd have to be for it.

Could you integrate a water harvester such as a BRAE system with a geothermal well?

Lake systems work great, the closed loop must be at the correct depth to insure constant temperature.
To answer a readers comment regarding municipal water supplied geothermal use see our website at www.encoreenergyinc.com click on the DeMarco Energy Miser Geothermal video.

Regards, enjoy Brian Mello

I have put in a waterfurnace 3 ton envision my power bill was cut by 40.4% on the first month. there is no way that that was bad for the enviroment. Why do we think that we have the power to change the temperature of the planet anyway? God is oniponant it will last as long as he wants it to and there is nothing we can do to change that. He made you and I and he made the earth to withstand us. Hard to believe but it really is just that simple, when you come to know that you will have a peace and love in your heart like you have neaver known.

I recently bought a house on a lake that is fed by the wisconsin river, is there restrictions from the DNR to instal a geo system?

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Call the DNR District Office and ask if a permit is needed for construction within a waterway. Describe the length of time needed to lay the loop , the lineal feet of tube, and whether there would be any effect on navigation.

I recently bought a house on a lake that is fed by the wisconsin river, is there restrictions from the DNR to instal a geo system?

Municipal water piping is problematic due to generally inadequate volume and flow. With ponds and lakes, you can avoid the muck and algae problem by drilling 2 shallow wells on the shore. pull water from one well and discharge down the other. very effective, clean, and the mass of the earth handles thermal changes without affecting pond/lake water temp. Very little data available on pond heating and the math is iffy due to so many variables such as pond volume, evaporation rate, turbulence and wind speed (and other factors affecting evaporation), and conduction to the earth below the pond. Here is some empirical data to give you an idea of pond heating: a very small pond of 30,000 gallons reached an equilibrium temp of 124 degrees F. with 5 tons of cooling in august in central Texas. The moral is, you can't use a swimming pool. shallow ground water, or surface water is ideal and if the volume is large pond or lake, or the water if moving, the heating is not measurable a few feet from the exchanger.