Study finds Minnesota’s hot rock could generate electricity
March 28, 2012 at 7:00 pm in Duluth News Tribune
University of Minnesota Duluth researchers find that even frigid Minnesota has ample geothermal energy miles below ground. Continue Reading
Study finds Minnesota’s hot rock could generate electricity
34 Comments
Hidden due to low comment rating. Click here to see.
Poorly-rated. Like or Dislike:
11 
21
No it’s closer to 3.78 miles Hugh.
Like or Dislike:
14 
5
Hidden due to low comment rating. Click here to see.
Poorly-rated. Like or Dislike:
10 
22
the energy needed to send the heated water to the surface is pretty minimal really, circulating a closed system along with convection currents is pretty easy. it costs more to put the system online up front. once it is up and running, it’s a pretty cheap system to maintain, similar to hydropower.
Well-loved. Like or Dislike:
19 
4
Pumps capable of lifting water to a 20,000ft head height?
Like or Dislike:
4 
11
Heat rises Hugh. Water has low friction.
Like or Dislike:
10 
2
low friction? Friction does not even come into play.
Water is heavy, if you stack water on top of water it gets heavier.
Like or Dislike:
2 
5
But then I forgot about the closed loop, which essentially creates a vacuum which negates the weight of the water.
Add to that the one-way valves, and it does not require that much power.
Like or Dislike:
4 
0
It’s pretty clear that none of you guys have ever taken a fluids dynamics class. There is substantial line friction in a 20,000ft long pipe, and the difference in water density isn’t adequate to raise the water by itself. Go back to school, experts.
Like or Dislike:
1 
5
Hopefully this would work more like a lava lamp than like a volcano.
Like or Dislike:
6 
13
I can vouch for its effectiveness right here in Duluth. We heat and cool our home and heat our hot water with a geothermal system. We had it installed 3 years ago and when they dug they only went 8 feet deep. It was installed in early March and the frostline was not farther down than 3 feet. We have heated our home for about $600 a year which is basically the cost to run the heatpump and fan. We keep our home at 72 degrees winter and summer, the system also provides central air in the summer when it circulates cool water without compressing. Works fantastic!
Well-loved. Like or Dislike:
26 
3
What was the initial investment, KDF? I assume you have a forced air exchanger. I prefer radiant heat and wonder if your system could be hooked up to a radiant system. Central air would be nice, but isn’t really necessary if you are in sight of the lake. Also, what fluid temps are you getting at your exchanger?
Like or Dislike:
11 
1
How much steam does you system generate? 48 degree water is only marginally viable for on site home heating, but fails miserably if you plan on using it to generate electricity to be transmitted any distance. And while your fuel bill dropped, what happened to your electric bill.
Like or Dislike:
10 
13
In 200 years when we run out of oil and gas we’ve got that to fall back on.
Like or Dislike:
12 
13
200 years is wishful thinking at best, David.
Like or Dislike:
13 
8
Where do you get your info, David? Yemen is out of oil in about 10 years. Saudi? A few decades at best. Have you seen how much global consumption is rising due to the explosive economic growth of China and India? If we are within a few decades of running out don’t you think it is prudent to start pursuing other options?
Like or Dislike:
13 
3
First, we will never run out of oil.
It is not a matter of “running out” it is a matter of it becoming too expensive to extract.
Like or Dislike:
2 
5
The investment was 10K, that is after rebates ($15k before). We had forced air fuel oil and were spending approximately $200 to $500 per month for fuel in all but the warmest months. That was when fuel was about $3 a gallon. We had our heat at about 65-68 degrees, depending on season. Then you add the electricity needed to run the fan on the oil furnace.
With the Geothermal system we pay about $80 to $100 or so a month for electricity to run the Geothermal pump and fan. We are fully electric in our home, so once we put in the Geo it was very simple to calculate the increase in cost. This also heats our hot water. We DO use the air in summer, we live quite near the shore but as my husband works outside all summer..believe me, it is nice to only pay about $7- $10 a MONTH for central air. We do not generate steam, this is a heating system, not electrical generating. The temp coming in is about 47 degrees and out about 10 degrees less (I can’t remember exactly, this was tested a couple times after install to verify) This does work, we do not use the supplemental backup heat (an electric heater attached to the heatpump) except if it becomes extremely cold (in three years it came on one time) We estimated that we would have return on our investment in 5-7 years. It is not for everyone because of limitations of a persons lot, to keep cost down you have to have space to dig. Vertical drilling is more expensive. It required 3 trenches 120 feet long and 8 feet deep, but honestly…we couldn’t be happer. I do think they use it with radiant heat, but the install might be different. We had Summitt Mechanical install and I would recommend them in a minute. This is viable, it is economical, efficient, and clean. There is a LOT of information about the technical aspects online. If a person is interested, like we were, and is looking at lowering cost for the long run, this is a good system. We are not at the mercy of fluctuations in fuel pricing and we plan to be in our home for many years..which helps compound the savings.
Well-loved. Like or Dislike:
20 
2
A ground source heat pump isn’t the same thing as a geothermal steam system. It would take more electricty to try to raise the temperature of water with a heat pump hot enough to produce steam than the amount of electrical generation you could get back using that steam in a turbine.
Like or Dislike:
8 
3
I’ll have to ask the hubby about the temps in and out..I think the ones I referenced were when they installed. Which was cool as they had disturbed the soil when they dug in early march. Regardless, the system works for us!
Like or Dislike:
10 
1
Hidden due to low comment rating. Click here to see.
Poorly-rated. Like or Dislike:
6 
19
Hidden due to low comment rating. Click here to see.
Poorly-rated. Like or Dislike:
6 
18
Unless you were ignoring it, Hugh, she said they were heating with oil before they put this system in.
Like or Dislike:
11 
3
Aren’t you forgetting the rebates, Hugh? Also replacing the pump would be inexpensive. Once this system is drilled the operating and maintenance costs are low.
Like or Dislike:
8 
2
Why should somebody else pay to subsidize your system? Isn’t this what’s wrong with our society, that we all expect somebody else, AKA, the Govt to pay for things?
Like or Dislike:
1 
5
And we heat our hot water with it. It is very low maintenance. AND, The compressor? Guaranteed for FIFTY years. So, with $80 to $100 to heat home and water per month in the cold months, it was a wise replacement for our old and tired oil furnace. To each his own I guess. I would not bet on 200 years supply of oil. Now THAT is hype!
Like or Dislike:
14 
1
40 years from now we are going to be wondering how we could be so naive to not think that taking internal heat from the Earth might have an adverse effect on the core temperature.
It is just like any thing else in life. Moderation is key.
Wish we could just find a happy medium with energy production. A combination of all types of power generation. Almost every source of power is going to have its adverse effects. Mitigating the effect should be our primary goal, not gaining the most energy out of the smallest amount of work .
Like or Dislike:
0 
3
I think it’s just great that Hugh likes to bash anything that sounds like progress. Just to give you a little information Hugh; it’s the temperature difference that runs the system not the water turning any turbines.
Working fluid such as ammonia with a low boiling point is heated using the ground water and condensed using either cold air or water to return it to a workable form.
Just a question: did America become a super power by sitting back on our butts and using old technology, or by inventing and improving technology? Also Hugh, we are still going to need oil to lubricate things after we develop new technology so it might not be a good idea to run out before we start thinking about this stuff.
Like or Dislike:
5 
1
I’m not talking about a home based heat exchanger! Fosnacht was talking about using geothermal heat to generate electricity! READ THE ARTICLE!
Like or Dislike:
1 
5
Same basic idea Hugh. I know I’m not an expert on everything; maybe you should admit the same.
Like or Dislike:
5 
2
There is one big difference. To get the temperatures needed to generate electricity they are drilling through the earth’s crust into the mantle where as the article said the earth itself is around 250 degrees- well above water’s boiling point. A home ground source heat pump has a loop buried just a few feet below the frost line. The source of the heat pump’s heat is actually from the sun not from the earth itself. The ground temperature at that level is around the average annual air temperature at that location.
Like or Dislike:
2 
0
Hey everyone! Look! A SPAMMER!!!
Like or Dislike:
5 
2
whoops, it’s gone now.
Didn’t mean KDF, was a post in between hers and mine.
Like or Dislike:
1 
2
Not me either.
Like or Dislike:
0 
2