cc >> Cassie Immel: Good evening.
Thank you for watching tonight's
I'm Cassie Immel from here Wednesday Nite at the Lab.
For tonight's presentation, Dr. Dave Hart presents
"Tapping Geothermal Resources in Wisconsin: Energy from
the Earth for Heating and Cooling our Homes."
Dr. Dave Hart is a professor in the Department of Environmental
Sciences in the University
hydrogeologists and geophysicists for the Wisconsin
Geological and Natural
His current research and History Survey.
the hydraulic properties of midcontinental rift sediments to
determine their suitability for carbon sequestration, the
hydrogeology of the Cedarburg bog in eastern Wisconsin, and
the connectedness of sand bodies
Lake Oshkosh. He is within also interested inlacial
developing web applications to
features and provide information allow citizen input of Wisconsin
Wisconsin. He received on sites of geologic interest in
College in Iowa and his PhD from here at the UW.
Please help me in welcoming Dr. Dave Hart.
[APPLAUSE] >> Dave Hart:
Thanks for your applause here. Thank you, Cassie.
tour of geothermal resources in IWisconsin, and I changed thea
title a little bit from the less
And so geothermal, colorful one that I sent Tom.
Does that mean is it a resource that's viable for Wisconsin or
is it the frozen tundra and maybe we should put our energy
into different energy resources.
I'm asking. That's So that's kind of the question
tonight's talk. I'm Dave kind of framework for
Geological and Natural Hart with the Wisconsin
I want to acknowledge two collaborators/co-workers.
One is James Tinjum, and
They're both kind of the other Dante Fratta.
Department of Engineering in kitty-corner here in the
Department there. I'd also the Geological Engineering
Department of Energy. They like to acknowledge the
interested in geothermal kind of got me funded and
They provided a grant to the in Wisconsin.
Geologists. Wisconsin's Ameristate geologist cametate
to me and said, Dave, I strongly
in Wisconsin, and when the urge you to look at geothermal
asks me to do things and director, the state geologist
generally follow his lead. strongly urges me to do them, I
good things that are going to come out of this research here.
Also, the Wisconsin Water and Well Systems, we're going to
collaborate with this driller on some research hopefully.
And then two engineers from Affiliated Engineers Inc.,
they provided some of the slides that I'll be showing you
tonight and some of the information.
So geothermal energy is not new.
centuries, in fact. Here's We've been using this for
like to get to eventually: the one of those places I'd
Here's the great bath. This Romis the Roman part and thend.
they added this later on. This is, I think, from second
century AD or so. And then here's the original
spring that kind of bubbled up. It was a sacred spring, then the
king took over and
So we had rainwater fall made it his bath.
It percolates downward almost two miles or so, or so they
estimate. Picks up
surface. Now, it's heat and comes to the
It's only 115 degrees, not exactly hot.
imagine if you're in England, F115 degrees may feel kind ofI
nice on some of those foggy, cold day.
Just another example of geothermal, if you found an
archeologist that could do a
The hot springs at Thermopylae whole presentation on this.
where you could, I suppose, go which translates as hot gates
This is very close to where the Persians met their demise by the
Spartans too. But I guess it was a swamp at
that time and smelled like
it and turned it into sulfura tourist area now.ditched
Another slide, this is, you've
of monkeys discovered in the probably seen this, this troop
in Japan were kind of nice late '60s that these hot springs
So it's not just humans that places to go hang out.
springs; some other species have figured this out as well.
All right, I'm going to take
research, our understanding of, it's really kind of a history of
the Earth and it kind of tracks the way we think about science.
And I know you guys see a lot of
go with that. Some of scienthe early research,ind of
Robert Boyle, Boyle's Gas Law,
high school. And he, you may have heard of that from
of his books: "Provided a man descends low enough into the
bowels of the Earth, he will find it very hot."
And he wasn't just speaking from
knew this, which it's not just a religious perspective, he
thinks it gets hot. There thare other traditions butat
there are others that believe it
not be founded on geothermal gets cold, so that may or may
But this was an enobservation here too.s.
Then we have an Englishman, Robert Were Fox the Younger, in
1820, in a report to the Royal
and here's that. We have Geological Society of Cornwall,
mines. So he noticed it on the temperature of
were getting hot and in 1820 that these mines
Society, Geological Society, makes his report to the Royal
increase of temperature in that there is a progressive
the greatest depths descenhitherto examined.ace to
And he now begs to submit the result of further inquiries to
this society. And his results, and so here I
think is really the first example where someone has
calculated, put a number on,
when you go down. Here people have noticed it gets warm
calculated how warm weit gets with depth.o's
And so he looks at Professor
surface temperature is 53 degrees Fahrenheit, and finds
out as he goes down in the mine it gets 6 degrees warmer for
every 300 feet. And if we look at the
temperature increase with depth,
two degrees per hundred feet I'll just divide it, that means
degrees. And that's of depta pretty decentm up two
number. We see numbers
Wisconsin, as I'll show later. like that around
math, you start at 50 degrees and you go 5,000 feet, about a
mile down, you can do 5,000 times 2, divided by 100.
So we have 10,000 divided by
So at a mile, we'd 100 gets us to 100 degrees.
Two miles, 250 degrees. And so right there that's
kind of a powerful thing. We'd know if we brought that
water up to the surface, if we
down, it would boil could at the surface. miles
It would be that hot. And so maybe we could use that
to run turbines or something. Some more early research kind of
just tracking along. In 1867, the British Association
for the Advancement of
And the purpose of this committee was to investigate the
rate of increase of underground temperatures downward in various
localities of dry land and underwater.
And I've captured the capitalization that they used at
that time. I'm not
used, but it must surbe for emphasis.hey
And what they're looking for
understand, they're looking at there is they're trying to
They're finally making the mines working conditions in mines.
little bit hot for the deep enough that it's getting a
We have this impression you go workers to work down there.
Well, that's because we're in a cave and it's 50 degrees.
If we keep going down, it's ngoing to start to become
uncomfortable. We could use that number that
Robert Fox calculated earlier,
down a thousand feet, it's going and we could go, yeah, we go
We're not going to to get pretty uncomfortable.
And so this committee wanted want to be there.
changing. And so to understand how things were
temperature measurements in wells.
And so you can imagine, if you
thermometer, just a regular hamercury thermometer, and it a
takes you five minutes to lower it to the bottom of your well,
you have to pull it back up,
right temperature. So ythis committee also drovee
some science. It drove
thermometer, and that's a kind the maximum temperature
little bit older, you'd get the thermometer in your mouth and
you'd have to shake it? That
thermometer. And that wawas actually, it seemse
to me, invented by a German, I
these measurements. He can't recall his name, to make
well, and then he woulcould pull it up.n the
He didn't have to pull it up
measurement. So this really quickly to try to get the
technology. And so the actually drove some
a well and you just take a idea here is you have
and then we can look at how the temperature here increases with
depth, and we can just see it going up and up and up and up.
And that would be the two degrees per hundred foot or so
that we saw earlier. And
Stewart Herschel still then we have Alexander
He was the grandson of the moving forward in time.
made all of the telescopes and astronomer, the Herschel who
And what he did, this grandson discovered all of the galaxies.
measured how well the of rocks conduct heat. he
He develop an apparatus to
conduct heat better than others, measure, some rocks are going to
well it conducts heat. And and let's put a number on how
flow, if we know the temperature so we can actually get heat
this thermal conductivity, change with depth and we get
Any large temperature wchange, more heat flow.t.
That makes sense. Larger
flow. That makes sense.
This law just kind
And then also, I think this GA Labour was his laboratory
helper, and apparently if he had
inventions or improvements patented one-hundredth of the
contriving for others, he would have been a rich man indeed.
So he just cared
He just wanted to ado his science.e.
And here's his apparatus. You have a sample here.
He had steam come in one end. He had water come in around the
other. And so you have hot and cold,
and then you've got heat flow.
around the sampler bar, it And then, as this water went
he knew how much heat it took to picked up the heat and because
he could figure out how much raise water one-degree Celsius,
side because he could measure the temperature being picked up
by this coil here and then he could measure the conductivity
of his rock. And now we're ready
for Lord Kelvin. And
physicist, and geologists love to remind physicists
that Lord Kelvin was wrong
And he was telling all the about the age of the Earth.
math, you guys are challenged, geologists, you guys don't know
no, no, the ocean's too salty, and the geologists were like,
did these rocks get here in the time we want, but Lord Kelvin
did some calculations using those gradients that were
measured by the committee, using
Herschel, we can calculate the conductivities measured by
And if we do that, we get about, the average heat flow.
pretty good number. 68 or they did that and they got a
So like this by that by mithat. You're going to getd.
68 milliwatts. So if we have a thousand square
meters, we're going to get 68 watts.
And so he's going to use this to
And so the idea is the Earth calculate the age of the Earth.
some hot temperature you have a sreally high heat flow, and atat
later times the heat flow is going to decrease.
And so if we plug in that number, 68.4, on this curve,
so here's heat flow as a
this and then he says, function of time, we plug in
100 million years old. And ah-ha, the Earth is around
the age of the Earth. And RJ he has a nice estimate for
where he says basically what was Lilly has a nice book out
was a hot potato. So you done was they assumed the Earth
the oven. In about take your potato out of
hot to touch. You let it cool.
After about 15 minutes and
Here's the Earth just it'sout of the oven.ure.
It's cooling and then you can calculate the temperature after
a hundred million years. And
calculate the Earth. so that's what was done to
the Earth is about 4.5 billion However, we know now that
was the heat of years oradioactive decay.issing
And there are three radioactive elements that are in the crust.
You'll find them in most every
Some rocks more than others. rock in low quantities.
And they've been around Potasince the Earth formed.rium.
They're still around today. And you can see some rocks have
more potassium, uranium,
For instance, granite and rhyolites, granite's a pretty
common rock, have about 2.95
So this by this by this is going microwatts per cubic meter.
That's not much. You need to a huge, huge volume ifts.
you want to even get a watt. A
meters is going to maybe get you football field by a hundred
this being produced. And several watts, maybe 10 watts of
continental crust. Basalt and gabbro, which is a
rock that we find in the oceanic
that you see erupting in Hawaii. crust, this would be the rock
microwatt per cubic meter. And That only would give you half a
this rock is going to make up most of the mantel here, has
hardly any but
And so here's the numbers that you come up with.
And so Lilly says you're
in the microwave. It's actually more like a hot potato
the inside by that radioactive getting heat heated from
conducting outward. And so decay, and there's heat
our heat flow working with what we know about the age of the
Earth. So the heat
geothermal increase with that we see, the
radioactivity in the crust from potassium, uranium, and thorium
and the heat flow from heat of
formed. Both of those formatthings are working first
together to give
And here's just a present day measurement of what we see in
the continental US. Blue is 25 milliwatts per square
meter, and red is 100 milliwatts per square meter.
And you can see we've got lots
The reddest part, or just about the reddest part, is
Yellowstone. That's sitting over a hotspot, a
lot like Hawaii where things
And then you can see over here are really coming up there.
and green here. So maybe in Wisconsin, we're kind of cold
tundra. We'll get wback to this map
later. I have a few quibbles with this
map, and we'll get back to it.
east, it's cooler; But you can see, moving to the
All right, now I'm going to switch into more talking
about the technology. More
use, talking about talking about our energy
And this, Jim Tinjum put this in our technology.
and it's what if it's a big hoax a talk, I couldn't resist it,
nothing. You can also and wetake the other siderld for
of that and say maybe we want to
actually a step forward makand not a step backward.is
But anyway, I like that cartoon.
sector in 2009, and the two Herthings that geothermal can by
probably speak to, the two
heating and cooling commercial sectors are the commercial,
cooling our homes, buildings, and heating and
So that's about 45% to half of our energy needs are those
two sectors. Maybe
that heating and cooling. I should also point out that
here in Wisconsin we import all of our energy except that which
we make through the power plants.
The uranium is maybe not the
power plants. But we biggest part of the nuclear
energy, and so anything we can import almost all of our
means more dollars that do to stay in Wisconsin.icient
So I think there's a good economic reason to take some of
this energy discussion to heart.
sources in 2009. You can Here's our electrical energy
we generate electricity see is through coal.how
Some natural gas, that would
They just put in the new, thank you, that would be the
Co-Gen plant here on campus.
doing most of the But work here in Madison.bably
Nuclear accounts for 20%. Hydroelectric a little bit, and
then renewables also
And that would include just a little bit.
Here's energy use closer to home.
In fact, it is my home. And we can see last year I spent
$1,600 on electricity and gas.
MG&E for a house my size, this And when I went and looked on
low. But we spend is typia fair amount oftle bit
our dollars on heating and
appliances. It's not cooling our homes, running our
cost. Here's US energy consumption by
energy source. Fossil fuels are 83% of our
current energy sources. Renewable energy is 7%.
A lot of that is biomass. So
wood burning, maybe that'the corn burning.anol,
Geothermal is a tiny little piece of that right now.
Hydroelectric is larger.
Where's nuclear? There's Solar and wind.
8% as well too. One thing nthat, there's no freeut
lunch in nature. Nature always, we like to say in
geology that Mother Nature
And kind of a corollary of that is all energy sources have
impacts. Whether or not it's oil spills,
whether or not it's people not
cluttered with windmills, wanwhether or not it's thezon
manufacturing process of
sources have impacts, and we photovoltaics, all energy
We need to understand those nimpacts and really be careful.
about, think about them and take
developing them. And some thare going to have worse're
impacts than others. Some are going to have impacts
that are farther away, not in my backyard, or in my backyard.
So those are all
US renewable energy technologies, you can see
biomass has grown quite a bit.
ethanol. Wind has That's really taken off. that's
Geothermal has held pretty
consta half. Solar as well. and
So when we look at sustainable
conservation with heat pumps energy, we can look at energy
energy with the geothermal. Now we're going to go to the,
I've kind of split geothermal into five different types.
The heat pump; the ground source or geoexchange; enhanced
geothermal systems, also known
you just take the hot water out of the ground and then you use
it to heat your buildings, you
just pump it around; don't do anything to it, you
electricity; and then co-produced fluids, hot water
produced during petroleum extraction to generate
electricity. So co-produced fluids, if you
remember on the map of heat flow
Texas and Louisiana, Arkansas, in the US, if you look down in
orange to it. A lot of they had a little bit of red and
oil fields. And when that corresponds to the
think it's like one barrel of oil you get 10 gallons of water.
That water is warm, and perhaps you can use, it's a byproduct.
They don't want it. What
it? They re-inject are they going to do with
but it might be hot enough it lots of times,
It's maybe not going to drive a turbine, but you can maybe use
it with a binary cycle generator
exchange it with some fluid that where you pump it up, you heat
water, and rather than just injecting this hot, briny, not
very useful water back into the ground, we can create
electricity with it. And
projects going with that. Hydrothermal, this has been in
use for a long time. First
Geysers in California, the used in Italy 1904.
cooling towers in geysers. plant, here's some of the
And just so comparison, MG&E Generates 725 megawatts.
190 megawatts, those big down on Blount Street generates
And so this you just take the hot water out of the steam out
of the ground, runs a turbine and then you reinject it.
So a really nice, simple way to go.
You have to be careful because
much water and inject you dtoo much cold water.t too
You can kind of kill off your fuel by sucking the heat up too
fast. So they need
And then also direct use. This is hot water.
You just pump it
If you live in one of those parts of the US where things are
red, you can probably heat a building.
The Idaho state capitol is heated this way.
A lot of the buildings in downtown Boise are heated this
way. There's a great
about bringing it, of snow photo, I thought
completely melted. They evejust use this geothermal's
direct use to keep their
It would be kind of sidewaa nice way to go.e-free.
I don't think we're going to
Wisconsin. The enhance be able to do that here in
of made the news in the last couple years or so.
This one intrigues me because we
a small footprint. Just a canregular power plant sizedwith
thing. And it can operate any time.
We can locate it anywhere as
deep enough. I want you long ato note what I sayilled
when I mean drill deep enough.
That's a problem. We don't Two to six miles deep.
deep economically. It's prohibitively expensive to
drill. You can imagine, currently you
need to replace you bits if you drilled down a mile and you have
to pull all of that drill rod,
maybe do it in 40-foot sections, it usually comes, you could
those big derricks. It's maybe 80-foot if you have one of
a couple days to pull all the drill rod, put a new bit back
on, go back down, drill for a day, and so the deeper you go,
the more bits you're going
You're going to be drilling in to have to replace.
like that, and the drilling gcosts are prohibitive at thisk
time. Here's the
the news. In Switzerland other one that made
closed a pilot plant down because, and this is the
geophysicist in me coming out,
disquieting earthquakes. some pilot plants caused
uncomfortable. They were So they made people
four, which would hurt this building if it happened, but we
would all be quite disturbed
So three and four generally don't cause damage, but they
make everybody uncomfortable. So those are some issues with
enhanced geothermal. And
sourced heat pumps. These just exchange heat between
the ground and a building, and
reverse or a refrigerator when it's just like a refrigerator in
You can either pull heat out you want to cool your house.
house, or vice versa. It of the ground, put it in your
just moves it from one doesn't generate energy, it
And it can function anywhere. All right, so let's run down our
options for Wisconsin. What can we viably do here?
Heat pump, definitely. We're
think nationwide it's a 10% growth for geothermal systems.
I know lots of well drillers
called somebody's son well in Wisconsin, they used to be
Ground Source Well Drilling. So a lot of these well drillers
are switching over from drilling
geothermal wells. It's water wells to drilling
So heat pump, it's viable. a growth industry.
Enhanced geothermal systems, It works in Wisconsin.
the drilling costs. And in maybe but we've got to reduce
very many earthquakes, so maybe we could do the enhanced
geothermal here and not make people uncomfortable.
Direct use, I doubt we do that. Temperatures are unlikely to be
hot enough and we'd put in a heat pump.
Hydrothermal, no. We don't
Wisconsin. We have a have any hot springs in
of 10,000 springs, not database at the survey
They're all nice, cool, clean places trout would like to live
not other things. And co-produced fluids, no.
There's no petroleum
Our survey would be three times as big as it is if we had
petroleum. Not that people haven't looked.
In kind of working on this
looked for really deeps wells in project, I've run across, I've
measure the temperatures, and there's still one if you go west
to Arena down in the Wisconsin
that someone drilled to look for River Valley there's a test well
2500 feet deep, and the bottom, I think it's like 1,800 feet of
that or 2,000 feet of that is through granite.
So please, if someone offers
drilling company and you hit you the chance to get into a
stop the rig. These grapeople kept going through to
several thousand
Similar story over in Sheboygan where there's a 4,500-foot well,
and it's at least a couple
That well, we'll be able thousand feet of granite.
The one in Sheboygan has been filled up and it may be lost and
no one knows where it is
test that well. I think anyit would have use as a to
geothermal well. The
granite has no use several thousand feet of
When you hit the granite, that's when you stop looking.
We know that now. Geothermal heat pumps.
So let's talk about the geothermal heat pumps, how they
might work in Wisconsin. So you have your building, you
have stable ground where water
condenser, your tempecoils, in the dirt.t your
You can put them in rock. You can put them in a pond.
You can do all sorts of different things with them.
You just need a stable water
to control the where water temperature is used
That's actually what we have building temperatures.
Wisconsin Center there. So a just across the way at the
trench two to three meters deep. horizontal loop, you dig a
I'm not going to be able It zig-zags back and forth.
My neighbors would not be pleased with the backhoe in
there. And then you put high density
pipe in the trench. You fill it back with soil.
This is what people do
You can do a vertical loop where out in the country.
actually I have a neighbor you drill several wells, and
installed on of these systems in several blocks away who
energy in Madison. And you his home and is using geothermal
you put your pipe down just drill a bore hole,
You can use the Earth to and you circulate there.
So the heating cycle is you have store and remove the energy.
you're going to heat you put your heat pump here, and if
heat out of the ground, you cincrease the temperature withe
your heat pump, and then you
exchanger, and you can run that to a blower or a heat
You can also use it to help heat heat your house with that.
well too. Cooling your hocycles, just the bit as
opposite. So rather than take the heat out
as we'd be doing this time of year, in the summer you put the
heat in. So it really balances out nicely
for places farther south. Here
heating than we do cooling. inSo if you're in southerne
Illinois, this works really,
have more balance. All the really well because then you
winter out of the Earth when you heat you take out in the
that back in in the summer heat your home, you can put all
So you can get things to as you're cooling your home.
need to be a little bit careful bwhen we're installing systemse
because we keep taking heat out and putting it into our house,
and we can end up cooling off our field, and what that means,
when we cool off our field is that efficiency of our heat pump
goes down and we have to put
So that's one of the things that we need to be a little bit.
careful with. I have a question.
What's the price tag on one of these babies?
Price tag? It depends.
Let me give you a range, though.
so let's say we're going to heat It depends if you want to heat,
feet. So if I just my house kind of 1500 square
of an auxiliary heating and maybe a quarter and I had room
for a trench, maybe $8,000. If I wanted to do everything
100% and I'm going to have
looking at $32,000. to dSo there's a range.ht be
We'll get to that in a little bit.
That's a great question, though.
well too. So here's That inthe unit, the heathere as
pump, an exchanger. It's
is really all it is. Here's abjust some photos of somee
people putting in the ground
holes. Here's some well drillers
looking like well drillers. There's a trench excavated.
Here you can see some of the
If you have a lot of wells, it tubes that come out the top.
these tubes going can getback and forth.ated all
Here's kind of the process. You drill, you put in your pipe
loop going down, comes back up, you fuse it, you make sure it
doesn't leak, you make sure the loops are ready for the unit,
and then you install
Very often these loops don't use your heat pump.
the heat, carry the heat. watThey use antifreeze so itmit
doesn't freeze and
And there are some crack your system.
If the system leaks is that antifreeze going to cause
problems, is it going to cause trouble?
And that's something we need to be thinking about.
So just some facts about
We could save 2.15 geothermal heat pumps.
if 100,000 homes did this. In my 25% to 50% savings on my
utility bill, if I put in that
maybe save $800 a year. And slet's do the math, it may or
may not work out for me if I'm
long time. It's going goingto be really closefor a
for me, and that 25% to 50% also
Is it more expensive heating oil depends where I get my fuel.
gas? The energy or isconsumption emissionstural
40% less than air source heat pumps.
That's central air
Because I'm not exchanging that heat, I'm not blasting that heat
into the hot air, I'm blasting
And 70% less in electric. Resistance heating efficiency.
more efficient than air source
gas furnaces. And heat pthat's even the 95%t than
efficient gas furnace, 75% more efficient than oil furnaces.
Penn, in 2000, did a study of emissions and economic analysis
of ground source heat pumps in Wisconsin.
And he looked at, he did this for, I think, Green Bay,
Madison, and then some place
but I'm just showing farther north than Green Bay,
For a large school, 390,000 square feet, energy in costs
savings. So what's
savings? That's an increase.
So a negative number
Sorry about that, but that's the means in increase here.
So negative means we're going to use more electricity for the
large school, but we're going to
We're not going to save all of this natural gas.
And our yearly annual energy burn that natural gas.
if we decide to heat savings are going to be $33,000
And our payback time is 10 and a half years.
So for a large system, something
kind of makes sense. And big like a school, it really
made is these systems have a one of the other points he
boilers that you can use, and that has value as well too.
So you can think about that.
going to be a little bit more Iefficient on the electricalre
side. And that
that's not a typo. We're number's not negative,
efficient because offices agenerally have more aire
conditioning than homes or schools.
I know my office temperature is cranked way lower than it is at
my home in the summertime for the air conditioning.
Natural gas will save about 10,000 therms and annual energy
savings $6,000, It's going to take a long time, 21 years to
pay back this. Home,
home, I'm going to save on this is similar to my
more electricity, I'm going to electricity or I'm going to use
only going to save about $70, according to their analysis, per
year, and it's going to take 26 years in Madison.
Yeah? >> So this is in terms of
dollars. >> Yeah.
When you're talking about natural gas you're not factoring
in what electricity might be
Yeah, I know. How big are usedwe going to draw thegas.
circle. That's a good point.
I mean, if you think
[INAUDIBLE] Yeah, right, of it globally.
of things associated with natural gas production as well,
too. Yeah, that's right.
Let's expand on that. So
right now the energy that produces our electricity is from
coal. So if we can
use, we're going to end up eliminate that coal
actually, sometimes switching in Madison to more electricity
results in higher emissions because of our electrical source
in Madison is coal. So if we could switch to Co-Gen
plant produced electricity or the wind generated produced
electricity, this number, our emissions would go way down,
we'd be a lot better off, and that would be something I hope
we eventually look at doing.
is a tough topic. One Thother thing to point out,rgy
though, is if you live out in the country and you use propane
to heat rather than natural gas,
in eight years rather than in 26 that higher cost you may recoup
So it may make more sense if that you would have in Madison.
What prices were used for you electricity and gas?try.
I would have to reference you to this study by Penn.
It would have been like the 2000 or '99 cost in Madison.
They used those. Natural
held steady because of gas has come down or has
It's a lot more abundant now. All these things are, the
interplay is, I think I probably
highly variable and dependent puon electric and gas costs.e
It's really tough to say. So, again, eight to 26 years.
Take your pick. But you're probably going to
come out ahead in 26 years. Now just look at some examples
around the Madison area.
Discovery, just across the The Wisconsin Institute of
geothermal well locations, way, those red dots are the
Here's another plot of it. the proposed ones.
of Discovery, and here there's Here's the Wisconsin Institute
the remainder here. They're 75 weall 300 feet deep, and then
they're at 20-foot spacing. 300 tons of heat pump capacity.
What is a ton? If you talk to a refrigeration
person they'll start talking in tons rather than kilowatts, and
a ton is the amount of energy needed to turn a ton of water
that's at 32 degrees
It comes from the old refrigeration days..
So when they talk about a ton,
or five tons, that's a lot of energy to turn four or five tons
of water into ice when
And here it's kilowatts, 14 to 18 kilowatts per well.
So when the engineers went out
doing due diligence here. They and tested the wells, they were
and said we can get four to five went out and tested a well
energy per well in one tons, 14 to 18 kilowatts of
Unfortunately, the system is location. So they tested it.
tons or seven to nine cominkilowatts per well.y two
So that heat pump that's
heat out of the ground, is circulating, that's taking the
they had anticipated. So having to work way harder than
below what the design was because there's not as much heat
coming out of the ground that the design had hinted at.
And so they think it might
The First Unitarian meeting bhouse in Madison has 16w.
geothermal wells they use. Epic Systems in Verona, this is
a huge system. They have 500 borings.
Each one is 300 feet below
energy reduction. So ground, and they've seen a 40%
facilities, it's making a ton of sense for them to use
geothermal. I do know the drilling out there
has been difficult. I know
carbonate, it's a limestone so that dolomite, it's a
maybe caves even, so when ithey're drilling they'll bes,
drilling and all the sudden they'll be in air or water.
So it's kind of hard and painful.
It's not easy for them to drill there as well either.
But it's been working for them. Here's an example, there's the
pipe that goes down, carries
And I should say they don't just the warm fluid back out.
also put a grout in so that there's a seal between the Earth
and the pipe so things aren't going to run into the ground.
And you can see here they are sticking up out of the ground.
And here's some more of the field that's looking off.
That's probably 151 right there, Highway 151.
And here's the collector system.
into a manifold. They all Allget connected and theyome
run to really big pumps, and
pumps that then heat the then they run to really big heat
Verona. So industry challenges.
Heat pump stuff has high first costs.
It's expensive with no
It's more expensive than guarantees of performance.
I think if we pay more attention your boilers and chillers.
going to say this, we can probably get better guarantees
at performance. If we start looking at what the
geology is, we can start to say better this is how many tons of
energy you can get
And that's one thing that I'm very interested in doing.
Uncertainties, variable fuel composition.
Again, geology. And seasonal underground water
flow. Hydrogeology.
And grouting materials. That's some engineering.
So I think there's room in
engineering has worked out. I tthink we need to be smarternd
about what we're doing
and we can come up with better, undmore efficient systems.gy,
And so now I'm going to kind of segue into the last piece is the
current geothermal research that we're doing here.
And just some basic information.
information for these systems. I We want to find basic
depth. What is the want to get temperatures with
gradient in Wisconsin? actual geothermal
efficiency? The hotter Can we improve heat pump
more efficient the system. water coming in, the
does that make more sense than five 200-foot wells?,
We're going deeper and we should
heat pump. Maybe that have will pay off to do itto our
that way. And then, also,
this is my enhanced geothermal pie in the sky.
Wisconsin produces
How deep do we need to drill its own electricity.
where we could use to befogenerate electricity?ures
And then heat flow. Will
because we're pulling thout all the heat?off
And is there enough energy to be
So here we're back at this map, and my quibble with this map is
they use three points to draw those contours around Wisconsin.
That's not really enough points for me.
I wish we had more. So
The geothermal gradients in Wisconsin, we're the coldest.
Come on, I just don't hardly believe that.
We can do better. So
remember, I forget his name right now, where Fox got
two degrees per hundred feet, they're saying we only have
.7 degrees per hundred feet.
have almost four degrees And the hotspots out here
So I was just wondering about that.
Are we really that cold?
two points in Wisconsin Thand one in Illinois.on
So there we really
And we have rocks with high heat have to be suspect.
granites that we know have high pradioactive heat production.
They should produce more heat.
temperatures. So let's So I was expecting higher
have. And here's look at the data we
The people who made the map didn't have access to this.
We just pulled it together in this project.
And you can see we go from .6 is the blue
to 2.5 is the red.
and I need to figure out what the scatter is, but I'm thinking
we're more in the 1.5.
We're doing a little bit We're out of the .7 range.
We probably have 1.5 or 1.4 bedegrees per hundred feet.ap.
We may even have two or three.
get a lot more heat out of the And that may mean that we can
So I would say that grounmap's a little low.deep.
And then if we look at how
with depth, there's geologa couple things.atures
The type of lithology insulates the underlying rock.
Sandstone is a good insulator.
as well. Granite Heat doesn't travel through it
insulator. Here's isome sandstone.n
Here's some granite.
groundwater moving from one aquifer down your well to
another one, that makes the heat
those measurements. And flothen heat produced in thetake
rocks. The granites have more heat;
sandstones, less heat. Here's is what we might expect.
A higher gradient across our
have gradient down insulator then we're going to
And so where we're going to collect additional data?
We're going to look in granites in central Wisconsin that are
going to have higher
going to look in granites raunderneath the sandstone.re
So this part of Wisconsin has lots of granites.
This part does too but this beige here is sandstone on top
of the granite. So we're
that sandstone that's acting going to drill through
get higher temperatures. So lithat sedimentary cover willcan
insulate the underlying granite.
well and this well in the next And we're going to drill this
thousand-foot well. We month or so, I'm thinking, a
here, and I'm just showing those drilled a series of three
granites. And here in Marathon County in the
site. This was we're out at the field
of a granite quarry ajust west of Wausau.m
And every time I wanted to do work in this quarry we would get
a half a foot or a foot of snow.
Caliber. And so every And time I wanted to goodge
down into this quarry, I always wondered if my Dodge Caliber was
going to make it back up the
snow-covered, and I wasn't sure it was going to make it out.
The driller had a plow in front of his pickup so here he
scraped it off for me. But
of working in a low spot, you're this is one of the pitfalls
get out. And so neverhere's the drill rigg to
drilling the thousand-foot well.
He just plowed through It took him only three days.
Here's some of the cuttings, the it. It went fast.
the top of the well grounas they drilled it.s out
And here's some of the results
Here we've got the depth. They from those three wells.
And then here's the temperature. were all 1,000 feet deep.
down here just to I put tget a sense of it.valent
And you can see they are all
They all are really high, and then they have a low spot here,
and then they come back up
And what I'm interpreting is in terms of temperature.
these in the fall so I think the these things right here, I took
the summer. So you can rock was still warmed up from
hot, cold. The shallow imagine hot, cold,
went out and measured this in the spring, this is probably
going to be down to zero
So this part of the record is going to get cold and hot, cold
and hot depending on
But as we go deeper, it's going to take longer for that
temperature record
And so I don't know what's going to go down and in.
temperatures here. It ocould be groundwater flowm
through cracks that are warming things up.
It could be global
Our climate could be getting climate change.
of that in this temperature log. warmer and we're seeing a record
it's pretty commonly seen. Or Pit could be clearing of thed
land surface in a hundred years.
cool. You strip it The foliage kind of kept things
those rocks heat up as well too. away in a quarry,
years. So I'm not The qsure which of these40-50
three things it is, but something's going on strange.
And then, when I did my deep
guys are right. It gradient, oh, gosh, maybe those
Fahrenheit per hundred feet. But was only .8 degrees
without the overlying that's isandstones.isconsin
And then I looked at the
production, how radioactive relathose rocks were.heat
So here's the heat production,
This is the kind of rock that we'd expect in Wisconsin,
similar to eastern US. It's a lot of granites without a
lot of cover on it. And I get something down here.
I expected more heat flow and hotter temperatures, and we're
not getting that and
It's a nice scientific question but I would have rather had the
other question where it's way hotter than I expected and we're
getting too hot of temperatures.
research. And so the But, anyway, that's a topic for
going to do is we're going to install one of those deep wells,
and we're going to see if we
thousand-foot well than what can get more heat out of a
series of shallow several they thundred feet wells.ch is a
And by doing that we can
antifreeze. Water maybeis easier to pump.than
Your pumping costs aren't as
or more heat with it. So we're high, and it can carry as much
This is the dish system, going to test this out.
Wisconsin Well & Water Systems. We're going to instrument it,
we'll do all the engineering
We have applied for a grant to and check it out.
at this system and see fund a graduate student to look
Maybe we can be more efficient. And so here's Dr. Tinjum and
myself and a couple of grad students.
And so I'll see if you
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