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Volcano power plan gets U.S. go-ahead

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October 31, 2012

A plan to tap the thermal energy of the Newberry Volcano is under way (Photo: Joshua Schre...

A plan to tap the thermal energy of the Newberry Volcano is under way (Photo: Joshua Schreiner)

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Having successfully negotiated the challenging regulatory slopes of the U.S. Bureau of Land Management, the U.S. Forest Service, the U.S. Department of Energy, and a host of Oregon state agencies, the Newberry Enhanced Geothermal Systems (EGS) demonstration project is in the process of creating a new geothermal reservoir in central Oregon. The core of the new reservoir is a two mile (3.2 km) deep well drilled about four miles (6.3 km) from the center of Newberry Volcano. The rock surrounding the wellbore reaches temperatures in the order of 600° F (315° C), and is nearly impermeable to water. That, however, is about to change.

Newberry Volcano is one of the largest and youngest volcanoes in the United States. Having last erupted about 1,300 years ago, it consists of over 400 individual volcanic vents, which, when combined, form a broad mounded landform referred to as a shield volcano. The Newberry EGS Demonstration geothermal reservoir is being formed in the high-temperature, low-permeability deep lava of the volcano's northwest flank.

The Newberry EGS demonstration project is located near the boundaries of the Newberry Nati...
The Newberry EGS demonstration project is located near the boundaries of the Newberry National Volcanic Monument

The Newberry EGS demonstration is the largest project funded to date by the DOE Geothermal Technologies Program. The DOE has granted over US$20 million to the project, an amount being matched by a partnership between AltaRock Energy and Davenport Newberry.

Artist's impression of an EGS electric power plant. Cold water is pumped down the left wel...
Artist's impression of an EGS electric power plant. Cold water is pumped down the left well, heated in the hot rock fractures of the reservoir, then returned to the surface by the production wells to supply the power plant (Image: DOE)

The goal of EGS is to produce electricity by extracting energy from the earth’s heat. To accomplish this, a subsurface system of fractures is formed in hot, impermeable rock, and water pumped down from the surface is circulated through these fractures and returned to the surface as the energy source for a geothermal power plant.

The starting point for creating a new geothermal reservoir is a deep well into hot, dry rock. Well NWG 55-29, drilled by Davenport Newberry in 2008, is well suited as the foundation for a geothermal reservoir. It is 10,060 feet (3066 m) deep into hot rock with very low water permeability.

Preexisting cracks in the deep rock are expanded by hydroshearing. The original, essential...
Preexisting cracks in the deep rock are expanded by hydroshearing. The original, essentially closed crack appears at the left. In the center, the crack is opened by water pressure, whereupon the faces slip a bit along the length of the crack. When the water is removed, the crack faces no longer match, so the crack remains permeable to the flow of water

Creating an EGS reservoir requires improving the natural permeability of the hot rock at depth. The process chosen by the Newberry EGS project is called stimulation, in which the natural permeability of deep rock is improved by causing small slips to occur in existing cracks, thereby opening a network of small cracks already present in the rock. This hydroshearing process differs significantly from the hydraulic fracturing used in oil and gas recovery – only enough pressure (about 1600 psi, or 10.9 MPa) is applied to open existing cracks, but not nearly enough (over 5000 psi, or 34 MPa) to form new cracks. In addition, hydroshearing uses only water: the chemical additives used in fracking are not required.

NWG 55-29 has a well casing to a depth of 6,462 feet (1,970 m), after which the well is open to the surrounding rock. This structure is important for the formation of an effective geothermal reservoir. If part of the network of cracks is formed at too shallow a depth, the surrounding rock will be cold, and the production wells will deliver a mix of hot and cold water, resulting in less effective extraction of energy and more complex power plant designs which are able to work at lower temperatures. With the casing, fracture networks will be formed for NWG 55-29 only below the lowest point of the well casing, at a depth where the surrounding rock is very hot indeed.

There is a problem that appears when creating a very deep geothermal reservoir. It takes less pressure to expand cracks at a depth of 7000 feet (2134 m) than it does at 10,000 feet (3,048 m), owing to the additional weight of the covering rock. Accordingly, the more you pump at pressure, the more crack network you open at 7000 feet, but you will never open substantially deeper cracks – the 7000 foot crack network acts as a pressure safety valve protecting the deeper rock.

The Newberry EGS project will involve three stages of stimulation, or crack network expans...
The Newberry EGS project will involve three stages of stimulation, or crack network expansion, at different depths to effectively use the power of the hot volcanic rock

AltaRock has developed a clever solution for this problem. Thermo-degradable Zonal Isolation Materials (TZIM) represents an important technological advancement in the development of EGS. TZIM is a biodegradable, non-toxic gel-like material. Mixed with the water being injected into well being converted into a geothermal reservoir during the hydroshearing process, the TZIM material seals the newly expanded crack network when the water is removed. A shield is thus formed around the wellbore so deeper fracture networks can be added to the reservoir. After the desired fracture networks are formed, the seals biodegrade to open the crack networks of the new reservoir. Simulation studies suggest that a series of three fracture networks will be suitable for the Newberry EGS project.

On October 18 the pumping equipment was running and a water pressure of 1600 psi (10.9 MPa) was built up inside NWG 55-29. The diagnostics (pumping rate, microseismic detectors, etc.) indicated that hydroshearing and expansion of a network of cracks in the hot rock had begun. However, an unexpected night of freezing weather on October 20 damaged some of the auxiliary equipment, leading to a temporary shutdown of operations. AltaRock hopes to resume testing the stimulation process later this week. The following video gives a very good (if slightly lengthy) description of the project.

Source: AltaRock Energy

About the Author
Brian Dodson From an early age Brian wanted to become a scientist. He did, earning a Ph.D. in physics and embarking on an R&D career which has recently broken the 40th anniversary. What he didn't expect was that along the way he would become a patent agent, a rocket scientist, a gourmet cook, a biotech entrepreneur, an opera tenor and a science writer.   All articles by Brian Dodson
28 Comments

Now that's using your noodle! I love seeing these kinds of projects gaining traction.

Pete Kratsch
31st October, 2012 @ 02:07 pm PDT

I'm so glad they successfully negotiated the challenging regulatory slopes of the U.S. Bureau of Land Management.

Christian Dillon
31st October, 2012 @ 05:18 pm PDT

Strange that they use steam turbines. Sterling cycle engines could use the heat without having to separate the steam from liquid water.

Pikeman
31st October, 2012 @ 05:30 pm PDT

Getting energy out of the ground like this is smart. Apposed to fracking, typically a mix of water, sand, and chemicals, including ones known to cause cancer injected underground at high pressure to fracture the rock surrounding an oil or gas well, which is completely stupid.

The Hoff
31st October, 2012 @ 05:52 pm PDT

I'm curious as to why they can't just produce tunnels that withstand the pressure down to a distance of which the temperature can instantly boil / steam water ... then just let steam rise up turn turbines, hit a "roof" turn to water and run-off back down the tunnel?

this would require no pumping to achieve and would be able to run continuously at a much more shallow distance than proposed for free

(turbine and pressure resistant tunnel maintenance aside.)

Murray Smart
31st October, 2012 @ 07:53 pm PDT

I can see why this got approved, at the end of the video he states it will generate not only electricity but more importantly TAX REVENUE.

Don't get me wrong, this is great that it is non-polluting, I'm all for it. Just really annoys me that other projects, that would cost the consumer less do not get developed because there would be no way to TAX them.

I guess that's the world we live in, keep fuel controlled centrally.

livin_the_dream
1st November, 2012 @ 01:28 am PDT

Love reading stories like this. The world needs more clever innovation and engineers / scientists to make it happen,

JT

Jules Tipler
1st November, 2012 @ 03:11 am PDT

Easier said than done. The cracks can't be predicted as well, errant pressure build ups can cause small earthquakes. If many of these are built overtime, this could start cooling the earth's crust, causing earthquakes in some parts of the world as pressure builds up. It could activate older pressures as a pathway is made to the hot layers. Water will find a way to hot areas and build pressure.

Geothermal energy is not that easy.

Dawar Saify
1st November, 2012 @ 05:51 am PDT

Geothermal energy is the most feasible-efficient-most abundant-greenest kind of energy available to us. In fact, it alone could power all humankind needs for a few hundred years to come. There would be absolutely no need for nuclear, solar, wind energy at all (won't even consider internal combustion engines).

Why isn't it appropriately developed now, on this 21st century, when so much has been achieved? By simple SELFISHNESS and GREED of corporations, which support a worldwide obsolete economic model based on debt and wars (yep, the most lucrative business of them all).

Check out "Zeitgeist" (including the "addendum" and "moning forward"). Plain, simple and honest truth...

Charlie Channels
1st November, 2012 @ 09:23 am PDT

One question i would ask is what could possibly go wrong? Steam explosions? Lava dome collapse? Good thing they've thought all this thru. Of course putting a 4' windmill on every telephone pole would generate giga watts of power but that would decentralize the power grid and possibly lead to an abundance of energy. This exotic stuff is much better.

If people realized simple solutions are the way out of complex problems, that might inspire people to look at our political system and determine that paper ballots would fix these weird election anomalies like what we've seen in the last 15 years.

Natano
1st November, 2012 @ 10:28 am PDT

@Natano

Political systems - all of them depend upon you voting for a few selected people who represent the least dubious values you can withstand, the Roman system was better where you got to veto as a plebian, not approve the least evil party.

L1ma
1st November, 2012 @ 01:40 pm PDT

I don't about calling this "new technology". New Zealand has making making electricity with steam from geothermal activity since 1958!

warren52nz
1st November, 2012 @ 03:23 pm PDT

Natano,

One risk is triggering earth tremors. There was a geothermal project in Basel, Switzerland that ended rather disastrously. Here's more information about those risks:

http://www.scientificamerican.com/article.cfm?id=geothermal-drilling-earthquakes

Gadgeteer
1st November, 2012 @ 03:50 pm PDT

Also tap Hawaii active volcanoes on Maui & the Big Island & send power to Mainland via cable from HI to CA, OR.

Stephen N Russell
1st November, 2012 @ 06:05 pm PDT

I love geothermal energy. But good lucky with all the lawsuits.. Just because you got approval doesn't mean you are home free.

Michael Mantion
1st November, 2012 @ 11:12 pm PDT

@stephen

Undersea cable from HI to mainland would be very expensive in terms of money and energy losses from such a long cable length.

Keith Yancey
2nd November, 2012 @ 07:21 am PDT

Now this strikes me as Fracking and must be immediately banned as it is liable to polute the water table leading to the deaths of hundreds of people in the vicinity. Also this was tried in Switzerland and caused earthquakes which with all that latent lather outpouring in the countryside will lead to even more deaths.

Brian J. Baker
2nd November, 2012 @ 11:16 am PDT

In all the cases that the EPA investigated Fracking has not caused water pollution.

Pikeman
2nd November, 2012 @ 01:37 pm PDT

Fracking has definitely affected water table purity - denial is not possible anymore. In New Zealand we have seen fracking sites closed due to this. I'd also want to ring a bell at any time people start enthusiasticly fracturing rock at depth - the concepts of stress relief, and stress transference, mean that it can feasibly lead to quake activity. Don't simply clap your hands and shout Hooray about this - technically, fracturing rocks beds may not be such a smart move, in the long run.

Henry Balfour
4th November, 2012 @ 06:24 pm PST

@ Henry Balfour

I know this is a bit off topic but could you provide a few names/links for the fracking site shutdown, we are currently trying to resist this in Ireland?

Cheers.

Paul

livin_the_dream
4th November, 2012 @ 11:38 pm PST

If you like geothermal energy go to Iceland or New Zealand they've been at it since WW2.

btw the EPA's investigation of fracking is a political fraud.

nutcase
6th November, 2012 @ 06:17 am PST

Here in NZ geothermal is a boon resource which delivers constant base load at low cost and there are many companies which utilize the resources to minimize energy costs thus drawing a competitive advantage in the market.

hydraulic fracturing is only a problem if your fracturing the aquifer cap and are drilling below the water table thereby allowing the two formerly separate fields (above and below the cap) to mix thereby contaminating both. But that said once you fracture the aquifer cap then good luck trying to fix it (you have just permanently polluted your fresh water aquifer). Its a risk assessment that possibly just needs to be regulated to ensure its safety.

cm
6th November, 2012 @ 05:02 pm PST

re; nutcase

The EPA has been unfailingly hostile to energy production. They did find that improperly installed well casings in or near the ground water have caused contamination but this was not caused by the Fracking.

Pikeman
6th November, 2012 @ 06:22 pm PST

It's hardly surprising that an organisation whose task is to protect the environment would be unfailingly hostile to energy production.

Reality is though, that they are in bed with the mother frackers.

Under federal law, wastes deemed "hazardous" are injected into strictly regulated Class I underground disposal wells. But more than two decades ago, the oil and gas industry worked with the EPA to exempt oil and gas fracking waste from being considered "hazardous" waste. Federal regulators recognize that "the exemption does not mean these wastes could not present a hazard to human health and the environment if improperly managed," according to EPA documents.

nutcase
7th November, 2012 @ 06:24 am PST

There IS an alternative - it involves an "OFF" button.

Don't get pissed off at me if those that find fault with EVERY possible alternative energy source. It is the ONLY viable alternative you leave - except you don't want to sacrifice your conveniences or connectivity.

Does that sound simplistic? The best solutions are often the simplest.

NK Fro
8th November, 2012 @ 06:23 am PST

This is great and clean, imagine the power we could get from Yellowstone...

Who would need coal in that part of the US? none of us.

Shawn Boike
10th November, 2012 @ 09:56 am PST

@ Shawn Boike

If we messed up in Yellowstone the sheer ferocity of the subsequent eruption will most likely drive us into a northern hemisphere ice age. The southern might be spared but judging from its 40000 year over due date the gases built will most likely be enough to throw ash as far down as the gulf of mexico. The drop in temperature which is estimated to be around 21 degrees based on the last super volcano eruption roughly 75000 years ago will kill most plant life. Yellowstone is an extinction level threat. You don't play with that.

Chance Rose
26th November, 2012 @ 09:43 pm PST

I have written about building Eco city -ecolism dot com- of 1 million houses, self-sustainable, self-sufficient and based on renewable energy, recycling, re-using and the rest of it. I think it is safer to use solar energy and designer wind turbine power, However, I would consider geothermal energy if it is safe. Fracturing the rock for gas proved to cause tremors and small earthquakes, we have experienced this in UK in Black pool area. The question is: How safe is the EGS system? Are we advanced enough to calculate the consequences of the causation of un-natural disturbance in the earth's natural balance?

Henry Maalouf Gilbert
11th December, 2012 @ 09:29 pm PST
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