Love Your Rock!

Enhanced Geothermal Systems

Enhanced or engineered geothermal systems (EGS), frac’ing or fracking programs, hydraulic shearing…call it what you want, but our ability to alter rock reservoirs has the power to change the geothermal energy industry. 

 Conventional geothermal energy programs need three things to be successful:

1.       Heat. Without this you don’t have a resource.

2.       A transfer medium. Required to transfer the heat; this is usually water.

3.       A rock environment. With enough porosity to move the heat through.

In the simplest terms, if a geothermal energy developer can move enough water through hot, fractured, or porous rock, he or she can use that heat to power a turbine—and, therefore, has a potential power project. Seems simple enough, right? But, what if this incredible heat resource is trapped in solid rock? One can’t economically move heat out of a solid rock thousands of meters underground. So, should such a developer simply walk away from the potential project or work to improve the situation? 

 The oil and gas industry had a similar problem with getting precious oil and gas resources out of tight formations. They knew these energy resources were in certain rock but, at first, couldn’t feasibly or economically recover it. However, there was a solution. Fluid-driven fractures could be formed at depth in the oilfield borehole and extended into targeted aquifer formations. Frac’ing or Fracking technology significantly increased the surface area to recover the petroleum resources, and is now commonly used by the oil and gas industry to access “unconventional” natural gas deposits trapped in shale, coalbed, and tight-sand formations. Add in the ability to drill horizontally within the right formation and the oil and gas industry exponentially improved petroleum recovery in that formation.

 Even for the geothermal industry, the cat is already out of the bag. Many geothermal energy developers have already begun to see the potential of similiar technology. Projects in Soultz France, Cooper Basin, Australia, and Newberry, in the US have all used pressured fluids to increase permeability and to increase heat recovery. In hard-rock and volcanic environments, man-made hydraulic fractures use internal fluid pressure to help open pre-existing weakness in the rock structure. The new fracture is then typically maintained by introducing a proppant (such as sand, ceramic, or particulates) into the injected fluid.

 Projects that were once left economically wanting now have the potential for increased profitability. And, those in the renewable energy industry understand that slight improvement could take a project into the realm of financial viable.  

 This technology is not without its’ detractors, however. Environmental and community groups have brought some of the technology’s downfalls into the public spotlight. Fresh water contamination, induced seismicity, and the toxic nature of some fracking fluids are just some of the concerns. To continue to be part of a clean energy solution for our planet,  the geothermal energy developers adopting this technology  need to  closely monitor and responsibly deal with  any and all concerns, real or imagined. The industry needs to ensure that any individual fracking program does leave a “black eye” on the geothermal industry as a whole.

 At the core, our planet is over 5,000°C and is approximately 6.3km thick and continues to produce vast amounts of heat. To put this in perspective; the heat stored in the only the top 3 km of the continental crust is equivalent to the energy consumed by mankind for some 100,000 years at the present rate. At a depth of 10km, the heat in the of the earth’s crust contains 50,000 times as much energy as found in all the world’s oil and gas reserves combined. In 2007, a US Department of Energy sponsored study, completed by independent experts led by the Massachusetts Institute of Technology (MIT), concluded that geothermal energy could provide 100,000 MWe or more in 50 years by using advanced EGS (enhanced geothermal energy) technology.

 The problem is clearly not a lack of heat (we have billions of years of heat available), it is getting that heat out of the ground cost effectively. The more the industry can research and test this technology in geothermal applications, the more this technology can be implementing to improve the economics and decrease the project risks of geothermal energy development. Love it or hate it, fracking technology has the potential to forever change how the geothermal energy industry extracts its’ heat resource. 

This article was written for North America Clean Energy Magazine  for November 2010 

Author:  Craig Dunn is a pioneer in geothermal energy exploration and development initiatives in Canada, with expertise in the industry’s efforts on developing high-temperature geothermal energy from untapped resources.

Earth Heat

Our planet’s core is about the same temperature as the surface of the sun. Can you say “energy resource?”

As a geologist working in the geothermal energy sector I am always amazed to find out how many people have little to no understand of our planet’s workings and that our planet has incredible potential for heat and power.  Even though it has already been development in dozens of countries worldwide and is a source of clean, constant power, geothermal energy is sort of the forgotten renewable energy.

Watching geothermal getting left out of the Wind, Solar, Biomass renewable energy party,  I have to say that I love it when geothermal energy gets covered in the media.  Here is one great article that is a great introduction to geothermal energy for power production and heat. Treehugger covers a lot of great “green stories” so hopefully a few more people learn about geothermal’s  incredible potential.

http://www.treehugger.com/files/2010/08/tapping-the-energy-below-the-earths-surface.php

LoveYourRock will continue to tweet and blog about geothermal energy as it is one more reason to appreciate what our planet has to offer.

As a scientist, I occassional get in my “what’s that made of” mindset.  It is like daydreaming about the world around you (when you should be driving, or listening, or working…) and how all the parts came together.  In the end everything tangible in our world is made up of the basic elements…. your car, your desk, your ipod, your computer, even your wife and kids. All of this can be traced back to our planet in it’s earliest days.

So come daydream with me!  As you look around, pick an item and see if you can figure out where it all began. If you can and have a little bit of chemistry background, try and go  right down to the element.

Let’s say you pick your bike, now  think of all the steps and parts that were involved in making that bike.

Aluminum or steel  frame… elements (Al, Fe)  mined from rocks within planet earth. ( thanks earth )

Plastic pedals… petroleum product, recovered from drilling for oil and million year old plants and animals;  (thanks Mr. Dinosaur)

Rubber tires… rubber tree grown from soil? unlikely.. more  likely petroleum product;

Leather seat… thanks cow, and the grass you ate, and the mineral rich soil that the grass was grown in, and the bright sun, and the organic chains of elements that go into making you.

Sometimes it takes a lot of thinking to get all the way back to the source, but this just extends the daydreaming.  I find this exercise to be a very nice mental distraction and stress reliever, but always a wonderful awareness of the source of all our “stuff”.  In the end, the vast majority of our  ”stuff”  comes from our planet, it’s mined (steel, aluminum), refined (oil, plastics), or harvested (wood, cotton, with some help from the sun).  When we get the final product it is so manufactured that we forget about all the steps and the original source. 

 We forget to be grateful for what our planet has given us; now no more daydreaming and back to work.

Love your rock is all about appreciation for the planet and the geology that gives us our everything.