Expert Interview: Eva Schill

[00:00:08] Jenny: Hi, this is Jenny from Lawrence Berkeley National Laboratory Strategic Communications Team. Today I have Eva Schill with me, who is the geothermal systems program lead in our energy geosciences division. And today we’re going to spend some time talking about enhanced geothermal energy and subsurface research. Can you tell us about yourself and your role at the lab?

[00:00:29] Eva Schill: So my name is Eva. I am a geologist. I studied in Germany and I also did my PhD in Germany in geophysics. So I’m quite familiar with the geological situation and also with exploration geophysics mainly. So my role at the lab here is I’m the Geothermal Program lead, and I’m actually trying to coordinate this program, which is really, I think an important program within the energy and geoscience division. So the geothermal program at Lawrence Berkeley lab includes a very broad variety of topics. So we are covering a lot of technologies, starting from conventional geothermal energy production, which is, for example, ongoing in the geysers in Northern California.

We are looking into new technologies such as enhanced geothermal systems. We are very active in the current field sites in Utah where these technologies were developed and brought forward. We are also looking into high-temperature heat storage, especially for industrial applications. So we are talking about temperatures above 100 degrees in order to support the heat demand of industry. And yeah, it’s not limited, but it goes up to the lithium production from Chief Summer Prine. We have a large project in the Imperial County in Southern California, and we are also looking into leads in production from produced waters, for example in the formation along the US Gulf Coast.

[00:02:24] Jenny: You’ve got your hands full. You’ve got a lot of projects and priorities to deal with. But I was wondering, can we maybe start by explaining what conventional geothermal energy is?

[00:02:37] Eva Schill: So, conventional geothermal energy production actually uses –as all of the geothermal energy uses– the terminal energy, which is stored naturally in the subsurface.

Conventional systems are basically the most used and oldest technology among geothermal technologies, and they benefit from so-called geothermal manifestations. That means points at the surface where we can basically see or feel geothermal heat coming out of the ground. Yeah, this can be fumaroles, this can be glaciers, this can be volcanoes usually.

So any place in the world where we can see real heat coming out of the earth. And these are actually areas where it is typically comparably easy to harvest this heat because it’s already coming out of the ground. We basically use the pathways that nature already provides to bring up the heat out of the inner part of the earth.

[00:03:49] Jenny: So now that we kind of know we have that definition of what. Conventional geothermal is, I’m gonna have you explain what enhanced geothermal energy is.

[00:04:01] Eva Schill: Enhanced Geothermal systems is actually a technology which has a long, long history, and the history started in the United States in the 1970s with a large experiment at the Los Alamos lab.

And it was the first time when people tried to create an artificial reservoir in the subsurface. And the subsurface actually is basically everywhere warm to hot. And it was the question, how can we harvest this heat? And the idea was to create fractures in the underground and to. Circulate water on this in order to produce the heat out of the subsurface where it doesn’t come up naturally.

The first experiments actually were successful, but it was really difficult to bring it up to industrial applications. And then we had long history of trying to use a natural permeable rock, a rock, which kind of, has not enough permeability to be economically viable, so we try to improve the permeability of these underground settings.

This was also very successful technology which is still applied mainly in central Europe. And in the recent years, we basically went back to the original concept of really creating new reservoirs and with. All the knowledge which we gained in the fracking operations in the shake gas fields, we could transfer this knowledge into geo and could create in the United States worldwide. First, EGS really engineered EGS uh, reservoirs

[00:05:51] Jenny:  Can you tell us why geothermal energy is such a promising alternative energy source?

[00:06:04] Eva Schill: The geothermal energy is a promising alternative source because it has really –compared to all other technologies–  a number of advantages. It has really a huge potential. So we basically have all the subsurface of the earth, which we can access.

So typically we access the surface down to five kilometers. I think by improving the technology we can go down in the future also to deeper levels, like say maybe up to 10 kilometers. That’s certainly something technically viable and it has already been done. So as I said, the potential is really huge compared to other technologies, and the really big advantage of geothermal is also that we can harvest the energy whenever we need it.

That means even if we need it 24/7 over the entire year, the energy is there and we can use it. You don’t need it the whole year, so you just access it when you need it. That’s, I think, really a big advantage. Then, as I said already, the impact at the surface is relatively small compared to other technologies.

[00:07:22] Jenny: Can you talk a little bit about why Berkeley lab is uniquely suited to lead research in geothermal systems?

[00:07:32] Eva Schill: So Berkeley Lab, first of all, has a very long history in geothermal research. So I think it’s 40 years of building up capacity. So we have really a very good scientific team here, and I mean, it’s not only about scientists who are working here, but over time we have also developed software, which has been very important for the development of geothermal systems, which is still used not only by Berkeley Lab, but also by universities and industries. So we have really contributed very significantly to this (to the development of geothermal in the US) and we are still doing this. We are looking into the future, and for example, nowadays we are talking a lot about exploiting geothermal systems, which have temperatures beyond what we are doing currently. So we are talking about temperatures above 400 degrees C and you can imagine that all the chemistry and also the mechanics, it’s completely different in such systems. And we are currently implementing all the knowledge which we have already gained into these codes and continuously developing this.

I think one of the biggest advantages here at the lab is that we are running the Geoscience Measurement Facility. This is a facility where we are able to design and build new instruments, which help us to better understand what is ongoing in these reservoirs. To monitor things like induced seismicity, but also to really understand how the subsurface deforms under the changes of the conditions.

[00:09:27] Jenny: So really, I just want to thank you so much for taking the time to talk with me today. I’ve learned a lot about enhanced geothermal and about our expertise in the subsurface and induced seismicity, and I hope that our listeners get a lot out of it too.

[00:09:41] Eva Schill: Thank you for choosing to interview me.

[00:09:43] Jenny: To learn more about Berkeley Lab subsurface research, visit earthsystems.lbl.gov.