DIAS’ Dr Emma Chambers explains her work on mapping geothermal energy and how it can contribute to Ireland’s climate goals.
For Dr Emma Chambers, whose day job involves mapping the Earth’s interior for energy hotspots, a core aim is to inspire the next generation to pursue STEM.
This takes many forms, she says, including hosting activities at university open days, getting involved with the Young Scientist and Technology Exhibition and Culture Night, and even joining a pen pal programme that partners scientists with young teens.
Chambers says it’s “crucial” to speak to diverse audiences. “Engaging with people in all walks of life and being able to adapt to communicate science in an appropriate way for each audience is a skill but necessary to get engagement.”
Part of the reason for this, as she sees it, is that the research is funded by the taxpayer. “We have a duty to make sure that the results are available to everyone, not just internally or to the scientific community.” This is why the models she’s producing will be open access.
Her research career started with a summer internship as part of her degree in geophysics at University of Southampton. She produced a digitised fault map of Ethiopia and located earthquakes in Cameroon to determine seismicity around Mount Cameroon.
She worked in industry for a couple of years after her degree before returning to academia to complete a PhD in geophysics at the University of Southampton.
In 2020, she took up a postdoctoral research fellowship at Dublin Institute for Advanced Studies (DIAS), working on a project called De-Risking Ireland’s Geothermal potential (DIG).
Chambers is now a research fellow at DIAS, where she specialises in creating models to map the geothermal potential under our feet. She is principal investigator on the MOD3LTHERM and GRANNUS projects.
Here, she tells us more about her work.
Tell us about your current research.
My team and I currently work to make and improve subsurface temperature maps to determine geothermal potential.
We focus on deep geothermal heat (greater than 1km depth) which can be connected into district heating networks and larger areas as well as in some locations be suitable for electricity generation if temperatures exceed 150 degrees Celsius (it’s warmer the deeper you go).
In contrast many people may have heard of shallow geothermal and ground source heat pumps. A ground source heat pump will convert shallow (less than 200m) subsurface heat for individual households and smaller residential complexes with the use of a heat pump.
In addition to the temperature maps, we produce an associated model uncertainty map, allowing future users to assess the confidence of a model value when using this temperature maps.
The models provide information on the subsurface structure of the Earth’s crust and upper mantle (the rigid part of the Earth known as the lithosphere) to as deep as the upper asthenosphere (the ductile part of the mantle underneath the lithosphere).
The reason we need to understand the deeper structure even though we’ll only ever extract heat from the first few kilometres in the Earth is because the main sources of heat are from heat rising from the Earth’s asthenosphere to the surface and from radiogenic elements in certain rocks in the crust such as granites. We therefore need to know the depth to the lithosphere asthenosphere boundary (the transition where Earth’s rigid lithosphere transitions to ductile asthenosphere) and the lithological crustal structure.
For geothermal applications we need to model this deeper structure and then focus in on the results in the upper 5km where most people are interested in developing geothermal technologies.
We initially produced a model using a joint geophysical-petrological inversion. A joint inversion relates different datasets to one another in order to calculate a new parameter, in this case temperature.
We take velocity, surface heat flow, thermal conductivity, crustal radiogenic heat production, elevation and depth to the crust mantle boundary (Mohorovičić discontinuity) and inverting directly for subsurface temperature.
The models were a good first start, however the associated model uncertainty was high, and certain areas lacked input data. In addition, the models are 1D and are collated to a pseudo 3D volume.
To improve on this, we proposed the MOD3LTHERM project to collect and integrate more data and move the modelling to 3D to account for lateral heat flow rather than assuming perfectly vertical conduction within a 1D column.
While I focus on improving the models in Ireland and applying to other environments such as Ethiopia, Bernard Asare Owusu (a PhD researcher based at DIAS) is applying the methodology to Iceland, incorporating melt into the models and modifying the approach to work at a local scale at the Krafla Geothermal powerplant. The Krafla geothermal area has known geothermal potential where the new models and methodologies we develop can be refined with a known subsurface temperature model and then this analysis can be applied globally.
While there have been temperature models created for Ireland in the past, they did not have an associated uncertainty and were not compared to locations with borehole subsurface temperature measurements. As researchers we create many models. A saying we have is all models are wrong, but some are useful. What we mean by this is that they are not a true representation of the Earth (only by digging down will you know exactly what it is like); however, the models can give an idea of what is most likely to be occurring.
By producing an associated model uncertainty map to go with the temperature, policymakers can now assess the likelihood of good subsurface heat and investigate local areas in more detail with an aim to develop future geothermal exploitation.
In your opinion, why is your research important?
With more extreme weather events globally, from prolonged and hotter heatwaves in Europe to devastating floods across the world, including in Ireland, it is undisputed that humans are making extremes of weather more likely. Similarly in a world where geopolitics is increasingly unstable, energy security is a priority for many countries.
Providing information on the location and potential for renewable resources is therefore part of the solution with much of the energy located locally.
Geothermal energy is a reliable, renewable, clean energy resource that won’t run out and is cost-effective when established.
Politically and socially improving our knowledge of the subsurface and the location of geothermal resources will help us to develop renewable resources to meet the Republic of Ireland’s and Northern Ireland’s climate action plans in the green economy, to comply with the EU 2030 framework of climate and energy, and to meet global climate targets.
The models we produce allow industry and other stakeholders to reduce the risk when exploiting geothermal resources.
What inspired you to become a researcher?
I’ve always wanted to find solutions that could help improve people’s lives and would ultimately be useful. Separately I wanted to find a way to combine my interest in physics and geography with my love of volcanoes and the outdoors. My great aunt often tells a story that when I was a child at the beach, instead of making sandcastles I would make sand volcanoes using seawater for lava!
What are some of the biggest challenges or misconceptions you face as a researcher in your field?
Often people are disbelieving when I say I work on developing geothermal resource extraction in Ireland. They assume Ireland is too cold and geothermal heating and energy only work in volcanic regions such as Iceland and Italy.
While it’s true we don’t have as warm temperatures as these areas, if you go deep enough into the ground (a few kilometres), you will have enough heat to warm your house and potentially for electricity generation.
The Earth is radiating heat from its core which is ~5,700-6,200 Kelvin; hotter than the surface of the sun. The heat needs to escape and rises to the surface. If we drill into the crust a few kilometres we can harness this heat, with temperatures on average in continents increasing by 25 to 30 °C per km. In some areas this will be warmer with better geothermal potential and others cooler, and we want to map these areas.
‘Science has always been political’
Another misconception is renewable energy isn’t efficient enough to power and heat our world.
As we start to harness these energy sources we will develop and advance technologies making these more efficient, more reliable, and it will be possible to power our world with renewables.
Every time we start something new, we have to develop the technologies to make things work. For example, computers used to be the size of rooms. If you’d told someone back then that nearly everyone would have a more efficient computer in their pocket in the form of a mobile phone, would people have said that’s not possible? Once we start, we will develop the technologies to make them more efficient and work.
Do you think public engagement with science and data has changed in recent years?
Connectivity in the world has increased with the arrival of the internet and in particular the speed of communication through social media and instant messaging. Some of the public engage with science through these platforms which will often be as quick snapshots. It is therefore essential to convey messages quickly, accurately and succinctly using these mediums and evolve our engagement style.
That’s not to say more conventional communication methods of science are no longer important but we as researchers need to adapt to communicate to the general public through a range of different platforms.
Also, science has always been political and those that say that science should stay out of politics don’t appreciate the connection between science and policy decisions. For example, my work creating subsurface temperature maps could be used to inform policy on energy and meeting our climate goals which inevitably is political.
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