IGC 2024 Iceland: A future of geothermal, extrapolated from a geothermal past - land efficient heat, with air quality and social security.

Contents

Who am I to talk geothermal at IGC?;?? Geothermal is different;?? Geothermal is a collective – the one is many;? Subsurface resource, risk, uncertainty;?? Energy portfolios, integrated geothermal, and industrial hubs/clusters;?? Crisis instigated security planning;?? One thing;?? Iceland and Giants and smog-free cities;?? Geocities;?? Geothermal Heat, Cool, Desalination;?? Geofood;?? Baseload?;?? Local jobs;?? Not everywhere is Iceland, but…;?? Municipalities, local governments, and departments of trade;?? What place geothermal power?;? Geotherms versus diagenesis;?? It’s only long-lived if you look after it;?? Places to ponder;??? Not really a gold mine, but we don’t need it to be;?? Commercial Innovation – tough but doable;?? Scale expectation – saving the world versus helping communities;? Itching to go like an iFarm ichi-go;?? Where to for Paetoro geothermal??

Who am I to talk geothermal at IGC?

Sometimes when I talk with people for the first time, who have been doing geothermal for decades, I can recognise a look.? A glossing over of the eye that signals a thought “Oh right, here’s another oil and gas person who has thought that they can switch to geothermal overnight”.? I can understand that.? Geothermal energy is a discipline that has been around for over a century.? It hasn’t been twiddling its thumbs waiting for rescue from oil and gas professionals. ?They have been tending the farm with purpose-built tractors for a century.? When someone turns up at the farm gate in a BMW offering them lessons in how to do it, they have a right to be a bit “cool”. ?It’s not that simple, it’s not that easy.

For me, I’ve been looking at geothermal professionally for just under a decade now, and I began looking at it from a very deliberate geology-oriented perspective.? I’m a kiwi, so I’ve always been aware of what high temperature geothermal can do for a place.? ?NZ is spectacularly blessed on this front - but being a geologist for over 35 years now, it was always very apparent that a lot of places had lower and medium temperature geothermal resources that weren’t being utilised.? I was interested, back in 2016, in why that wasn’t happening.? I started looking at the UK, not because I thought it was sitting on some undiscovered gold mine, but because I knew resource had been looked at since the 1970’s but hadn’t really gotten very far in half a century.? I wanted to get to the bottom of the issue of why that was the case.? So I looked into the UK in more detail. Particularly the hydrothermal resource available.?

Some things very quickly become apparent with geothermal very soon after you engage with any degree of seriousness.??

Firstly it is engineering dominated.? Not that oil and gas isn’t, but the value associated with a hot water or steam commodity compared to a hydrocarbon one, means the emphasis on getting production well and facilities engineering optimal is far more project critical right from the start.?

Secondly, drilling.? How we do it, how fast we do it, what hole type we have, how deep we have to go, what drilling technologies we use.? This up-front cost dominates project commerciality.

Thirdly, water.?? Volumes and chemistry.? The scale of the flow rates required, and the importance of the water chemistry, impacts the lifetime and viability of the project.? To be commercial those flow rates have to be big.? The price retrieved per volume has a couple of orders magnitude difference with hydrocarbons, so geothermal has to move a lot of fluid.? And it all has [natural] chemicals in it that like to precipitate as water cools.? Maintenance of geothermal wells is neglected at peril.

Yet these are technical issues.? The real story coming out of this look at geothermal in the UK was that it is not the lack of resource that is ever really the issue, or the inability technically to engineer usage.? It is the cost, the uncertainty, the project timescale, and wider awareness of what can be done, that together conspire together to be the [historic] bust.

What is the same however, is that geothermal needs reservoir.? Now I can hear all you closed-loop proponents out there saying “no it doesn’t” but let me elaborate.?? It needs a heat reservoir, and it needs a fluid flowing through it.? In hydrothermal we utilise a reservoir that was created naturally over a large area to “catch heat” in the fluids of connected pores in the rock.?? In closed-loop we drill a hole and we pump water through a much smaller area/length of hot rock.? In EGS (Enhanced Geothermal Systems) we enhance or create fractures of some rocks over a bit of a wider area around the well.? That reduced area relative to natural reservoirs might not matter if things are hot enough to do what we want it to, but that’s the truth of it.? We want water (or at least some working fluid) running through underground hole(s) in the warm rock below.? However big or small they happen to be.? A “reservoir” be it natural or manufactured.? A combination of heat, and fluid, underground.

So, while I am also interested as a structural geologist in EGS approaches, I tend to gravitate as a geologist to the hydrothermal wing of geothermal.? That part which relies on natural water residing in natural reservoirs, be they tectonically fractured, karst, primary sedimentary, or enhanced by other diagenesis (e.g. feldspar dissolution).?

So this is where I as a geologist proclaim that I can talk about geothermal.?? This part is not too dissimilar.? Looking for where the hydrothermal resource is – that’s very comparable to what I’ve done for over thirty years.?? At the same time, I recognise the drilling aspect is key - and different.?? I recognise the geochemistry is pivotal.? I recognise the well and facilities engineering requires far earlier optimisation.? I recognise that I need to talk to these people far earlier than is the case with hydrocarbons.? I recognise that it is the commerciality, not what can be done technically, that is typically the bust when things are bust.?

But for all that, we still have to start with what resource we have – and that’s where I plant my flag – but working to be savvy to all the stuff that comes "later".?? Because when the commodity price per volume is a hundred times less than hydrocarbons, we don’t have the luxury of finding the commodity first and thinking about the rest later.? We have to begin with joined up thinking of everything right at the start.???

Going to Iceland IGC 2024 and standing up to talk geothermal to a discipline so mature, especially in a country that has been doing it so long, is not then done lightly, or from a perspective of how to change what has been done.? It is to recognise the distinctiveness of the resources and risks and uncertainties that are peculiar to geothermal,? and to adjust exploration methods accordingly.?

Geothermal is different

We have already touched on some of the key differences with geothermal – but there are some other fundamental aspects of it that are also worth stressing before going any further.? But before doing even that,? let’s get one thing out of the way.?? Geothermal is not just about temperature.? Whether you are doing closed-loop or open system, the thing that matters is flow rate.? Much, much fluid.? Heat is a function of both mass and temperature, and although heat pumps are an extra cost, they mean that in 2024 temperatures lower than what we want is an easier problem than flow rates too low – not enough water.? It doesn’t matter how hot your rocks are, if you are not getting the flow rates you need your project is dead. ?It is easier to live with lower temperatures than it is to live with low flow rates.? ??The former has workarounds.? The latter does not.?

A fundamental aspect of geothermal is also that is not chasing a secondary buoyant immiscible fluid underground. It is chasing a fluid that is pervasive and perhaps the universe’s best solvent – great at collecting and dissolving other stuff – especially if hot.? Hydrocarbon "pools" are dependent on their buoyancy finding a sealed structure which dramatically reduces the number of places that can reasonably harbour a commercial accumulation.?? And if we find the seal and the structure with our exploration geophysics, then we don’t need that great a reservoir to give flow rates that are commercial for such a valuable commodity by volume.? With geothermal we have far less geometric constraint on structure and seal – so our exploration geophysics is far less helpful.? It is helpful, but it doesn’t take us as far.?

We always have some water, and we always have some heat.? And then the reservoir – we are not looking for a reservoir that can flow 3000 bpd, we are looking for a reservoir that can flow 30000 bpd.? That means geothermal is far more vulnerable in its success rates to the variabilities in reservoir. It’s not enough to find fair or even good reservoir, in hydrothermal applications – we need excellent reservoir.? Again, exploration geophysics onshore can give some clues on that, but it is far less proficient and more involved than just “finding a half-decent reservoir” that is so often enough in a hydrocarbon context.??

The good news is that because we are not limited by buoyancy and structure of a seal – our commodity can be obtained throughout the thickness of any good reservoir that is present.? We are not limited to the top and can produce more pervasively through depth, without being restricted necessarily by buoyancies and structural geometries.? Note though, that given the volumes of fluid we want, we are also drawn to wanting larger holes at depth – which has cost implications.

What does this mean?? It means geothermal ultimately relies heavily on drilling.? Seeing what the reservoir is like once we get down there.? There are far fewer shortcuts to seeing whether the quality required is present through remote routes.? We have to go there and see.?? That radically impacts the exploration strategies appropriate for geothermal compared to petroleum.?? It throws a spotlight on drilling intelligently, and efficiently, and with a very keen eye on value of information. These differences are things I feel qualified to discuss, in the humility of knowing the geothermal sector often already “gets it” pretty much by instinct.? Yet to formalise these differences remains an evolving work in progress in 2024, and it is I think helpful to all-comers to state them explicitly.??

One last key difference is that geothermal heat does not travel.? It is a transient physical entity which dissipates with time and cannot be traded around the world as a distinct chemical entity like hydrocarbons.? It can, if temperature is sufficient (> ~140 deg C), be commercially converted to power and transported some distance, within limits - but if used in a heat capacity, the usage is essentially constrained to be a local one.?? That has both disadvantages and advantages, as we will see.

Geothermal is a collective – the one is many

One message emanating from IGC 2024, was a need for geothermal “unity”.? In a context of not embroiling outsiders in a swathe of internal discussions, disagreements, and internal technical competition.?? That is a point well made.?? It is helpful to provide a simple “umbrella” for a collection of different things that all at the end of the day, utilise heat from below the surface.? ?This is in part to compete effectively with the external competitors, who for all their own individual complexities, present a simple front.?

It is also impossible though, not to recognise the inherent diversity of geothermal.? It is not one thing, it is a dozen, at least.? Conventional hydrothermal direct use, including district heating.? Use of that hydrothermal heat in binary power plants utilising different working fluids.? High temperature/enthalpy flash and dry steam power plants.?? Ground sourced heat pumps. Shallow geothermal with heat pumps. ?Mineral extraction from geothermal fluids. Supercritical investigations.? Enhanced geothermal systems using artificial fracture stimulations.? Closed loop systems relying on conduction only.? Similarly deep borehole heat exchangers.?? Oil and gas co-production or repurposing.? Aquifer thermal energy storage.? Hybrid geothermal and solar/wind.? Geothermal anywhere by virtue of ultradeep drilling.? People will agree and disagree over which of these are strictly “geothermal” and which aren’t – but the point is – there is a wealth of different ways of using heat – and cool, from below the surface.?

A corollary to that is that all of these have different levels of maturity and technological readiness, different risks, different rewards, regulatory framework, technological and commercial complexity, even different commodities – heat, power, mineral, different uncertainties, and different costs. ?That means there is a huge range of different customers, and different clients, and different risk profiles and capital expenditures, suited to different investors.?

That last point is a critical one.?? We can usefully package geothermal as one thing for purposes of public and political awareness – but from an investment and use point of view we cannot.? We need to isolate the different “flavours” of geothermal appropriate to different customers, and the different comfort levels of investors with different various risks and sizes of capital investment.? Otherwise we end up pitching flip-flops to Lapland or woolly jumpers to the amazon.

Critically also, each one of these different facets of geothermal has different competitors.? That is crucial, crucial, crucial.?

Subsurface resource, risk, uncertainty

It can come across as arrogant to say I’m interested in all subsurface resource, and the associated quantitative and probabilistic assessment of size, risk and uncertainty.? Be it geothermal, water, mineral, hydrocarbon, energy storage, waste disposal.? Not only that, I’m interested in how all these interact with what surface resources ( wind, solar, hydro, nuclear,? energy storage etc.) can offer simultaneously.?? It is a bit arrogant to say that, but I try to approach this with humility, consultation and deference to those who are expert and specialist in each aspect.?? What I would say in 2024, is that it is also an arrogance to think we can proceed effectively without considering these things together.? However imperfectly, we need more people to try and look at the bigger picture.? It’s hard, but it’s interesting – and vital.?

To be clear these days I work predominantly in geothermal and mineral exploration.? I actively turn down work personally to do solely with oil and gas or CCS resource exploration.? That’s not to deny a past, it is to recognise a future. I do contemplate the former to some extent if geothermal co-production or repurposing is a stepping stone to standalone geothermal deployment. ?That does not mean I do not take valuable lessons from my historical experience in petroleum systems or am uninterested in how those resources continue to be evaluated and what learnings that can bring.? Or in how some circumstances there can arise evolutionary “launchpads” from them into other resource evaluations.?

What I would say is that after nearly a decade of looking at geothermal, what is most glaringly obvious to me is the differences with other subsurface resource types.?? That is in part a personal perspective thing.?? Of course there are things in common, and mutual synergies, but it is possible to exaggerate those.

As a New Zealander, I’m reminded of how often people have said to me that parts of New Zealand’s South Island remind them of Scotland.? While I recognise what they are saying, I as a kiwi see much more deeply how they are so different.? A perception thing – not right and wrong, but perception. So too with geothermal – yes, it deals with drilling wells into the subsurface, and also in trying to understand elements of the subsurface as much as we can before we do that, just like petroleum.? But from there on in, what I see more than anything, is the difference, more than any similarity, with other resource exploration and production (E&P) sectors and approaches.? And especially in the customer being catered to, and the expectations of return amount and timeframe of the most typical investors.

One thing I have to say is that personally what I am most interested in is the workflows that can activate geothermal exploration as a standalone exercise not reliant on other subsurface resource activity.? That’s not to diminish the worth of those that embark on that latter route – it would be silly not to – but the question of interest to me is to wonder how we can take geothermal exploration – and indeed more generic integrated subsurface exploration – to the next level in the 21st century.? Without dependence on pre-existing drilling for a leg-up.? That’s harder, but needed if we are to persist effectively into century-scale time windows.

Energy portfolios, ?integrated geothermal, and industrial hubs/clusters

One topic to semi-regularly turn up in geothermal discussions is the concept of the portfolio.? Now the idea behind a portfolio is that risk and cost and reward and uncertainty is shared across many more individual projects, to deliver both a scale of reward, and an insurance against failure of any one project.? In a portfolio we can have a mix of things that are high risk but high reward if they come in (but few in number), things that are moderate risk and moderate reward (and arguably the bread and butter), and things that are low risk but low reward (and maybe quite common).?? The thing is, from a human resource point of view, low reward things can often take up just as much human time and operating resource (buildings, computers, etc.) - so quite often we see companies resolving themselves into ones that do the moderate and high-risk stuff, and others that specialise in lots of the lower risk stuff.?

Portfolio approaches are a common, dare I say it universal strategy in most oil and gas companies.? A high risk but large “frontier” prospect might on paper deliver a few hundred million of barrels, or even more, but have a risk anywhere between 10 and 25%.?? It might cost 100-150 million USD to drill a large deepwater offshore prospect at those odds.? It can cost a quarter to half a million dollars per day to operate such a rig.? But at $80 per barrel, half a billion barrels is 40 billion USD.? So it can pay.? In a mature area, the risks might be significantly less, more like 30-60% say, or for step out near field exploration maybe even better – but the potential rewards will as a generalisation be smaller and smaller as the “big things” are steadily found.?

However, it’s key to realise that this value of finding hydrocarbons, is sufficient to pay for quite a few failures.? That is not a luxury that geothermal has.? So the concept of a portfolio is immediately harder.? Where it is possible to mix and match petroleum opportunity risk levels wholly effectively solely within the petroleum sector, that is more challenging with geothermal.?

The good news is that depending on the project, the risk might not be that bad.?? For a relatively well understood area and a conventional hydrothermal project for district heating - we might be dealing with an individual well success chance in the 70-80% realm.? What is less favourable is that we would need a whole lot of successes to pay for any failure.?? We do not have the luxury of hydrocarbon prices from successes to pay for many failures.? We are dealing with hot water or power prices that might give us 1-2 orders of magnitude less return to “insure” against failure.??

Now, it has to be said many countries keen to promote geothermal exploration offer favourable failure insurance schemes that help.? Yet still, the concept of a portfolio approach that is wholly contained by a variety of geothermal opportunities – doesn’t really hold water if you’ll pardon the pun.? The range of reward and the range of risk just isn’t sufficient to carry any failures, in all except the most resource-blessed of places (and the Iceland’s of the world and their like might be an exception).?

But that is not the end of the story.? Fortunately there is another strategy at hand, and that is simply to widen the portfolio beyond energy from just geothermal.? Simple.? Let’s imagine a single geothermal project for a few wells and a small ORC binary power plant has a CAPEX price tag of say USD 60 million with a commercial success chance estimated at 60-70%.?? For a single customer, with a facility that might be costing a similar amount, that’s a lot of money and a lot of make-or-break risk of failure to put in one basket.?

Let’s though for a moment imagine a wider industrial hub that is a collective of different customers and manufacturers, that together involves a capital expenditure approaching a billion dollars and is looking to a range of low carbon energy supplies from local solar, wind, energy storage provision, and from grid connection to wider hydroelectric and nuclear scale power.?? To such a project, the chance of getting secure price-stable low land footprint bonus heat and power on or close to site for 30-50 years from geothermal – that may well make sense.? And if in the end it doesn’t work, it’s far less of an issue.? It’s a bonus worth pursuing in the success case, a risk worth taking in the failure case.?

This to me was one of the great messages to come out of IGC 2024.? It is something that Iceland itself instigated early on, with early development of renewable energy clusters.? For Iceland, given the special nature of their geothermal resource, it was possible for them to base a large part of that on geothermal resource alone, even given the equally impressive strength of local hydroelectric and wind resources.?

What is truly amazing to see though is China (with honourable mention to Arctic Green Energy, and a nod to the Icelandic involvement), by instinct and consultation adopting a far larger scale and just as proactive approach they label “geothermal plus”.? This is precisely that exercise of integrating geothermal resource into a far bigger picture of other energy resources and range of customers.?? It is a portfolio approach in essence.? If the geothermal comes in, it adds a great bonus.? If it doesn’t quite live up to expectation, there is no bust.? The risk and cost and reward is shared in a larger collective.? And insured by it.

This is in a sense not radical, yet to be doing it at scale in other ways is. It is no panacea, but it will, I believe, be transformative for geothermal application, especially of heat applications.? The muscle being deployed, as is so often the case with China is impressive.? That is not to pretend all is sweetness and roses, but the drive to innovate and use resources such as is available is profound. The integration of geothermal resources into a non-exclusively geothermal, energy and industrial hub portfolio, is a deeply impactful move and will I believe be widely copied in coming decades. The earlier that discussion of new hubs can be integrated with where geothermal resource is located, the better.

Crisis instigated security planning

One of the most profound learnings to come out of Iceland, and I’m grateful to a host of Icelandic presenters, and attendees for being so honest about it, is just how much of Iceland’s geothermal advance was precipitated out of the Icelandic financial crisis of 2008 to 2011.? To be clear the country was doing great things in geothermal long before then – harnessing power since 1969 – and harnessing heat since people first stepped on its shores – so obviously manifest is the resource.? Yet the collapse of the Icelandic banking system and the currency in 2008 plunged the country into not one crisis, but a plethora of them.? One of which was energy.? An island in the middle of the Atlantic, heavily dependent on pricey hydrocarbon imports that suddenly become even more pricey in real terms – this was not a situation that could be allowed to persist without great difficulty and cost.

Now I don’t know the history in detail, and it is clear that significant investment in both geothermal power and district heating for Reykjavik in particular had happened prior to 2008.?? What seems clear however, is that the financial crisis focused minds intensely and precipitated greater discussion and collaboration on how to propel geothermal development further forward. This, to provide greater domestic energy security for the city and nation, and for local businesses.? That geothermal worked to help give this domestic energy security - especially for municipal heating - is a compelling account.

Being a New Zealand myself, there is something I recognise in the ability of smaller countries, isolated by ocean, to come together quickly in a crisis and get in the same room to talk across sectors and disciplines - and it is clear that Iceland has been an exemplary case of this in the time since 2008.? One thing that we have to probably admit, is that the scale of resource that Iceland has geothermally is not something that can be replicated in many places.? The quality of resource means at once it is both cheaper and easier to take advantage of geothermal resource in Iceland.?

That is not to diminish what the Icelanders achieved.? Their great achievement was to look around collaboratively and talk, and plan to make the most of what resource they did have.?? That is something that can and should be replicated anywhere.?? It is this multi-sector planning effort, borne out of national crisis, that is the inspirational story.?

It led to me asking the question - I wonder if Iceland could have been forewarned in the early 2000’s - would it have been bold enough then, to end up doing what it did?? Or was there something about the nature of things that a crisis had to happen first, to precipitate the discussions leading to the strong position Iceland finds itself in today:? still not without vulnerabilities, as any small nation always is, but with a far greater domestic core security to fall back on as a result.??

We cannot really know the answer to that time-travelling question, but what we can do is extrapolate Iceland’s experience and learning into other places and the “now”.? At a time when many countries from the biggest to the smallest, are facing increasing energy-sourcing crises, and looking to turn from hydrocarbon sourced energy - we can all learn from the collaborative exercise Iceland instigated, to haul itself out of a deep hole.?

One thing

This then, is one thing that geothermal resource, can help offer.? A low land-footprint domestic energy security that can be inserted into industrial hubs and urban areas. Particularly for heating applications. That - is a big chunk of energy demand in many places.?

Iceland and Giants and smog-free cities

One feature was so striking from the conference that while it has already mentioned a number of times already, it deserves repeating: Namely the Artic Green Energy partnership between Iceland and China’s energy giant Sinopec.? Depending on how you choose to define and measure geothermal, it represents one of the largest, if not the largest geothermal company in terms of MW output, with 6500 shallow geothermal wells and 1000 medium to deep wells, and a combined capacity of 10 GWth.? For more information check out the web pages:

• https://www.arcticgreen.com/whoarewe,
• https://www.arcticgreen.com/news/arctic-green-ceo-at-the-5th-icelandic-geothermal-congress-closing-ceremony

By comparison, the nearest geothermal power company is US player Calpine, sitting on 0.725 GWe.? Although the company itself produces 26 GWe, most of that is from fossil fuels.

• https://www.calpine.com/operations/power-operations/our-fleet/california/big-geysers
• https://calpineactsonclimate.com/wp-content/uploads/2021/08/Calpine_Final-2020-Sustainability-Report.pdf

It is the wholly integrated “geothermal plus” approach of Arctic Green in China that is most striking.? This is not geothermal in isolation, it is geothermal thought about in a holistic energy analysis, to see where it fits in best.? I have been looking at geothermal and the wider energy scene for a long time, singing this tune in my own way, and this was the first presentation where I have really seen it thought about – and put into practice at scale? - in those terms, in a place where geothermal is not featuring as a greatly anomalous heat flow.?? Without wanting to get too glowing, for I am sure there is no shortage of issues and complexities, I believe Arctic Green Energy and Sinopec are to be congratulated for setting a trend that I have no doubt will expand and continue.

What is particularly impressive about the alliance, is that here we have by many measures one of the world’s largest countries (I believe India is now ahead in population by a few million) and economies, co-operating with one of the smallest.? Precisely because - credit where it’s due – they recognise smartness when they see it – and Iceland’s renewable energy cluster (https://energycluster.is) is just that – smart.?

The really striking thing though is that despite the huge disparity in size of these two countries, the key drivers for instigation of these efforts are historically very similar.? Namely, a drive to achieve smog-free cities and a transition from fossil fuels, especially coal, amidst a drive to achieve domestic energy security.? That simple.??

If it can make sense for a country of 400 thousand, and if it can make sense for a country of 1.43 billion, then it can make sense for pretty much everyone in-between.? This to me is another profound message coming out of IGC 2024:? air quality and domestic energy security.? And in energy security is social security. ?If that at times comes at a bit of a premium, it comes at a bit of a premium.? It has value.?

GeoCities

A theme emerging over the past five years for me in geothermal application, and emphatically reiterated at IGC 2024 – not least with Reykjavik itself – is the importance of cities in driving geothermal development.? The urban planning session at the conference spoke directly to this aspect.? The greatest progress is overwhelmingly in a district heating perspective.? Either with direct use of medium depth heat or heat-pump assisted use of shallower depth heat.?

It is something that continues to progress at 100 MWth scales over time in many cities, often quite “under the radar”.? For perspective, a single geothermal well might typically deliver something in the range of a few MW (MWe or MWth).? There are stellar examples that go double digit, but they are not the expectation in Earth’s more typical geotherms (a geotherm is here shorthand for a geothermal gradient, i.e. an approximate temperature-increase per km).? Typical binary power plants – the usual modern application in all except the highest temperature and enthalpy settings - range in size from 1 to circa 50 MWe, but something kicking around 10 MWe is the likely average.? The bigger 100 MWe-plus non-binary dry steam and flash power plants are (presently at least) limited to higher temperature regions of very visible surface geothermal manifestations.

So for cities to be enacting, quietly in the background, multi-stage, multi-well district heating systems that are reaching up into totals approaching the 100 MWth scale, is the biggest and most frustratingly under-told story in geothermal today.? ?

Around 600 MWth is related to deep reservoirs in Paris Basin (Boissavy et al 2019).? Szeged in Hungary has a geothermal heat system delivering about 205 MWth (https://geotherm.szetav.hu/).? Reykjavik of course has long been leading the way with its 750 MWth system.? Munich region utilises about 325 MWth and 40 MWe (https://geothermie-allianz.de/en/geothermal-in-bavaria/).? Boise, in Idaho, has a system of about 100 MWth (NREL).?? Aarhus Denmark is actively constructing a system expected to be 110 MWth.? Zakopane/Podhale in Poland has a system kicking around the 40 MWth ballpark. China is deploying shallow and deeper geothermal district heating systems in Beijing, Tainjin, Tanggu, Xianyan/Xiong’an, Renqui, Dandong, Yingkou, Tengchong, and Xi’an.?

Studies are prolific elsewhere – up to ~ 260 MWth has been contemplated in Utrecht Netherlands (Liu et al).? Budapest is planning a 150-200 MWth project.?? Vienna is looking at a 20 MWth system initially, with plans eventually to increase overall capacity tenfold.? We learnt at IGC 2024 from Vlatko Kova?i? about Karvolac in Croatia seeking its own system, probably in the 10 MWth ballpark initially.?

We talk about a future of geothermal scaling up – but this is geothermal scaling up already in the here and now.? Cities.? Heat.? To be clear, not every city has the resources these cities do, and not every city may be looking to heating as the greatest priority.? For many cool may be far more important, but as the next section talks to, geothermal is not without possibilities here too.

Geothermal Heat, Cool, Desalination

2 GWth geothermal heating capacity from five cities in Europe. That tells us something. Admittedly five of the stars, but it’s not something we hear said very much.? Even as we devote a lot of attention to new technologies delivering say 3MW per well. That’s not to sneeze at the latter.? Progress is progress wherever it happens, but it can be frustrating at times that the scales of these ongoing, if admittedly long-lived city-scale efforts, are not communicated better.?? It is the single biggest success story of deeper geothermal in the world today.? Addressing the needs of cities, where 56% of the world’s population lives in 2024, and where by 2030 it is likely to be above 60%.

Let’s though, consider the megacities of Latin America, Asia, and Africa.? Although everyone likes hot water occasionally, it is often the cool in these cities that is in greater demand.? The potential contribution of “geothermal” resource in a wider sense to a cooling application comes in two fundamental modes.?

The first it not in the strict sense geothermal, as it simply takes pre-existing cool from fluids at the surface and stores it in subterranean reservoirs that are sufficiently shallow and have sufficiently thermally insulated reservoirs (e.g. sandwiching shales, basalts).? This, to preserve that cool and reutilise it on demand, in daily or seasonal cycles.? This typically known as aquifer thermal energy storage or ATES.? The same can and is being done for heat – especially in China and Netherlands, and increasingly in other parts of the world – but storing cool is another option.? This is particularly possible in the many cities of the world that coincide with deltas and estuaries, adjacent to lake or sea, that can make use of favourable geology and favourable juxtaposition with relatively deep and cool water.? Such things seem set to take off – and Paul Ramsak at IGC 2024 spoke to some of the options.? ATES however is not per se geothermal “generation” of cool, rather subsurface preservation of it.?

One of the intriguing applications of lower temperature geothermal for cooling though, is absorption and adsorption chillers, which can function with lower temperature heat in the 80 deg C bracket that is widely available in many geothermal reservoirs around the world.? Adsorption chillers adsorb the water on to a solid while absorption chillers dissolve the water into liquids.? They are similar though in principle and both use evaporation, absorption or adsorption and condensation to chill water, and take advantage of either a solid or liquid to adhere to and collect water.

They utilise liquid refrigerants such as water to boil and evaporate, extracting latent heat of evaporation in the process and leaving remaining liquid cooler as a result, for extraction and use.? Unlike compression cooling units, they take the evaporated gas back to a liquid without use of electricity by using absorption or adsorption chambers filled with a particular absorbent or adsorbent, which may vary.? They take advantage of either adsorption or absorption - allowing water to adsorb or absorb in/to a solid/liquid, with consequent desorption at a particular temperature, humidity and pressure setting.? This in turn allows condensation and conveyance to a different temperature and humidity and pressure setting, where evaporation takes place (i.e. in the evaporator) where circulation water can be chilled as it provides the latent heat of evaporation and cools as a result.

In any case, it is a bit of a mind bender getting the head round these processes but suffice to say they allow cool to be generated out of heat in the 80-120 deg C bracket that is not really commercially viable for geothermal power generation.? A bracket that is widely available at less than 3km depth in many regions of the world.

In the same vein, we have options for geothermal desalination processes like Multiple Effect distillation (MED), membrane distillation (MD), and multi-stage flash (MSF) which can work with temperatures of 65-80 deg C to produce fresh water. ?With MED, the most widespread form of thermal (as opposed to non-heat dependent membrane based) desalination, the vaporisation at lower temperatures is facilitated by chambers of different pressure.?

The catch with both geothermal cool and geothermal desalination is that these are all considerable and not cheap extra bits of kit, on top of the already present costs of geothermal drilling.? So, of course the key question is precisely how much cool or how much fresh water can be generated and at what cost.? Given the number of geothermal wells that are feasible in particular locations, these may often be more of a local assistance that truly city scale solutions, but in places where the price of cooling and the price of fresh water is especially high, they may have a useful and significant contributory role.?

Geothermal heat for cities though is a staple.? It comes as is, with little modification required to use it, via heat exchangers and pipe infrastructure.? In some places it might require the added costs and power needs of heat pumps to provide required temperatures, but in the remaining years of the 21st century, it would seem a no-brainer for cities to map and understand their subterranean heat resources and make use of what is there.? Many cities are placed where they are originally, precisely because there are aquifers.? This is not a confluence that is as rare as we might imagine, and the small land footprint of geothermal energy deployment fits in beautifully with urban applications. ?The IGC 2024 session on heating and cooling placed these elements in apt focus.

Geofood

If cities are one great under-told story of medium to lower temperature geothermal applications, then food and drink processing is another.? The sheer diversity of food and drink applications able to take advantage of lower temperature/enthalpy geothermal heat make it an obvious partner to geothermal usage.? Not least because related plants can often be very sizeable – of a capital expenditure in their own right to take on geothermal investment in their stride.?

At the other end of the scale though – and once again, as exemplified by Iceland Renewable Energy Cluster and business park examples - is the ability to cluster smaller food and drink production organisations to take advantage of collectives of renewable energy of different type.? In such collectives, geothermal energy can be a key component where risk is spread with other options, when the foresight is taken to site such clusters near to potential or proven geothermal resource.? The examples from IGC 2024 in Kenya and Iceland are notable in their diversity, and in their application to climates about as diametrically opposite as one can be.? If it can work for these climates, it can pretty much work for any climate.

Baseload?

I admit to being at a bit of a divergence with many on the subject of “baseload” and its future relevance.? Baseload, if we take the US EIA definition of the term represents “The minimum amount of electric power delivered or required over a given period of time at a steady rate”.?

Geothermal, along with bioenergy options and nuclear, traditionally uses “baseload” as a key selling point.? These are the most able amongst the “low carbon” or “renewable” options to deliver steady 24/7 supply at some “base” level.? Hence baseload.?

That ability of course continues.?

The area where things are changing is in the partnering of renewables with energy storage of various types.? Whether it is batteries, pumped hydro, liquid and compressed air, etc., there is a growing number of options that partner intermittent surface based low carbon energy resource with?energy storage of various types and duration to provide “quasi-baseload” equivalence.? Just though, as geothermal has the burden of drilling costs, energy storage also has the complication of added construction costs, and often added land footprint and/or other mining impacts.? So the tussle has become more interesting.? Way more interesting.

The thing is, the introduction of this new component impacts the customer planning attitudes, especially in times of relative uncertainty about what is going to become cheaper, and what is going to become more expensive.? Baseload is attractive if it ties a customer into a cheap power or heat price for a long time.? But in times of so much uncertain development and evolution of heat and power price – is it?? Is it the desire of the customer to bet long term as much as it used to be, when so much is in flux??

For now at least, this is compounded by the fact when solar or wind energy is available, it is typically cheap.? So far, more to the point, without making any presumptions about perpetual continuance of the trend, it has been becoming cheaper with time.? That means any energy customer who has done their homework recognises that there will be times when cheaper energy is available from intermittent renewables.? That impacts any desire to commit longer term to more expensive, but potentially more secure types of energy sourcing.? Note I said “impacts”, and not “removes”.? The customer still wants that security for when the intermittent sources aren’t there.? So, a key question is how much energy storage options with intermittent renewables provide that.? Or if, even despite that, there is still value in the assurance of an assured “baseload” style delivery.?

It raises the possibility that hybrid heat and power purchasing agreements that involve both geothermal and other intermittent renewables and energy storage options, (including hydroelectric in that) are likely to become more competitive than purely geothermal power and heat purchasing agreements.? This is because it allows the customer to take advantage of the cheapest energy when it is available, and store the less cheap, for when it is not.? This is something that an increasing number of companies are seeming to get.? Not least the Arctic Green Energy – Sinopec partnership with its “geothermal plus” style approach.?

To proclaim that baseload is dead is at times tempting.? Perhaps a little premature, but what is clear, is that dispatchability and load following versatility is clearly an increasing demand.? The competitive landscape for power and heat has changed fundamentally and permanently. Whatever geothermal does in the future, its competitiveness will be increased if it moves from focusing just on baseload and into the options for delivering versatility and diversity of supply to a customer.?

Once again, that can be easier if the customer is a collective, an industrial hub, than if it is a sole customer from a sole company.? In a world where cheaper intermittent energy supplies are periodically available, “baseload” can for many be a disadvantage, if it freezes into contracts a reliance on a more expensive energy source.? Awareness of how to blend geothermal with other energy sources so that the optimum is delivered to the customer, will dictate, I believe, who succeeds in geothermal, and who doesn’t.? That’s not necessarily a simple formula, but those who rise to deal with that complexity are likely onto a long-term winner.

Local jobs

There is a bit of a danger to thinking local employment can sell everything or is a reason in itself for pushing for something.?? The reality is that anything new can provide new jobs.? The best job security always comes from what works best, and that should be the focus.? The reality is also that the number of jobs related to geothermal projects is typically more of the tens and hundreds scale than the thousands.? That said it is impossible to not point out local employment as a key attribute and bonus of geothermal projects, and especially geothermal heating projects.?

We have earlier talked about one of the disadvantages of geothermal heat as being a transient resource requiring customers and use close by.? At the same time we note up to 25 km is not impossible for modern geothermal heating networks and large resources – such as at Hellisheiei for Reykjavik.? Larger distances become more problematic.?

Given the growing awareness of geothermal as an option, and a wealth of customers and applications that have some degree of location flexibility (food processing & drying, algae & greenhouse cultivation, data centres, timber drying, paper manufacture, aquaculture, etc.) there is a growing knowledge of how commercial levels of industry can be assembled where resource is, that historically has been more bit lacking.? Steadfast geothermal-heat aware countries like New Zealand, Japan, Indonesia, China, Iceland, US, Kenya, Philippines, are leading the way in these things.

The corollary though, of this general inability to take geothermal heat very far away is that while it is limiting in some ways, it is great news for local community employment.? Geothermal heat is good news for local jobs.? This is being demonstrated time and time again throughout the world, with great examples throughout the IGC 2024 conference.? It does not necessarily mean an influx of huge numbers of jobs, but it does mean a number of jobs that are often greatly impactful for the smaller rural communities where geothermal resource is sometimes extracted.? The customer follows the resource location, and hence so do the jobs.

Not everywhere is Iceland, but…

IGC 2024, I suspect for anyone involved in any way in geothermal, has been an excuse to see geothermal at work in Iceland.? This is a special place.? This is the only place on the planet where a mid-oceanic ridge plate boundary emerges above sea level.?? Seeing the structure and geomorphology of that as a geologist was a huge insight.? To witness, albeit briefly and distally, an eruption taking place along it, was icing on the cake, with all deference sensitivity to those whose livelihoods have been affected or disrupted by such things.?

It does nevertheless serve to drive home the point that Iceland is special.? The resource it has is not to be found everywhere.? It is hotter in the subsurface than most other places, which means equivalent temperatures are shallower and cheaper to access than most other places.? The very nature of a mid-ocean ridge style structure means that the heat is widely distributed.? So I suppose that means we need to limit our expectations of how globally applicable such usage can be.? Or at least to recognise that other modes of energy sourcing will be more competitive against geothermal elsewhere than they are in Iceland.

This is a country after all bestowed equally generously with vast amounts of wind and water power. You only have to take a walk around a Reykjavik headland, or visit Gullfoss falls, to get a sense of that.?

Yet what Iceland has demonstrated emphatically to the rest of the world is really two key things.

Firstly, where you have significant direct use heat resource available, use it.? It makes sense.? It frees up everything else for everything else and provides domestic heating energy security with a clear air bonus.? Using heat for heat is the most efficient use of geothermal heat resource.?? If I understand correctly modern heat exchangers operate in the 98-100% efficiency realm, so what’s not to like.?

Secondly, collaborate and plan energy of all flavours.? Optimise use of whatever it is you have.? This is something that is translatable anywhere.? It would seem that in Iceland a financial crisis precipitated such collaboration and planning, but we have no need to wait for a crisis, having already been able to witness in the Icelandic example how successful this can be.??

Admittedly in smaller countries like Iceland, it might be a bit easier, because energy professionals are more familiar with each other, and it’s easier to get the CEO’s, COO’s and CTO’s in the same room as national and municipal policy makers and technical professionals, to plan.? We should not in large countries take that as an excuse not to try.? The value of doing so is something Iceland has demonstrated amply, and one of the reasons no doubt that China has proven so keen to partner with them in things geothermal and in holistic renewable energy integration.? Including the development of industrial energy clusters and hubs.??

Municipalities, local governments, and departments of trade

It has long been a mantra of mine, but it seemed undiluted after attending IGC 2024, that local government, and particularly that of cities, has a key role in driving optimal use of energy resources on their own “turfs”.? They know the land, they know the businesses, they know the public.? That enables them to take bold initiatives in a given place where a central government might be more hesitant and simply unaware of the potential.?

What was equally interesting to me, particularly in some examples from Africa, was that where central government was taking a leading role, it tended to be the departments of trade and industry rather than the departments of energy.? In some places they are one and the same, but it was to me notable, and makes perfect sense given the nature of geothermal.? A sense of geothermal essentially being “customer driven exploration and production”, leads logically and almost inevitably to the most productive conversations taking place with those who best understand business and trade in an area.? Not necessarily with those acquainted with national level energy issues. ?They, without putting too finer point on it, are more often beholden than is helpful to historical vested interests. ?

What place geothermal power?

It would be possible in reading this far perhaps (if you have – my thanks!), to get an impression that I am more enthusiastic about geothermal heat than power.?? In one context, that is true, it is where I see the already manifesting global scalability of geothermal happening in a way that seems set to continue.?

That, however, is not to dismiss the important role geothermal power has to play.? Particularly in places where high heat flow is obviously manifesting, and the temperatures required (>140 deg C) can be reached at fairly shallow depths.? In such places it makes perfect sense to make use of such heat, simply because of the versatility of power.? Only so much of it can be used directly for heat applications, and so a surplus inevitably exists in these very hot areas.?? Geothermal power generation, to be clear, is not the most efficient use of heat – since the translation to power involves efficiencies typically in the range 8-20% - but efficiency only matters where there is constraint on supply.?? Where there is a constantly renewing sustainable resource, using it at 20% efficiency is a big win over not using it at all.

Binary power plants are also a game changer.? They can range from the small 1 MW size single well based outfit to the 100 MW Ngatamariki plant in New Zealand.? Dry steam and flash geothermal power plants get even bigger, in areas where steam is available.? But ORC Binary plants can utilise medium enthalpy resources and have the added advantage of isolating the geothermal fluids from the working fluids of the plant, so any emissions that might take place naturally are typically vastly reduced.?

Although the situation is dynamic, probably a concerted effort to deploy geothermal heating assets in relatively immature areas for geothermal development can lead to a better understanding of where local geothermal power resource might also be present.? A great example of where both have been walking and developing hand-in-hand, one helping the other – is in the Molasse Basin of Bavaria south of Munich, as mentioned previously.?

At the same time, we see the emergence of EGS approaches in the United States, and R&D happening on the supercritical superhot front – including in Iceland.? What we have to recognise is that in most places going hotter means going deeper and that means an increase in costs and an increase in risk.? With supercritical may come the prize of an order of magnitude more power, so it is perfectly sensible to contemplate, but always the challenge with geothermal, is not just to drill to these objectives, but to maintain production reliability for the life of a commercial geothermal plant.? Especially if the fluids involved are hotter and more chemically aggressive, as is typical of very high enthalpy geothermal.? So while many reasons exist to be cheerful, the commercial effectiveness of any new approaches do take a while to prove-up with repeated case studies.?

The other thing that has to be said about geothermal power, is that it operates in a far more competitive playing field.? It is not enough to produce geothermal power profitably – the requirement is to do so more profitably than the competing sources plus or minus any associated energy storage requirements.? So, geothermal power definitely continues to have a new and growing role, but it does have to swim faster in a much bigger river, with a lot of other swimmers vying for the same finish line.? Not that power can’t be used to produce heat fairly efficiently, but with global electrification drives taking place, the sense is people are going to want all the power they can get for power.? If geothermal heat for heat can free some of that power diversion up – it has an added fair wind behind it that geothermal power doesn’t.? That doesn’t mean geothermal power doesn’t have a role, but it does mean that geothermal heat is an easier sell on many counts in many places.

Geotherms versus diagenesis

There is another very real physical reason why geothermal heat is fundamentally more scalable than geothermal power.? Essentially up until about 2.5-3 km, with some exceptions, it is mostly physical compaction processes that influence the porosity of sedimentary reservoirs, especially clastic ones (as opposed to carbonates).? That means porosity and permeability decrease gradually but fairly predictably with depth.? After about 2.5-3 km though, a whole range of diagenetic processes start to kick in that start to occlude porosity and permeability.? This means the risks and the chance of success increase significantly deeper than this 3km depth ?threshold. Especially give that our requirement is for excellent reservoir to produce the volumes required for profitability. ??

So let’s assume 15 degrees at surface and a typical geotherm of around 25 deg C/km.? We are talking 3x25 + 15 = 90 degrees C.? So, that’s telling us that power temperatures are in normal geothermal gradients targeting a risker geological domain deeper than 3km.? Geothermal heat however, is not.? It sits more comfortably around that 2.5 to 3 km threshold.? Except in places with exceptionally high geothermal gradients, we can therefore expect geothermal power to be targeting a diagenetically tougher geological reservoir chance of success, whereas pursuit of hydrothermal heat source for heat is a much more assured pastime. ??

Again, this is not to imply this is some kind of show-stopper for power, it just emphasises another reason why geothermal heat is inherently more scalable than geothermal power.?? It’s just easier – that simple. ??For all the great things discussed about geothermal power potential at IGC 2024, the striking thing discussing heat applications, is that they are already pretty much global in distribution, volcanic area or not, and progressing apace, with size that is respectable.?

It’s only long-lived if you look after it.

The longevity of geothermal power, at a 24/7 provision level, is one of its great and oft-used selling points.? However the corollary to that is that things are only long lived if you look after them.? Talking “off the record” to many long-experienced geothermal operations experts, there is a bit of a general consensus that geothermal maintenance is not what it could be.? We have already mentioned the vastly greater volumes of water that need to be involved in profitable geothermal operations.? Given all the rock-sourced chemicals naturally tied up in one of the world’s greatest solvents percolating through rock, along with all the temperature and pressure changes – that means scale and corrosion is an inherent aspect of geothermal.? It was great then to see the topic taking a prominent role at IGC 2024, including the innovation award to Blue Spark, with their “High Pulsed Power” technology for scale treatment, amongst other downhole maintenance issues.? (https://bluesparkenergy.com/bluespark).?

Places to ponder

The reality is that pretty much everywhere does have something to think about in “geothermal” terms in a wide sense of the term, incorporating everything from shallow geothermal with heat pumps to the superhot power stuff.? It does however vary considerably from place to place.? Those countries with obvious surface manifestations of high geothermal heat flow – volcanism, widespread thermal area manifestations – will of course have an ongoing relationship of geothermal utilisation for both heat and power. ??

Complicating matters, there are some of those where the geothermal manifestations are located in areas that are largely remote from population and industry.? The most obvious of these is South America.? However, the increasing awareness of industries that have flexibility to locate anywhere, bodes well for these countries – as does a general move towards electrification in every country.? The latter implies greater development of national grids than exist at present.? That may increase access of geothermal power resource to geothermal power customer with time.?

However, and it’s a big however, there are many more other countries and regions where the interesting story is underexploited hydrothermal heat. ?At IGC 2024 Iceland’s former president mentioned, nay, singled-out India.? To the extent that I almost felt a bit picked on for any Indian delegates.? ?To be fair, I get the sense that Iceland and India have been talking already and it was more of a friendly jibe. In discussion with some of those Indian delegates there is an obvious barrier for hot places though, isn’t there.? Mumbai isn’t at first glance the kind of place we imagine crying out for a district heating system.? ?Yet to imagine heat isn’t widely used globally is the misconception we battle.? Concrete block drying.? Timber drying.? Food drying.?

A point well made at the conference (forgive me, I forget by which delegate but I believe one of our ?Kenyan colleagues) is that drying food preserves saves the costs of much more energy intensive refrigerated food transport. ?And while geothermally cooling and desalination are somewhat tougher propositions from a commercial point of view – progress and research and pilot deployment – including at Masdar city in the UAE - is ongoing.? ?Hot countries use heat.? Let’s work to dispel the notion they don’t.? They might not want it to heat the living-room, but they want and use it.

So, there are places where I see immediate application for this lower to medium temperature geothermal.?? Many of them are places where historical oil and gas exploration means we already have a great understanding of subsurface reservoirs that can be put to good use.? So I think, like ?the esteemed former president of Iceland, of heat applications not only of the Indian subcontinent, but also of the Middle East and North Africa, of southern and Eastern Europe, of Central Asia, and of the forelands of great mountain chains around the world, including the Andes, Rockies, Himalaya, Tien-Shan.? And of alpine and arctic regions, where the cooler air temperatures mean geothermal heat gives added punch in terms of energy delivery, usage options, and impact.?

Not really a gold mine, but we don’t need it to be

As someone who has worked a little bit with critical minerals and hydrocarbons historically – I tend to veer away from talk of geothermal energy as some new gold mine personally.? Of course it has value – if it didn’t we wouldn’t be talking about it.?? Yet I am chastened by my own look at the UK.? The very feature of geothermal and hydrothermal energy is that the value per volume delivery is much lower than other commodities.? I have no compunction in being honest about that because I believe that it is only in doing so that we can utilise it effectively.? To recognise that we need much bigger volumes to be profitable is not some showstopper, it is a guide to appropriate focus on areas that can deliver just that.? We don’t need it to be gold for it still to be useful.?

A case in point is the recent discovery of 55 degrees C water in a town of West Iceland, where traditionally geothermal resource has been less intense are less utilised than in other parts of Iceland.? Allegedly local media have been trumpeting the finding of ?geothermal “gold”.?

Now don’t get me wrong, the blessing geothermal energy has been to Iceland means we can happily accept their enthusiasm for talking about such discoveries in these terms.?? They know well how to put such discoveries to great use.? ?The reality though, is that hot water is not gold.?? It’s not oil.?? It is something we need way more of to be commercially viable with.? That is the key challenge.?

Commercial innovation – tough but doable

This is why, for all the great things happening with geothermal & drilling technologies and in operational maintenance, the thing that most grabs my attention for propelling geothermal forward, is commercial innovation.? I’ve been trumpeting that tune for some years now, and I’m not alone.? I can see it gathering momentum, like some snowball rolling down the hillside.? I’m not expecting some great global salvation from geothermal personally – there is a reality that digging holes is always expensive and evaluation of subsurface resource that is time consuming - ?which means it will always have fierce competition.? But there are enough places where the scale of resource is good enough to make those costs worthwhile, and for it to rise up from being a <1% contribution globally to something bigger.??

I’m not the most enthusiastic proponent of targets but If I had one mentally, it would be for 5% of primary energy as an ambitious yet potentially doable one.? The biggest activator to that I see, controversially perhaps, not as technology – though it can help – but rather the commercial and policy innovations that recognise the benefits geothermal energy can bring and integrate it more fully.??

This is – to be clear - not easy.? Yet it is intrinsically doable, and far more certain of delivering reward with patience, than unproven new technologies.? The latter have their place but have a much larger associated risk.?? Commercial innovation is not glamorous, it is at times tedious, and filled with constant setbacks.? However, it is fundamentally doable.? Fundamentally doable.? Where there is a will, and where there is awareness.? The latter is the key to the former.?

Scale expectation - Saving the world versus helping communities

Having mentioned a global target, the lesson which will endure with me from IGC 2024, is a more local one, simply the ongoing story of help to local communities that geothermal, in all its various flavours, has given and continues to give.? Steadily, incrementally.?? Sometimes at a bigger scale than others – but almost always it is the low carbon, low land-footprint domestic energy security for a community or city that has helped clinched the deal.? With a bonus of not huge numbers of local jobs but nevertheless steady ongoing jobs that are tied sustainably to the locations involved.?

I sometimes run a bit counter to tide in that I believe expectation management is an important part of deploying new things.? Longer term credibility matters, so being honest about what can be delivered, and managing to deliver it, is more important in the end than being enthusiastic. There’s nothing wrong with enthusiasm, but it is not that which carries the day in the end.?? It is success. ?What geothermal resource can deliver, in joined-up integration with other resources, is good enough without needing to exaggerate it.

Itching to go like an iFarm ichi-go

Yet, for all that, genuine enthusiasm is indeed contagious, and IGC 2024 had plenty of it.? The talk that sticks in my mind is that of Ken Noda, from iFarm in Iceland, located very close to Keflavik airport ( https://en.ifarm-inc.com ).? A smaller but dedicated firm taking advantage of geothermal heat to grow Japanese varieties of strawberry – initially for local consumption – In Iceland.? Japan, as Ken explained, has a special relationship with strawberries – being the world’s largest per capita consumer, and originator over 300 varieties, - more than half the varieties in the world.? Japanese strawberries being renowned for their sweetness.?

This to me was emblematic of so much of where geothermal is heading.? Japanese strawberries grown in Iceland are not going to change the world necessarily.? Not without hitherto undiscovered superpowers…? Yet here is a story that is replicable anywhere with renewable resource.?? An enthusiastic, enterprising business, seizing opportunity to take advantage of local cheaper energy to deliver local goods with local jobs, providing long term security against things that would otherwise be imported at greater cost and greater environmental impact.?

Japanese strawberries from Iceland might not be earth shattering in themselves, but this kind of thinking just might.

Where to for Paetoro geothermal?

If we are honest, I think for many of us involved in geothermal, it can be a labour of love rather than immediate income security.? There is a lot to understand that is not necessarily easy for newcomers to the topic, and a competitive energy marketplace.? Commercial awareness and regulatory frameworks and understanding of local resource possibilities take time.?

There can be weeks where we ponder whether the ongoing effort is warranted.? I came away from IGC 2024 with the affirmation that yes, it is.? Precisely what contribution geothermal brings to the remainder of the 21st century and beyond, only time will tell.? Yet it seems certain that the increasingly holistic approach to its integration in a wider energy equation is set to expand deployment. As a geologist, for reasons already stated, I believe that contribution will be weighted heavily into heat applications.?

That then is where I rest my remaining efforts – mainly in the lower to medium enthalpy heat domain, and to an extent the binary power plants possible hydrothermally in areas where heat flow is a bit elevated.? I look particularly to the application of geothermal to industrial and district heating uses in a way that is only just beginning but which is already achieving scale.? In some places, this resource is complemented by the more obvious higher enthalpy heat for both power and cascaded heat.

There are some regions I particularly look to, as having been in “shadows” of geothermal development to date, for whatever reason.? These include South America – not just the volcanic resources of the high Andes, but also the lower temperature forelands to the east of them.? Chile, Argentina, Peru, and Bolivia, amongst others.? Then also to SE Europe – the Pannonian Basin countries of Hungary, Slovakia, Croatia, Serbia, but also to Greece, North Macedonia, Kosova, and others in the region.? ?

Then, the Middle East, North Africa, and Central Asia.?? Places where hydrocarbon production obviously dominates so much of the energy scene now.?? And yet in 2024 even these countries are getting that there is merit to keeping hydrocarbon resources for a posterity that does not burn them and making the most of other rich local geothermal resources to help supply needs in the here and now.

If, going into IGC 2024 I was a bit hesitant and wondering whether to keep up the personal momentum on the geothermal front, Iceland has done a noble job of reaffirming for me that is it worth it.? Not because it will take over world energy.?? Rather simply, that where it can be deployed, it can help, at local, human levels.?

There is something that is a very raw and a very 2024-kind of human pleasure in Reykjavik, in taking a hot shower without feeling guilty about doing so.? Not to pretend that any sort of energy use is without impact or to be done wastefully.? Yet it is to know that there is a deeply human, deeply personal value and wellbeing - in recognising good local energy stewardship.? Something that we are far too slow to put a worthy price to.? ?

Geothermal can help.? Land efficient heat with air quality and social security.