Why don't we all just use Geothermal Energy?

so here's our planet as most of us are used to seeing it not rotating next to me above my desk obviously do you get what i mean what we don't see all that often is the stuff going on inside the planet the bit we all live on is this tiny crust on the outside and although it can be as deep as 40 kilometers in places it's still barely noticeable in the big scheme of things underneath the crust there's nearly 3 000 kilometers of mantle which is made up of silica rock and minerals it's still a solid layer but it's bloody hot the bit just below the crust can reach almost 900 degrees celsius and the deeper it goes the harder it gets until down here it's well over 2000 degrees c then you've got about another 2 200 kilometers of outer core made up mainly of molten iron anything between 3 000 and 3 800 degrees celsius and right in the center there's this solid iron core which is hotter than the surface of the sun at 6000 degrees c and why is it solid when it's at a temperature that's far higher than the melting point of iron it's pressure in it there's so much pressure from the layers surrounding it that the molecules in the core literally don't have the room to move around in any liquidy kind of a way so they stay firmly compressed together as a solid anyway i digress the point is there is a lot of heat energy captured inside our planet it's been there for billions of years and it will most likely be there for a few billion more and that heat gets into our skinny 40 kilometers of crust as well the bit we stand on is the same temperature as the air around us but it gets warmer and warmer the deeper you get until you reach the base of the crust which is at the same temperature as the mantle it's touching nearly 900 degrees celsius so there's a lot of heat available just below the entire surface of the planet as well so what we all know is geothermal energy and in theory we ought to be able to tap into it to provide a virtually limitless supply of heat and power for the entire planet with almost zero carbon dioxide emissions so why haven't we done that then hello welcome to just ever think the golden poster child of geothermal energy is of course iceland they're a long way north only about 250 kilometers away from the arctic circle with typical air temperatures that are often only just above freezing and yet they get much of their electricity and heat from geothermal energy so how come iceland have been so successful compared to most other parts of the world well that skinny crust i mentioned earlier is broken up into tectonic plates that can more or less move independently of one another anyone living on a fault line will know what it feels like when two adjoining plates push against each other until something gives you get an earthquake iceland straddles the eurasian and north american tectonic plates and those two plates are actually moving slowly apart and that's allowing huge amounts of heat from the mantle below to escape into the upper regions of the crust under iceland's landmass most parts of the earth's crust get about 35 degrees celsius hotter for every kilometer you go down but if you go down a kilometer below iceland you hit temperatures of about 200 degrees celsius that powers the famous icelandic volcanoes and the hot steaming geysers and it also provides geothermal heat very close to the surface that can be so easily tapped into that iceland has really got more than it needs they've built themselves seven geothermal power stations to generate electricity from the underground energy they still do it by driving a turbine to rotate an electrical generator just like a traditional fossil fuel or nuclear power plant but they don't need to burn coal or gas or fire neutrons at radioactive material to provide the heat to convert water into steam to turn the turbine they use a fairly straightforward system called flash steam a borehole is drilled about three kilometers deep and cold water is sent down into it the water gets super heated by the geothermal temperatures and expands into steam which then comes hurtling back up the other side to drive the turbine it doesn't rely on the weather conditions it's always on so it can be used for constant and predictable base load power and it produces negligible co2 emissions all that cheap electricity has allowed iceland to develop a thriving aluminium industry that now accounts for about 40 percent of the island's exports turning iceland into one of europe's richest nations they also pump geothermally heated water all over the island in a network of heavily insulated pipes to provide district heating for homes and businesses and greenhouses that supply a rich variety of healthy food for the population they've got so much spare hot water they can afford to heat outdoor swimming pools all year round and even pump some of it into freezing lakes to keep bits of it warm enough for the fish to survive through the coldest months of winter but on a global scale geothermal energy only accounts for about one percent of total electricity capacity so why aren't we embracing this seemingly inexhaustible carbon-free natural resource more enthusiastically well the answer is that some countries are going for it but most of them are located on or near to the fault lines where tectonic plates butt up against each other of the 20 or so countries currently generating geothermal power the united states is the largest producing about 2.5 gigawatts worth in 2019 with 725 megawatts coming from the world's largest geothermal plant at the geysers located in the mayakamas mountains about 30 miles north of santa rosa in california then comes indonesia the philippines turkey new zealand mexico kenya italy and japan in 2018 the international energy agency predicted growth of as much as 4.5 gigawatts in geothermal energy production in the five years from then until 2023 which would have equated to about five percent growth per year but in their latest tracking report released in june 2020 they found that growth has only been about three percent per year and that geothermal energy is not currently on track to reach the sustainable development scenario or sds which the iea published as an outline of how to meet the energy related components of the united nations sustainable development goals to contribute to hitting those goals alongside other renewables like solar wind and hydropower the iea say that geothermal energy production would need to grow by more like 10 per year between now and 2030 but to reach that target geothermal energy needs to be adopted on a truly global basis which means finding ways of tapping into our planet's energy in all the other countries of the world that aren't fortunate enough to be located above fault lines a system called binary power is an alternative to the more traditional flash steam system in a binary system hot water from a naturally occurring underground aquifer is pumped up into a heat exchanger where it gives up its heat to a secondary fluid that has a much lower boiling point the secondary fluid then turns to vapor to drive the turbine the beauty of this system is that it only needs the water to be at about 100 degrees celsius so in theory you don't need to drill so deeply to hit the right temperature and that makes it a system that could be used by many countries regardless of their location but you still need to get at the hot water however deep it may be and you still need to ensure that the supply doesn't run out and that brings us to the increasingly contentious subject of enhanced geothermal systems or egs the united states office of energy efficiency and renewable energy offers this neatly sanitized explanation of how egs works the egs concept is to extract heat by creating a subsurface fracture system to which water can be added through injection wells creating an enhanced or engineered geothermal system requires improving the natural permeability of rock that reminds you of anything sounds a bit like fracking doesn't it and although the liquid injected down into the fractures is just water and not the nasty concoction of chemicals and abrasives that get shoved down the fracking lines and even though it's a much lower pressure than hydraulic fracking it is still designed to open up natural rock fractures to create underground reservoirs of water and there are plenty of geologists and geophysicists who think that that increases the risk of earthquakes in those areas egs has been linked to a 5.5 magnitude earthquake in pohang south korea in 2017 causing 75 million us dollars of damage in an interview for this 2020 article at yale's climate connections website john olly cavan a research physicist with the u.s geological survey explained these faults are going to slip eventually but egs can certainly speed up the clock but of course all the other environmental climate and energy security benefits of geothermal are extremely compelling according to this 2017 study the energy reserves in the upper 10 kilometers of the earth crust are approximately 1.3 times 10 to the 27 joules which probably means as little to you as it does to me but the study says those reserves could potentially supply all our global energy needs for approximately 217 million years so the motivation to get these egs systems set up around the world is very high as the director of the geothermal resources council will pettit puts it you can effectively put a power plant anywhere all you have to do is drill deep enough and you will find hot rock so maybe with the right regulations in place we would still have a workable solution right well possibly but even if that were the case there remain some fairly big technical and economic obstacles in the way of geothermal progress drilling is very expensive and there's no guarantee of success when the pressurized water starts getting pumped in you might not open enough decent fractures to make the project economically viable in which case you've wasted a lot of time and money try selling that concept an investor pitch presentation and you'll find your audience thinning out pretty quickly there are also minerals like quartz and limestone in the rock formations which are already saturated into existing aquifers and can also contaminate new water being pumped in these sorts of minerals can cause scaling and fouling that can lead to failures and components like pumps and heat exchangers and that causes expensive delays which again hits the economic viability of a project so as the prices of solar panels and energy storage have tumbled over the past decade so large corporate investors have found themselves much more inclined to put their money into that technology and wind instead nevertheless at the cop21 climate conference in paris in 2015 the iea sister organization the international renewable energy agency or irena was instrumental in forming the global geothermal alliance or gga gga is a coalition for action to increase the use of geothermal energy both in power generation and direct use of heat calling on governments businesses and other stakeholders to support investment in geothermal energy's potential the goal is a five-fold growth in install capacity for geothermal power generation and more than twofold growth in geothermal heating by 2030. there are currently 46 member states and the alliance aims to support those countries with four priority actions to identify and map geothermal resources around the world scope out the assistance that countries may need with regulation and policy support the development of legal fiscal and infrastructure capacity and promote geothermal's role in supporting decarbonisation and the implementation of national climate plans just like all other renewable energy sources geothermal energy will be a major element of many of the nationally determined contributions that participating nations are required to present at cop26 in late 2021 if the safety of the systems can be properly assessed and regulated and some of the technical challenges can be overcome then perhaps this ancient energy source first tapped into by the romans in their hot water spas could become a major player in our 21st century transition to a more sustainable carbon neutral future that's it for this week before i go i just want to let you know about an initiative called the google.org impact challenge on climate it's a 10 million euro fund to support bold ideas that aim to use technology to accelerate europe's progress towards a greener more resilient future selected organizations may receive up to 2 million euros in funding and possible customized post grant support from the google for startups accelerator to help bring their ideas to life they're looking for ideas that address topics like increased access to our use of renewable energy decarbonisation of transportation improvements to air quality natural resource planning and protection and circular economy and design applications are open now but the closing date is november the 6th so if you've got a bright idea that needs some funding then go over to the address below to have a look at the entry criteria and i'll leave a clickable link in the description box below as well i must also say a big thank you to our amazing supporters over at patreon who allow me to keep the channel ad free and maintain independent content you can support the channel as well and have your say on channel content in monthly polls by visiting www.patreon.comthink and of course you can hugely support the channel absolutely for free by subscribing and hitting that like button and if you want to be notified when new videos come out then make sure you hit the little bell icon as well dead easy to subscribe you just need to click down there somewhere or on that icon there as always thanks very much for watching have a great week and remember to just have a think see you next week you

Channel: Just Have a Think

Views: 877,487

Rating: 4.9114408 out of 5

Keywords: geothermal, geothermal energy, enhanced geothermal systems, renewable energy, sustainable energy, climate change, climate crisis, climate emergency

Id: -Ss_wHCS1Aw

Length: 14min 38sec (878 seconds)

Published: Sun Sep 27 2020

Reddit Comments

[u/HoneyGlazedBadger]

In fairness, Iceland's 750 megawatts goes a lot further, seeing as there are only 365,000 Icelanders.

[u/NedryIsInSector1104]

Doc, what the hell is a jiggwat?!

[u/brock_lee]

And we have almost 1,000 times as many people as Iceland.

[u/PM_Orion_Slave_Tits]

Wow, they can power over 2 flux capacitors

[u/nullcharstring]

The US also has a large number of undeveloped potential geothermal sites, mostly because investors don't consider building a power plant on top of a volcano a safe investment.

[u/The_God_of_Abraham]

The US also generates more than twice as much nuclear energy than anyone else--more than 30% of the world's total, and 20% of total US electrical production.

And since nuclear energy is that only scalable, reliable, zero-emission energy source that humans have, it's reasonable to say that the US is leading the world in green power.

Of course, no one ever says that, because there are narratives to maintain.

[u/Youpunyhumans]

America also has literally 1000 times the population of Iceland...