Geothermal — Silver Bullet of Clean Energy?
This article was inspired by my trip to Iceland last year. I loved the country’s nature, people, geysirs and its approach to clean tech. So I couldn’t help but wonder, why are we not all tapping into geothermal? Enjoy the brief intro to the topic!
What is going on?
In the search for clean energy to power our lives, there is an overlooked candidate right beneath our feet. The geothermal energy, coming from the heat of the planet, lacks the prestige of wind and solar despite having an enormous potential to support energy decarbonisation efforts. It is estimated, that just 0.1% of the Earth’s heath could support humanity’s total energy needs for 2 million years! The energy is harvested by drilling a hole (a well), injecting water down the shaft, where it is heated by the rocks before being pumped up to the surface. This hot water can be then used both for electricity creation (spinning turbines) or simply for heating buildings. Unlike solar or wind, geothermal energy provides baseload power, meaning that it is continuous and not dependent on sun shining or wind blowing.
Harvesting geothermal energy is more accessible with heat being closer to the surface — think back to your geography class and the locations on tectonic plates, with volcanos, earthquakes and geysers. As such, it is no surprise that countries with the most geothermal energy generation are USA, Indonesia, Philippines and Iceland — the geothermal energy superpower. Indeed, the unique position between two drifting tectonic plates enables Iceland to generate 95% of heating and 30% of electricity from geothermal sources. You are probably familiar with the image of steaming hot tubs in Iceland, while temperature is below zero. So…
Why can’t we all be like Iceland?
Iceland found itself in a position with the government, investments, and research aligned on utilising the country’s geographical location to expand clean energy projects. But other places do not have the geographical advantage and have to dig deeper into the ground and their wallets to scale geothermal power. The cost of a geothermal plant is heavily weighted against its initial expenses of drilling, which represents around 50% of total costs. Additionally, the expenses of a new project grow significantly with depth: harder rock, equipment failure and more hours required. It costs around $5 million to drill a 4km borehole but around $20 million to drill a 10km deep one. Furthermore, just like drilling for fracking, drilling for geothermal can induce the risk of seismic activity. South Korea’s second largest earthquake, of 5.4 magnitude, was likely to be triggered by a geothermal plant, and in 2006, Basel, Switzerland, experienced an earthquake of 3.4 magnitude due to geothermal projects. However, Switzerland gave geothermal projects another chance and manages and monitors seismic risks via thorough rock layers research and by avoiding high water pressure by tapping into warm water only.
The future of geothermal Death Star
There is an exciting new Millimetre Wave Drilling device called gyrotron coming straight out of the MIT kitchen. For all Star Wars fans, think about the Death Star’s death ray and that is what a gyrotron does, its electromagnetic waves evaporate rocks! “A gyrotron’s operation is based on the stimulated cyclotron radiation of electrons oscillating in a strong magnetic field typically provided by a superconducting magnet”. For us — less technical folks, the process is similar to the one of a microwave.
Quaise Energy, the company behind the gyrotron that spun out from MIT, has exciting plans for the device, where it plans to combine traditional drilling into maximum depth available and firing up gyrotron for the deeper and more challenging drills. Such an approach would allow for tapping into geothermal in areas that would not be traditionally considered. Quaise estimates that the dual approach to drilling will significantly decrease the cost of new wells.
Furthermore, the company is planning to repurpose coal power plants to use the existing infrastructure and plug it into a renewable base load! Think about all the fossil fuel companies that will have to adopt their business model to low carbon economy, this sounds like the perfect solution. Additionally, the ‘drilling” skillset is largely transferable from fossil fuels to geothermal, a win win! Quaise started its testing phase last summer, and we can’t wait to hear about first results.
And there is more… geothermal brine, the hot salty water that is pumped to the surface, can contain precious minerals. As such, besides generating power, geothermal energy companies can also extract lithium or silica as part of the process. Previously, this mineral extraction was labelled promising but pricey. However, with the demand for electric vehicles (EVs) soaring, the scales of economic viability to extract lithium and other minerals, as part of the drilling process, have tipped!
Final thoughts
As you can tell, we are pretty excited about the potential of geothermal energy! With the planet getting hotter on the surface, why not tap into the heat underneath us to help us cool the planet down? The concept of retrofitting fossil fuel plants and re-train drill professionals for geothermal, embodies the idea of just transition to a low carbon economy, combining both social and environmental benefits.
However, geothermal energy constitutes only 0.5% of global renewables-based installed capacity for electricity generation, and heating/cooling. Clearly, more funding is required to scale and mainstream geothermal globally. With being baseload AND renewable, geothermal sounds like the silver bullet of clean energy. So let’s give it more attention, after all, “we all share a common ground, let’s make it a sustainable one!”
