Imagine for a second that you are magma, minding your own business at around 1,000°C, three to four miles underground. Over the course of the next six months, what begins as a distant scratching becomes a racket, as a drill burrows nearer, stopping before it hits your magma chamber.
That is what has happened to a volcano on the Reykjanes peninsula in Iceland. Since August 2016, researchers at the Iceland Deep Drilling Project (IDDP) have been cutting deeper into a volcano than ever before, creating the world’s hottest borehole. In January, the project stopped digging when drill sensors picked up ‘supercritical’ pressures and temperatures at around 430°C. Under such conditions, water has the properties of both a solid and a liquid, but is ten times more powerful than regular steam when it comes to energy generation.
Their success, which the engineers described as a ‘significant milestone in the geothermal industry,’ was an explorative mission collecting core samples and testing temperatures. It is, however, part of an ongoing attempt to use the intense heat energy of magma. ‘If the best outcome is that the well can be used for highly efficient energy production,’ they write, ‘it would open new dimensions in geothermal utilisation.’ In theory, once a well is established, water could be poured in, heated to supercritical levels, and used to generate enough energy to power 50,000 homes.
It’s not the first time engineers have drilled towards magma. In 2009, the IDDP bored two kilometres down into Iceland’s Krafla geothermal field and unexpectedly struck a magma reservoir. At the time, the well was the most powerful ever drilled and was used to create superheated steam until it suffered corrosion problems in 2012. The new Reykjanes borehole breaks the record in depth and for its potential power.
If the project succeeds, it could result in opportunities for other volcanic nations. The team concludes:
“If deep supercritical wells, here and elsewhere in the world, can produce more power than conventional geothermal wells, fewer wells would be needed to produce the same power output, leading to less environmental impact and improved economics”
This was published in the April 2017 edition of Geographical magazine.