Sparks

The best locations for thermal power stations

 By Benjamin Plackett

Geo-thermal power is a promising alternative energy source in some parts of the world, notably Iceland where heat is extracted from water that is pumped into the volcanic ground, which then drives turbines as steam and generates electricity…

But like many renewable energies, the yield needs to be made as efficient as possible to viably compete with more traditional sources. One way to do this is to build the power plant as close to a volcano as possible. That’s where the Earth’s crusty mantle is at is thinest, which means engineers don’t have to dig so deep to get to the heat. It also means the heated water doesn’t need to travel such a great distance, which reduces the amount of energy lost through convection.

The Nesjavellir Geothermal Power Plant in Þingvellir (Gretar Ívarsson)

But of course there’s a trade off. By the very nature of the beast, building a power plant near a volcano is not without considerable risk. Eruptions mean energy production may be frequently brought to a halt or in the worst case scenario the plant could be destroyed and workers put in harm’s way.

In a study recently published in the Journal of Geophysical Research, scientists from the University of Gothenburg have come up with a way to help. They’ve provided suggestions for the best places in Iceland to construct geo-thermal plants that both maximize energy production and minimize the risk. They studied three parts of a crack in the Earth’s crust where two plates are sliding away from each other. This ridge traverses Iceland from its southwest to its northeast and is where many of the Nordic country’s volcanos are found. “The study includes data with extremely high precision. Data from 1967 to the present, together with the very best modeling software, have yielded the best picture to date of the anatomy of the divergent boundary,” said Tariqul Islam in a statement, lead author of the article.

Divergent plate boundary (Domdomegg)

The researchers have carefully followed the movement of the diverging plates from nearly 100 fixed measurement points. This data has allowed them to create detailed maps to show how the plates are moving away from each other and also the varying size of the crack between them. The idea is that Icelandic engineers in the future might use this map to make informed decisions about the energy potential and associated risks of a proposed site before building power plants.

The Krafla Geothermal Power Plant (Hansueli Krapf)

“This is a start. The next step will be to use powerful computers to create high-resolution 3-D models of the entire zone of divergence. This will enable us to see how the interaction between the different spreading segments and how the different volcanos affect each other,” said Islam.

SEE MORE: Taming a monster by Robin Wylie

about the author
Benjamin Plackett
I’m a journalist based in London. I report on all things science, tech, and health for a number of different publications. My work has been published by The Daily Dot, Inside Science and CNN among others. I earned my M.A. in Journalism at New York University and my B.Sci in Biology from Imperial College, London.