By Jacob Kushner,Features correspondent
In the volcanic region of East Africa’s Great Rift Valley, tectonic shifts are tearing the continent apart – and releasing unimaginable quantities of clean energy.
Drive along the dusty dirt road that winds through Kenya’s Hell’s Gate National park, past the zebra, gazelles and giraffes, and you’ll see a plume of steam shooting skyward in the distance. Vehicles must sometimes swerve to avoid running over warthogs as they enter a vast valley dotted with dozens of steam vents – a factory of clouds.
Blasts of steam billow loudly, releasing heat from deep within the Earth. But even more powerful is the steam you don’t see: that which twists through miles of tubes to push past turbines, generating a type of clean energy that won’t run out for millions of years.
Atop this infernal labyrinth of tubes is Kenya’s Olkaria Geothermal Project, where a new addition to the powerplant is about to go online. At 86 megawatts, the Olkaria VI expansion will push the project’s total production to 791.5 megawatts. That’s about 27% of all the energy in Kenya, according to KenGen, the parastatal company that operates Olkaria. Already, Kenya relies on geothermal steam for 38% of its power – a greater proportion than any other nation.
“When Olkaria VI is complete, it will be the largest single geothermal plant in the world,” according to Cyrus Karingithi, who leads infrastructure and resource development for Olkaria.
Globally, geothermal energy is a $4.6bn (£3.3bn) industry, with more than 500 powerplants electrifying millions of households across South-east Asia, North America, Europe and beyond. Geothermal is, after all, the second most abundant source of energy in the world behind solar.
But it in terms of how much we tap this source of power, geothermal lags well behind. In 2016, the energy the world harvested from geothermal was just 4% that from solar, despite geothermal having some important advantages. Wind turbines are useless on a still day, and solar panels’ energy falls when the sun is covered by clouds and at night. Meanwhile, no matter the time of day, the Earth below us is steadily releasing vast quantities of heat, whatever the weather.
This is where the continent is breaking up – Anna Mwangi
To appreciate the potential of this heat, there is nowhere better to look than where it blasts through the surface in the towers of steam erupting from Hell’s Gate, around 90 kilometres (56 miles) north-west of Kenya’s capital, Nairobi.
Heat from the depths
On cloudy days here, it’s hard to tell which clouds come from the sky, and which ones come from the ground. One morning in February, Anna Mwangi, a geophysicist who works for firms including KenGen, is tasked with exploring for new geothermal drill sites. She points at a faint whisp of steam rising from a small hole in the rocky hillside.
“You can boil an egg in it,” she says with a smile. The area around Olkaria is teeming with natural geothermal vents such as these, some hot enough they burn to the touch. The steam, Mwangi explains, is what gives Hell’s Gate National Park its name: The landscape looks like the underworld is boiling over.
