By Nadia Macias
UTEP News Service
With few natural resources to help generate electricity, Kenya is turning toward a unique form of energy, and something it has in abundance: volcanoes.
For the past several decades, the country has relied heavily on hydropower, a source that has proved undependable due to frequent droughts causing power shortages, brownouts and blackouts.
“Hydropower is going down drastically,” said Peter Omenda, Ph.D., general manager of the Geothermal Development Co. (GDC) in Kenya and a UTEP alumnus. “One reason is climate change – rivers don’t have as much water as before. Also, all of our big rivers have already been tapped. We need more power from other sources.”
In 2010 the country had a population of more than 40 million – 77 percent of whom did not have access to electricity.
Along with GDC CEO Silas Simiyu, Ph.D. – another UTEP alumnus – Omenda helps run the company that was established to speed up the development of geothermal resources to help generate electricity in Kenya.
The company has its eye on 14 sites within the Great Rift Valley that have a potential of more than 15,000 megawatts – enough to power 15 million homesteads – and is using UTEP geology specialists to help them in their endeavor.
Led by Aaron Velasco, Ph.D., professor of geological sciences, UTEP faculty are helping the GDC map the subsurface around volcanoes in the valley to locate magma chambers and generate steam power.
“Recent volcanoes have magma chambers underneath them,” said Steven Harder, D.Sc., a research professor of geological sciences who is helping the GDC. “Locating these chambers – they’re not always directly underneath the volcano and we don’t know how deep they are – is a problem.”
And so, the team is conducting two separate experiments to locate the chambers.
“Probably the best way to do it is through seismic tomography,” Harder said. “You’re familiar with a CT scan that images your body? This is the same sort of thing except that instead of imaging your body, we’re trying to image the magma chamber.”
To do so, Harder and Galen Kaip, special research associate of geological sciences at UTEP, are setting off explosions about 80 to 90 meters below ground to create miniature earthquakes around the volcanoes Paka and Silai.
Using multiple seismometers, devices that measure ground movement, the team is able to gauge where waves travel faster and slower in the ground.
“Seismic waves will propagate faster through solid rock than they will through partially molten rock,” Harder said. “And that’s what we’re looking for – this area of slow propagation.”
Another way to locate geothermal prospects is by studying a volcano’s natural tremors and earthquakes. Velasco is doing so around Menegai and has set up multiple seismometers to record data.
Both projects are based on the concept that waves travel at different speeds through different mediums.
“Part of this is not just me going in as an expert,” Velasco said. “It’s part of them getting the ability to be able to do this on their own and so we’ve been training people there – how to handle the data, how to maintain the stations. It’s a true collaborative.”
After interpreting the data to locate the magma chambers, the GDC will drill down about 2 to 3 kilometers – which costs an average of $5 to $7 million according to Omenda – to reach the chambers and collect the steam through pipelines for power generation.
“By 2030, we want to produce 5,000 megawatts of power,” Omenda said. “It’s a long way away, but if everything goes well that will be able to power about five million homesteads.”
He added, “For Kenya, geothermal energy is the best option. It is good for the environment and it’s also the cheapest option.”