Harnessing the Rift Valleys’ Geothermal Energy

Sub-Saharan Africa remains the most under-electrified region on Earth. Geothermal energy along the Rift Valley could be a game changer. This renewable energy flows under the earth 24-7, and can serve both as base load or as peak power.

Photo from Unsplash: Matt Plamer

Sub-Saharan Africa remains the most under-electrified region on Earth. Despite having some of the fastest economic growing countries in the world, especially in East Africa, lack of electrification is one of the most crucial challenges for further development. Renewable electricity is gaining momentum with solar, wind and hydropower leading the way. However, today the conventional most polluting options, considered cheap, are usually still the ‘go to’.

Yet, countries along the Rift Valley – down from Tanzania all the way up to Djibouti – have some of the worlds’ best potential for one the most stable, least environmentally impactful energy right under their feet. Earth heat, or more technically known as #geothermal energy, can be piped to the surface to produce heat and electricity. This renewable energy flows under the earth 24-7, without interlude, is independent of weather conditions, and can serve both as base load or, be operated to meet seasonal variations and as peak power. It is thought possible to produce up to 8.3% of the total world electricity with geothermal resources, serving 17% of the world population. Currently 39 countries could obtain 100% of their electricity from geothermal resources (Dauncey, 2001); yet only 6 to 7% of the world’s potential has been tapped.

Geothermal fluids contain a variable quantity of gas, largely nitrogen and carbon dioxide with some hydrogen sulphide. However, as most gases are concentrated in the disposal water which is reinjected into drill holes, the gases are not released into the environment. The range in CO2 emissions from geothermal fields used for electricity production is variable, but it is lower than that of other fossil fuels. The figure below compares CO2 emission from different energy sources in the USA. Geothermal emissions from Iceland are even lower due to the country’s geological context.

Geothermal fields are common on tectonic plate boundaries, as the crust of the earth is fractured allowing gassy water to bubble up a few kilometres underneath the surface – such as the East African Rift Valley. #Kenya is the first country in Africa to utilise its geothermal resources. In 2010, 33 million Kenyans lacked electricity, and by 2016 that number had fallen to less than 22 million—even as the country added another 7 million people to its population. The percentage of Kenyans with access to electricity tripled from 19% to 56%. No country on Earth has made more rapid progress, and geothermal energy had an important role to play.

While drilling is expensive, the heat source itself is free and in the long run it’s relatively cheap as geothermal fields can last from 100-300 years. Today, 36% of Kenya’s grid is supplied with hydroelectricity. However, as the country suffers from long spouts of dry spells – which are only going to worsen with the desertification of northern Kenya - hydroelectric stations periodically shut down. Otherwise, 5% of its generation capacity come from wind and solar, a figure that’s set to increase with the opening of a 310-megawatt wind farm near Lake Turkana. Geothermal is an ideal candidate to compensate for these renewables’ downsides, by providing yearlong stable base-load power whilst the other renewables would ‘complete’ the grid.

The rest of East African countries bordering the Rift Valley should surely follow-suit. Unfortunately, many of these countries such as Tanzania, Uganda, and Ethiopia are also abundantly rich in either crude oil, coal or off-shore natural gas. While natural gas in the least impactful of those three, it still emits significantly more than geothermal. The abundance of more conventional and ‘known’ resources of energy, provides great temptation for an electricity deprived region lacking in technical and financial prowess. More attention should be given by donor agencies and concerned international bodies to the geothermal potential of this region.

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I like to add my sources, but i lost them for this one :/

I do remember that Nat Geo had a nice article on this. All figures are from reliable sources - academic papers that have been used as a source often - or reputable journalists/newspapers.