Green power from hot springs

If you guess that “hot natural energy source in Africa” is referring to the sun, you’d be way off the mark in this particular case. Because not all good things come from above: In the case of the Olkaria I Geothermal Power Plant in Kenya, it actually comes from very deep underground. This plant is the result of a multifaceted and long-term project – including a first for Fichtner – as you will read in a moment.

Harnessing the Potential of the Earth

When it comes to green power, the first thing that people think of is the sun and wind as renewable energy sources. But there is a huge, practically inexhaustible energy potential slumbering beneath the Earth’s surface: hot springs! In just the East African part of the Great Rift Valley – the East African Rift System that will presumably split off part of Africa from the continent in a few million years – the sources are sufficient to install more than 20,000 megawatts of electrical power. That’s more electricity than Germany’s million-strong cities need combined.

Geothermal power plants are to tap and leverage this potential. With the help of Fichtner’s extensive experience in building them, precisely that is already being implemented.

We Are Sitting at the Source

Shortly after the well was built, KenGen called us in to design the facilities and oversee the project. KenGen – Kenya Electricity Generating Company – is Kenya’s largest producer of electrical power. It is a state-owned company working to develop these Kenyan natural energy sources step by step. Including with the Olkaria project near the town of Naivasha. In the Olkaria I geothermal field, the “Olkaria I Additional Unit 6” power plant went on stream in 2022, today supplying up to 83 MW of electrical power.

The Gateway to Hell – and the Spa

Olkaria, located in the East African part of the Rift Valley, and just under 100 km northwest of the capital Nairobi, is a geothermal hotspot that is not only used for power generation. The hot springs in the “Hell’s Gate National Park” are so well developed that guests can use them for an extensive spa. Its beautiful blue pools in a green landscape are free of the devil, yet the heat of hell is still palpable and has been perfectly usable since 2013 – for relaxation and health treatments. The mineral content is known to be effective in helping with conditions such as arthritis.

“We’re familiar with geothermal power plants, but it is a first for us to be involved in a plant where the geothermal fields are very deep underground.”

Time and again, we see that every project is unique. As familiar as we are with geothermal power plants, a facility where the geothermal fields are so deep underground is uncharted territory for Fichtner. Incidentally, these geological features do not mean that little energy reaches the surface. Quite the opposite. The underground water is under high pressure and extremely hot, expanding as it is pumped and forcing over 500 tons of steam per hour through twelve 3,000 m-deep well bores at the site. At over 200 °C, the temperature of the steam is sufficient to operate a downstream steam turbine with generator.

Fichtner Is Actively Involved in All Project Phases

Fichtner has been supporting the Olkaria I project for several years and is working on the power plant section. As owner’s engineer, we are tasked with assisting in the implementation of the new power plant unit. This includes designing the steam field and power plant, preparing RFPs and assisting in the evaluation of bids from EPC contractors, overseeing contract negotiations and awarding contracts to two EPC contractors, as well as providing construction supervision and support during the warranty period.

After hot commissioning was successfully completed and all the performance tests as well as the 30-day reliability run were passed, the power plant’s official inauguration ceremony was held on 27 July 2022. The commissioning of Olkaria Unit 6 increases Kenya’s total geothermal power generation capacity to 944 MW, bringing it within striking distance of the 1 GW club. This makes Kenya the largest geothermal power producer in Africa and the sixth largest in the world.

“We are gaining experience at the Olkaria I Unit 6 power plant that we will be able to apply again in other projects. In developing large renewable energy sources, we’re working for our clients while at the same time also benefiting the climate and humanity.”

A Partnership with a Future

Following the successful start of commercial operations, Fichtner will continue to provide support until June 2023. Feasibility studies for further units in Olkaria are currently being tendered by KenGen, and we are, of course, aiming to be involved in the geothermal projects on site in the future.

June 2023