From Steam to Silicon: KenGen’s Bold Move to Extract Silica from Geothermal Brine at Olkaria
By: Robert Buluma
Deep beneath the volcanic heart of Kenya’s Rift Valley lies a resource that has powered the nation for decades. The geothermal reservoirs of Olkaria have long been known for their immense energy potential, supplying reliable baseload electricity that has transformed Kenya into one of the global leaders in geothermal power generation. But what if geothermal energy could offer more than electricity?
What if the hot fluids that power turbines could also yield valuable industrial minerals?
That is the ambitious question now being explored by (KenGen), which has issued a Request for Proposal (RFP) for the development of a semi-industrial silica extraction plant from geothermal brine at the Olkaria Geothermal Project.
If successful, this initiative could mark a turning point—not only for Kenya’s geothermal sector but for the global geothermal industry itself. It represents a shift toward resource cascading, where geothermal fluids are utilized for multiple economic outputs before being reinjected back into the earth.
In simple terms: geothermal energy could become a multi-product industry.
The Hidden Mineral Wealth in Geothermal Brine
When geothermal wells are drilled deep into the Earth’s crust, the steam and hot water brought to the surface carry with them a cocktail of dissolved minerals. Among the most abundant of these is silica.
It's a no brainer that the Olkaria's lithium capacity aren't viable for exploration, a layman's way of saying "low lithium affinity" but when you see a company starts to think for a silica prototype phase then scaling has been a norm , but what's a better way of oportunizing on problems? Your gues is good as mine.
Silica, chemically known as silicon dioxide, is one of the most widely used industrial materials in the world. It plays a critical role in:
- Glass manufacturing
- Electronics and semiconductors
- Construction materials
- Rubber and plastics
- Solar panels and photovoltaic technology
- High-performance industrial coatings
In geothermal operations, however, silica has traditionally been seen as a problem rather than an opportunity.
When geothermal fluids cool, silica tends to precipitate out of solution, forming scale inside pipes, turbines, and reinjection wells. This scaling reduces efficiency, increases maintenance costs, and can even damage equipment.
For decades, geothermal engineers have struggled to prevent silica deposition.
KenGen’s latest initiative flips the narrative entirely.
Instead of fighting silica, the company wants to capture it and turn it into a valuable commercial product.
A New Chapter for Olkaria
The Olkaria geothermal complex is located within , an area known for its dramatic volcanic landscape, steaming vents, and underground reservoirs of superheated water.
This region hosts Africa’s most advanced geothermal infrastructure and forms the backbone of Kenya’s renewable electricity system.
Much of the development has been driven by KenGen and the , which together have transformed Kenya into the leading geothermal producer in Africa.
Geothermal energy currently supplies a large share of Kenya’s electricity, helping stabilize the national grid and reduce reliance on hydropower during drought periods.
But beneath the turbines and pipelines lies a largely untapped opportunity.
Geothermal brines at Olkaria contain significant concentrations of dissolved silica, which, if properly processed, could yield high-purity silica products for industrial markets.
KenGen’s RFP signals the company’s intention to explore that possibility through the construction of a semi-industrial extraction facility.
Why a Semi-Industrial Plant?
The proposed plant is not yet intended to be a full commercial facility. Instead, it will operate at a semi-industrial scale, serving as a crucial stepping stone between laboratory research and large-scale deployment.
This stage is critical because extracting minerals from geothermal fluids is technically complex.
Several challenges must be addressed:
- Efficient precipitation and recovery of silica
- Maintaining geothermal plant efficiency
- Preventing unwanted scaling
- Ensuring environmental compliance
- Producing silica with consistent industrial quality
A semi-industrial plant allows engineers and researchers to test technologies, optimize extraction processes, and evaluate the economic viability of silica production.
If the pilot proves successful, it could lead to large-scale mineral recovery operations integrated directly into geothermal power plants.
Turning Waste into Value
For decades, geothermal brine has been treated primarily as a by-product of power generation.
After steam is separated and electricity is produced, the remaining fluids are typically reinjected back into the geothermal reservoir to maintain pressure and sustainability.
However, geothermal brines often contain valuable elements such as:
- Silica
- Lithium
- Boron
- Potassium
- Rare minerals
Across the world, researchers and energy companies are increasingly exploring how to extract these materials.
One of the most notable examples is the lithium extraction initiatives underway in California’s region, where geothermal brines are being evaluated as a potential source of battery-grade lithium.
KenGen’s silica project represents a similar concept: turning geothermal fluids into a multi-resource stream.
The Global Race for Geothermal Minerals
The geothermal industry is quietly entering a new phase.
Traditionally, geothermal projects focused solely on electricity generation. But today, companies and governments are recognizing that geothermal reservoirs can also serve as sources of strategic minerals.
Countries such as:
- Iceland
- Japan
- New Zealand
- United States
are investing in research to recover valuable materials from geothermal fluids.
The idea is simple yet transformative: a geothermal plant could become a combined energy and mineral production facility.
If successfully implemented, this approach could significantly improve the economics of geothermal projects.
Power generation alone can be capital-intensive, with high upfront drilling costs. But adding mineral recovery could introduce new revenue streams, making geothermal developments more financially attractive.
Kenya’s Strategic Opportunity
Kenya is uniquely positioned to lead this emerging field.
The country sits along the East African Rift System, one of the most active geothermal regions on Earth. This geological advantage provides abundant geothermal resources with high temperatures and significant mineral content.
Over the years, Kenya has built deep expertise in geothermal exploration, drilling, and power plant operation.
Institutions such as KenGen and the Geothermal Development Company have accumulated decades of operational experience.
Now, the next frontier may lie not only in producing electricity, but also in unlocking the mineral potential of geothermal fluids.
The silica extraction plant at Olkaria could therefore serve as a prototype for geothermal mineral recovery across Africa.
Industrial Applications of Geothermal Silica
If KenGen successfully extracts high-quality silica, the material could be used in several industries.
Some of the most promising applications include:
1. High-performance construction materials
Silica is a critical component in cement and concrete formulations, improving durability and strength.
2. Rubber and tire manufacturing
Precipitated silica is widely used as a reinforcing filler in rubber products.
3. Electronics and semiconductors
Ultra-pure silica forms the basis of silicon wafers used in electronic devices.
4. Solar energy technology
Silicon derived from silica is essential for photovoltaic panels.
5. Specialty chemicals
Silica nanoparticles are used in coatings, adhesives, and advanced materials.
The potential market for silica is vast, meaning that even modest production volumes could generate significant economic value.
Environmental Benefits
Silica extraction from geothermal brine could also deliver environmental advantages.
By removing silica before reinjection, geothermal operators could:
- Reduce scaling in pipelines and wells
- Improve plant efficiency
- Lower maintenance costs
- Extend equipment lifespan
Additionally, integrating mineral recovery into geothermal operations promotes a circular resource model, where every component of the geothermal fluid is utilized as efficiently as possible.
This approach aligns with global trends toward sustainable resource management and industrial decarbonization.
Engineering Challenges Ahead
Despite its promise, silica extraction from geothermal brine remains a technically demanding process.
Key challenges include:
Process Optimization
Engineers must determine the optimal conditions for silica precipitation without disrupting geothermal operations.
Product Purity
Industrial markets often require high-purity silica, which demands careful processing and filtration.
Economic Viability
Extraction costs must remain low enough to compete with conventional silica production methods.
Integration with Power Plants
The extraction process must operate seamlessly alongside geothermal power generation.
These challenges are precisely why KenGen is seeking proposals from experienced consultants and technology providers.
The RFP calls for innovative solutions capable of developing, designing, and implementing a semi-industrial silica extraction facility.
A New Business Model for Geothermal
If successful, the Olkaria silica project could redefine how geothermal resources are viewed.
Instead of being seen as single-purpose energy systems, geothermal plants could evolve into multi-resource hubs capable of producing:
- Electricity
- Industrial minerals
- Battery materials
- Heat for industrial processes
This cascading use of geothermal fluids could significantly improve the economics of geothermal power projects.
In an era where the global energy transition demands both clean power and critical minerals, geothermal reservoirs could quietly become one of the most strategic natural resources.
What This Means for the Future of Geothermal in Kenya
Kenya has already established itself as a global geothermal leader.
Projects in Olkaria have helped demonstrate that geothermal power can provide reliable, renewable electricity at scale.
But the silica extraction initiative hints at something even bigger.
It suggests that Kenya is beginning to explore the next generation of geothermal innovation, where energy production is integrated with mineral recovery and advanced industrial applications.
For researchers, engineers, and investors, the message is clear: geothermal energy is evolving.
The steam that spins turbines may soon become only one part of a much larger value chain.
The Road Ahead
KenGen’s RFP represents the first step in what could become a transformative journey for the geothermal sector.
The semi-industrial silica extraction plant at Olkaria will serve as a testing ground for new technologies, new business models, and new ways of thinking about geothermal resources.
If successful, it could pave the way for:
- Large-scale silica production from geothermal fluids
- Integration of mineral extraction into geothermal plants
- Expanded geothermal value chains across Africa
And perhaps most importantly, it could demonstrate that the Earth’s geothermal reservoirs hold far more than just heat.
They may also contain the raw materials for the technologies of tomorrow.
See also: KenGen Launches International Tender for Essential Geothermal Wellhead
At Alphaxioms, we continue to monitor and analyze emerging geothermal innovations—from lithium extraction to silica recovery—because the future of geothermal energy lies not only beneath the surface, but in the new industries it can unlock.
You can apply here to be considered.
Source: Kengen
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