GDC to set up a geothermal-powered industrial park at Menengai fields

Geothermal Development Company staff work on one of the steam wells in Menengai, Nakuru County on November 11, 2014. [Joseph Kipsang, Standard]

The geothermal fields at Menengai in Nakuru County could in the coming years emerge as an industrial hub.

In addition to power production using geothermal steam, the Geothermal Development Company (GDC) is looking at additional uses for the steam.

The State-run company, which de-risked the fields by exploring for geothermal steam, drilled wells and built steam gathering systems has already identified areas where geothermal steam can be used, including horticulture, fish farming and grain drying.

GDC has been running a demonstration project at Menengai, where it used water heated using geothermal for milk processing, heated greenhouses, and dry grains such as wheat and maize as well as heated fish ponds.

The demonstration project was meant to give potential investors a glimpse into the energy savings they would make if they set up shop at Menengai.

GDC said with time, it will attract enough firms in Menengai and would have a complex that includes horticulture farms, dairy processors, grain dryers as well as an expansive geothermal resort and spa. This is starting to take shape following the signing of an agreement between GDC and Karsan Ramji, the producers of Ndovu Cement.

The manufacturer will set up a factory at Menengai and use steam to produce electricity to power its operations as well as to dry raw materials

Eng Martha Mburu, GDC's manager in charge of the direct use department, explained that there would be major savings for firms that would use geothermal steam for their heating processes.

When pasteurising milk at the demonstration project, she noted that there were savings of up to 60 per cent when compared to ordinary methods using fossil fuels or grid electricity.

The savings are across the different projects that the company has at the demonstration area. At the aqua pond, for example, the tilapia fish matured at six months compared to the nine months they ordinarily take in unheated ponds. The grain dryer showed that one can save up to 60 per cent of the grain drying costs.

"We have a number of wells that are not suitable for electricity generation because the wellhead pressure is low. Most of the time, this well is not useful in electricity generation unless you connect a wellhead generator such that it generates on its own," said Ms Mburu, explaining the rationale behind direct use. "In our case, we have the department of direct use, which is charged with ensuring that all wells not connected to the steam gathering system remain useful. At the demonstration project, we have been able to show how beneficial geothermal heat can be for process heating and the huge cost savings that companies can make. Here, we get hot water at 130 degrees Celsius - which would require a lot of fossil fuel to heat under normal circumstances."

Fresh water is heated using geothermal brine. To do this, the brine - which gushes out of the well at about 170 degrees Celsius - is poured into a basin where fresh water passes through using a separate pipe.

Through this process referred to as heat exchange, the fresh water is heated to about 130 degrees.

"It is this hot fresh water that has been heated using geothermal water that now powers our processes. After mining the heat from the geothermal water, we dispose of the geothermal brine and then we started working with the hot freshwater," said Ms Mburu.

"We put the geothermal brine in an evaporation lagoon and with time it evaporates, lined the pond so that it does not seep into the ground and affect the fauna and flora. The brine used to heat fresh water and then dispose of at the evaporation lagoon is the same water that is used in spas. The minerals that it contains are good for the skin, it is used the way it is. We do not treat it. The only thing that we do is cool it to maybe 20-30 degrees Celsius so that it does not scald the skin."

At the demonstration centre, GDC has been growing vegetables at greenhouses that are aimed at showcasing to investors what can be done using geothermal steam. It also has a milk processor, fish ponds and a grain drier.

"These applications require different temperatures - we cannot put water at 80 degrees in a fish pond, it will cook the fish. We cascade the water, starting with applications that require a high amount of heat first and ensure that the energy is spent efficiently," said Ms Mburu.

GDC had in 2019 invited firms to express interest in putting up operations at Menengai and using steam and brine for different operations.

About 10 companies expressed interest but Ms Mburu said uncertainties at the time, including the Covid-19 outbreak in early 2020 scuttled the plans.

It restarted the process last year, and she says GDC is currently in talks with several firms that are looking at setting up at Menengai.

The company has leased 3,000 acres from the Kenya Forest Service (KFS) where it has drilled geothermal wells and power producers are setting up electricity production. The area will also be used by the industries that are keen on using the steam directly to power their operations.

"The investors will implement the projects. They will lease the land and develop the industries and we will pipe the steam and geothermal water... our job will be to supply the energy and bill the energy at an agreed tariff," said Ms Mburu.

One such company is Karsan Ramji, which signed an agreement with GDC last week. Under the deal, GDC shall supply Ndovu Cement with steam and brine. The cement maker will install a wellhead generation unit that has a capacity of four megawatts (MW) to power the cement factory and a drying unit that has a capacity of 700 tonnes per day.

"We are taking a departure from conventional power generation into an exciting and promising realm of captive power and thermal heat. And this is critical. It means, we are, in essence, expanding the geothermal pie and making it accessible and profitable," said GDC Chief Executive Paul Ngugi.

"This engagement, the first of its kind, opens new investment frontiers around the geothermal ecosystem. It is also part of GDC's diversification strategy towards financial sustainability. Today, GDC is on a path of optimisation of the geothermal steam."

Karsan Ramji Chief Executive Kishor Varsani said the firm plans to put up its second cement production plant in Nakuru, which is in addition to its Athi River plant. He added that geothermal use was key to its expansion because the firm has a strategy that requires new operations to be powered by renewable energy. It would also significantly reduce operational costs.

Other direct-use areas that GDC expects to attract investors to pump money into include a geothermal heated Spa-Complex.

In inviting firms to express interest to put up and operate the spa, GDC said the complex should ideally consist of cold swimming pool, geothermally heated swimming pool, steam-heated sauna and baths, a therapeutic facility and geothermally heated and cooled cottages within the vicinity of the Spa complex.