Kalahari GeoEnergy plans small geothermal pilot plant for 2022

Geothermal developer Kalahari GeoEnergy is planning to set up a small pilot plant at its Bweenga geothermal site in Zambia in 2022.

In an update to ThinkGeoEnergy, Kalahari GeoEnergy has shared details on its ongoing work on the Bweengwa geothermal project in Lochinvar, Zambia in Southern Africa.

The pre-feasibility resource definition drilling undertaken in 2020 identified a shallow (200-350mbgl) tabular outflow reservoir of ~110OC in the top 50m of the basement west and northwest of the Bwanda Hot springs. Consistent hydrochemistry results and geothermal gradients point to ~125OC at 650mbgl, and ~150OC deeper. Due to pandemic restrictions the 2020 programme was delayed by 4 months, while the USTDA grant funding for the actual feasibility study (the “FS”) was due to expire in mid-2021. Therefore, it was decided to focus the FS on the shallow outflow.

With the data from the resource definition drilling the FS started in February 2021 and is to be completed in January. The resource capacity of the shallow outflow has been calculated as 5-6Mwe. To de-risk assumptions about production wells intersecting higher temperature/flow rates at targeted depth in the FS the company is currently deepening two existing slim wells to modelled production depth. This work should be complete by mid-December, and flow test is planned for the new year.

As long promoted, Kalahari GeoEnergy is taking the opportunity to assess the direct cascaded applications that will have an impact on the currently subsistence farming local economy, increase food security by improved agriculture processing and have a positive impact on the local environment. The company has a grant funded study on fish farming currently underway and due for completion in December. It is also investigating horticulture, dairy processing and legume out-grower and processing. Such operations would provide additional revenue and be of significance in the local economy.

The intended next step is to install a pilot plant to demonstrate both power production and at least two direct applications; the company is currently costing this with the realistic prospect of grant/concessional finance under a CFI programme. The plan is to set this up during 2022 whilst the team will go through the approval and fund-raising process for a commercial scale plant. An RFP has been issued for the pilot plant to operate on existing slim wells which have a capacity of 500kWe; the RFP will be updated if as anticipated, the current well deepening results in higher temperature/flow. The Pilot power plant is to be capped at 250kW capacity being the trigger capacity for a full generating licence.

Separately, Kalahari GeoEnergy has analysed the gas content of the brine as containing 2.3% helium; when it flows test the two wells currently being deepened, it will measure gas contained and collect further gas samples for multi gas analysis. The company is being supported by one of the leading gas recovery and distributors. If found to be realistic this could be a secondary revenue stream.

The completion of the Bweengwa FS in January will be an appropriate time to assess our options and corporate structure going forward.

Meanwhile, when practical considering the latest travel restrictions imposed in response to the Omicron Covid variant, the company will commence the verification of historic data at its Chiweta target in the northern region of Malawi.

Source: Company