In Zambia, a local geothermal exploration company’s ongoing feasibility study has modelled an initial power capacity of 5-7MWe on the shallow outflow reservoir within the Bwanda section of the Bweengwa River Geothermal Resource Area.
The company, Kalahari GeoEnergy, also stated that a further capacity of about 10-12MWe could conceivably be expected from ongoing exploration work at other selected sites. While gas sampling also confirmed high levels of helium in the geothermal fluids.
Kalahari chief executive, Peter Vivian-Neal, commented: “We are working with a team, including our feasibility study partners Geologica in the US and REPP in the UK, that have significant expertise both in-country and internationally.
“Our collaborative work means that ultimately, geothermal power may provide a valuable component in Zambia’s drive to diversify sources of energy, increase generation capacity and the distribution of productive power, as well as the ‘power to empower’ the community.”
Highlights of the geothermal feasibility study and exploration work
The project thus far includes geology, geophysics, hydrochemistry, LiDAR, and the drilling and testing of 21 temperature gradient holes and slim wells totalling 6,156m. While further drilling and testing are to be undertaken to de-risk the reservoir boundaries.
A gas sampling of both the Bweengwa hot springs and gases from the drilled slim wells has identified up to 2.3% helium as determined using a high-precision multi-collector mass spectrometer at the University of Oxford. This is in part associated with regional crustal-scale faults and the geothermal system. The system has also been confirmed to be suitable for the production of hydrogen.
Kalahari GeoEnergy is engaging Prospero Zambia to conduct studies of suitable direct application of thermal energy from the plant. These applications include aquiculture, horticulture, dairy processing and crop processing, which will in addition to commercial activity also generate social uplift and provide food security through climate mitigation, and indirectly boost tourism to the contiguous Lochinvar National Park.
The ongoing feasibility study is due for completion in Q4 2021 and is funded by USTDA and conducted by Geologica Geothermal Group. While the geothermal project is funded by Kalahari GeoEnergy shareholders, the Renewable Energy Performance Platform (REPP) and USTDA.
“Kalahari wants to advance not only the generation of electricity, but the development and social uplift in our communities in and around the Bweengwa project through the agricultural and industrial uses of the residual thermal energy,” concluded Vivian-Neal.
Systematic exploration has to date included geology, geophysics, hydrochemistry, and the drilling of 21 temperature gradient holes and slim wells totalling 6,156m. Exploration is ongoing along the lateral extensions of the reservoir to confirm the continuity of the geothermal system.