An updated geothermal model, power capacity estimates and prefeasibility results based on 50 Mwe development of Paka geothermal Field

Paka geothermal field is the latest geothermal field on focus in Kenya through the Geothermal Development Company. The field is located within the Paka volcanic complex in the northern Kenya rift segment. The current surface geoscientific data model indicates a likely geothermal sweet spot located within the summit area and northeast of Paka. These two localities have been separated as two subfields i.e. the summit area field and the northeast field (Mibei et al in prep). We estimate a possible p90 developed reservoir size of 200 Mwe and a mean 320 Mwe using the Power density method for the Paka field (Cumming, 2016). This is however preliminary and could change as more drilling data is obtained. As a development approach, we focus on the summit area field where we project 12 proposed wells pads that can each host 1 vertical well and additional 3 to 4 directional full-size geothermal wells. In the map plan (Fig 1b), we also show that the possible power plant site for phase I development. A financial model is provided assuming the following parameters; an electricity tariff of 0.0088 US$/kWh, a success rate of 33%, 50% and 75% at exploration, appraisal and production drilling respectively, a 50 Mwe capacity plant and operation period of 25 years under PPP arrangement. The assumed success rate is very modest considering the reported excellent results (100 % success) of exploration drilling achieved so far from the field. Even with these modest success rates our financial model show that the 50 Mwe phase 1 development with the aforementioned parameters is economically viable with econometric indicators such as NPV showing positive values and IRR showing figures above the considered WACC in the model.