Stanford Geothermal WorkshopFebruary 9-11, 2026

Kenya Electricity Generating Company operates five major geothermal power plants and fifteen wellhead units with a combined capacity of 799 MW. Within the Olkaria Geothermal Field, Olkaria I Additional Unit (IAU) power plant is located in the East production field. It shares steam gathering and hot reinjection infrastructure with Olkaria II power plant. This interconnection includes common steam lines, separator stations, and reinjection systems, allowing for flexible steam supply, minimal venting, and improved plant availability. Despite these benefits, challenges arise from the shared infrastructure, particularly related to unbalanced mass flow during hot reinjection. The most significant issue occurs when a unit or several units are shut down for maintenance or emergencies, disrupting steam line continuity. Such interruptions reduce brine available for reinjection, causing wells to overheat and pressures to exceed inflow capacity. This imbalance often leads to separator flooding and brine carryover, which can trip units due to high scrubber levels and introduce silica scaling complications. These disruptions compromise reinjection efficiency and plant stability. The effects are amplified by the interconnected nature of the steam field, where a change in one plant’s status directly impacts the other. As such, understanding and managing mass flow distribution is critical for sustainable field performance. This paper examines the implications of hot reinjection challenges on power plant operations with a focus on mass flow imbalance and infrastructure interconnectivity at Olkaria.

Topic: Injection