Techno-economic assessment of grid-solar-diesel generator battery hybrid energy systems for Kenya Pipeline Company, Eldoret terminal

Abstract

The Kenya Pipeline Company (KPC) Eldoret Terminal uses grid electricity and reliance on backup diesel generator during power outages. This hampers operational efficiency while contributing to financial strain and environmental emissions. With abundance of solar irradiance, there is a need to transition to a sustainable hybrid energy system (HES). The main objective of this study was to carry out a techno- economic assessment of grid-solar PV-diesel generator-battery hybrid energy systems. The specific objectives were to investigate and analyze energy consumption patterns, to design and simulate an optimum grid-solar PV-battery-diesel generator HES using PVsyst and (Hybrid Optimization Model for Multiple Energy Resources) HOMER modelling tools and to perform techno-economic analysis of the optimum hybrid energy system. The methodology outlined a step-by-step approach used to design a HES. The site was selected, and data was collected through surveys with the maintenance team, reviews of structural and utility documents, interviews to gather operational data, and observational entries from a data logger to document the energy profile. The design phase involved configuring a HES that integrated photovoltaic modules with existing diesel generators and grid power, optimized through precise calculations of energy consumption, PV module placement, battery system sizing, and inverter sizing. Simulation tools were utilized to aid in designing and performing economic assessments, determining the system’s feasibility and economic viability through calculations of the Net Present Cost (NPC), Levelized Cost of Energy (LCOE), and emissions. Based on data collected, KPC consumed 108,732 kWh of grid power and diesel generator at the terminal rated at 550 kVA consumed 1,807.31 litres with an energy production of 10,975kW in 2023. The terminal spent about Kshs 17.876 million on provision of electricity in 2023. The hybrid system was introduced a solar PV system covering a total estimated area of 2365 m2 and an initial investment of Kshs 232,938,000, with a payback period of 8 years. The optimized HES entailed the PV module and grid integration, featuring a (LCOE) of 9.83 Kshs/kWh and NPC of Kshs 236 million while producing an annual CO 2 emission of 100,106kg. This scaled down by more than 50%. The study concluded that the grid-solar hybrid connection was well suited for a sustainable energy management system. It was recommended that solar charged batteries be prioritized as the power back up instead of the expensive diesel generator and environmentally polluting.