Investigation of hybrid power-to-hydrogen/natural gas and hydrogen-to-X system in Cameroon

Abstract

In Sub-Saharan Africa (SSA), the capacity to generate energy faces significant hurdles. Despite efforts to integrate renewable energy sources and natural gas power plants into the energy portfolio, the desired reduction in environmental impact and alleviation of energy poverty remain elusive. Hence, exploring a spectrum of hybrid technologies, encompassing storage and hydrogen-based solutions, is imperative to optimize energy production while mitigating harmful emissions. To exemplify this necessity, the 216 MW Kribi gas power plant in Cameroon is the case study. The primary aim is to investigate cutting-edge emissions and energy schemes within the SSA. This paper assessed the minimum complaint load technique and four power-to-fuel options from technical, financial, and environmental perspectives to assess the viability of a natural gas fuel system powered with hydrogen in a hybrid mode. The system generates hydrogen by using water electrolysis, with photovoltaic electricity and gas power plant. This research also assesses process efficiency, storage capacity, annual costs, carbon avoided costs, and production prices for various fuels. Results showed that the LCOE from a photovoltaic solar plant is 0.19$/kWh, with the Power-to-Hydrogen process (76.2% efficiency) being the most efficient, followed by the ammonia and urea processes. The study gives a detailed examination of the hybrid hydrogen natural gas fuel system. According to the annual cost breakdown, the primary costs are associated with the acquisition of electrical energy and electrolyser CAPEX and OPEX, which account for 95% of total costs. Urea is the cheapest mass fuel. However, it costs more in terms of energy. Hydrogen is the most cost-effective source of energy. In terms of energy storage and energy density by volume, the methane resulted as the most suitable solution, while the ammonia resulted as the best H2 storage medium in terms of kg of H2 per m3 of storage (108 kgH2/m3). By substituting the fuel system with 15% H2, the environmental effects are reduced by 1622 tons per year, while carbon capture technology gathered 16,664 tons of CO2 for methanation and urea operations, yielding a total carbon averted cost of 21 $/ton.