Abstract
The global increase in energy consumption is forcing the energy sector to evaluate the energy transition from fossil-based systems to renewable energy sources. Unfortunately, the impact of non-dispatchable generation affects grid stability and the ability to meet nighttime loads. In addition, a shift from summer to winter is required to increase the penetration of renewables. The introduction of storage technologies and the energy mix could overcome some of the problems associated with the green revolution. The aim of the work is to assess the best combination of generation systems and storage to meet the electricity needs of a 100 MW peak load city in the Latvian region with an annual energy load of 700 GWh. The energy hub considered represents a valuable evolution of a traditional gas-fired power plant coupled with the most cost-effective renewable resource generators: photovoltaic and wind turbines. To exploit the renewable surplus, part of the electricity is converted into hydrogen, which drives a fuel cell and a methanation system linked to the gas turbine. The method used is Trnsys-based numerical modelling coupled with multivariable particle swarm optimization to minimize the levelized cost of electricity under different renewable penetration scenarios. The LCOE is 0.099 EUR/kWh for an 80 % RES production and rises to 0.265 EUR/kWh for a fully renewable system.