MODELING AND DESIGN OPTIMIZATION OF CARBON-FREE HYBRID ENERGY SYSTEMS WITH THERMAL AND HYDROGEN STORAGE

The study is focused on replacing all coal and natural gas electricity generation in the state of Texas with solar, wind, and nuclear power. As an integral part of the designed hybrid energy system, both thermal and hydrogen storages are used to minimize overproduction and allow for load following. The Dymola system model uses wind speed and solar irradiation data for 2020 to meet the real load data for Texas in 2020. An optimization algorithm is developed to find an optimum design point, aiming to minimize the system's levelized cost of electricity (LCOE) while meeting the demand at all times of the year. The optimized LCOE of the system was $73.04/MWh, which results from 61 Natrium nuclear power plants, 5317 3.2-MW wind turbines, and 307.9 km2 of solar panels. Most of the demand is met by nuclear power with the rest being a near even split between wind and solar. While this optimized LCOE is greater than the current LCOE, it provides carbon-free electricity for the entire state of Texas. Although the stored hydrogen in salt caverns contributed only to a small portion of the total electricity production, it provides a large amount of green hydrogen to future clean energy markets.