Optimization of the electricity generation mix using economic criteria with zero-emissions for stand-alone systems: Case applied to Grand Canary Island in Spain

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The extensive use of greenhouse gas-free energy sources is essential to achieve net zero emissions targets in electricity generation by mid-century; if such sources also increase the economic competitiveness by producing cheaper energy, the outlook is even better. With this purpose, the current study presents the combined use of the NuScale design, a promising type of small modular reactor (SMR), along with renewable sources and storage technologies. The widespread use of highly variable generation sources, such as wind and solar PV, poses significant challenges in trying to match electricity generation and demand. Therefore, more reliable generation sources and/or storage technologies combined with these highly volatile sources are necessary to meet the demand with guarantees and affordable costs. This issue is even more pronounced in isolated regions, such as islands, where at least one more reliable generation source and/or substantial energy storage capacity is required. The system, in many cases, is autonomous and needs to be 100% self-sufficient. Furthermore, to achieve the future goal of zero greenhouse gas emissions, it is necessary to eliminate fossil fuels in all areas, particularly in power generation, which significantly contributes to the total greenhouse gas emissions. Therefore, developing techniques to assess the feasibility of the combined use of different carbon-free technologies is required. Using renewable energies with nuclear energy coupled with storage technologies is a very good possibility to achieve these objectives. It was, in all likelihood, the best option in the case of isolated locations where the system must be self-sufficient precisely because of its isolation. The use of nuclear energy is a key part of the analysis if there is no reliable energy capable of covering approximately the off-peak demand, the rest of the systems will have to be greatly oversized, i.e., the power to be installed from renewables and/or storage will be unaffordable. Therefore, it is very useful to study these problems, especially in the case of islands. Specifically, this analysis has been applied to the Island of Grand Canary in Spain. This island has about 1500 km2 and nearly one million inhabitants, with a off-peak electricity demand of about 250 MW and a peak demand value of about 500 MW. The software HOMER was used to analyze and compare different alternatives, estimating the best combination to get the lower Levelized Cost Of Energy (LCOE). The system's total initial investment cost is 1968 M€, the LCOE is 7.8 c€/kWh (25 years), and the payback is around 6.4 years.