An optimization framework for capacity planning of island electricity systems.

Meeting decarbonization goals requires taking significant action on electricity systems, which are a major source of CO 2 emissions. Decarbonizing island electricity systems raises additional challenges due to their heavy historical dependence on fossil fuels and strict power-reserve and reliability requirements. To address this challenge, this paper presents a comprehensive optimization model for long-term capacity planning of island electricity systems. Our model determines an optimal mix of generation and transmission capacity to satisfy energy demand at least cost while respecting the strict technical constraints that are inherent in island systems. In addition, our model considers the use of thermal and renewable generation, electric vehicles providing electricity-system services, batteries, pumped-hydroelectric storage, and ac and high-voltage dc transmission lines. We demonstrate our model with a case study of the Canary Islands archipelago. Our results show that combining the aforementioned technologies reduces generation costs by up to 25% and capacity requirements up to 50% (relative to a case without the technologies). In addition, without any mechanism to internalize the social cost of carbon, fossil-fueled thermal generation is the lowest-cost source of energy. Environmental considerations demonstrate the benefits of renewable generation and result in these carbon-free energy sources supplying about 40% of the energy mix. [Display omitted] • Carbon pricing can increase renewable-energy supply up to 40%. • Energy storage reduce costs up to 23% and favors more renewable-energy capacity. • Transmission interconnectors reduce costs but do not increase renewable-energy use. • Combining technologies reduces costs by 25% and capacity requirements by 50%. • Strict reserve requirements may keep renewable-energy shares below 3%. [ABSTRACT FROM AUTHOR]