Daniel Vázquez Pombo

This paper presents a new mixed-integer linear programming formulation for combined generation, storage and demand response expansion planning. The proposed formulation captures flexibility dynamics in integrated energy systems in long horizons with large temporal resolution. The objective function considers costs related to: investment, operation, emission penalties, fixed and variable maintenance. The considered units are: generators, storage (batteries and hydro-pumped) and demand response units (desalination, power-to-X, electric vehicles and electrolysers). The operation is modelled as an hourly unit commitment including time-dependent startup costs and intertemporal constraints such as ramping limits and minimum up and down times. This flexibility enabling formulation boosts renewable integration and contributes towards decarbonisation of other energy sectors such as transport. A commercial solver is used to evaluate the formulation for large scale cases considering 20 years horizon and 12 full weeks per year imposing minimum renewable shares of 50 and 100% in year 9 and 19, respectively. The formulation exceeds tractability limits of previous works, achieves lower over-installation and renewable curtailment by integrating flexibility in the generation expansion problem, and allows to size demand responsive units if desired.

Reference systems are key enabling platforms facilitating the evaluation and comparison of different methods and technologies prior to prototyping and field deployment. In the context of the energy transition, where the number and diversity of the grid-related research is ever expanding, we propose a reference system based on two islands of Cape Verde. These isolated power systems capture the behaviour of modern, mid & large size grids ranging from 20 to 100 % renewable energy penetration, accommodating a very diverse technological mix. The topology is based on the real transmission system as of 2021, considers sector coupling and the role of power electronics-interfaced units. The Open-Access data was provided by the local system operator and the largest renewable utility of the country. The main objective is to enable off-the-shelf usage by minimizing the amount customization required for any possible study. In that way, it is suitable for a range of traditional and modern studies such as: power flow, energy management, control, stability, reliability, resiliency etc. We showcase the usefulness of this reference system with four short studies regarding grid strength, frequency stability, optimal sizing & placement of battery systems and synthetic inertia provision.