V. Ramos

Wind Power Viability on a Small Island

Arousa, a natural reserve island facing the Atlantic Ocean, aims to reduce its dependency on conventional energy sources. This work has two main objectives: to investigate the potential of wind power and to study the implementation of a wind farm in Arousa. The resource is characterized by its narrow range of directions (SW and NE in winter and summer, respectively) and marked monthly and hourly variability. The windiest months are in summer (July and August) and winter (February and March). Regarding the hourly variability, there occur two periods of higher wind speed: the afternoon (from 1 to 5 pm) and late evening (from 8 pm to midnight). Rayleigh and Weibull distributions are fitted to the annual and monthly data series. While the Rayleigh distribution tends to overestimate slightly the resource, its Weibull counterpart provides a good fit. Overall, a substantial wind resource exists in Arousa. On these grounds, the viability and implementation of a wind farm are analyzed, taking the Vestas V82--1.65 MW turbine as a reference. Performance parameters (capacity factor, availability factor, and efficiency) are computed on annual and monthly bases. The results prove that a wind farm with six turbines is capable of fulfilling the electricity demand of the island extrapolated 25 years into the future, providing an adequate storage solution (e.g., hydrogen).

Assessing the utility and effectiveness of the IEC standards for wave energy resource characterisation

Over the next decades, wave energy aims to become a commercially viable source of energy. For this purpose, a complete understanding of the wave resource characterisation is needed. In this context, the International Electrotechnical Commission (IEC) has developed a technical specification for the assessment of the wave resource, IEC-TS 62600-101: Marine energy-Wave, tidal and other water current converters-Part 101: Wave energy resource assessment and characterisation (IEC-TS). IEC-TS classifies resource assessment studies into three different categories: reconnaissance, feasibility and design. The requirements for the model setup (mesh resolution, boundary conditions) and the effort (validation process, computational times) vary considerably from one class to the other. Accordingly, the main goal of this work is to explore this methodology using the Irish West coast as a case study. Overall, it was found that the methodology proposed performs well, offering a detailed characterisation of the resource; however, with the aim of making the technical specification more manageable, some aspects related to the validation and model setup procedures may be revisited for future editions. (Iglesias, Lopez, Carballo, Castro, Fraguela, & Frigaard 2009, Lopez, Veigas, & Iglesias 2015, Veigas, Lopez, & Iglesias 2014), with the aim of determining the average wave power over a coastal region. However, for a better understanding of the practical resource, the assessment should cover a large portion of the available energy (at least 90%) (Carballo & Iglesias 2012) and also take into consideration the seasonal variability of the resource (Carballo, Sanchez, Ramos, Fraguela, & Iglesias 2015b, Carballo, Sanchez, Ramos, Fraguela, & Iglesias 2015a, Neill & Hashemi 2013). On these grounds, the International Electrotechnical Commission (IEC) has recently put forward a series of recommendations to develop a standard methodology with the aim of ensuring consistency and accuracy in wave resource characterisation: IEC-TS 62600-101: Marine energy Wave, tidal and other water current converters-Part 101: Wave energy resource assessment and characterisation (from now on referred as IEC-TS) [2]. The IECTS classifies the resource assessment studies into three different categories: reconnaissance, feasibility and design, with the notation of Class 1, 2 and 3, respectively. Class 1 is intended to obtain a first approximation of the wave energy resource