• Energy Research
• 14. Life underwater close
• GB close
• Wind Energy Science close

Abstract. Many coastal regions in Norway, Spain, Portugal, Japan or the United States are comprised of large water depths (> 50 m) making the installation of typical bottom-fixed off-shore wind turbines very difficult and expensive. This is the reason why the floating wind turbines (FOWT) are a promising solution able to exploit the high energy potential contained in these regions. The Advanced Multi-Rotor Turbine for Deep Water Off-shore Energy (AMRowe) has been undertaken to design and develop a cost–competitive, innovative floating Polish multi rotor system, aiming at the optimal usage of European off-shore wind potential. In the article, a prospective deep off-shore location in the south Baltic Sea is identified. The authors built a cost model to prove its superiority over the sites already commissioned by the Polish government. A set of metocean conditions tallied for a 50-year period is used to assess performance of the proposed multi rotor floating wind turbine and to benchmark it against a single rotor 5 MW baseline turbine. The typical load cases are also investigated to observe impact on a single rotor blade in an multi-rotor arrangement in order to begin search for the key design drivers.

Abstract. The vast majority of isolated electricity production systems such as Islands depends on fossil fuels. Porto Santo Island, a Portuguese UNESCO Biosphere Reserve candidate from Madeira Archipelago situated in the Atlantic Ocean, aims to become a sustainable territory in order to reduce its carbon footprint. A sustainable pathway goes through the integration of renewable energy in the electricity production system, in particular, the potential of offshore wind energy. The scope of this work has three main purposes: (1) the offshore wind resource assessment in Porto Santo Island, (2) the determination of a zone of interest regarding the combination of different parameters such us the bathymetry, distance to the coastline and integrated in the national situation plan of maritime space (3) the estimation of the annual energy production from the best-fitted Weibull Distribution. In the first place, a methodology for data analysis was defined processing netcdf data regarding a ten year wind hindcast from WRF (Weather Research and Forecasting) atmospheric model at 100 m above mean sea level from Ocean Observatory, annual and monthly mean offshore wind energy resource maps were created and a comparison with about 20 year times series of surface winds derived from remotely satellite scatterometer observations at different locations was made. Results show that the average annual mean wind speeds reach the range of 6.6–7.6 m/s in specific areas, situated in the northern part of Porto Santo Island with a Weibull distribution shape parameter (k) of 2.4–2.9. Based on the results, the wind resource assessment, the estimation of the annual wind energy production and capacity factors were calculated from the best-fitted Weibull distribution for each of the geographical coordinates selected. Comparisons with observational data show that WRF model is a proficient wind generating tool. The technical energy production potential and a priority zoning for offshore wind power development is performed using wind turbine generators of 3.3 MW–8.0 MW capacity, that could generate between 12 and 26 GWh of energy per year, while avoiding CO2 emissions. The results show that an offshore wind farm plan is an eligible choice, with an average annual wind power density reaching about 300 W/m2 at 100 m height in the north region.