Led by Professor Alexandre Simos of the Department of Naval and Ocean Engineering at the Polytechnic School of the University of Sao Paulo (EPUSP) in Brazil, and thanks to funding provided by the Office of Naval Research Global (ONR Global), a group of researchers are finding ways to increase the country's wind power generation capacity by leading an effort to reduce the structural weight in new designs of Floating Offshore Wind Turbines (FOWTs).
FOWTs have many opportunities and obstacles. Among the advantages is the availability of constant wind at a suitable speed for the use of turbines at their optimum efficiency. Among the disadvantages are the high costs of installation, mooring lines and the large length of cables required for energy transmission. In this context, saving structural weight on the floater is important.
The design of FOWTs can be a complicated task as variables such as the responses to waves, current and wind loads, the static and dynamic stabilities, and the structural behaviour of the mooring lines should be considered. Therefore, there have been several research projects aimed at developing numerical codes and laying the grounds for the experimental benchmarking of FOWTs.
While floating offshore wind turbines will provide an alternative energy source for seabasing, Paul Sundaram, Science Director of ONR Global in Sao Paulo, has noted that "the goal was to understand through modelling how to design and manage complex structures in the dynamic ocean environment. This is very important for the US Navy, to design and build engineered resilient systems in the ocean".
Technology will play a major role in the future expansion of wind energy in Brazil. Regulation for the installation of offshore wind farms has already been discussed in the Brazilian Congress, and the industry is preparing for new developments in the sector, which has a huge potential, especially on the country's northeast coast.
Since FOWTs are relatively new devices, there is still space for design optimisation. For example, new concepts of floating hulls aimed at reducing the motions of the turbine are still being designed and proposed. In addition, to make the use of FOWTs in deep waters (greater than 1000 m) economically feasible, the design of optimised moorings made of light materials will also be a challenge.
"Such structures will be strategic for sea-based transportation as a renewable energy source. FOWTs are usually more effective in deeper waters where wind speeds are higher, and winds are steadier. Small increases in wind speeds can lead to a much larger energy production", notes Sundaram.
Read the article online at: https://www.energyglobal.com/wind/06012020/brazil-looks-to-expand-its-offshore-wind-sector/