REMS Blog

16/01/18

It is wise to start by welcoming the new cohort 2021 to the REMS centre and wish them loads of fun and success in their future researches. The week of the 18th of September was a particularly eventful for the REMS students. It was a week of conferences where both the annual REMS and the EAWE conferences were organised successively at Cranfield University. The sharing of knowledge and passions was demonstrated through various presentations which enabled a unique network to be established between both researchers and industry representatives. That said two REMS students had to leave the conference quite briskly as a result of their deployment for a field experiment. Those two students are Paul Causon and Waseem Khodabux who in the scope of their doctorate are analysing the marine growth effects and pitting corrosion on wind turbine foundation.

The weather displayed a certain kindness on those autumnal days of the 19th and 20th of September 2017. When such a small window of opportunity appears, it does make sense to take a leap. The van was booked waiting for the keys to be collected at the main reception for the adventure for our two protagonists, Waseem and Paul to begin. The destination was Bridlington also known as the lobster capital of Britain and which eventually has also transformed into a major port for offshore wind related projects due to its proximity to various windfarms on the east coast. In that area, quite a few windfarms going through different technological iterations from Round 1 to 3 have been installed. The colossal Dogger Bank also forms part of that cluster of offshore structures populating the seas around that region.

The anchors, plates, frames, ropes, cable ties and spacer were all loaded and it was time to hit the road. It turned out to be quite an impressive experience where Paul was describing the various hurdles that would have to be overcome once the pair were on the deployment boat. During the whole journey to Bridlington a plan was devised. When they reached the hotel they smiled. It had a Disco ball and it seemed the more mature generation were out partying in droves in the hotel. Unfortunately Paul and Waseem could not join the fun as there was work to do; instead they hit the road again to Tesco to gather some essentials for trial the next day.

It was already late by the time they returned to the hotel. They jumped into their respective beds and got up early at around 4am and directed themselves to the quay. The boat was a fishing one, sporting a crane of 500kgs lift capacity at the rear of it. They were welcomed by a small but experienced crew of researchers and the captain, loaded the experiment stuff and had a safety briefing by the captain of the boat.


Paul busy assembling the coupons and fine tuning the tying

The pair set off and as soon as they got familiar with the rocking motion of the waves set out to assemble the experiment. It involved the delicate task of tying the frames to the coupons and the buoys. A lot of rope cutting and cable ties tightening were needed but finally the task was complete. It was time to deploy the experiment. Moment of truth. The crane buzzed into life and the hook was hoisted down. Paul and Waseem retreated to the safety zone. There was the firm grip of the hook to the anchor and the operator manipulated the levers and soon the whole assembly was on the move. The anchor was released in the water first and seconds later, the whole assembly was sinking in the depth of the ocean. This was it, an experience to remember and cherish for a very long time. They cannot wait to go back for the full deployment but before then have to wait for a weather window.


Anchors going in the water Waseem posing

P.S. The trial assembly survived two storms and is still going strong.

Waseem Khodabux, Paul Causon
21/06/17
Offshore wind energy remains an untapped power resource in the United States of America considering the strong offshore wind power potential (of approx.. 4,150 GW according to NREL) along the US coasts, where major population centres are located. Due to slow wind speeds in regions with shallow waters located along the Gulf Coast and mid-Atlantic Coast, proven technology which is currently widely deployed in European shallow waters cannot be directly applied in the US. In contrary, US has significant potential in deep-water locations where floating offshore wind turbine structures are required.

Dr Todd Griffith from Sandia National Laboratories gave a prestige lecture on the 21st of April in Cranfield University providing an overview of the research projects currently taking place at Sandia National Laboratories addressing the unique conditions of the US offshore environment. Sandia is a US Federally Funded Research and Development Centre with the mission to deliver essential science and technology to address National Security challenges.


Figure 1 Snapshots from the Prestige Lecture given by Dr Todd Griffith from Sandia National Laboratories

Dr Griffith presented projects conducted by the Wind Energy Technologies Department of Sandia National Laboratories, covering:
  • Large-scale hurricane resilient wind turbine blade designs
  • Novel floating vertical axis wind turbines for deep-water siting
  • Offshore wind farm code development, and
  • Structural health monitoring & prognostics management systems.

Sandia has developed a series of detailed 100-meter blade reference models that are available to designers and researchers for design studies and cost analysis; while turbine models reaching 50 MW rated capacity using segmented ultralight morphing rotors based on bio-inspired load alignment (e.g. palm tree) have also been designed. The rotor’s load alignment reduces the required mass for blade stiffening, and makes the turbines more resistant to storms, while their segmented design allows the massive blades to be manufactured in segments which reduces the transportation and manufacturing costs.


Figure 2 Load alignment configuration. Source: Dr Todd Griffith’s presentation


Further research studies conducted at Sandia National Laboratories involve: Hi-resolution modeling of floating wind turbines, wherein a state of the art eddy simulation code has been formulated in order to simulate atmospheric turbulence with wind farms in both land-based and offshore environments; structural health and prognostics management with a focus on damage detection and analysis of effects of damage (state of health and remaining life), and floating offshore vertical-axis wind turbines, among others.



Figure 3 Results for Floating 13.2 MW Turbine. Source: Dr Todd Griffith’s presentation


Sandia has developed 6 public domain designs, covering a range of different areas: power performance models, structural models, economic models, anchor and mooring design, PTO design, O&M / Installation, permitting & environment.
Conclusively, this is an exciting time for marine renewables with significant growth prospects within the next decade. However, while there is the necessary technical know-how and proven technology is already deployed in European waters, as we move further from shore and as extreme scale wind turbines start to be deployed, conventional designs will no longer be applicable. Hence, innovative solutions focusing on reducing technology risks and cost of energy (COE) adjusted to location specific conditions need to be invented for different marine hydro-kinetic technologies.

More information on Sandia’s activities may be found here: http://energy.sandia.gov/energy/renewable-energy/wind-power/offshore-wind/

Author - Anastasia Ioannou