Tidal turbines (akin to underwater wind turbines) are at a stage of development where full-scale prototype devices have been deployed and tested in the seas surrounding the UK and other locations in the world. The next step is to deploy farms or arrays of multiple devices to demonstrate operability, cost reduction and the ability to generate electricity at a larger scale. In order to do this device developers and funders of the technology must have confidence and assurances that these arrays of tidal turbines will perform as predicted; but how do you predict something that you have never done before? Computer-based numerical models can simulate things before they are constructed or installed but without data to validate these models how can anyone know if they will be accurate? This project addresses such a question "How can we aid industry to best validate dynamic (real time) array models for:(a) optimised array design and layout, (b) prediction of dynamic loadings and fatigue effects (rotors and blades) through inflow turbulence and device-device interactions and (c) reliability or planning for O&M considering the lack of publically-available data? Our answer is to: 1. To provide real, time -series data of loadings and power performance experienced by tidal turbines under realistic inflow conditions and when devices interact with one another (in array type configurations). At present there is little if any data on this (mostly average values or short time-scale experimental runs) which cannot sufficiently validate models. We will provide scale test data with all parameters required to use data sets for validation purposes 2. To provide measured time-series data for larger multiple-row arrays than has been previously conducted 3. To quantify so-called "steady loads" and measure changes in performance over time through long-term testing of a scale device(s) in the sea And to make project data available directly to relevant marine energy stakeholders in a very timely manner

This work assesses the feasibility of using energy storage to make a step-change improvement in control for off-grid and on-grid wave energy arrays. This has been brought about by a need for arrays of smaller wave energy devices to utilise the less-energetic wave resource off the coast of China. For a lower energy resource, control of arrays is even more important in order to optimise performance and to improve survivability. As the focus is on future deployment of arrays in China, the step-change is only possible with the expertise in wave climate, off-grid connection of devices and power systems in China; hence this contribution is provided by project partners in China.

Globally, a billion tons of the sulfur-containing molecule dimethylsulfoniopropionate (DMSP) is made each year. The common belief was that DMSP is only made by marine eukaryotes, including phytoplankton, seaweeds, a few plants and some corals, but our preliminary work shows that marine bacteria also make DMSP, and at levels similar to those reported for some phytoplankton. For the first time, we have shown that marine bacteria likely use DMSP as an osmoprotectant to buffer cells against the salinity of seawater. The research that we propose will redefine the field of DMSP production and its catabolism. DMSP is the main precursor of the environmentally important gas dimethylsulfide (DMS). Microbial DMSP lysis generates ~300 million tons of DMS per annum. Much of this DMS is used by bacteria, but ~10 % is released from the seas into the air, giving the seaside its characteristic smell. Once in the atmosphere, chemical products arising from DMS oxidation aid cloud formation over the oceans, to an extent that affects sunlight reaching the Earth's surface, with effects on climate. In turn, these products are delivered back to Earth as rain, representing a key component of the global sulfur cycle. DMS is also a potent chemoattractant for many organisms including seabirds, crustaceans and marine mammals, which associate DMS with food. Although previous studies have described the pathways for DMSP synthesis, remarkably NONE of the enzymes or corresponding genes have been identified in ANY DMSP-producing organism. Our preliminary data: 1. show that some marine bacteria make DMSP via the same pathway used by phytoplankton. 2. identified the key gene in bacterial DMSP production "mmtB" - the first gene shown to be involved in DMSP synthesis in any organism. 3. show that our model marine bacterium Labrenzia likely makes DMSP as an osmoprotectant. 4. show that bacteria containing mmtB produce DMSP, and some also contain DMSP lyase genes whose products liberate DMS from DMSP. 5. show that the mmtB gene is abundant in marine environments. Our project: The mmtB gene encodes an enzyme that catalyses one of the four predicted steps in DMSP synthesis, but we do not know the identity the other three genes. To fully understand the process of DMSP synthesis in bacteria, we need to identify the missing synthesis genes so that we can study their regulation and enzymology. We will use complementary molecular genetic approaches to identify the unknown DMSP synthesis genes and, in the process, characterise the full complement of genes whose expression is affected by salinity in Labrenzia. To understand how and why bacteria in the environment produce DMSP and DMS, we will study key model bacteria isolated from marine samples. These bacteria will be grown in microcosms under conditions similar to those of their natural habitat, and their environmental growth conditions will be varied whilst monitoring DMS and DMSP synthesis, at both the process and gene expression level. This will indicate whether environmental factors such as temperature, oxidative stress, etc., affect the production of DMSP and concomitantly the production of the climate-active gas DMS. The importance of bacterial DMSP production in marine environments will be examined. We will sample selected marine environments and investigate the activity of bacterial DMSP synthesis compared to eukaryotic DMS/DMSP pathways. We will determine if the environmental factors that regulate DMS/DMSP production in our model bacteria have the same effect on natural microbial communities that are present in important marine environments. We will also use a powerful suite of microbial ecology techniques, combined with molecular genetic tools, to identify the microbes and key genes involved in producing DMSP via the MmtB enzyme in these environments. This work will help us in the future to model how changes in the environment impact on the balance of these climate processes.

The project is a feasibility study on the use of flexible blades to increase the durability and survivability of tidal turbines. The highly turbulent flow experienced by tidal turbines leads to continuous load variations limiting the fatigue endurance. It is proposed to use flexible blades in order to control the flow field around the blades and allow constant stresses on the turbine's blades and shaft. Under the effect of a variation of the onset flow velocity at a certain location along the blade span, the flexible blade will change the local angle of attack and the foil shape. The new flow field around the blade section will be as such to minimise the load change on the blade section. The reduced, if not completely avoided, load variations will enhance the fatigue endurance of the blade and the shaft.

In the past decade, tidal stream energy converters have become a major focus for renewable energy R&D with a number of turbine farms now in its planning and development phase. The majority of existing designs for tidal energy devices utilize sea-bed mounted turbine energy converters. These underwater devices however present many challenges related to economic and technical viability in terms of their installations and maintenances cost. In recent years, a floating type tidal energy device is being developed. The installation of such a device comprises of single or multiple turbines mounted on a floating platform anchored to the sea-bed with mooring lines. Research and industry teams in China and UK have presented multiple demonstrations both on a model scale and a full scale floating tidal energy converter. All of the results add credibility to their technical feasibility and cost effective nature as compared to fixed turbines. Despite the advantages of floating tidal current turbines (FTCT) over their fixed counterparts, the existing design guidance is not deemed to be ready for the commercial market. The key challenges include guaranteeing the safety of supporting platform and floating mooring lines, the survivability of large scale rotor under extreme sea conditions, the accurate assessment for the proper site selection and the reliable evaluation of environmental impacts. Existing industry design tools rely very much on the simplified models or individual component design rules which negatively impact the energy extraction process/amount/supply. The proposed project aims to integrate the work already carried out at University of Strathclyde in UK in the field of offshore renewable energy and floating offshore structure with the work performed at (a) Harbin Engineering University in China in the area of floating tidal turbine and (b) Ocean University of China in China in the field of tidal resources and environment impacts assessment. The main goal of the proposed research is to explore whether an integrated method is feasible to better understand the fundamental physics associated with a coupled floating tidal energy system through numerical framework with experimental comparisons and validations. This would then potentially provide more accurate industry design guidelines for the future commercialized FTCTs and other floating marine energy devices.