ScienceDirect EERA DeepWind'2014, 11th Deep Sea Offshore Wind R&D Conference First verification test and wake measurement results using a Ship-LIDAR System

Abstract Measuring wind offshore in deep water depths will be a future challenge. Where the sea bed foundation installation for fixed meteorological masts is impossible, floating systems tend to be a sophisticated solution. In addition to the use of moored lidarbuoy systems, ship-lidar systems are an alternative solution for a number of different applications. In this paper we describe general aspects of motion influences on lidar measurements as well as two motion-correction methods for motion-influenced lidar measurements. The implementation of the ship-lidar system and different scanning modes will be presented. First measurements were carried out as part of the EERA-DTOC project. Hence a verification of one of the two correction algorithms as well as first results from wake measurements behind the Alpha Ventus offshore wind farm will be shown. This comprises distinct wind speed wake losses and an increasing turbulence intensity in a distance of approximately 2 km behind the wind farm

Categorization of established methodologies used in operation and maintenance simulations of offshore wind farms, a literature review

Offshore wind energy has widely been labeled as a cost driver in the transition towards renewable energy sources. Results of the first offshore wind tender system in Germany, showed extreme improvements regarding costs. For those results, participants of the tender needed to understand the effects of different future scenarios. Operation and Maintenance (O&M) simulation tools are one important aspect in assessing the impact of different scenarios on the live cycle costs. By understanding, which methodologies are used in the industry, future improvements can be identified. Additionally, it allows understanding the cost improvements better. Many researchers have addressed O&M simulation in their studies; this resulted in several existing academic tools. Previous work has mainly focused on single aspects of the simulation. This specialization limits present academic and established tools. Some of those tools, originated from research are presently established in the industry. The advantage of established simulation tools is their commercial use in industrial applications. A literature review using mainly science direct, wiley online library, springer and google scholar has been performed to identify sixteen O&M simulation tools which are established in the market. The focus is on tools with sufficiently published methodologies. This paper aims to identify categories for important aspects of the simulation of O&M in offshore wind. This allow to categorize the methodologies, used in those tools. Five categories have been chosen to describe the present tools and allow a fast assessment of future developments or academic approaches. This paper suggests five different categories for assessing the methodologies. Those categories are the wind turbine failure model, the environmental conditions model, the offshore logistic model, the offshore activity model and the commercial model. The wind turbine failure model defines the activities, which needs to be performed. Environmental conditions determine, the energy production of the wind farms as well as the accessibility of the turbines. With the offshore logistic model weather restrictions for vessel or helicopter can be modeled. Additional routing problems can be simulated too. Offshore activities can be simulated to determine the priority of task execution. With the commercial model fluctuating costs and revenue from the energy production can be simulated. The literature review showed the methodologies used in the established sixteen simulation tools. All tools have been summarized in a table describing the used methodologies. Significant differences in the used methodologies have been found in our analysis. For the methodologies used in simulations, only trends can be identified. This can be partly attributed to the fact that our study put a focus on established simulation tools. Future research need to incorporate methodologies used in academic O&M simulation tools. By comparing academic and established approaches, shortcomings can be identified. On the one hand, this will allow re-search to create better simulation tools. On the other hand comparsions with decision making processes in the industry can be assessed against the models used for the simulation. In summary, it can be said trends for methodologies used in simulation tools can be identified. The results of the study indicate that there is no common standard for a holistic simulation approach. However, the narrow market for simulation tools still show room for improvement

The MALIBU project: Developing a simulation environment for floating lidar systems: Poster presented at Offshore Wind R&D Conference 2018, Bremerhaven, 14.-16.11.2018

Assessing the uncertainty of floating lidar systems (FLS) for different wind and wave climates is a challenging task. One possible solution to close this gap is a validated simulation environment for floating lidar systems. An approach for such a simulation environment is under development within the German research project MALIBU (code number 0324197). This poster gives an overview about the simulation model which is being developed. Furthermore first project results regarding the validation aspects for the moving lidar environment and the buoy model are presented. In addition the poster gives an outlook on further project goals