Step-WEC: STEP CHANGE FOR WAVE ENERGY CONVERSION THROUGH FLOATING MULTI-BODY MULTI-MODE SYSTEMS IN SWELL

海洋能源应能为英国2020年前30%发电量的可再生能源目标做出实质性贡献，波能潜力很大。然而，波能转换需要每单位成本的功率输出阶梯变化，才能很容易在商业上可行。在这里，我们解决的问题是‘如果结构尺寸不是目标，并且如果几种运动模式被用于能量转换，那么可以转换的最大功率是多少？’我们还知道，系统必须是浮动的，以避免固定的床上安装结构的高成本。这里的目的是研究具有多模式运动的多(最初是两个)身体系统，提供来自不同运动模式的能量输出的叠加。事实上，一种具有升降和俯仰的特殊形式的两体装置已经被设计出来(并获得了专利)，并在实验室中展示了高效率，显示了这种潜力。我们特别感兴趣的是始终存在的、主要是规则的、提供基本负荷的涌浪。因为英国西部附近的小涌浪主要在9-11 S范围内，一个系统将被调整以利用这些海浪，因为知道对于更大的海浪，实质性的产生是直接的。然而，在这方面，涌浪和随机(风)波的相互作用是一个重要但尚未探索的考虑因素。业务测试和大规模部署需要采用通用方法。为了研究复杂的多体、多模式反应，需要发展方法学。对于中至深水，还需要评估系泊载荷。极端负荷和生存能力的重要方面将不会在这个项目中具体涉及，但将与正在进行的超级世代海洋挑战项目X-MED和Smarty建立联系。因此，总体目标是基于两个或多个具有多模式响应的动态连接体，设计、分析和优化用于在涌浪和混合涌浪/风浪中进行大约10兆瓦容量的波能转换的浮动系统，并评估它们之间的相互作用，特别是阵列内的发电。

Marine energy should make a substantial contribution to the UK renewable energy target of 30% electricity by 2020 and the potential of wave energy is high. However wave energy conversion requires a step change in power output per unit cost to be readily commercially viable. Here we address the question 'what is the maximum power which can be converted if structure size is no object and if several modes of motion are exploited for power conversion?' We further know that the system must be floating to avoid the high costs of fixed, bed-mounted structures. The intention here is to investigate multi (initially two) body systems with multiple mode motion providing superposition of energy output from the different modes of motion. A particular form of two-body device with heave and pitch has in fact been devised (and patented) and high efficiency has been demonstrated in the lab, showing the potential. We are particularly interested in ever-present, predominantly regular, swell waves providing a base load. For small swell around the west of UK periods are predominantly in the 9-11 s range and a system would be tuned to exploit these waves, knowing that for larger waves substantial generation is straightforward. However the interaction of swell and random (wind) waves is an important but unexplored consideration in this context. Generic methodologies need to be applied for operational testing and large-scale deployment. To investigate complex multi-body multi-mode response methodologies need to be developed. Mooring loads also need to be evaluated for intermediate-to-deep water. The important aspect of extreme loading and survivability will not be specifically covered in this project but links will be made with the on-going Supergen Marine Challenge projects X-MED and SMARTY. The overall aim is thus to design, analyse and optimise floating systems for wave energy conversion of approximately 10 MW capacity in swell and mixed swell/wind waves based on two or more dynamically connected bodies with multi-mode response and to assess their interaction, particularly power generation, within an array.