This is the latest Offshore Wind Accelerator (OWA) project designed to help reduce the cost of energy from offshore wind. Over the next three months the most comprehensive test of scanning LIDAR technology will take place, where four different scanning LiDAR systems will be put through their paces, alongside three vertical profiling LiDARs for validation purposes. The project is being supported by independent renewable energy company, RES and maritime safety organisation, Commissioners of Irish Lights.
Accurate wind resource measurements are critical to calculating the potential energy yield from a wind farm, which in turn dictates the terms of the project financing. This can be a significant proportion of the overall project cost, accounting for around 45% for an average wind farm.
Scanning LiDAR is not a new technology, however. Conventionally, it is used by the defence and aerospace industries to monitor for oncoming weather fronts.
Wind resource is usually measured using large steel towers called met masts, which require a large capital investment (£10-£12m) incurred at risk before a project gets the go ahead, adding significant upfront costs which could inhibit the exploration of new sites. The OWA project aims to test how accurately scanning LiDAR technology could measure wind resource for potential wind farm sites, which may then help deliver significant cost savings in the early stages of wind farm development.
Scanning LiDAR technology also has the potential to reduce the risk associated with spatial variation. Measurements taken traditionally by met masts can be limited in that they only provide a measurement of the wind resource at a single point in space. For an offshore wind farm covering an area of up to 200 square kilometres, this can create uncertainty on the wind speed at locations far from the measurement point. This is known as spatial variation, where measurements may not representative of the entire site. This is translated into risk incurring additional financing costs to wind farm development. However, scanning LiDAR technology has the potential to reduce this risk associated with spatial variation. These systems are capable of scanning with a usable range of between 10 to 30 kilometres, to impressive levels of detail, taking over 100 measurements per minute.
Megan Smith, Project Manager, Wakes Research at the Carbon Trust commented: “Many factors can impact available wind resource at a potential wind farm site including its proximity to shore, neighbouring wind farms, and as a result of tidal currents. This project forms a really important stage of the OWA’s efforts to increase the industry’s understanding of wind resource measurement and validate the technologies capable of delivering results. Project financing is a significant proportion of cost, so anything we can do to get a deeper understanding of yield will increase investor confidence and lower the cost of financing. Scanning LIDAR has the potential to take our understanding to a completely new level. In information terms it is the difference between taking a still photo compared to having a three dimensional video with full sound. The need to test the sensitivity of the technology is the next frontier in getting industry acceptance.”