Posters

Abstract

Countries in the Nordics and Baltics have committed to significant offshore wind capacity targets by 2030, a region which currently has under 3GW operational capacity and limited historical wind measurements. This region represents a unique set of challenges, in a new offshore wind environment. A key driver to understanding the viability of a wind farm project is the expected long-term mean wind speed and distribution. At early project development planning of offshore wind farms, typically no wind measurement data are available, therefore preliminary wind estimates are derived based on modelled wind data sets. Modelled datasets can only give an initial impression of the expected wind regime, and are not a substitute for high-quality measurements. At an early feasibility stage there is, therefore, high uncertainty in preliminary wind speed estimates, especially in regions where the level of validation is limited, such as the Nordics and Baltics. They also carry a significant risk of over- or under-estimation of the wind speed. This risk can be minimized through the design and execution of a robust wind measurement campaign strategy within the early project phase. This must form an important milestone of a project, and should be given due care and consideration, with the objective of delivering high-quality wind measurements to input to later stages of development. However, a well-designed measurement campaign can represent a significant proportion of development expenditure at the early stage of a project, where the risk profile is still high and budgets potentially tight. Therefore, in this study, the authors present a compelling argument demonstrating the significant cost benefits that can be achieved by investing in a more comprehensive wind measurement campaign at an early stage, particularly in cold climates. This region represents an interesting case study, as the site accessibility challenges introduced by sea ice prevents year-round on-site measurements. The authors have assessed different wind measurement strategies comprising a combination of on-site and near-site coastal measurements, for varying durations. Especially in cold climate regions, practical limitations in duration and measurement systems requires special attention. An indicative uncertainty analysis has been undertaken to inform the relative wind speed uncertainty in a future wind resource assessment based on the measurements from each strategy considering the possible combinations of the measured datasets. The resulting uncertainties have been used as an input to high-level probabilistic LCOE (Levelised Cost of Energy) modelling in this study. Thus, the impact of the reduced uncertainty of the annual energy production as an important parameter to the LCOE estimation is shown. Qualitative assessment of risks and benefits associated with each wind measurement campaign strategy will be discussed. The authors shall also share their experience of floating Lidar campaigns in cold climates. This work demonstrates the cost-benefits of performing robust offshore measurement campaign strategies in the Nordics and Baltics in terms of both wind uncertainty and costs. It concludes that the risk can be significantly minimized, with additional off-site measurement location(s) and even with reduced on-site measurement periods due to site accessibility limitations in cold climates.