An innovative weather downtime tool for offshore wind marine operations

Presentation Description: Weather downtime is a major factor in the development of offshore wind projects and site specific predictions are required for all offshore operations. This paper presents a novel way to efficiently assess weather downtime for any offshore site and vessel combination.
Offshore contractors are keen to identify periods when the weather is below the working limits of their vessels. One method of assessing weather downtime is to perform a statistical analysis of historical metocean records, but obtaining site specific records can be challenging and costly.
The European Centre for Medium-Range Weather Forecasts (ECMWF) developed ERA5 which is a state-of-the-art and open-source climate reanalysis database. It provides hourly estimates of several atmospheric, land and oceanic climate variables on a global grid, but accessing it can be time consuming and cumbersome.
This paper presents a methodology for quickly assessing weather downtime at any site using available ERA5 data and vessel operational specifications. The methodology is implemented in a tool known as “GDG-WDAT” which interrogates the ERA5 database, enabling site specific downloads (including US sites). The tool assesses the weather downtime for any given period in a year based on given vessel operational limits, providing valuable information to offshore wind farm developers, contractors, and maintenance providers. The paper presents how downtime is assessed and provides specific examples for the US East and West Coast.